| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.widget; |
| |
| import android.content.Context; |
| import android.content.res.TypedArray; |
| import android.graphics.Canvas; |
| import android.graphics.Color; |
| import android.graphics.Paint; |
| import android.util.AttributeSet; |
| import android.util.Log; |
| import android.util.Pair; |
| import android.view.Gravity; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.view.accessibility.AccessibilityEvent; |
| import android.view.accessibility.AccessibilityNodeInfo; |
| |
| import com.android.internal.R; |
| |
| import java.lang.reflect.Array; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import static android.view.Gravity.*; |
| import static android.view.View.MeasureSpec.EXACTLY; |
| import static android.view.View.MeasureSpec.makeMeasureSpec; |
| import static java.lang.Math.max; |
| import static java.lang.Math.min; |
| |
| /** |
| * A layout that places its children in a rectangular <em>grid</em>. |
| * <p> |
| * The grid is composed of a set of infinitely thin lines that separate the |
| * viewing area into <em>cells</em>. Throughout the API, grid lines are referenced |
| * by grid <em>indices</em>. A grid with {@code N} columns |
| * has {@code N + 1} grid indices that run from {@code 0} |
| * through {@code N} inclusive. Regardless of how GridLayout is |
| * configured, grid index {@code 0} is fixed to the leading edge of the |
| * container and grid index {@code N} is fixed to its trailing edge |
| * (after padding is taken into account). |
| * |
| * <h4>Row and Column Specs</h4> |
| * |
| * Children occupy one or more contiguous cells, as defined |
| * by their {@link GridLayout.LayoutParams#rowSpec rowSpec} and |
| * {@link GridLayout.LayoutParams#columnSpec columnSpec} layout parameters. |
| * Each spec defines the set of rows or columns that are to be |
| * occupied; and how children should be aligned within the resulting group of cells. |
| * Although cells do not normally overlap in a GridLayout, GridLayout does |
| * not prevent children being defined to occupy the same cell or group of cells. |
| * In this case however, there is no guarantee that children will not themselves |
| * overlap after the layout operation completes. |
| * |
| * <h4>Default Cell Assignment</h4> |
| * |
| * If a child does not specify the row and column indices of the cell it |
| * wishes to occupy, GridLayout assigns cell locations automatically using its: |
| * {@link GridLayout#setOrientation(int) orientation}, |
| * {@link GridLayout#setRowCount(int) rowCount} and |
| * {@link GridLayout#setColumnCount(int) columnCount} properties. |
| * |
| * <h4>Space</h4> |
| * |
| * Space between children may be specified either by using instances of the |
| * dedicated {@link Space} view or by setting the |
| * |
| * {@link ViewGroup.MarginLayoutParams#leftMargin leftMargin}, |
| * {@link ViewGroup.MarginLayoutParams#topMargin topMargin}, |
| * {@link ViewGroup.MarginLayoutParams#rightMargin rightMargin} and |
| * {@link ViewGroup.MarginLayoutParams#bottomMargin bottomMargin} |
| * |
| * layout parameters. When the |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} |
| * property is set, default margins around children are automatically |
| * allocated based on the prevailing UI style guide for the platform. |
| * Each of the margins so defined may be independently overridden by an assignment |
| * to the appropriate layout parameter. |
| * Default values will generally produce a reasonable spacing between components |
| * but values may change between different releases of the platform. |
| * |
| * <h4>Excess Space Distribution</h4> |
| * |
| * GridLayout's distribution of excess space is based on <em>priority</em> |
| * rather than <em>weight</em>. |
| * <p> |
| * A child's ability to stretch is inferred from the alignment properties of |
| * its row and column groups (which are typically set by setting the |
| * {@link LayoutParams#setGravity(int) gravity} property of the child's layout parameters). |
| * If alignment was defined along a given axis then the component |
| * is taken as <em>flexible</em> in that direction. If no alignment was set, |
| * the component is instead assumed to be <em>inflexible</em>. |
| * <p> |
| * Multiple components in the same row or column group are |
| * considered to act in <em>parallel</em>. Such a |
| * group is flexible only if <em>all</em> of the components |
| * within it are flexible. Row and column groups that sit either side of a common boundary |
| * are instead considered to act in <em>series</em>. The composite group made of these two |
| * elements is flexible if <em>one</em> of its elements is flexible. |
| * <p> |
| * To make a column stretch, make sure all of the components inside it define a |
| * gravity. To prevent a column from stretching, ensure that one of the components |
| * in the column does not define a gravity. |
| * <p> |
| * When the principle of flexibility does not provide complete disambiguation, |
| * GridLayout's algorithms favour rows and columns that are closer to its <em>right</em> |
| * and <em>bottom</em> edges. |
| * |
| * <h5>Limitations</h5> |
| * |
| * GridLayout does not provide support for the principle of <em>weight</em>, as defined in |
| * {@link LinearLayout.LayoutParams#weight}. In general, it is not therefore possible |
| * to configure a GridLayout to distribute excess space in non-trivial proportions between |
| * multiple rows or columns. |
| * <p> |
| * Some common use-cases may nevertheless be accommodated as follows. |
| * To place equal amounts of space around a component in a cell group; |
| * use {@link #CENTER} alignment (or {@link LayoutParams#setGravity(int) gravity}). |
| * For complete control over excess space distribution in a row or column; |
| * use a {@link LinearLayout} subview to hold the components in the associated cell group. |
| * When using either of these techniques, bear in mind that cell groups may be defined to overlap. |
| * <p> |
| * See {@link GridLayout.LayoutParams} for a full description of the |
| * layout parameters used by GridLayout. |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public class GridLayout extends ViewGroup { |
| |
| // Public constants |
| |
| /** |
| * The horizontal orientation. |
| */ |
| public static final int HORIZONTAL = LinearLayout.HORIZONTAL; |
| |
| /** |
| * The vertical orientation. |
| */ |
| public static final int VERTICAL = LinearLayout.VERTICAL; |
| |
| /** |
| * The constant used to indicate that a value is undefined. |
| * Fields can use this value to indicate that their values |
| * have not yet been set. Similarly, methods can return this value |
| * to indicate that there is no suitable value that the implementation |
| * can return. |
| * The value used for the constant (currently {@link Integer#MIN_VALUE}) is |
| * intended to avoid confusion between valid values whose sign may not be known. |
| */ |
| public static final int UNDEFINED = Integer.MIN_VALUE; |
| |
| /** |
| * This constant is an {@link #setAlignmentMode(int) alignmentMode}. |
| * When the {@code alignmentMode} is set to {@link #ALIGN_BOUNDS}, alignment |
| * is made between the edges of each component's raw |
| * view boundary: i.e. the area delimited by the component's: |
| * {@link android.view.View#getTop() top}, |
| * {@link android.view.View#getLeft() left}, |
| * {@link android.view.View#getBottom() bottom} and |
| * {@link android.view.View#getRight() right} properties. |
| * <p> |
| * For example, when {@code GridLayout} is in {@link #ALIGN_BOUNDS} mode, |
| * children that belong to a row group that uses {@link #TOP} alignment will |
| * all return the same value when their {@link android.view.View#getTop()} |
| * method is called. |
| * |
| * @see #setAlignmentMode(int) |
| */ |
| public static final int ALIGN_BOUNDS = 0; |
| |
| /** |
| * This constant is an {@link #setAlignmentMode(int) alignmentMode}. |
| * When the {@code alignmentMode} is set to {@link #ALIGN_MARGINS}, |
| * the bounds of each view are extended outwards, according |
| * to their margins, before the edges of the resulting rectangle are aligned. |
| * <p> |
| * For example, when {@code GridLayout} is in {@link #ALIGN_MARGINS} mode, |
| * the quantity {@code top - layoutParams.topMargin} is the same for all children that |
| * belong to a row group that uses {@link #TOP} alignment. |
| * |
| * @see #setAlignmentMode(int) |
| */ |
| public static final int ALIGN_MARGINS = 1; |
| |
| // Misc constants |
| |
| static final String TAG = GridLayout.class.getName(); |
| static final boolean DEBUG = false; |
| static final int PRF = 1; |
| static final int MAX_SIZE = 100000; |
| static final int DEFAULT_CONTAINER_MARGIN = 0; |
| static final int UNINITIALIZED_HASH = 0; |
| |
| // Defaults |
| |
| private static final int DEFAULT_ORIENTATION = HORIZONTAL; |
| private static final int DEFAULT_COUNT = UNDEFINED; |
| private static final boolean DEFAULT_USE_DEFAULT_MARGINS = false; |
| private static final boolean DEFAULT_ORDER_PRESERVED = true; |
| private static final int DEFAULT_ALIGNMENT_MODE = ALIGN_MARGINS; |
| |
| // TypedArray indices |
| |
| private static final int ORIENTATION = R.styleable.GridLayout_orientation; |
| private static final int ROW_COUNT = R.styleable.GridLayout_rowCount; |
| private static final int COLUMN_COUNT = R.styleable.GridLayout_columnCount; |
| private static final int USE_DEFAULT_MARGINS = R.styleable.GridLayout_useDefaultMargins; |
| private static final int ALIGNMENT_MODE = R.styleable.GridLayout_alignmentMode; |
| private static final int ROW_ORDER_PRESERVED = R.styleable.GridLayout_rowOrderPreserved; |
| private static final int COLUMN_ORDER_PRESERVED = R.styleable.GridLayout_columnOrderPreserved; |
| |
| // Instance variables |
| |
| final Axis horizontalAxis = new Axis(true); |
| final Axis verticalAxis = new Axis(false); |
| boolean layoutParamsValid = false; |
| int orientation = DEFAULT_ORIENTATION; |
| boolean useDefaultMargins = DEFAULT_USE_DEFAULT_MARGINS; |
| int alignmentMode = DEFAULT_ALIGNMENT_MODE; |
| int defaultGap; |
| int lastLayoutParamsHashCode = UNINITIALIZED_HASH; |
| |
| // Constructors |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context, AttributeSet attrs, int defStyle) { |
| super(context, attrs, defStyle); |
| if (DEBUG) { |
| setWillNotDraw(false); |
| } |
| defaultGap = context.getResources().getDimensionPixelOffset(R.dimen.default_gap); |
| TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.GridLayout); |
| try { |
| setRowCount(a.getInt(ROW_COUNT, DEFAULT_COUNT)); |
| setColumnCount(a.getInt(COLUMN_COUNT, DEFAULT_COUNT)); |
