Java tutorial
/* * 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.os.Handler; import android.support.v4.app.ActivityCompat; import android.support.v4.app.SharedElementCallback; import android.support.v4.view.ViewCompat; import android.support.v17.leanback.R; import android.support.v17.leanback.transition.TransitionListener; import android.support.v17.leanback.transition.TransitionHelper; import android.support.v17.leanback.widget.DetailsOverviewRowPresenter.ViewHolder; import android.app.Activity; import android.content.Intent; import android.graphics.Matrix; import android.text.TextUtils; import android.util.Log; import android.view.View; import android.view.ViewGroup; import android.view.View.MeasureSpec; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import java.util.List; final class DetailsOverviewSharedElementHelper extends SharedElementCallback { private static final String TAG = "DetailsOverviewSharedElementHelper"; private static final boolean DEBUG = false; private ViewHolder mViewHolder; private Activity mActivityToRunTransition; private boolean mStartedPostpone; private String mSharedElementName; private int mRightPanelWidth; private int mRightPanelHeight; private ScaleType mSavedScaleType; private Matrix mSavedMatrix; private boolean hasImageViewScaleChange(View snapshotView) { return snapshotView instanceof ImageView; } private void saveImageViewScale() { if (mSavedScaleType == null) { // only save first time after initialize/restoreImageViewScale() ImageView imageView = mViewHolder.mImageView; mSavedScaleType = imageView.getScaleType(); mSavedMatrix = mSavedScaleType == ScaleType.MATRIX ? imageView.getMatrix() : null; if (DEBUG) { Log.d(TAG, "saveImageViewScale: " + mSavedScaleType); } } } private static void updateImageViewAfterScaleTypeChange(ImageView imageView) { // enforcing imageView to update its internal bounds/matrix immediately imageView.measure(MeasureSpec.makeMeasureSpec(imageView.getMeasuredWidth(), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(imageView.getMeasuredHeight(), MeasureSpec.EXACTLY)); imageView.layout(imageView.getLeft(), imageView.getTop(), imageView.getRight(), imageView.getBottom()); } private void changeImageViewScale(View snapshotView) { ImageView snapshotImageView = (ImageView) snapshotView; ImageView imageView = mViewHolder.mImageView; if (DEBUG) { Log.d(TAG, "changeImageViewScale to " + snapshotImageView.getScaleType()); } imageView.setScaleType(snapshotImageView.getScaleType()); if (snapshotImageView.getScaleType() == ScaleType.MATRIX) { imageView.setImageMatrix(snapshotImageView.getImageMatrix()); } updateImageViewAfterScaleTypeChange(imageView); } private void restoreImageViewScale() { if (mSavedScaleType != null) { if (DEBUG) { Log.d(TAG, "restoreImageViewScale to " + mSavedScaleType); } ImageView imageView = mViewHolder.mImageView; imageView.setScaleType(mSavedScaleType); if (mSavedScaleType == ScaleType.MATRIX) { imageView.setImageMatrix(mSavedMatrix); } // only restore once unless another save happens mSavedScaleType = null; updateImageViewAfterScaleTypeChange(imageView); } } @Override public void onSharedElementStart(List<String> sharedElementNames, List<View> sharedElements, List<View> sharedElementSnapshots) { if (DEBUG) { Log.d(TAG, "onSharedElementStart " + mActivityToRunTransition); } if (sharedElements.size() < 1) { return; } View overviewView = sharedElements.get(0); if (mViewHolder == null || mViewHolder.mOverviewFrame != overviewView) { return; } View snapshot = sharedElementSnapshots.get(0); if (hasImageViewScaleChange(snapshot)) { saveImageViewScale(); changeImageViewScale(snapshot); } View imageView = mViewHolder.mImageView; final int width = overviewView.getWidth(); final int height = overviewView.getHeight(); imageView.