| /* |
| * Copyright (C) 2014 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.support.v17.leanback.widget; |
| |
| import android.support.v17.leanback.app.HeadersFragment; |
| import android.support.v17.leanback.graphics.ColorOverlayDimmer; |
| import android.view.View; |
| import android.view.ViewGroup; |
| |
| /** |
| * An abstract {@link Presenter} that renders a {@link Row}. |
| * |
| * <h3>Customize UI widgets</h3> |
| * When a subclass of RowPresenter adds UI widgets, it should subclass |
| * {@link RowPresenter.ViewHolder} and override {@link #createRowViewHolder(ViewGroup)} |
| * and {@link #initializeRowViewHolder(ViewHolder)}. The subclass must use layout id |
| * "row_content" for the widget that will be aligned to the title of any {@link HeadersFragment} |
| * that may exist in the parent fragment. RowPresenter contains an optional and |
| * replaceable {@link RowHeaderPresenter} that renders the header. You can disable |
| * the default rendering or replace the Presenter with a new header presenter |
| * by calling {@link #setHeaderPresenter(RowHeaderPresenter)}. |
| * |
| * <h3>UI events from fragments</h3> |
| * RowPresenter receives calls from its parent (typically a Fragment) when: |
| * <ul> |
| * <li> |
| * A Row is selected via {@link #setRowViewSelected(Presenter.ViewHolder, boolean)}. The event |
| * is triggered immediately when there is a row selection change before the selection |
| * animation is started. |
| * Subclasses of RowPresenter may override {@link #onRowViewSelected(ViewHolder, boolean)}. |
| * </li> |
| * <li> |
| * A Row is expanded to full width via {@link #setRowViewExpanded(Presenter.ViewHolder, boolean)}. |
| * The event is triggered immediately before the expand animation is started. |
| * Subclasses of RowPresenter may override {@link #onRowViewExpanded(ViewHolder, boolean)}. |
| * </li> |
| * </ul> |
| * |
| * <h3>User events</h3> |
| * RowPresenter provides {@link OnItemSelectedListener} and {@link OnItemClickedListener}. |
| * If a subclass wants to add its own {@link View.OnFocusChangeListener} or |
| * {@link View.OnClickListener}, it must do that in {@link #createRowViewHolder(ViewGroup)} |
| * to be properly chained by the library. Adding View listeners after |
| * {@link #createRowViewHolder(ViewGroup)} is undefined and may result in |
| * incorrect behavior by the library's listeners. |
| * |
| * <h3>Selection animation</h3> |
| * <p> |
| * When a user scrolls through rows, a fragment will initiate animation and call |
| * {@link #setSelectLevel(Presenter.ViewHolder, float)} with float value between |
| * 0 and 1. By default, the RowPresenter draws a dim overlay on top of the row |
| * view for views that are not selected. Subclasses may override this default effect |
| * by having {@link #isUsingDefaultSelectEffect()} return false and overriding |
| * {@link #onSelectLevelChanged(ViewHolder)} to apply a different selection effect. |
| * </p> |
| * <p> |
| * Call {@link #setSelectEffectEnabled(boolean)} to enable/disable the select effect, |
| * This will not only enable/disable the default dim effect but also subclasses must |
| * respect this flag as well. |
| * </p> |
| */ |
| public abstract class RowPresenter extends Presenter { |
| |
| static class ContainerViewHolder extends Presenter.ViewHolder { |
| /** |
| * wrapped row view holder |
| */ |
| final ViewHolder mRowViewHolder; |
| |
| public ContainerViewHolder(RowContainerView containerView, ViewHolder rowViewHolder) { |
| super(containerView); |
| containerView.addRowView(rowViewHolder.view); |
| if (rowViewHolder.mHeaderViewHolder != null) { |
| containerView.addHeaderView(rowViewHolder.mHeaderViewHolder.view); |
| } |
| mRowViewHolder = rowViewHolder; |
| mRowViewHolder.mContainerViewHolder = this; |
| } |
| } |
| |
| /** |
| * A view holder for a {@link Row}. |
| */ |
| public static class ViewHolder extends Presenter.ViewHolder { |
| ContainerViewHolder mContainerViewHolder; |
| RowHeaderPresenter.ViewHolder mHeaderViewHolder; |
| Row mRow; |
| boolean mSelected; |
| boolean mExpanded; |
| boolean mInitialzed; |
| float mSelectLevel = 0f; // initially unselected |
| protected final ColorOverlayDimmer mColorDimmer; |
| |
| /** |
| * Constructor for ViewHolder. |
| * |
| * @param view The View bound to the Row. |
| */ |
| public ViewHolder(View view) { |