| setOrientation(a.getInt(ORIENTATION, DEFAULT_ORIENTATION)); |
| setUseDefaultMargins(a.getBoolean(USE_DEFAULT_MARGINS, DEFAULT_USE_DEFAULT_MARGINS)); |
| setAlignmentMode(a.getInt(ALIGNMENT_MODE, DEFAULT_ALIGNMENT_MODE)); |
| setRowOrderPreserved(a.getBoolean(ROW_ORDER_PRESERVED, DEFAULT_ORDER_PRESERVED)); |
| setColumnOrderPreserved(a.getBoolean(COLUMN_ORDER_PRESERVED, DEFAULT_ORDER_PRESERVED)); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context, AttributeSet attrs) { |
| this(context, attrs, 0); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context) { |
| //noinspection NullableProblems |
| this(context, null); |
| } |
| |
| // Implementation |
| |
| /** |
| * Returns the current orientation. |
| * |
| * @return either {@link #HORIZONTAL} or {@link #VERTICAL} |
| * |
| * @see #setOrientation(int) |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| */ |
| public int getOrientation() { |
| return orientation; |
| } |
| |
| /** |
| * Orientation is used only to generate default row/column indices when |
| * they are not specified by a component's layout parameters. |
| * <p> |
| * The default value of this property is {@link #HORIZONTAL}. |
| * |
| * @param orientation either {@link #HORIZONTAL} or {@link #VERTICAL} |
| * |
| * @see #getOrientation() |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| */ |
| public void setOrientation(int orientation) { |
| if (this.orientation != orientation) { |
| this.orientation = orientation; |
| invalidateStructure(); |
| requestLayout(); |
| } |
| } |
| |
| /** |
| * Returns the current number of rows. This is either the last value that was set |
| * with {@link #setRowCount(int)} or, if no such value was set, the maximum |
| * value of each the upper bounds defined in {@link LayoutParams#rowSpec}. |
| * |
| * @return the current number of rows |
| * |
| * @see #setRowCount(int) |
| * @see LayoutParams#rowSpec |
| * |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| */ |
| public int getRowCount() { |
| return verticalAxis.getCount(); |
| } |
| |
| /** |
| * RowCount is used only to generate default row/column indices when |
| * they are not specified by a component's layout parameters. |
| * |
| * @param rowCount the number of rows |
| * |
| * @see #getRowCount() |
| * @see LayoutParams#rowSpec |
| * |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| */ |
| public void setRowCount(int rowCount) { |
| verticalAxis.setCount(rowCount); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| /** |
| * Returns the current number of columns. This is either the last value that was set |
| * with {@link #setColumnCount(int)} or, if no such value was set, the maximum |
| * value of each the upper bounds defined in {@link LayoutParams#columnSpec}. |
| * |
| * @return the current number of columns |
| * |
| * @see #setColumnCount(int) |
| * @see LayoutParams#columnSpec |
| * |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| */ |
| public int getColumnCount() { |
| return horizontalAxis.getCount(); |
| } |
| |
| /** |
| * ColumnCount is used only to generate default column/column indices when |
| * they are not specified by a component's layout parameters. |
| * |
| * @param columnCount the number of columns. |
| * |
| * @see #getColumnCount() |
| * @see LayoutParams#columnSpec |
| * |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| */ |
| public void setColumnCount(int columnCount) { |
| horizontalAxis.setCount(columnCount); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether or not this GridLayout will allocate default margins when no |
| * corresponding layout parameters are defined. |
| * |
| * @return {@code true} if default margins should be allocated |
| * |
| * @see #setUseDefaultMargins(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| */ |
| public boolean getUseDefaultMargins() { |
| return useDefaultMargins; |
| } |
| |
| /** |
| * When {@code true}, GridLayout allocates default margins around children |
| * based on the child's visual characteristics. Each of the |
| * margins so defined may be independently overridden by an assignment |
| * to the appropriate layout parameter. |
| * <p> |
| * When {@code false}, the default value of all margins is zero. |
| * <p> |
| * When setting to {@code true}, consider setting the value of the |
| * {@link #setAlignmentMode(int) alignmentMode} |
| * property to {@link #ALIGN_BOUNDS}. |
| * <p> |
| * The default value of this property is {@code false}. |
| * |
| * @param useDefaultMargins use {@code true} to make GridLayout allocate default margins |
| * |
| * @see #getUseDefaultMargins() |
| * @see #setAlignmentMode(int) |
| * |
| * @see MarginLayoutParams#leftMargin |
| * @see MarginLayoutParams#topMargin |
| * @see MarginLayoutParams#rightMargin |
| * @see MarginLayoutParams#bottomMargin |
| * |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| */ |
| public void setUseDefaultMargins(boolean useDefaultMargins) { |
| this.useDefaultMargins = useDefaultMargins; |
| requestLayout(); |
| } |
| |
| /** |
| * Returns the alignment mode. |
| * |
| * @return the alignment mode; either {@link #ALIGN_BOUNDS} or {@link #ALIGN_MARGINS} |
| * |
| * @see #ALIGN_BOUNDS |
| * @see #ALIGN_MARGINS |
| * |
| * @see #setAlignmentMode(int) |
| * |
| * @attr ref android.R.styleable#GridLayout_alignmentMode |
| */ |
| public int getAlignmentMode() { |
| return alignmentMode; |
| } |
| |
| /** |
| * Sets the alignment mode to be used for all of the alignments between the |
| * children of this container. |
| * <p> |
| * The default value of this property is {@link #ALIGN_MARGINS}. |
| * |
| * @param alignmentMode either {@link #ALIGN_BOUNDS} or {@link #ALIGN_MARGINS} |
| * |
| * @see #ALIGN_BOUNDS |
| * @see #ALIGN_MARGINS |
| * |
| * @see #getAlignmentMode() |
| * |
| * @attr ref android.R.styleable#GridLayout_alignmentMode |
| */ |
| public void setAlignmentMode(int alignmentMode) { |
| this.alignmentMode = alignmentMode; |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether or not row boundaries are ordered by their grid indices. |
| * |
| * @return {@code true} if row boundaries must appear in the order of their indices, |
| * {@code false} otherwise |
| * |
| * @see #setRowOrderPreserved(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| */ |
| public boolean isRowOrderPreserved() { |
| return verticalAxis.isOrderPreserved(); |
| } |
| |
| /** |
| * When this property is {@code true}, GridLayout is forced to place the row boundaries |
| * so that their associated grid indices are in ascending order in the view. |
| * <p> |
| * When this property is {@code false} GridLayout is at liberty to place the vertical row |
| * boundaries in whatever order best fits the given constraints. |
| * <p> |
| * The default value of this property is {@code true}. |
| |
| * @param rowOrderPreserved {@code true} to force GridLayout to respect the order |
| * of row boundaries |
| * |
| * @see #isRowOrderPreserved() |
| * |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| */ |
| public void setRowOrderPreserved(boolean rowOrderPreserved) { |
| verticalAxis.setOrderPreserved(rowOrderPreserved); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether or not column boundaries are ordered by their grid indices. |
| * |
| * @return {@code true} if column boundaries must appear in the order of their indices, |
| * {@code false} otherwise |
| * |
| * @see #setColumnOrderPreserved(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public boolean isColumnOrderPreserved() { |
| return horizontalAxis.isOrderPreserved(); |
| } |
| |
| /** |
| * When this property is {@code true}, GridLayout is forced to place the column boundaries |
| * so that their associated grid indices are in ascending order in the view. |
| * <p> |
| * When this property is {@code false} GridLayout is at liberty to place the horizontal column |
| * boundaries in whatever order best fits the given constraints. |
| * <p> |
| * The default value of this property is {@code true}. |
| * |
| * @param columnOrderPreserved use {@code true} to force GridLayout to respect the order |
| * of column boundaries. |
| * |
| * @see #isColumnOrderPreserved() |
| * |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public void setColumnOrderPreserved(boolean columnOrderPreserved) { |
| horizontalAxis.setOrderPreserved(columnOrderPreserved); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| // Static utility methods |
| |
| static int max2(int[] a, int valueIfEmpty) { |
| int result = valueIfEmpty; |
| for (int i = 0, N = a.length; i < N; i++) { |
| result = Math.max(result, a[i]); |
| } |
| return result; |
| } |
| |
| @SuppressWarnings("unchecked") |
| static <T> T[] append(T[] a, T[] b) { |
| T[] result = (T[]) Array.newInstance(a.getClass().getComponentType(), a.length + b.length); |
| System.arraycopy(a, 0, result, 0, a.length); |
| System.arraycopy(b, 0, result, a.length, b.length); |
| return result; |
| } |
| |
| static Alignment getAlignment(int gravity, boolean horizontal) { |
| int mask = horizontal ? HORIZONTAL_GRAVITY_MASK : VERTICAL_GRAVITY_MASK; |
| int shift = horizontal ? AXIS_X_SHIFT : AXIS_Y_SHIFT; |
| int flags = (gravity & mask) >> shift; |
| switch (flags) { |
| case (AXIS_SPECIFIED | AXIS_PULL_BEFORE): |
| return LEADING; |
| case (AXIS_SPECIFIED | AXIS_PULL_AFTER): |
| return TRAILING; |
| case (AXIS_SPECIFIED | AXIS_PULL_BEFORE | AXIS_PULL_AFTER): |
| return FILL; |
| case AXIS_SPECIFIED: |
| return CENTER; |
| case (AXIS_SPECIFIED | AXIS_PULL_BEFORE | RELATIVE_LAYOUT_DIRECTION): |
| return START; |
| case (AXIS_SPECIFIED | AXIS_PULL_AFTER | RELATIVE_LAYOUT_DIRECTION): |
| return END; |
| default: |
| return UNDEFINED_ALIGNMENT; |
| } |
| } |
| |
| /** @noinspection UnusedParameters*/ |
| private int getDefaultMargin(View c, boolean horizontal, boolean leading) { |
| if (c.getClass() == Space.class) { |
| return 0; |
| } |
| return defaultGap / 2; |
| } |
| |
| private int getDefaultMargin(View c, boolean isAtEdge, boolean horizontal, boolean leading) { |
| return isAtEdge ? DEFAULT_CONTAINER_MARGIN : getDefaultMargin(c, horizontal, leading); |
| } |
| |
| private int getDefaultMarginValue(View c, LayoutParams p, boolean horizontal, boolean leading) { |
| if (!useDefaultMargins) { |
| return 0; |
| } |
| Spec spec = horizontal ? p.columnSpec : p.rowSpec; |
| Axis axis = horizontal ? horizontalAxis : verticalAxis; |
| Interval span = spec.span; |
| boolean leading1 = (horizontal && isLayoutRtl()) ? !leading : leading; |
| boolean isAtEdge = leading1 ? (span.min == 0) : (span.max == axis.getCount()); |
| |
| return getDefaultMargin(c, isAtEdge, horizontal, leading); |
| } |
| |
