| /* |
| * Copyright (C) 2019 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 com.android.systemui.globalactions; |
| |
| import android.content.Context; |
| import android.util.AttributeSet; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.widget.LinearLayout; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| /** |
| * Layout which uses nested LinearLayouts to create a grid with the following behavior: |
| * |
| * * Try to maintain a 'square' grid (equal number of columns and rows) based on the expected item |
| * count. |
| * * Determine the position and parent of any item by its index and the total item count. |
| * * Display and hide sub-lists as needed, depending on the expected item count. |
| * |
| * While we could implement this behavior with a GridLayout, it would take significantly more |
| * time and effort, and would require more substantial refactoring of the existing code in |
| * GlobalActionsDialog, since it would require manipulation of layout properties on the child items |
| * themselves. |
| * |
| */ |
| |
| public class ListGridLayout extends LinearLayout { |
| private static final String TAG = "ListGridLayout"; |
| private int mExpectedCount; |
| private int mCurrentCount = 0; |
| private boolean mSwapRowsAndColumns; |
| private boolean mReverseSublists; |
| private boolean mReverseItems; |
| |
| // number of rows and columns to use for different numbers of items |
| private final int[][] mConfigs = { |
| // {rows, columns} |
| {0, 0}, // 0 items |
| {1, 1}, // 1 item |
| {1, 2}, // 2 items |
| {1, 3}, // 3 items |
| {2, 2}, // 4 items |
| {2, 3}, // 5 items |
| {2, 3}, // 6 items |
| {3, 3}, // 7 items |
| {3, 3}, // 8 items |
| {3, 3} // 9 items |
| }; |
| |
| public ListGridLayout(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| } |
| |
| /** |
| * Sets whether this grid should prioritize filling rows or columns first. |
| */ |
| public void setSwapRowsAndColumns(boolean swap) { |
| mSwapRowsAndColumns = swap; |
| } |
| |
| /** |
| * Sets whether this grid should fill sublists in reverse order. |
| */ |
| public void setReverseSublists(boolean reverse) { |
| mReverseSublists = reverse; |
| } |
| |
| /** |
| * Sets whether this grid should add items to sublists in reverse order. |
| * @param reverse |
| */ |
| public void setReverseItems(boolean reverse) { |
| mReverseItems = reverse; |
| } |
| |
| /** |
| * Remove all items from this grid. |
| */ |
| public void removeAllItems() { |
| for (int i = 0; i < getChildCount(); i++) { |
| ViewGroup subList = getSublist(i); |
| if (subList != null) { |
| subList.removeAllViews(); |
| subList.setVisibility(View.GONE); |
| } |
| } |
| mCurrentCount = 0; |
| } |
| |
| /** |
| * Adds a view item to this grid, placing it in the correct sublist and ensuring that the |
| * sublist is visible. |
| * |
| * This function is stateful, since it tracks how many items have been added thus far, to |
| * determine which sublist they should be added to. To ensure that this works correctly, call |
| * removeAllItems() instead of removing views individually with removeView() to ensure that the |
| * counter gets reset correctly. |
| * @param item |
| */ |
| public void addItem(View item) { |
| ViewGroup parent = getParentView(mCurrentCount, mReverseSublists, mSwapRowsAndColumns); |
| if (mReverseItems) { |
| parent.addView(item, 0); |
| } else { |
| parent.addView(item); |
| } |
| parent.setVisibility(View.VISIBLE); |
| mCurrentCount++; |
| } |
| |
| /** |
| * Get the parent view associated with the item which should be placed at the given position. |
| * @param index The index of the item. |
| * @param reverseSublists Reverse the order of sublists. Ordinarily, sublists fill from first to |
| * last, whereas setting this to true will fill them last to first. |
| * @param swapRowsAndColumns Swap the order in which rows and columns are filled. By default, |
| * columns fill first, adding one item to each row. Setting this to |
| * true will cause rows to fill first, adding one item to each column. |
| * @return |
| */ |
| @VisibleForTesting |
| protected ViewGroup getParentView(int index, boolean reverseSublists, |
| boolean swapRowsAndColumns) { |
| if (getRowCount() == 0 || index < 0) { |
| return null; |
| } |
| int targetIndex = Math.min(index, getMaxElementCount() - 1); |
| int row = getParentViewIndex(targetIndex, reverseSublists, swapRowsAndColumns); |
| return getSublist(row); |
| } |
| |
| @VisibleForTesting |
| protected ViewGroup getSublist(int index) { |
| return (ViewGroup) getChildAt(index); |
| } |
| |
| private int reverseSublistIndex(int index) { |
| return getChildCount() - (index + 1); |
| } |
| |
| private int getParentViewIndex(int index, boolean reverseSublists, boolean swapRowsAndColumns) { |
| int sublistIndex; |
| int rows = getRowCount(); |
| if (swapRowsAndColumns) { |
| sublistIndex = (int) Math.floor(index / rows); |
| } else { |
| sublistIndex = index % rows; |
| } |
| if (reverseSublists) { |
| sublistIndex = reverseSublistIndex(sublistIndex); |
| } |
| return sublistIndex; |
| } |
| |
| /** |
| * Sets the expected number of items that this grid will be responsible for rendering. |
| */ |
| public void setExpectedCount(int count) { |
| mExpectedCount = count; |
| } |
| |
| private int getMaxElementCount() { |
| return mConfigs.length - 1; |
| } |
| |
| private int[] getConfig() { |
| if (mExpectedCount < 0) { |
| return mConfigs[0]; |
| } |
| int targetElements = Math.min(getMaxElementCount(), mExpectedCount); |
| return mConfigs[targetElements]; |
| } |
| |
| /** |
| * Get the number of rows which will be used to render children. |
| */ |
| public int getRowCount() { |
| return getConfig()[0]; |
| } |
| |
| /** |
| * Get the number of columns which will be used to render children. |
| */ |
| public int getColumnCount() { |
| return getConfig()[1]; |
| } |
| } |