| super(view); |
| mColorDimmer = ColorOverlayDimmer.createDefault(view.getContext()); |
| } |
| |
| /** |
| * Returns the Row bound to the View in this ViewHolder. |
| */ |
| public final Row getRow() { |
| return mRow; |
| } |
| |
| /** |
| * Returns whether the Row is in its expanded state. |
| * |
| * @return true if the Row is expanded, false otherwise. |
| */ |
| public final boolean isExpanded() { |
| return mExpanded; |
| } |
| |
| /** |
| * Returns whether the Row is selected. |
| * |
| * @return true if the Row is selected, false otherwise. |
| */ |
| public final boolean isSelected() { |
| return mSelected; |
| } |
| |
| /** |
| * Returns the current selection level of the Row. |
| */ |
| public final float getSelectLevel() { |
| return mSelectLevel; |
| } |
| |
| /** |
| * Returns the view holder for the Row header for this Row. |
| */ |
| public final RowHeaderPresenter.ViewHolder getHeaderViewHolder() { |
| return mHeaderViewHolder; |
| } |
| } |
| |
| private RowHeaderPresenter mHeaderPresenter = new RowHeaderPresenter(); |
| private OnItemSelectedListener mOnItemSelectedListener; |
| private OnItemClickedListener mOnItemClickedListener; |
| private OnItemViewSelectedListener mOnItemViewSelectedListener; |
| private OnItemViewClickedListener mOnItemViewClickedListener; |
| |
| boolean mSelectEffectEnabled = true; |
| |
| @Override |
| public final Presenter.ViewHolder onCreateViewHolder(ViewGroup parent) { |
| ViewHolder vh = createRowViewHolder(parent); |
| vh.mInitialzed = false; |
| Presenter.ViewHolder result; |
| if (needsRowContainerView()) { |
| RowContainerView containerView = new RowContainerView(parent.getContext()); |
| if (mHeaderPresenter != null) { |
| vh.mHeaderViewHolder = (RowHeaderPresenter.ViewHolder) |
| mHeaderPresenter.onCreateViewHolder((ViewGroup) vh.view); |
| } |
| result = new ContainerViewHolder(containerView, vh); |
| } else { |
| result = vh; |
| } |
| initializeRowViewHolder(vh); |
| if (!vh.mInitialzed) { |
| throw new RuntimeException("super.initializeRowViewHolder() must be called"); |
| } |
| return result; |
| } |
| |
| /** |
| * Called to create a ViewHolder object for a Row. Subclasses will override |
| * this method to return a different concrete ViewHolder object. |
| * |
| * @param parent The parent View for the Row's view holder. |
| * @return A ViewHolder for the Row's View. |
| */ |
| protected abstract ViewHolder createRowViewHolder(ViewGroup parent); |
| |
| /** |
| * Called after a {@link RowPresenter.ViewHolder} is created for a Row. |
| * Subclasses may override this method and start by calling |
| * super.initializeRowViewHolder(ViewHolder). |
| * |
| * @param vh The ViewHolder to initialize for the Row. |
| */ |
| protected void initializeRowViewHolder(ViewHolder vh) { |
| vh.mInitialzed = true; |
| } |
| |
| /** |
| * Set the Presenter used for rendering the header. Can be null to disable |
| * header rendering. The method must be called before creating any Row Views. |
| */ |
| public final void setHeaderPresenter(RowHeaderPresenter headerPresenter) { |
| mHeaderPresenter = headerPresenter; |
| } |
| |
| /** |
| * Get the Presenter used for rendering the header, or null if none has been |
| * set. |
| */ |
| public final RowHeaderPresenter getHeaderPresenter() { |
| return mHeaderPresenter; |
| } |
| |
| /** |
| * Get the {@link RowPresenter.ViewHolder} from the given Presenter |
| * ViewHolder. |
| */ |
| public final ViewHolder getRowViewHolder(Presenter.ViewHolder holder) { |
| if (holder instanceof ContainerViewHolder) { |
| return ((ContainerViewHolder) holder).mRowViewHolder; |
| } else { |
| return (ViewHolder) holder; |
| } |
| } |
| |
| /** |
| * Set the expanded state of a Row view. |
| * |
| * @param holder The Row ViewHolder to set expanded state on. |
| * @param expanded True if the Row is expanded, false otherwise. |
| */ |
| public final void setRowViewExpanded(Presenter.ViewHolder holder, boolean expanded) { |
| ViewHolder rowViewHolder = getRowViewHolder(holder); |
| rowViewHolder.mExpanded = expanded; |
| onRowViewExpanded(rowViewHolder, expanded); |
| } |
| |
| /** |
| * Set the selected state of a Row view. |
| * |
| * @param holder The Row ViewHolder to set expanded state on. |
| * @param selected True if the Row is expanded, false otherwise. |
| */ |