| int getMargin1(View view, boolean horizontal, boolean leading) { |
| LayoutParams lp = getLayoutParams(view); |
| int margin = horizontal ? |
| (leading ? lp.leftMargin : lp.rightMargin) : |
| (leading ? lp.topMargin : lp.bottomMargin); |
| return margin == UNDEFINED ? getDefaultMarginValue(view, lp, horizontal, leading) : margin; |
| } |
| |
| private int getMargin(View view, boolean horizontal, boolean leading) { |
| if (alignmentMode == ALIGN_MARGINS) { |
| return getMargin1(view, horizontal, leading); |
| } else { |
| Axis axis = horizontal ? horizontalAxis : verticalAxis; |
| int[] margins = leading ? axis.getLeadingMargins() : axis.getTrailingMargins(); |
| LayoutParams lp = getLayoutParams(view); |
| Spec spec = horizontal ? lp.columnSpec : lp.rowSpec; |
| int index = leading ? spec.span.min : spec.span.max; |
| return margins[index]; |
| } |
| } |
| |
| private int getTotalMargin(View child, boolean horizontal) { |
| return getMargin(child, horizontal, true) + getMargin(child, horizontal, false); |
| } |
| |
| private static boolean fits(int[] a, int value, int start, int end) { |
| if (end > a.length) { |
| return false; |
| } |
| for (int i = start; i < end; i++) { |
| if (a[i] > value) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private static void procrusteanFill(int[] a, int start, int end, int value) { |
| int length = a.length; |
| Arrays.fill(a, Math.min(start, length), Math.min(end, length), value); |
| } |
| |
| private static void setCellGroup(LayoutParams lp, int row, int rowSpan, int col, int colSpan) { |
| lp.setRowSpecSpan(new Interval(row, row + rowSpan)); |
| lp.setColumnSpecSpan(new Interval(col, col + colSpan)); |
| } |
| |
| // Logic to avert infinite loops by ensuring that the cells can be placed somewhere. |
| private static int clip(Interval minorRange, boolean minorWasDefined, int count) { |
| int size = minorRange.size(); |
| if (count == 0) { |
| return size; |
| } |
| int min = minorWasDefined ? min(minorRange.min, count) : 0; |
| return min(size, count - min); |
| } |
| |
| // install default indices for cells that don't define them |
| private void validateLayoutParams() { |
| final boolean horizontal = (orientation == HORIZONTAL); |
| final Axis axis = horizontal ? horizontalAxis : verticalAxis; |
| final int count = (axis.definedCount != UNDEFINED) ? axis.definedCount : 0; |
| |
| int major = 0; |
| int minor = 0; |
| int[] maxSizes = new int[count]; |
| |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| LayoutParams lp = (LayoutParams) getChildAt(i).getLayoutParams(); |
| |
| final Spec majorSpec = horizontal ? lp.rowSpec : lp.columnSpec; |
| final Interval majorRange = majorSpec.span; |
| final boolean majorWasDefined = majorSpec.startDefined; |
| final int majorSpan = majorRange.size(); |
| if (majorWasDefined) { |
| major = majorRange.min; |
| } |
| |
| final Spec minorSpec = horizontal ? lp.columnSpec : lp.rowSpec; |
| final Interval minorRange = minorSpec.span; |
| final boolean minorWasDefined = minorSpec.startDefined; |
| final int minorSpan = clip(minorRange, minorWasDefined, count); |
| if (minorWasDefined) { |
| minor = minorRange.min; |
| } |
| |
| if (count != 0) { |
| // Find suitable row/col values when at least one is undefined. |
| if (!majorWasDefined || !minorWasDefined) { |
| while (!fits(maxSizes, major, minor, minor + minorSpan)) { |
| if (minorWasDefined) { |
| major++; |
| } else { |
| if (minor + minorSpan <= count) { |
| minor++; |
| } else { |
| minor = 0; |
| major++; |
| } |
| } |
| } |
| } |
| procrusteanFill(maxSizes, minor, minor + minorSpan, major + majorSpan); |
| } |
| |
| if (horizontal) { |
| setCellGroup(lp, major, majorSpan, minor, minorSpan); |
| } else { |
| setCellGroup(lp, minor, minorSpan, major, majorSpan); |
| } |
| |
| minor = minor + minorSpan; |
| } |
| lastLayoutParamsHashCode = computeLayoutParamsHashCode(); |
| invalidateStructure(); |
| } |
| |
| private void invalidateStructure() { |
| layoutParamsValid = false; |
| horizontalAxis.invalidateStructure(); |
| verticalAxis.invalidateStructure(); |
| // This can end up being done twice. Better twice than not at all. |
| invalidateValues(); |
| } |
| |
| private void invalidateValues() { |
| // Need null check because requestLayout() is called in View's initializer, |
| // before we are set up. |
| if (horizontalAxis != null && verticalAxis != null) { |
| horizontalAxis.invalidateValues(); |
| verticalAxis.invalidateValues(); |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| protected void onSetLayoutParams(View child, ViewGroup.LayoutParams layoutParams) { |
| super.onSetLayoutParams(child, layoutParams); |
| invalidateStructure(); |
| } |
| |
| final LayoutParams getLayoutParams(View c) { |
| if (!layoutParamsValid) { |
| validateLayoutParams(); |
| layoutParamsValid = true; |
| } |
| return (LayoutParams) c.getLayoutParams(); |
| } |
| |
| @Override |
| protected LayoutParams generateDefaultLayoutParams() { |
| return new LayoutParams(); |
| } |
| |
| @Override |
| public LayoutParams generateLayoutParams(AttributeSet attrs) { |
| return new LayoutParams(getContext(), attrs); |
| } |
| |
| @Override |
| protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { |
| return new LayoutParams(p); |
| } |
| |
| // Draw grid |
| |
| private void drawLine(Canvas graphics, int x1, int y1, int x2, int y2, Paint paint) { |
| int dx = getPaddingLeft(); |
| int dy = getPaddingTop(); |
| if (isLayoutRtl()) { |
| int width = getWidth(); |
| graphics.drawLine(width - dx - x1, dy + y1, width - dx - x2, dy + y2, paint); |
| } else { |
| graphics.drawLine(dx + x1, dy + y1, dx + x2, dy + y2, paint); |
| } |
| } |
| |
| private void drawRect(Canvas canvas, int x1, int y1, int x2, int y2, Paint paint) { |
| canvas.drawRect(x1, y1, x2 - 1, y2 - 1, paint); |
| } |
| |
| @Override |
| protected void onDraw(Canvas canvas) { |
| super.onDraw(canvas); |
| |
| if (DEBUG) { |
| int height = getHeight() - getPaddingTop() - getPaddingBottom(); |
| int width = getWidth() - getPaddingLeft() - getPaddingRight(); |
| |
| Paint paint = new Paint(); |
| paint.setStyle(Paint.Style.STROKE); |
| paint.setColor(Color.argb(50, 255, 255, 255)); |
| |
| int[] xs = horizontalAxis.locations; |
| if (xs != null) { |
| for (int i = 0, length = xs.length; i < length; i++) { |
| int x = xs[i]; |
| drawLine(canvas, x, 0, x, height - 1, paint); |
| } |
| } |
| |
| int[] ys = verticalAxis.locations; |
| if (ys != null) { |
| for (int i = 0, length = ys.length; i < length; i++) { |
| int y = ys[i]; |
| drawLine(canvas, 0, y, width - 1, y, paint); |
| } |
| } |
| |
| // Draw bounds |
| paint.setColor(Color.BLUE); |
| for (int i = 0; i < getChildCount(); i++) { |
| View c = getChildAt(i); |
| drawRect(canvas, c.getLeft(), c.getTop(), c.getRight(), c.getBottom(), paint); |
| } |
| |
| // Draw margins |
| paint.setColor(Color.MAGENTA); |
| for (int i = 0; i < getChildCount(); i++) { |
| View c = getChildAt(i); |
| drawRect(canvas, |
| c.getLeft() - getMargin1(c, true, true), |
| c.getTop() - getMargin1(c, false, true), |
| c.getRight() + getMargin1(c, true, false), |
| c.getBottom() + getMargin1(c, false, false), paint); |
| } |
| } |
| } |
| |
| // Add/remove |
| |
| /** |
| * @hide |
| */ |
| @Override |
| protected void onViewAdded(View child) { |
| super.onViewAdded(child); |
| invalidateStructure(); |
| } |
| |
| /** |
| * @hide |
| */ |
| @Override |
| protected void onViewRemoved(View child) { |
| super.onViewRemoved(child); |
| invalidateStructure(); |
| } |
| |
| /** |
| * We need to call invalidateStructure() when a child's GONE flag changes state. |
| * This implementation is a catch-all, invalidating on any change in the visibility flags. |
| * |
| * @hide |
| */ |
| @Override |
| protected void onChildVisibilityChanged(View child, int oldVisibility, int newVisibility) { |
| super.onChildVisibilityChanged(child, oldVisibility, newVisibility); |
| if (oldVisibility == GONE || newVisibility == GONE) { |
| invalidateStructure(); |
| } |
| } |
| |
| private int computeLayoutParamsHashCode() { |
| int result = 1; |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| if (c.getVisibility() == View.GONE) continue; |
| LayoutParams lp = (LayoutParams) c.getLayoutParams(); |
| result = 31 * result + lp.hashCode(); |
| } |
| return result; |
| } |
| |
| private void checkForLayoutParamsModification() { |
| int layoutParamsHashCode = computeLayoutParamsHashCode(); |
| if (lastLayoutParamsHashCode != UNINITIALIZED_HASH && |
| lastLayoutParamsHashCode != layoutParamsHashCode) { |
| invalidateStructure(); |
| Log.w(TAG, "The fields of some layout parameters were modified in between layout " + |
| "operations. Check the javadoc for GridLayout.LayoutParams#rowSpec."); |
| } |
| } |
| |
| // Measurement |
| |
| private void measureChildWithMargins2(View child, int parentWidthSpec, int parentHeightSpec, |
| int childWidth, int childHeight) { |
| int childWidthSpec = getChildMeasureSpec(parentWidthSpec, |
| mPaddingLeft + mPaddingRight + getTotalMargin(child, true), childWidth); |
| int childHeightSpec = getChildMeasureSpec(parentHeightSpec, |
| mPaddingTop + mPaddingBottom + getTotalMargin(child, false), childHeight); |
| child.measure(childWidthSpec, childHeightSpec); |
| } |
| |
| private void measureChildrenWithMargins(int widthSpec, int heightSpec, boolean firstPass) { |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| if (c.getVisibility() == View.GONE) continue; |
| LayoutParams lp = getLayoutParams(c); |
| if (firstPass) { |
| measureChildWithMargins2(c, widthSpec, heightSpec, lp.width, lp.height); |
| } else { |
| boolean horizontal = (orientation == HORIZONTAL); |
| Spec spec = horizontal ? lp.columnSpec : lp.rowSpec; |
| if (spec.alignment == FILL) { |
| Interval span = spec.span; |
| Axis axis = horizontal ? horizontalAxis : verticalAxis; |
| int[] locations = axis.getLocations(); |
| int cellSize = locations[span.max] - locations[span.min]; |
| int viewSize = cellSize - getTotalMargin(c, horizontal); |
| if (horizontal) { |
| measureChildWithMargins2(c, widthSpec, heightSpec, viewSize, lp.height); |
| } else { |
| measureChildWithMargins2(c, widthSpec, heightSpec, lp.width, viewSize); |
| } |
| } |
| } |
| } |
| } |
| |
| @Override |
| protected void onMeasure(int widthSpec, int heightSpec) { |
| checkForLayoutParamsModification(); |
| |
| /** If we have been called by {@link View#measure(int, int)}, one of width or height |
| * is likely to have changed. We must invalidate if so. */ |
| invalidateValues(); |
| |
| measureChildrenWithMargins(widthSpec, heightSpec, true); |
| |
| int width, height; |
| |
| // Use the orientation property to decide which axis should be laid out first. |