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY)); imageView.layout(0, 0, width, height); final View rightPanel = mViewHolder.mRightPanel; if (mRightPanelWidth != 0 && mRightPanelHeight != 0) { rightPanel.measure(MeasureSpec.makeMeasureSpec(mRightPanelWidth, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(mRightPanelHeight, MeasureSpec.EXACTLY)); rightPanel.layout(width, rightPanel.getTop(), width + mRightPanelWidth, rightPanel.getTop() + mRightPanelHeight); } else { rightPanel.offsetLeftAndRight(width - rightPanel.getLeft()); } mViewHolder.mActionsRow.setVisibility(View.INVISIBLE); mViewHolder.mDetailsDescriptionFrame.setVisibility(View.INVISIBLE); } @Override public void onSharedElementEnd(List<String> sharedElementNames, List<View> sharedElements, List<View> sharedElementSnapshots) { if (DEBUG) { Log.d(TAG, "onSharedElementEnd " + mActivityToRunTransition); } if (sharedElements.size() < 1) { return; } View overviewView = sharedElements.get(0); if (mViewHolder == null || mViewHolder.mOverviewFrame != overviewView) { return; } restoreImageViewScale(); // temporary let action row take focus so we defer button background animation mViewHolder.mActionsRow.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); mViewHolder.mActionsRow.setVisibility(View.VISIBLE); mViewHolder.mActionsRow.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS); mViewHolder.mDetailsDescriptionFrame.setVisibility(View.VISIBLE); } void setSharedElementEnterTransition(Activity activity, String sharedElementName, long timeoutMs) { if (activity == null && !TextUtils.isEmpty(sharedElementName) || activity != null && TextUtils.isEmpty(sharedElementName)) { throw new IllegalArgumentException(); } if (activity == mActivityToRunTransition && TextUtils.equals(sharedElementName, mSharedElementName)) { return; } if (mActivityToRunTransition != null) { ActivityCompat.setEnterSharedElementCallback(mActivityToRunTransition, null); } mActivityToRunTransition = activity; mSharedElementName = sharedElementName; if (DEBUG) { Log.d(TAG, "postponeEnterTransition " + mActivityToRunTransition); } ActivityCompat.setEnterSharedElementCallback(mActivityToRunTransition, this); ActivityCompat.postponeEnterTransition(mActivityToRunTransition); if (timeoutMs > 0) { new Handler().postDelayed(new Runnable() { @Override public void run() { if (mStartedPostpone) { return; } if (DEBUG) { Log.d(TAG, "timeout " + mActivityToRunTransition); } startPostponedEnterTransition(); } }, timeoutMs); } } void onBindToDrawable(ViewHolder vh) { if (DEBUG) { Log.d(TAG, "onBindToDrawable, could start transition of " + mActivityToRunTransition); } if (mViewHolder != null) { if (DEBUG) { Log.d(TAG, "rebind? clear transitionName on current viewHolder " + mViewHolder.mOverviewFrame); } ViewCompat.setTransitionName(mViewHolder.mOverviewFrame, null); } // After we got a image drawable, we can determine size of right panel. // We want right panel to have fixed size so that the right panel don't change size // when the overview is layout as a small bounds in transition. mViewHolder = vh; mViewHolder.mRightPanel.addOnLayoutChangeListener(new View.OnLayoutChangeListener() { @Override public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) { mViewHolder.mRightPanel.removeOnLayoutChangeListener(this); mRightPanelWidth = mViewHolder.mRightPanel.getWidth(); mRightPanelHeight = mViewHolder.mRightPanel.getHeight(); if (DEBUG) { Log.d(TAG, "onLayoutChange records size of right panel as " + mRightPanelWidth + ", " + mRightPanelHeight); } } }); mViewHolder.mRightPanel.postOnAnimation(new Runnable() { @Override public void run() { if (DEBUG) { Log.d(TAG, "setTransitionName " + mViewHolder.mOverviewFrame); } ViewCompat.setTransitionName(mViewHolder.mOverviewFrame, mSharedElementName); Object transition = TransitionHelper .getSharedElementEnterTransition(mActivityToRunTransition.getWindow()); if (transition != null) { TransitionHelper.addTransitionListener(transition, new TransitionListener() { @Override public void onTransitionEnd(Object transition) { if (DEBUG) { Log.d(TAG, "onTransitionEnd " + mActivityToRunTransition); } // after transition if the action row still focused, transfer // focus to its children if (mViewHolder.mActionsRow.isFocused()) { mViewHolder.mActionsRow.requestFocus(); } TransitionHelper.removeTransitionListener(transition, this); } }); } startPostponedEnterTransition(); } }); } private void startPostponedEnterTransition() { if (!mStartedPostpone) { if (DEBUG) { Log.d(TAG, "startPostponedEnterTransition " + mActivityToRunTransition); } ActivityCompat.startPostponedEnterTransition(mActivityToRunTransition); mStartedPostpone = true; } } }