| public final void setRowViewSelected(Presenter.ViewHolder holder, boolean selected) { |
| ViewHolder rowViewHolder = getRowViewHolder(holder); |
| rowViewHolder.mSelected = selected; |
| onRowViewSelected(rowViewHolder, selected); |
| } |
| |
| /** |
| * Subclass may override this to respond to expanded state changes of a Row. |
| * The default implementation will hide/show the header view. Subclasses may |
| * make visual changes to the Row View but must not create animation on the |
| * Row view. |
| */ |
| protected void onRowViewExpanded(ViewHolder vh, boolean expanded) { |
| updateHeaderViewVisibility(vh); |
| vh.view.setActivated(expanded); |
| } |
| |
| /** |
| * Subclass may override this to respond to selected state changes of a Row. |
| * Subclass may make visual changes to Row view but must not create |
| * animation on the Row view. |
| */ |
| protected void onRowViewSelected(ViewHolder vh, boolean selected) { |
| if (selected) { |
| if (mOnItemViewSelectedListener != null) { |
| mOnItemViewSelectedListener.onItemSelected(null, null, vh, vh.getRow()); |
| } |
| if (mOnItemSelectedListener != null) { |
| mOnItemSelectedListener.onItemSelected(null, vh.getRow()); |
| } |
| } |
| updateHeaderViewVisibility(vh); |
| } |
| |
| private void updateHeaderViewVisibility(ViewHolder vh) { |
| if (mHeaderPresenter != null && vh.mHeaderViewHolder != null) { |
| RowContainerView containerView = ((RowContainerView) vh.mContainerViewHolder.view); |
| containerView.showHeader(vh.isExpanded()); |
| } |
| } |
| |
| /** |
| * Set the current select level to a value between 0 (unselected) and 1 (selected). |
| * Subclasses may override {@link #onSelectLevelChanged(ViewHolder)} to |
| * respond to changes in the selected level. |
| */ |
| public final void setSelectLevel(Presenter.ViewHolder vh, float level) { |
| ViewHolder rowViewHolder = getRowViewHolder(vh); |
| rowViewHolder.mSelectLevel = level; |
| onSelectLevelChanged(rowViewHolder); |
| } |
| |
| /** |
| * Get the current select level. The value will be between 0 (unselected) |
| * and 1 (selected). |
| */ |
| public final float getSelectLevel(Presenter.ViewHolder vh) { |
| return getRowViewHolder(vh).mSelectLevel; |
| } |
| |
| /** |
| * Callback when select level is changed. The default implementation applies |
| * the select level to {@link RowHeaderPresenter#setSelectLevel(RowHeaderPresenter.ViewHolder, float)} |
| * when {@link #getSelectEffectEnabled()} is true. Subclasses may override |
| * this function and implement a different select effect. In this case, you |
| * should also override {@link #isUsingDefaultSelectEffect()} to disable |
| * the default dimming effect applied by the library. |
| */ |
| protected void onSelectLevelChanged(ViewHolder vh) { |
| if (getSelectEffectEnabled()) { |
| vh.mColorDimmer.setActiveLevel(vh.mSelectLevel); |
| if (vh.mHeaderViewHolder != null) { |
| mHeaderPresenter.setSelectLevel(vh.mHeaderViewHolder, vh.mSelectLevel); |
| } |
| if (isUsingDefaultSelectEffect()) { |
| ((RowContainerView) vh.mContainerViewHolder.view).setForegroundColor( |
| vh.mColorDimmer.getPaint().getColor()); |
| } |
| } |
| } |
| |
| /** |
| * Enables or disables the row selection effect. |
| * This will not only affect the default dim effect, but subclasses must |
| * respect this flag as well. |
| */ |
| public final void setSelectEffectEnabled(boolean applyDimOnSelect) { |
| mSelectEffectEnabled = applyDimOnSelect; |
| } |
| |
| /** |
| * Returns true if the row selection effect is enabled. |
| * This value not only determines whether the default dim implementation is |
| * used, but subclasses must also respect this flag. |
| */ |
| public final boolean getSelectEffectEnabled() { |
| return mSelectEffectEnabled; |
| } |
| |
| /** |
| * Return whether this RowPresenter is using the default dimming effect |
| * provided by the library. Subclasses may(most likely) return false and |
| * override {@link #onSelectLevelChanged(ViewHolder)}. |
| */ |
| public boolean isUsingDefaultSelectEffect() { |
| return true; |
| } |
| |
| final boolean needsDefaultSelectEffect() { |
| return isUsingDefaultSelectEffect() && getSelectEffectEnabled(); |
| } |
| |
| final boolean needsRowContainerView() { |
| return mHeaderPresenter != null || needsDefaultSelectEffect(); |
| } |
| |
| /** |
| * Return true if the Row view can draw outside its bounds. |
| */ |