| if (orientation == HORIZONTAL) { |
| width = horizontalAxis.getMeasure(widthSpec); |
| measureChildrenWithMargins(widthSpec, heightSpec, false); |
| height = verticalAxis.getMeasure(heightSpec); |
| } else { |
| height = verticalAxis.getMeasure(heightSpec); |
| measureChildrenWithMargins(widthSpec, heightSpec, false); |
| width = horizontalAxis.getMeasure(widthSpec); |
| } |
| |
| int hPadding = getPaddingLeft() + getPaddingRight(); |
| int vPadding = getPaddingTop() + getPaddingBottom(); |
| |
| int measuredWidth = Math.max(hPadding + width, getSuggestedMinimumWidth()); |
| int measuredHeight = Math.max(vPadding + height, getSuggestedMinimumHeight()); |
| |
| setMeasuredDimension( |
| resolveSizeAndState(measuredWidth, widthSpec, 0), |
| resolveSizeAndState(measuredHeight, heightSpec, 0)); |
| } |
| |
| private int protect(int alignment) { |
| return (alignment == UNDEFINED) ? 0 : alignment; |
| } |
| |
| private int getMeasurement(View c, boolean horizontal) { |
| return horizontal ? c.getMeasuredWidth() : c.getMeasuredHeight(); |
| } |
| |
| final int getMeasurementIncludingMargin(View c, boolean horizontal) { |
| if (c.getVisibility() == View.GONE) { |
| return 0; |
| } |
| return getMeasurement(c, horizontal) + getTotalMargin(c, horizontal); |
| } |
| |
| @Override |
| public void requestLayout() { |
| super.requestLayout(); |
| invalidateValues(); |
| } |
| |
| final Alignment getAlignment(Alignment alignment, boolean horizontal) { |
| return (alignment != UNDEFINED_ALIGNMENT) ? alignment : |
| (horizontal ? START : BASELINE); |
| } |
| |
| // Layout container |
| |
| /** |
| * {@inheritDoc} |
| */ |
| /* |
| The layout operation is implemented by delegating the heavy lifting to the |
| to the mHorizontalAxis and mVerticalAxis instances of the internal Axis class. |
| Together they compute the locations of the vertical and horizontal lines of |
| the grid (respectively!). |
| |
| This method is then left with the simpler task of applying margins, gravity |
| and sizing to each child view and then placing it in its cell. |
| */ |
| @Override |
| protected void onLayout(boolean changed, int left, int top, int right, int bottom) { |
| checkForLayoutParamsModification(); |
| |
| int targetWidth = right - left; |
| int targetHeight = bottom - top; |
| |
| int paddingLeft = getPaddingLeft(); |
| int paddingTop = getPaddingTop(); |
| int paddingRight = getPaddingRight(); |
| int paddingBottom = getPaddingBottom(); |
| |
| horizontalAxis.layout(targetWidth - paddingLeft - paddingRight); |
| verticalAxis.layout(targetHeight - paddingTop - paddingBottom); |
| |
| int[] hLocations = horizontalAxis.getLocations(); |
| int[] vLocations = verticalAxis.getLocations(); |
| |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| if (c.getVisibility() == View.GONE) continue; |
| LayoutParams lp = getLayoutParams(c); |
| Spec columnSpec = lp.columnSpec; |
| Spec rowSpec = lp.rowSpec; |
| |
| Interval colSpan = columnSpec.span; |
| Interval rowSpan = rowSpec.span; |
| |
| int x1 = hLocations[colSpan.min]; |
| int y1 = vLocations[rowSpan.min]; |
| |
| int x2 = hLocations[colSpan.max]; |
| int y2 = vLocations[rowSpan.max]; |
| |
| int cellWidth = x2 - x1; |
| int cellHeight = y2 - y1; |
| |
| int pWidth = getMeasurement(c, true); |
| int pHeight = getMeasurement(c, false); |
| |
| Alignment hAlign = getAlignment(columnSpec.alignment, true); |
| Alignment vAlign = getAlignment(rowSpec.alignment, false); |
| |
| Bounds colBounds = horizontalAxis.getGroupBounds().getValue(i); |
| Bounds rowBounds = verticalAxis.getGroupBounds().getValue(i); |
| |
| // Gravity offsets: the location of the alignment group relative to its cell group. |
| //noinspection NullableProblems |
| int gravityOffsetX = protect(hAlign.getAlignmentValue(null, |
| cellWidth - colBounds.size(true))); |
| //noinspection NullableProblems |
| int gravityOffsetY = protect(vAlign.getAlignmentValue(null, |
| cellHeight - rowBounds.size(true))); |
| |
| boolean rtl = isLayoutRtl(); |
| int startMargin = getMargin(c, true, !rtl); |
| int topMargin = getMargin(c, false, true); |
| int endMargin = getMargin(c, true, rtl); |
| int bottomMargin = getMargin(c, false, false); |
| |
| // Same calculation as getMeasurementIncludingMargin() |
| int mWidth = startMargin + pWidth + endMargin; |
| int mHeight = topMargin + pHeight + bottomMargin; |
| |
| // Alignment offsets: the location of the view relative to its alignment group. |
| int alignmentOffsetX = colBounds.getOffset(c, hAlign, mWidth); |
| int alignmentOffsetY = rowBounds.getOffset(c, vAlign, mHeight); |
| |
| int dx = gravityOffsetX + alignmentOffsetX + startMargin; |
| int dy = gravityOffsetY + alignmentOffsetY + topMargin; |
| |
| cellWidth -= startMargin + endMargin; |
| cellHeight -= topMargin + bottomMargin; |
| |
| int width = hAlign.getSizeInCell(c, pWidth, cellWidth, PRF); |
| int height = vAlign.getSizeInCell(c, pHeight, cellHeight, PRF); |
| |
| int cx = rtl ? targetWidth - paddingRight - x1 - dx - width : paddingLeft + x1 + dx; |
| int cy = paddingTop + y1 + dy; |
| if (width != c.getMeasuredWidth() || height != c.getMeasuredHeight()) { |
| c.measure(makeMeasureSpec(width, EXACTLY), makeMeasureSpec(height, EXACTLY)); |
| } |
| c.layout(cx, cy, cx + width, cy + height); |
| } |
| } |
| |
| @Override |
| public void onInitializeAccessibilityEvent(AccessibilityEvent event) { |
| super.onInitializeAccessibilityEvent(event); |
| event.setClassName(GridLayout.class.getName()); |
| } |
| |
| @Override |
| public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { |
| super.onInitializeAccessibilityNodeInfo(info); |
| info.setClassName(GridLayout.class.getName()); |
| } |
| |
| // Inner classes |
| |
| /* |
| This internal class houses the algorithm for computing the locations of grid lines; |
| along either the horizontal or vertical axis. A GridLayout uses two instances of this class - |
| distinguished by the "horizontal" flag which is true for the horizontal axis and false |
| for the vertical one. |
| */ |
| final class Axis { |
| private static final int NEW = 0; |
| private static final int PENDING = 1; |
| private static final int COMPLETE = 2; |
| |
| public final boolean horizontal; |
| |
| public int definedCount = UNDEFINED; |
| private int maxIndex = UNDEFINED; |
| |
| PackedMap<Spec, Bounds> groupBounds; |
| public boolean groupBoundsValid = false; |
| |
| PackedMap<Interval, MutableInt> forwardLinks; |
| public boolean forwardLinksValid = false; |
| |
| PackedMap<Interval, MutableInt> backwardLinks; |
| public boolean backwardLinksValid = false; |
| |
| public int[] leadingMargins; |
| public boolean leadingMarginsValid = false; |
| |
| public int[] trailingMargins; |
| public boolean trailingMarginsValid = false; |
| |
| public Arc[] arcs; |
| public boolean arcsValid = false; |
| |
| public int[] locations; |
| public boolean locationsValid = false; |
| |
| boolean orderPreserved = DEFAULT_ORDER_PRESERVED; |
| |
| private MutableInt parentMin = new MutableInt(0); |
| private MutableInt parentMax = new MutableInt(-MAX_SIZE); |
| |
| private Axis(boolean horizontal) { |
| this.horizontal = horizontal; |
| } |
| |
| private int calculateMaxIndex() { |
| // the number Integer.MIN_VALUE + 1 comes up in undefined cells |
| int result = -1; |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| LayoutParams params = getLayoutParams(c); |
| Spec spec = horizontal ? params.columnSpec : params.rowSpec; |
| Interval span = spec.span; |
| result = max(result, span.min); |
| result = max(result, span.max); |
| } |
| return result == -1 ? UNDEFINED : result; |
| } |
| |
| private int getMaxIndex() { |
| if (maxIndex == UNDEFINED) { |
| maxIndex = max(0, calculateMaxIndex()); // use zero when there are no children |
| } |
| return maxIndex; |
| } |
| |
| public int getCount() { |
| return max(definedCount, getMaxIndex()); |
| } |
| |
| public void setCount(int count) { |
| this.definedCount = count; |
| } |
| |
| public boolean isOrderPreserved() { |
| return orderPreserved; |
| } |
| |
| public void setOrderPreserved(boolean orderPreserved) { |
| this.orderPreserved = orderPreserved; |
| invalidateStructure(); |
| } |
| |
| private PackedMap<Spec, Bounds> createGroupBounds() { |
| Assoc<Spec, Bounds> assoc = Assoc.of(Spec.class, Bounds.class); |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| LayoutParams lp = getLayoutParams(c); |
| Spec spec = horizontal ? lp.columnSpec : lp.rowSpec; |
| Bounds bounds = getAlignment(spec.alignment, horizontal).getBounds(); |
| assoc.put(spec, bounds); |
| } |
| return assoc.pack(); |
| } |
| |
| private void computeGroupBounds() { |
| Bounds[] values = groupBounds.values; |
| for (int i = 0; i < values.length; i++) { |
| values[i].reset(); |
| } |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| LayoutParams lp = getLayoutParams(c); |
| Spec spec = horizontal ? lp.columnSpec : lp.rowSpec; |
| groupBounds.getValue(i).include(c, spec, GridLayout.this, this); |
| } |
| } |
| |
| public PackedMap<Spec, Bounds> getGroupBounds() { |
| if (groupBounds == null) { |
| groupBounds = createGroupBounds(); |
| } |
| if (!groupBoundsValid) { |
| computeGroupBounds(); |
| groupBoundsValid = true; |
| } |
| return groupBounds; |
| } |
| |
| // Add values computed by alignment - taking the max of all alignments in each span |
| private PackedMap<Interval, MutableInt> createLinks(boolean min) { |
| Assoc<Interval, MutableInt> result = Assoc.of(Interval.class, MutableInt.class); |
| Spec[] keys = getGroupBounds().keys; |
| for (int i = 0, N = keys.length; i < N; i++) { |
| Interval span = min ? keys[i].span : keys[i].span.inverse(); |
| result.put(span, new MutableInt()); |
| } |
| return result.pack(); |
| } |
| |
| private void computeLinks(PackedMap<Interval, MutableInt> links, boolean min) { |
| MutableInt[] spans = links.values; |
| for (int i = 0; i < spans.length; i++) { |
| spans[i].reset(); |
| } |
| |
| // Use getter to trigger a re-evaluation |
| Bounds[] bounds = getGroupBounds().values; |
| for (int i = 0; i < bounds.length; i++) { |
| int size = bounds[i].size(min); |
| MutableInt valueHolder = links.getValue(i); |
| // this effectively takes the max() of the minima and the min() of the maxima |
| valueHolder.value = max(valueHolder.value, min ? size : -size); |
| } |
| } |
| |
| private PackedMap<Interval, MutableInt> getForwardLinks() { |
| if (forwardLinks == null) { |
| forwardLinks = createLinks(true); |
| } |
| if (!forwardLinksValid) { |
| computeLinks(forwardLinks, true); |
| forwardLinksValid = true; |
| } |
| return forwardLinks; |
| } |
| |
| private PackedMap<Interval, MutableInt> getBackwardLinks() { |
| if (backwardLinks == null) { |
| backwardLinks = createLinks(false); |
| } |
| if (!backwardLinksValid) { |
| computeLinks(backwardLinks, false); |
| backwardLinksValid = true; |
| } |
| return backwardLinks; |
| } |
| |
| private void include(List<Arc> arcs, Interval key, MutableInt size, |
| boolean ignoreIfAlreadyPresent) { |
| /* |
| Remove self referential links. |
| These appear: |
| . as parental constraints when GridLayout has no children |
| . when components have been marked as GONE |
| */ |
| if (key.size() == 0) { |
| return; |
| } |
| // this bit below should really be computed outside here - |
| // its just to stop default (row/col > 0) constraints obliterating valid entries |
| if (ignoreIfAlreadyPresent) { |
| for (Arc arc : arcs) { |
| Interval span = arc.span; |
| if (span.equals(key)) { |
| return; |
| } |
| } |
| } |
| arcs.add(new Arc(key, size)); |
| } |
| |
| private void include(List<Arc> arcs, Interval key, MutableInt size) { |
| include(arcs, key, size, true); |
| } |
| |
| // Group arcs by their first vertex, returning an array of arrays. |
| // This is linear in the number of arcs. |
| Arc[][] groupArcsByFirstVertex(Arc[] arcs) { |
| int N = getCount() + 1; // the number of vertices |
| Arc[][] result = new Arc[N][]; |
| int[] sizes = new int[N]; |
| for (Arc arc : arcs) { |
| sizes[arc.span.min]++; |
| } |
| for (int i = 0; i < sizes.length; i++) { |
| result[i] = new Arc[sizes[i]]; |
| } |
| // reuse the sizes array to hold the current last elements as we insert each arc |
| Arrays.fill(sizes, 0); |
| for (Arc arc : arcs) { |
| int i = arc.span.min; |
| result[i][sizes[i]++] = arc; |
| } |
| |
| return result; |
| } |
| |
| private Arc[] topologicalSort(final Arc[] arcs) { |
| return new Object() { |
| Arc[] result = new Arc[arcs.length]; |
| int cursor = result.length - 1; |
| Arc[][] arcsByVertex = groupArcsByFirstVertex(arcs); |
| int[] visited = new int[getCount() + 1]; |
| |
| void walk(int loc) { |
| switch (visited[loc]) { |
| case NEW: { |
| visited[loc] = PENDING; |
| for (Arc arc : arcsByVertex[loc]) { |
| walk(arc.span.max); |
| result[cursor--] = arc; |
| } |
| visited[loc] = COMPLETE; |
| break; |
| } |
| case PENDING: { |
| assert false; |
| break; |
| } |
| case COMPLETE: { |
| break; |
| } |
| } |
| } |
| |
| Arc[] sort() { |
| for (int loc = 0, N = arcsByVertex.length; loc < N; loc++) { |
| walk(loc); |
| } |
| assert cursor == -1; |
| return result; |
| } |
| }.sort(); |
| } |
| |
| private Arc[] topologicalSort(List<Arc> arcs) { |
| return topologicalSort(arcs.toArray(new Arc[arcs.size()])); |
| } |
| |
| private void addComponentSizes(List<Arc> result, PackedMap<Interval, MutableInt> links) { |
| for (int i = 0; i < links.keys.length; i++) { |
| Interval key = links.keys[i]; |
| include(result, key, links.values[i], false); |
| } |
| } |
| |
| private Arc[] createArcs() { |
| List<Arc> mins = new ArrayList<Arc>(); |
| List<Arc> maxs = new ArrayList<Arc>(); |
| |
| // Add the minimum values from the components. |
| addComponentSizes(mins, getForwardLinks()); |
| // Add the maximum values from the components. |
| addComponentSizes(maxs, getBackwardLinks()); |
| |
| // Add ordering constraints to prevent row/col sizes from going negative |
| if (orderPreserved) { |
| // Add a constraint for every row/col |
| for (int i = 0; i < getCount(); i++) { |
| include(mins, new Interval(i, i + 1), new MutableInt(0)); |
| } |
| } |
| |
| // Add the container constraints. Use the version of include that allows |
| // duplicate entries in case a child spans the entire grid. |
| int N = getCount(); |
| include(mins, new Interval(0, N), parentMin, false); |
| include(maxs, new Interval(N, 0), parentMax, false); |
| |
| // Sort |
| Arc[] sMins = topologicalSort(mins); |
| Arc[] sMaxs = topologicalSort(maxs); |
| |
| return append(sMins, sMaxs); |
| } |
| |
| private void computeArcs() { |
| // getting the links validates the values that are shared by the arc list |
| getForwardLinks(); |
| getBackwardLinks(); |
| } |
| |
| public Arc[] getArcs() { |
| if (arcs == null) { |
| arcs = createArcs(); |
| } |
| if (!arcsValid) { |
| computeArcs(); |
| arcsValid = true; |
| } |
| return arcs; |
| } |
| |
| private boolean relax(int[] locations, Arc entry) { |
| if (!entry.valid) { |
| return false; |
| } |
| Interval span = entry.span; |
| int u = span.min; |
| int v = span.max; |
| int value = entry.value.value; |
| int candidate = locations[u] + value; |
| if (candidate > locations[v]) { |
| locations[v] = candidate; |
| return true; |
| } |
| return false; |
| } |
| |
| private void init(int[] locations) { |
| Arrays.fill(locations, 0); |
| } |
| |
| private String arcsToString(List<Arc> arcs) { |
| String var = horizontal ? "x" : "y"; |
| StringBuilder result = new StringBuilder(); |
| boolean first = true; |
| for (Arc arc : arcs) { |
| if (first) { |
| first = false; |
| } else { |
| result = result.append(", "); |
| } |
| int src = arc.span.min; |
| int dst = arc.span.max; |
| int value = arc.value.value; |
| result.append((src < dst) ? |
| var + dst + " - " + var + src + " > " + value : |
| var + src + " - " + var + dst + " < " + -value); |
| |
| } |
| return result.toString(); |
| } |
| |
| private void logError(String axisName, Arc[] arcs, boolean[] culprits0) { |
| List<Arc> culprits = new ArrayList<Arc>(); |
| List<Arc> removed = new ArrayList<Arc>(); |
| for (int c = 0; c < arcs.length; c++) { |
| Arc arc = arcs[c]; |
| if (culprits0[c]) { |
| culprits.add(arc); |
| } |
| if (!arc.valid) { |
| removed.add(arc); |
| } |
| } |
| Log.d(TAG, axisName + " constraints: " + arcsToString(culprits) + " are inconsistent; " |
| + "permanently removing: " + arcsToString(removed) + ". "); |
| } |
| |
| /* |
| Bellman-Ford variant - modified to reduce typical running time from O(N^2) to O(N) |
| |
| GridLayout converts its requirements into a system of linear constraints of the |
| form: |
| |
| x[i] - x[j] < a[k] |
| |
| Where the x[i] are variables and the a[k] are constants. |
| |
| For example, if the variables were instead labeled x, y, z we might have: |
| |
| x - y < 17 |
| y - z < 23 |
| z - x < 42 |
| |
| This is a special case of the Linear Programming problem that is, in turn, |
| equivalent to the single-source shortest paths problem on a digraph, for |
| which the O(n^2) Bellman-Ford algorithm the most commonly used general solution. |
| |
| Other algorithms are faster in the case where no arcs have negative weights |
| but allowing negative weights turns out to be the same as accommodating maximum |
| size requirements as well as minimum ones. |
| |
| Bellman-Ford works by iteratively 'relaxing' constraints over all nodes (an O(N) |
| process) and performing this step N times. Proof of correctness hinges on the |
| fact that there can be no negative weight chains of length > N - unless a |
| 'negative weight loop' exists. The algorithm catches this case in a final |
| checking phase that reports failure. |
| |
| By topologically sorting the nodes and checking this condition at each step |
| typical layout problems complete after the first iteration and the algorithm |
| completes in O(N) steps with very low constants. |
| */ |
| private void solve(Arc[] arcs, int[] locations) { |
| String axisName = horizontal ? "horizontal" : "vertical"; |
| int N = getCount() + 1; // The number of vertices is the number of columns/rows + 1. |
| boolean[] originalCulprits = null; |
| |
| for (int p = 0; p < arcs.length; p++) { |
| init(locations); |
| |
| // We take one extra pass over traditional Bellman-Ford (and omit their final step) |
| for (int i = 0; i < N; i++) { |
| boolean changed = false; |
| for (int j = 0, length = arcs.length; j < length; j++) { |
| changed |= relax(locations, arcs[j]); |
| } |
| if (!changed) { |
| if (originalCulprits != null) { |
| logError(axisName, arcs, originalCulprits); |
| } |
| return; |
| } |
| } |
| |
| boolean[] culprits = new boolean[arcs.length]; |
| for (int i = 0; i < N; i++) { |
| for (int j = 0, length = arcs.length; j < length; j++) { |
| culprits[j] |= relax(locations, arcs[j]); |
| } |
| } |
| |
| if (p == 0) { |
| originalCulprits = culprits; |
| } |
| |
| for (int i = 0; i < arcs.length; i++) { |
| if (culprits[i]) { |
| Arc arc = arcs[i]; |
| // Only remove max values, min values alone cannot be inconsistent |
| if (arc.span.min < arc.span.max) { |
| continue; |
| } |
| arc.valid = false; |
| break; |
| } |
| } |
| } |
| } |
| |
| private void computeMargins(boolean leading) { |
| int[] margins = leading ? leadingMargins : trailingMargins; |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| if (c.getVisibility() == View.GONE) continue; |
| LayoutParams lp = getLayoutParams(c); |
| Spec spec = horizontal ? lp.columnSpec : lp.rowSpec; |
| Interval span = spec.span; |
| int index = leading ? span.min : span.max; |
| margins[index] = max(margins[index], getMargin1(c, horizontal, leading)); |
| } |
| } |
| |
| // External entry points |
| |
| public int[] getLeadingMargins() { |
| if (leadingMargins == null) { |
| leadingMargins = new int[getCount() + 1]; |
| } |
| if (!leadingMarginsValid) { |
| computeMargins(true); |
| leadingMarginsValid = true; |
| } |
| return leadingMargins; |
| } |
| |
| public int[] getTrailingMargins() { |
| if (trailingMargins == null) { |
| trailingMargins = new int[getCount() + 1]; |
| } |
| if (!trailingMarginsValid) { |
| computeMargins(false); |
| trailingMarginsValid = true; |
| } |
| return trailingMargins; |
| } |
| |
| private void computeLocations(int[] a) { |
| solve(getArcs(), a); |
| if (!orderPreserved) { |
| // Solve returns the smallest solution to the constraint system for which all |
| // values are positive. One value is therefore zero - though if the row/col |
| // order is not preserved this may not be the first vertex. For consistency, |
| // translate all the values so that they measure the distance from a[0]; the |
| // leading edge of the parent. After this transformation some values may be |
| // negative. |
| int a0 = a[0]; |
| for (int i = 0, N = a.length; i < N; i++) { |
| a[i] = a[i] - a0; |
| } |
| } |
| } |
| |
| public int[] getLocations() { |
| if (locations == null) { |
| int N = getCount() + 1; |
| locations = new int[N]; |
| } |
| if (!locationsValid) { |
| computeLocations(locations); |
| locationsValid = true; |
| } |
| return locations; |
| } |
| |
| private int size(int[] locations) { |
| // The parental edges are attached to vertices 0 and N - even when order is not |
| // being preserved and other vertices fall outside this range. Measure the distance |
| // between vertices 0 and N, assuming that locations[0] = 0. |