| public boolean canDrawOutOfBounds() { |
| return false; |
| } |
| |
| @Override |
| public final void onBindViewHolder(Presenter.ViewHolder viewHolder, Object item) { |
| onBindRowViewHolder(getRowViewHolder(viewHolder), item); |
| } |
| |
| protected void onBindRowViewHolder(ViewHolder vh, Object item) { |
| vh.mRow = (Row) item; |
| if (vh.mHeaderViewHolder != null) { |
| mHeaderPresenter.onBindViewHolder(vh.mHeaderViewHolder, item); |
| } |
| } |
| |
| @Override |
| public final void onUnbindViewHolder(Presenter.ViewHolder viewHolder) { |
| onUnbindRowViewHolder(getRowViewHolder(viewHolder)); |
| } |
| |
| protected void onUnbindRowViewHolder(ViewHolder vh) { |
| if (vh.mHeaderViewHolder != null) { |
| mHeaderPresenter.onUnbindViewHolder(vh.mHeaderViewHolder); |
| } |
| vh.mRow = null; |
| } |
| |
| @Override |
| public final void onViewAttachedToWindow(Presenter.ViewHolder holder) { |
| onRowViewAttachedToWindow(getRowViewHolder(holder)); |
| } |
| |
| protected void onRowViewAttachedToWindow(ViewHolder vh) { |
| if (vh.mHeaderViewHolder != null) { |
| mHeaderPresenter.onViewAttachedToWindow(vh.mHeaderViewHolder); |
| } |
| } |
| |
| @Override |
| public final void onViewDetachedFromWindow(Presenter.ViewHolder holder) { |
| onRowViewDetachedFromWindow(getRowViewHolder(holder)); |
| } |
| |
| protected void onRowViewDetachedFromWindow(ViewHolder vh) { |
| if (vh.mHeaderViewHolder != null) { |
| mHeaderPresenter.onViewDetachedFromWindow(vh.mHeaderViewHolder); |
| } |
| cancelAnimationsRecursive(vh.view); |
| } |
| |
| /** |
| * Set the listener for item or row selection. A RowPresenter fires a row |
| * selection event with a null item. Subclasses (e.g. {@link ListRowPresenter}) |
| * can fire a selection event with the selected item. |
| */ |
| public final void setOnItemSelectedListener(OnItemSelectedListener listener) { |
| mOnItemSelectedListener = listener; |
| } |
| |
| /** |
| * Get the listener for item or row selection. |
| */ |
| public final OnItemSelectedListener getOnItemSelectedListener() { |
| return mOnItemSelectedListener; |
| } |
| |
| /** |
| * Set the listener for item click events. A RowPresenter does not use this |
| * listener, but a subclass may fire an item click event if it has the concept |
| * of an item. The {@link OnItemClickedListener} will override any |
| * {@link View.OnClickListener} that an item's Presenter sets during |
| * {@link Presenter#onCreateViewHolder(ViewGroup)}. So in general, you |
| * should choose to use an OnItemClickedListener or a {@link |
| * View.OnClickListener}, but not both. |
| */ |
| public final void setOnItemClickedListener(OnItemClickedListener listener) { |
| mOnItemClickedListener = listener; |
| } |
| |
| /** |
| * Get the listener for item click events. |
| */ |
| public final OnItemClickedListener getOnItemClickedListener() { |
| return mOnItemClickedListener; |
| } |
| |
| /** |
| * Set listener for item or row selection. RowPresenter fires row selection |
| * event with null item, subclass of RowPresenter e.g. {@link ListRowPresenter} can |
| * fire a selection event with selected item. |
| */ |
| public final void setOnItemViewSelectedListener(OnItemViewSelectedListener listener) { |
| mOnItemViewSelectedListener = listener; |
| } |
| |
| /** |
| * Get listener for item or row selection. |
| */ |
| public final OnItemViewSelectedListener getOnItemViewSelectedListener() { |
| return mOnItemViewSelectedListener; |
| } |
| |
| /** |
| * Set listener for item click event. RowPresenter does nothing but subclass of |
| * RowPresenter may fire item click event if it does have a concept of item. |
| * OnItemViewClickedListener will override {@link View.OnClickListener} that |
| * item presenter sets during {@link Presenter#onCreateViewHolder(ViewGroup)}. |
| * So in general, developer should choose one of the listeners but not both. |
| */ |
| public final void setOnItemViewClickedListener(OnItemViewClickedListener listener) { |
| mOnItemViewClickedListener = listener; |
| } |
| |
| /** |
| * Set listener for item click event. |
| */ |
| public final OnItemViewClickedListener getOnItemViewClickedListener() { |
| return mOnItemViewClickedListener; |
| } |
| |
| /** |
| * Freeze/Unfreeze the row, typically used when transition starts/ends. |
| */ |
| public void freeze(ViewHolder holder, boolean freeze) { |
| } |
| |
| } |