| return locations[getCount()]; |
| } |
| |
| private void setParentConstraints(int min, int max) { |
| parentMin.value = min; |
| parentMax.value = -max; |
| locationsValid = false; |
| } |
| |
| private int getMeasure(int min, int max) { |
| setParentConstraints(min, max); |
| return size(getLocations()); |
| } |
| |
| public int getMeasure(int measureSpec) { |
| int mode = MeasureSpec.getMode(measureSpec); |
| int size = MeasureSpec.getSize(measureSpec); |
| switch (mode) { |
| case MeasureSpec.UNSPECIFIED: { |
| return getMeasure(0, MAX_SIZE); |
| } |
| case MeasureSpec.EXACTLY: { |
| return getMeasure(size, size); |
| } |
| case MeasureSpec.AT_MOST: { |
| return getMeasure(0, size); |
| } |
| default: { |
| assert false; |
| return 0; |
| } |
| } |
| } |
| |
| public void layout(int size) { |
| setParentConstraints(size, size); |
| getLocations(); |
| } |
| |
| public void invalidateStructure() { |
| maxIndex = UNDEFINED; |
| |
| groupBounds = null; |
| forwardLinks = null; |
| backwardLinks = null; |
| |
| leadingMargins = null; |
| trailingMargins = null; |
| arcs = null; |
| |
| locations = null; |
| |
| invalidateValues(); |
| } |
| |
| public void invalidateValues() { |
| groupBoundsValid = false; |
| forwardLinksValid = false; |
| backwardLinksValid = false; |
| |
| leadingMarginsValid = false; |
| trailingMarginsValid = false; |
| arcsValid = false; |
| |
| locationsValid = false; |
| } |
| } |
| |
| /** |
| * Layout information associated with each of the children of a GridLayout. |
| * <p> |
| * GridLayout supports both row and column spanning and arbitrary forms of alignment within |
| * each cell group. The fundamental parameters associated with each cell group are |
| * gathered into their vertical and horizontal components and stored |
| * in the {@link #rowSpec} and {@link #columnSpec} layout parameters. |
| * {@link android.widget.GridLayout.Spec Specs} are immutable structures |
| * and may be shared between the layout parameters of different children. |
| * <p> |
| * The row and column specs contain the leading and trailing indices along each axis |
| * and together specify the four grid indices that delimit the cells of this cell group. |
| * <p> |
| * The alignment properties of the row and column specs together specify |
| * both aspects of alignment within the cell group. It is also possible to specify a child's |
| * alignment within its cell group by using the {@link GridLayout.LayoutParams#setGravity(int)} |
| * method. |
| * |
| * <h4>WRAP_CONTENT and MATCH_PARENT</h4> |
| * |
| * Because the default values of the {@link #width} and {@link #height} |
| * properties are both {@link #WRAP_CONTENT}, this value never needs to be explicitly |
| * declared in the layout parameters of GridLayout's children. In addition, |
| * GridLayout does not distinguish the special size value {@link #MATCH_PARENT} from |
| * {@link #WRAP_CONTENT}. A component's ability to expand to the size of the parent is |
| * instead controlled by the principle of <em>flexibility</em>, |
| * as discussed in {@link GridLayout}. |
| * |
| * <h4>Summary</h4> |
| * |
| * You should not need to use either of the special size values: |
| * {@code WRAP_CONTENT} or {@code MATCH_PARENT} when configuring the children of |
| * a GridLayout. |
| * |
| * <h4>Default values</h4> |
| * |
| * <ul> |
| * <li>{@link #width} = {@link #WRAP_CONTENT}</li> |
| * <li>{@link #height} = {@link #WRAP_CONTENT}</li> |
| * <li>{@link #topMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * {@code false}; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #leftMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * {@code false}; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #bottomMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * {@code false}; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #rightMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * {@code false}; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #rowSpec}<code>.row</code> = {@link #UNDEFINED} </li> |
| * <li>{@link #rowSpec}<code>.rowSpan</code> = 1 </li> |
| * <li>{@link #rowSpec}<code>.alignment</code> = {@link #BASELINE} </li> |
| * <li>{@link #columnSpec}<code>.column</code> = {@link #UNDEFINED} </li> |
| * <li>{@link #columnSpec}<code>.columnSpan</code> = 1 </li> |
| * <li>{@link #columnSpec}<code>.alignment</code> = {@link #LEFT} </li> |
| * </ul> |
| * |
| * See {@link GridLayout} for a more complete description of the conventions |
| * used by GridLayout in the interpretation of the properties of this class. |
| * |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_row |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_rowSpan |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_column |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_columnSpan |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_gravity |
| */ |
| public static class LayoutParams extends MarginLayoutParams { |
| |
| // Default values |
| |
| private static final int DEFAULT_WIDTH = WRAP_CONTENT; |
| private static final int DEFAULT_HEIGHT = WRAP_CONTENT; |
| private static final int DEFAULT_MARGIN = UNDEFINED; |
| private static final int DEFAULT_ROW = UNDEFINED; |
| private static final int DEFAULT_COLUMN = UNDEFINED; |
| private static final Interval DEFAULT_SPAN = new Interval(UNDEFINED, UNDEFINED + 1); |
| private static final int DEFAULT_SPAN_SIZE = DEFAULT_SPAN.size(); |
| |
| // TypedArray indices |
| |
| private static final int MARGIN = R.styleable.ViewGroup_MarginLayout_layout_margin; |
| private static final int LEFT_MARGIN = R.styleable.ViewGroup_MarginLayout_layout_marginLeft; |
| private static final int TOP_MARGIN = R.styleable.ViewGroup_MarginLayout_layout_marginTop; |
| private static final int RIGHT_MARGIN = |
| R.styleable.ViewGroup_MarginLayout_layout_marginRight; |
| private static final int BOTTOM_MARGIN = |
| R.styleable.ViewGroup_MarginLayout_layout_marginBottom; |
| |
| private static final int COLUMN = R.styleable.GridLayout_Layout_layout_column; |
| private static final int COLUMN_SPAN = R.styleable.GridLayout_Layout_layout_columnSpan; |
| |
| private static final int ROW = R.styleable.GridLayout_Layout_layout_row; |
| private static final int ROW_SPAN = R.styleable.GridLayout_Layout_layout_rowSpan; |
| |
| private static final int GRAVITY = R.styleable.GridLayout_Layout_layout_gravity; |
| |
| // Instance variables |
| |
| /** |
| * The spec that defines the vertical characteristics of the cell group |
| * described by these layout parameters. |
| * If an assignment is made to this field after a measurement or layout operation |
| * has already taken place, a call to |
| * {@link ViewGroup#setLayoutParams(ViewGroup.LayoutParams)} |
| * must be made to notify GridLayout of the change. GridLayout is normally able |
| * to detect when code fails to observe this rule, issue a warning and take steps to |
| * compensate for the omission. This facility is implemented on a best effort basis |
| * and should not be relied upon in production code - so it is best to include the above |
| * calls to remove the warnings as soon as it is practical. |
| */ |
| public Spec rowSpec = Spec.UNDEFINED; |
| |
| /** |
| * The spec that defines the horizontal characteristics of the cell group |
| * described by these layout parameters. |
| * If an assignment is made to this field after a measurement or layout operation |
| * has already taken place, a call to |
| * {@link ViewGroup#setLayoutParams(ViewGroup.LayoutParams)} |
| * must be made to notify GridLayout of the change. GridLayout is normally able |
| * to detect when code fails to observe this rule, issue a warning and take steps to |
| * compensate for the omission. This facility is implemented on a best effort basis |
| * and should not be relied upon in production code - so it is best to include the above |
| * calls to remove the warnings as soon as it is practical. |
| */ |
| public Spec columnSpec = Spec.UNDEFINED; |
| |
| // Constructors |
| |
| private LayoutParams( |
| int width, int height, |
| int left, int top, int right, int bottom, |
| Spec rowSpec, Spec columnSpec) { |
| super(width, height); |
| setMargins(left, top, right, bottom); |
| this.rowSpec = rowSpec; |
| this.columnSpec = columnSpec; |
| } |
| |
| /** |
| * Constructs a new LayoutParams instance for this <code>rowSpec</code> |
| * and <code>columnSpec</code>. All other fields are initialized with |
| * default values as defined in {@link LayoutParams}. |
| * |
| * @param rowSpec the rowSpec |
| * @param columnSpec the columnSpec |
| */ |
| public LayoutParams(Spec rowSpec, Spec columnSpec) { |
| this(DEFAULT_WIDTH, DEFAULT_HEIGHT, |
| DEFAULT_MARGIN, DEFAULT_MARGIN, DEFAULT_MARGIN, DEFAULT_MARGIN, |
| rowSpec, columnSpec); |
| } |
| |
| /** |
| * Constructs a new LayoutParams with default values as defined in {@link LayoutParams}. |
| */ |
| public LayoutParams() { |
| this(Spec.UNDEFINED, Spec.UNDEFINED); |
| } |
| |
| // Copying constructors |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(ViewGroup.LayoutParams params) { |
| super(params); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(MarginLayoutParams params) { |
| super(params); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(LayoutParams that) { |
| super(that); |
| this.rowSpec = that.rowSpec; |
| this.columnSpec = that.columnSpec; |
| } |
| |
| // AttributeSet constructors |
| |
| /** |
| * {@inheritDoc} |
| * |
| * Values not defined in the attribute set take the default values |
| * defined in {@link LayoutParams}. |
| */ |
| public LayoutParams(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| reInitSuper(context, attrs); |
| init(context, attrs); |
| } |
| |
| // Implementation |
| |
| // Reinitialise the margins using a different default policy than MarginLayoutParams. |
| // Here we use the value UNDEFINED (as distinct from zero) to represent the undefined state |
| // so that a layout manager default can be accessed post set up. We need this as, at the |
| // point of installation, we do not know how many rows/cols there are and therefore |
| // which elements are positioned next to the container's trailing edges. We need to |
| // know this as margins around the container's boundary should have different |
| // defaults to those between peers. |
| |
| // This method could be parametrized and moved into MarginLayout. |
| private void reInitSuper(Context context, AttributeSet attrs) { |
| TypedArray a = |
| context.obtainStyledAttributes(attrs, R.styleable.ViewGroup_MarginLayout); |
| try { |
| int margin = a.getDimensionPixelSize(MARGIN, DEFAULT_MARGIN); |
| |
| this.leftMargin = a.getDimensionPixelSize(LEFT_MARGIN, margin); |
| this.topMargin = a.getDimensionPixelSize(TOP_MARGIN, margin); |
| this.rightMargin = a.getDimensionPixelSize(RIGHT_MARGIN, margin); |
| this.bottomMargin = a.getDimensionPixelSize(BOTTOM_MARGIN, margin); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| private void init(Context context, AttributeSet attrs) { |
| TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.GridLayout_Layout); |
| try { |
| int gravity = a.getInt(GRAVITY, Gravity.NO_GRAVITY); |
| |
| int column = a.getInt(COLUMN, DEFAULT_COLUMN); |
| int colSpan = a.getInt(COLUMN_SPAN, DEFAULT_SPAN_SIZE); |
| this.columnSpec = spec(column, colSpan, getAlignment(gravity, true)); |
| |
| int row = a.getInt(ROW, DEFAULT_ROW); |
| int rowSpan = a.getInt(ROW_SPAN, DEFAULT_SPAN_SIZE); |
| this.rowSpec = spec(row, rowSpan, getAlignment(gravity, false)); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| /** |
| * Describes how the child views are positioned. Default is {@code LEFT | BASELINE}. |
| * See {@link android.view.Gravity}. |
| * |
| * @param gravity the new gravity value |
| * |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_gravity |
| */ |
| public void setGravity(int gravity) { |
| rowSpec = rowSpec.copyWriteAlignment(getAlignment(gravity, false)); |
| columnSpec = columnSpec.copyWriteAlignment(getAlignment(gravity, true)); |
| } |
| |
| @Override |
| protected void setBaseAttributes(TypedArray attributes, int widthAttr, int heightAttr) { |
| this.width = attributes.getLayoutDimension(widthAttr, DEFAULT_WIDTH); |
| this.height = attributes.getLayoutDimension(heightAttr, DEFAULT_HEIGHT); |
| } |
| |
| final void setRowSpecSpan(Interval span) { |
| rowSpec = rowSpec.copyWriteSpan(span); |
| } |
| |
| final void setColumnSpecSpan(Interval span) { |
| columnSpec = columnSpec.copyWriteSpan(span); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) return false; |
| |
| LayoutParams that = (LayoutParams) o; |
| |
| if (!columnSpec.equals(that.columnSpec)) return false; |
| if (!rowSpec.equals(that.rowSpec)) return false; |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = rowSpec.hashCode(); |
| result = 31 * result + columnSpec.hashCode(); |
| return result; |
| } |
| } |
| |
| /* |
| In place of a HashMap from span to Int, use an array of key/value pairs - stored in Arcs. |
| Add the mutables completesCycle flag to avoid creating another hash table for detecting cycles. |
| */ |
| final static class Arc { |
| public final Interval span; |
| public final MutableInt value; |
| public boolean valid = true; |
| |
| public Arc(Interval span, MutableInt value) { |
| this.span = span; |
| this.value = value; |
| } |
| |
| @Override |
| public String toString() { |
| return span + " " + (!valid ? "+>" : "->") + " " + value; |
| } |
| } |
| |
| // A mutable Integer - used to avoid heap allocation during the layout operation |
| |
| final static class MutableInt { |
| public int value; |
| |
| public MutableInt() { |
| reset(); |
| } |
| |
| public MutableInt(int value) { |
| this.value = value; |
| } |
| |
| public void reset() { |
| value = Integer.MIN_VALUE; |
| } |
| |
| @Override |
| public String toString() { |
| return Integer.toString(value); |
| } |
| } |
| |
| final static class Assoc<K, V> extends ArrayList<Pair<K, V>> { |
| private final Class<K> keyType; |
| private final Class<V> valueType; |
| |
| private Assoc(Class<K> keyType, Class<V> valueType) { |
| this.keyType = keyType; |
| this.valueType = valueType; |
| } |
| |
| public static <K, V> Assoc<K, V> of(Class<K> keyType, Class<V> valueType) { |
| return new Assoc<K, V>(keyType, valueType); |
| } |
| |
| public void put(K key, V value) { |
| add(Pair.create(key, value)); |
| } |
| |
| @SuppressWarnings(value = "unchecked") |
| public PackedMap<K, V> pack() { |
| int N = size(); |
| K[] keys = (K[]) Array.newInstance(keyType, N); |
| V[] values = (V[]) Array.newInstance(valueType, N); |
| for (int i = 0; i < N; i++) { |
| keys[i] = get(i).first; |
| values[i] = get(i).second; |
| } |
| return new PackedMap<K, V>(keys, values); |
| } |
| } |
| |
| /* |
| This data structure is used in place of a Map where we have an index that refers to the order |
| in which each key/value pairs were added to the map. In this case we store keys and values |
| in arrays of a length that is equal to the number of unique keys. We also maintain an |
| array of indexes from insertion order to the compacted arrays of keys and values. |
| |
| Note that behavior differs from that of a LinkedHashMap in that repeated entries |
| *do* get added multiples times. So the length of index is equals to the number of |
| items added. |
| |
| This is useful in the GridLayout class where we can rely on the order of children not |
| changing during layout - to use integer-based lookup for our internal structures |
| rather than using (and storing) an implementation of Map<Key, ?>. |
| */ |
| @SuppressWarnings(value = "unchecked") |
| final static class PackedMap<K, V> { |
| public final int[] index; |
| public final K[] keys; |
| public final V[] values; |
| |
| private PackedMap(K[] keys, V[] values) { |
| this.index = createIndex(keys); |
| |
| this.keys = compact(keys, index); |
| this.values = compact(values, index); |
| } |
| |
| public V getValue(int i) { |
| return values[index[i]]; |
| } |
| |
| private static <K> int[] createIndex(K[] keys) { |
| int size = keys.length; |
| int[] result = new int[size]; |
| |
| Map<K, Integer> keyToIndex = new HashMap<K, Integer>(); |
| for (int i = 0; i < size; i++) { |
| K key = keys[i]; |
| Integer index = keyToIndex.get(key); |
| if (index == null) { |
| index = keyToIndex.size(); |
| keyToIndex.put(key, index); |
| } |
| result[i] = index; |
| } |
| return result; |
| } |
| |
| /* |
| Create a compact array of keys or values using the supplied index. |
| */ |
| private static <K> K[] compact(K[] a, int[] index) { |
| int size = a.length; |
| Class<?> componentType = a.getClass().getComponentType(); |
| K[] result = (K[]) Array.newInstance(componentType, max2(index, -1) + 1); |
| |
| // this overwrite duplicates, retaining the last equivalent entry |
| for (int i = 0; i < size; i++) { |
| result[index[i]] = a[i]; |
| } |
| return result; |
| } |
| } |
| |
| /* |
| For each group (with a given alignment) we need to store the amount of space required |
| before the alignment point and the amount of space required after it. One side of this |
| calculation is always 0 for START and END alignments but we don't make use of this. |
| For CENTER and BASELINE alignments both sides are needed and in the BASELINE case no |
| simple optimisations are possible. |
| |
| The general algorithm therefore is to create a Map (actually a PackedMap) from |
| group to Bounds and to loop through all Views in the group taking the maximum |
| of the values for each View. |
| */ |
| static class Bounds { |
| public int before; |
| public int after; |
| public int flexibility; // we're flexible iff all included specs are flexible |
| |
| private Bounds() { |
| reset(); |
| } |
| |
| protected void reset() { |
| before = Integer.MIN_VALUE; |
| after = Integer.MIN_VALUE; |
| flexibility = CAN_STRETCH; // from the above, we're flexible when empty |
| } |
| |
| protected void include(int before, int after) { |
| this.before = max(this.before, before); |
| this.after = max(this.after, after); |
| } |
| |
| protected int size(boolean min) { |
| if (!min) { |
| if (canStretch(flexibility)) { |
| return MAX_SIZE; |
| } |
| } |
| return before + after; |
| } |
| |
| protected int getOffset(View c, Alignment alignment, int size) { |
| return before - alignment.getAlignmentValue(c, size); |
| } |
| |
| protected final void include(View c, Spec spec, GridLayout gridLayout, Axis axis) { |
| this.flexibility &= spec.getFlexibility(); |
| int size = gridLayout.getMeasurementIncludingMargin(c, axis.horizontal); |
| Alignment alignment = gridLayout.getAlignment(spec.alignment, axis.horizontal); |
| // todo test this works correctly when the returned value is UNDEFINED |
| int before = alignment.getAlignmentValue(c, size); |
| include(before, size - before); |
| } |
| |
| @Override |
| public String toString() { |
| return "Bounds{" + |
| "before=" + before + |
| ", after=" + after + |
| '}'; |
| } |
| } |
| |
| /** |
| * An Interval represents a contiguous range of values that lie between |
| * the interval's {@link #min} and {@link #max} values. |
| * <p> |
| * Intervals are immutable so may be passed as values and used as keys in hash tables. |
| * It is not necessary to have multiple instances of Intervals which have the same |
| * {@link #min} and {@link #max} values. |
| * <p> |
| * Intervals are often written as {@code [min, max]} and represent the set of values |
| * {@code x} such that {@code min <= x < max}. |
| */ |
| final static class Interval { |
| /** |
| * The minimum value. |
| */ |
| public final int min; |
| |
| /** |
| * The maximum value. |
| */ |
| public final int max; |
| |
| /** |
| * Construct a new Interval, {@code interval}, where: |
| * <ul> |
| * <li> {@code interval.min = min} </li> |
| * <li> {@code interval.max = max} </li> |
| * </ul> |
| * |
| * @param min the minimum value. |
| * @param max the maximum value. |
| */ |
| public Interval(int min, int max) { |
| this.min = min; |
| this.max = max; |
| } |
| |
| int size() { |
| return max - min; |
| } |
| |
| Interval inverse() { |
| return new Interval(max, min); |
| } |
| |
| /** |
| * Returns {@code true} if the {@link #getClass class}, |
| * {@link #min} and {@link #max} properties of this Interval and the |
| * supplied parameter are pairwise equal; {@code false} otherwise. |
| * |
| * @param that the object to compare this interval with |
| * |
| * @return {@code true} if the specified object is equal to this |
| * {@code Interval}, {@code false} otherwise. |
| */ |
| @Override |
| public boolean equals(Object that) { |
| if (this == that) { |
| return true; |
| } |
| if (that == null || getClass() != that.getClass()) { |
| return false; |
| } |
| |
| Interval interval = (Interval) that; |
| |
| if (max != interval.max) { |
| return false; |
| } |
| //noinspection RedundantIfStatement |
| if (min != interval.min) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = min; |
| result = 31 * result + max; |
| return result; |
| } |
| |
| @Override |
| public String toString() { |
| return "[" + min + ", " + max + "]"; |
| } |
| } |
| |
| /** |
| * A Spec defines the horizontal or vertical characteristics of a group of |
| * cells. Each spec. defines the <em>grid indices</em> and <em>alignment</em> |
| * along the appropriate axis. |
| * <p> |
| * The <em>grid indices</em> are the leading and trailing edges of this cell group. |
| * See {@link GridLayout} for a description of the conventions used by GridLayout |
| * for grid indices. |
| * <p> |
| * The <em>alignment</em> property specifies how cells should be aligned in this group. |
| * For row groups, this specifies the vertical alignment. |
| * For column groups, this specifies the horizontal alignment. |
| * <p> |
| * Use the following static methods to create specs: |
| * <ul> |
| * <li>{@link #spec(int)}</li> |
| * <li>{@link #spec(int, int)}</li> |
| * <li>{@link #spec(int, Alignment)}</li> |
| * <li>{@link #spec(int, int, Alignment)}</li> |
| * </ul> |
| * |
| */ |
| public static class Spec { |
| static final Spec UNDEFINED = spec(GridLayout.UNDEFINED); |
| |
| final boolean startDefined; |
| final Interval span; |
| final Alignment alignment; |
| |
| private Spec(boolean startDefined, Interval span, Alignment alignment) { |
| this.startDefined = startDefined; |
| this.span = span; |
| this.alignment = alignment; |
| } |
| |
| private Spec(boolean startDefined, int start, int size, Alignment alignment) { |
| this(startDefined, new Interval(start, start + size), alignment); |
| } |
| |
| final Spec copyWriteSpan(Interval span) { |
| return new Spec(startDefined, span, alignment); |
| } |
| |
| final Spec copyWriteAlignment(Alignment alignment) { |
| return new Spec(startDefined, span, alignment); |
| } |
| |
| final int getFlexibility() { |
| return (alignment == UNDEFINED_ALIGNMENT) ? INFLEXIBLE : CAN_STRETCH; |
| } |
| |
| /** |
| * Returns {@code true} if the {@code class}, {@code alignment} and {@code span} |
| * properties of this Spec and the supplied parameter are pairwise equal, |
| * {@code false} otherwise. |
| * |
| * @param that the object to compare this spec with |
| * |
| * @return {@code true} if the specified object is equal to this |
| * {@code Spec}; {@code false} otherwise |
| */ |
| @Override |
| public boolean equals(Object that) { |
| if (this == that) { |
| return true; |
| } |
| if (that == null || getClass() != that.getClass()) { |
| return false; |
| } |
| |
| Spec spec = (Spec) that; |
| |
| if (!alignment.equals(spec.alignment)) { |
| return false; |
| } |
| //noinspection RedundantIfStatement |
| if (!span.equals(spec.span)) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = span.hashCode(); |
| result = 31 * result + alignment.hashCode(); |
| return result; |
| } |
| } |
| |
| /** |
| * Return a Spec, {@code spec}, where: |
| * <ul> |
| * <li> {@code spec.span = [start, start + size]} </li> |
| * <li> {@code spec.alignment = alignment} </li> |
| * </ul> |
| * |
| * @param start the start |
| * @param size the size |
| * @param alignment the alignment |
| */ |
| public static Spec spec(int start, int size, Alignment alignment) { |
| return new Spec(start != UNDEFINED, start, size, alignment); |
| } |
| |
| /** |
| * Return a Spec, {@code spec}, where: |
| * <ul> |
| * <li> {@code spec.span = [start, start + 1]} </li> |
| * <li> {@code spec.alignment = alignment} </li> |
| * </ul> |
| * |
| * @param start the start index |
| * @param alignment the alignment |
| */ |
| public static Spec spec(int start, Alignment alignment) { |
| return spec(start, 1, alignment); |
| } |
| |
| /** |
| * Return a Spec, {@code spec}, where: |
| * <ul> |
| * <li> {@code spec.span = [start, start + size]} </li> |
| * </ul> |
| * |
| * @param start the start |
| * @param size the size |
| */ |
| public static Spec spec(int start, int size) { |
| return spec(start, size, UNDEFINED_ALIGNMENT); |
| } |
| |
| /** |
| * Return a Spec, {@code spec}, where: |
| * <ul> |
| * <li> {@code spec.span = [start, start + 1]} </li> |
| * </ul> |
| * |
| * @param start the start index |
| */ |
| public static Spec spec(int start) { |
| return spec(start, 1); |
| } |
| |
| /** |
| * Alignments specify where a view should be placed within a cell group and |
| * what size it should be. |
| * <p> |
| * The {@link LayoutParams} class contains a {@link LayoutParams#rowSpec rowSpec} |
| * and a {@link LayoutParams#columnSpec columnSpec} each of which contains an |
| * {@code alignment}. Overall placement of the view in the cell |
| * group is specified by the two alignments which act along each axis independently. |
| * <p> |
| * The GridLayout class defines the most common alignments used in general layout: |
| * {@link #TOP}, {@link #LEFT}, {@link #BOTTOM}, {@link #RIGHT}, {@link #CENTER}, {@link |
| * #BASELINE} and {@link #FILL}. |
| */ |
| /* |
| * An Alignment implementation must define {@link #getAlignmentValue(View, int, int)}, |
| * to return the appropriate value for the type of alignment being defined. |
| * The enclosing algorithms position the children |
| * so that the locations defined by the alignment values |
| * are the same for all of the views in a group. |
| * <p> |
| */ |
| public static abstract class Alignment { |
| Alignment() { |
| } |
| |
| /** |
| * Returns an alignment value. In the case of vertical alignments the value |
| * returned should indicate the distance from the top of the view to the |
| * alignment location. |
| * For horizontal alignments measurement is made from the left edge of the component. |
| * |
| * @param view the view to which this alignment should be applied |
| * @param viewSize the measured size of the view |
| * @return the alignment value |
| */ |
| abstract int getAlignmentValue(View view, int viewSize); |
| |
| /** |
| * Returns the size of the view specified by this alignment. |
| * In the case of vertical alignments this method should return a height; for |
| * horizontal alignments this method should return the width. |
| * <p> |
| * The default implementation returns {@code viewSize}. |
| * |
| * @param view the view to which this alignment should be applied |
| * @param viewSize the measured size of the view |
| * @param cellSize the size of the cell into which this view will be placed |
| * @param measurementType This parameter is currently unused as GridLayout only supports |
| * one type of measurement: {@link View#measure(int, int)}. |
| * |
| * @return the aligned size |
| */ |
| int getSizeInCell(View view, int viewSize, int cellSize, int measurementType) { |
| return viewSize; |
| } |
| |
| Bounds getBounds() { |
| return new Bounds(); |
| } |
| } |
| |
| static final Alignment UNDEFINED_ALIGNMENT = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| return UNDEFINED; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>start</em> |
| * edges of the other views in its cell group. |
| */ |
| private static final Alignment LEADING = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| return 0; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>end</em> |
| * edges of the other views in its cell group. |
| */ |
| private static final Alignment TRAILING = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| return viewSize; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>top</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment TOP = LEADING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>bottom</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment BOTTOM = TRAILING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>start</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment START = LEADING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>end</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment END = TRAILING; |
| |
| private static Alignment getAbsoluteAlignment(final Alignment a1, final Alignment a2) { |
| return new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| if (view == null) { |
| return UNDEFINED; |
| } |
| Alignment alignment = view.isLayoutRtl() ? a2 : a1; |
| return alignment.getAlignmentValue(view, viewSize); |
| } |
| }; |
| } |
| |
| /** |
| * Indicates that a view should be aligned with the <em>left</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment LEFT = getAbsoluteAlignment(START, END); |
| |
| /** |
| * Indicates that a view should be aligned with the <em>right</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment RIGHT = getAbsoluteAlignment(END, START); |
| |
| /** |
| * Indicates that a view should be <em>centered</em> with the other views in its cell group. |
| * This constant may be used in both {@link LayoutParams#rowSpec rowSpecs} and {@link |
| * LayoutParams#columnSpec columnSpecs}. |
| */ |
| public static final Alignment CENTER = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| return viewSize >> 1; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>baselines</em> |
| * of the other views in its cell group. |
| * This constant may only be used as an alignment in {@link LayoutParams#rowSpec rowSpecs}. |
| * |
| * @see View#getBaseline() |
| */ |
| public static final Alignment BASELINE = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| if (view == null) { |
| return UNDEFINED; |
| } |
| int baseline = view.getBaseline(); |
| return (baseline == -1) ? UNDEFINED : baseline; |
| } |
| |
| @Override |
| public Bounds getBounds() { |
| return new Bounds() { |
| /* |
| In a baseline aligned row in which some components define a baseline |
| and some don't, we need a third variable to properly account for all |
| the sizes. This tracks the maximum size of all the components - |
| including those that don't define a baseline. |
| */ |
| private int size; |
| |
| @Override |
| protected void reset() { |
| super.reset(); |
| size = Integer.MIN_VALUE; |
| } |
| |
| @Override |
| protected void include(int before, int after) { |
| super.include(before, after); |
| size = max(size, before + after); |
| } |
| |
| @Override |
| protected int size(boolean min) { |
| return max(super.size(min), size); |
| } |
| |
| @Override |
| protected int getOffset(View c, Alignment alignment, int size) { |
| return max(0, super.getOffset(c, alignment, size)); |
| } |
| }; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should expanded to fit the boundaries of its cell group. |
| * This constant may be used in both {@link LayoutParams#rowSpec rowSpecs} and |
| * {@link LayoutParams#columnSpec columnSpecs}. |
| */ |
| public static final Alignment FILL = new Alignment() { |
| @Override |
| public int getAlignmentValue(View view, int viewSize) { |
| return UNDEFINED; |
| } |
| |
| @Override |
| public int getSizeInCell(View view, int viewSize, int cellSize, int measurementType) { |
| return cellSize; |
| } |
| }; |
| |
| static boolean canStretch(int flexibility) { |
| return (flexibility & CAN_STRETCH) != 0; |
| } |
| |
| private static final int INFLEXIBLE = 0; |
| private static final int CAN_STRETCH = 2; |
| } |