/*
* 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.app;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Parcelable;
import android.transition.TransitionUtils;
import android.view.View;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import java.util.List;
import java.util.Map;
/**
* Listener provided in
* {@link Activity#setEnterSharedElementCallback(SharedElementCallback)} and
* {@link Activity#setExitSharedElementCallback(SharedElementCallback)} as well as
* {@link Fragment#setEnterSharedElementCallback(SharedElementCallback)} and
* {@link Fragment#setExitSharedElementCallback(SharedElementCallback)}
* to monitor the Shared element transitions. The events can be used to customize Activity
* and Fragment Transition behavior.
*/
public abstract class SharedElementCallback {
private Matrix mTempMatrix;
private static final String BUNDLE_SNAPSHOT_BITMAP = "sharedElement:snapshot:bitmap";
private static final String BUNDLE_SNAPSHOT_IMAGE_SCALETYPE = "sharedElement:snapshot:imageScaleType";
private static final String BUNDLE_SNAPSHOT_IMAGE_MATRIX = "sharedElement:snapshot:imageMatrix";
static final SharedElementCallback NULL_CALLBACK = new SharedElementCallback() {
};
/**
* Called immediately after the start state is set for the shared element.
* The shared element will start at the size and position of the shared element
* in the launching Activity or Fragment.
*
* @param sharedElementNames The names of the shared elements that were accepted into
* the View hierarchy.
* @param sharedElements The shared elements that are part of the View hierarchy.
* @param sharedElementSnapshots The Views containing snap shots of the shared element
* from the launching Window. These elements will not
* be part of the scene, but will be positioned relative
* to the Window decor View. This list is null for Fragment
* Transitions.
*/
public void onSharedElementStart(List<String> sharedElementNames,
List<View> sharedElements, List<View> sharedElementSnapshots) {}
/**
* Called after the end state is set for the shared element, but before the end state
* is captured by the shared element transition.
* <p>
* Any customization done in
* {@link #onSharedElementStart(java.util.List, java.util.List, java.util.List)}
* may need to be modified to the final state of the shared element if it is not
* automatically corrected by layout. For example, rotation or scale will not
* be affected by layout and if changed in {@link #onSharedElementStart(java.util.List,
* java.util.List, java.util.List)}, it will also have to be set here again to correct
* the end state.
* </p>
*
* @param sharedElementNames The names of the shared elements that were accepted into
* the View hierarchy.
* @param sharedElements The shared elements that are part of the View hierarchy.
* @param sharedElementSnapshots The Views containing snap shots of the shared element
* from the launching Window. These elements will not
* be part of the scene, but will be positioned relative
* to the Window decor View. This list will be null for
* Fragment Transitions.
*/
public void onSharedElementEnd(List<String> sharedElementNames,
List<View> sharedElements, List<View> sharedElementSnapshots) {}
/**
* Called after {@link #onMapSharedElements(java.util.List, java.util.Map)} when
* transferring shared elements in. Any shared elements that have no mapping will be in
* <var>rejectedSharedElements</var>. The elements remaining in
* <var>rejectedSharedElements</var> will be transitioned out of the Scene. If a
* View is removed from <var>rejectedSharedElements</var>, it must be handled by the
* <code>SharedElementCallback</code>.
* <p>
* Views in rejectedSharedElements will have their position and size set to the
* position of the calling shared element, relative to the Window decor View and contain
* snapshots of the View from the calling Activity or Fragment. This
* view may be safely added to the decor View's overlay to remain in position.
* </p>
* <p>This method is not called for Fragment Transitions. All rejected shared elements
* will be handled by the exit transition.</p>
*
* @param rejectedSharedElements Views containing visual information of shared elements
* that are not part of the entering scene. These Views
* are positioned relative to the Window decor View. A
* View removed from this list will not be transitioned
* automatically.
*/
public void onRejectSharedElements(List<View> rejectedSharedElements) {}
/**
* Lets the SharedElementCallback adjust the mapping of shared element names to
* Views.
*
* @param names The names of all shared elements transferred from the calling Activity
* or Fragment in the order they were provided.
* @param sharedElements The mapping of shared element names to Views. The best guess
* will be filled into sharedElements based on the transitionNames.
*/
public void onMapSharedElements(List<String> names, Map<String, View> sharedElements) {}
/**
* Creates a snapshot of a shared element to be used by the remote Activity and reconstituted
* with {@link #onCreateSnapshotView(android.content.Context, android.os.Parcelable)}. A
* null return value will mean that the remote Activity will have a null snapshot View in
* {@link #onSharedElementStart(java.util.List, java.util.List, java.util.List)} and
* {@link #onSharedElementEnd(java.util.List, java.util.List, java.util.List)}.
*
* <p>This is not called for Fragment Transitions.</p>
*
* @param sharedElement The shared element View to create a snapshot for.
* @param viewToGlobalMatrix A matrix containing a transform from the view to the screen
* coordinates.
* @param screenBounds The bounds of shared element in screen coordinate space. This is
* the bounds of the view with the viewToGlobalMatrix applied.
* @return A snapshot to send to the remote Activity to be reconstituted with
* {@link #onCreateSnapshotView(android.content.Context, android.os.Parcelable)} and passed
* into {@link #onSharedElementStart(java.util.List, java.util.List, java.util.List)} and
* {@link #onSharedElementEnd(java.util.List, java.util.List, java.util.List)}.
*/
public Parcelable onCaptureSharedElementSnapshot(View sharedElement, Matrix viewToGlobalMatrix,
RectF screenBounds) {
if (sharedElement instanceof ImageView) {
ImageView imageView = ((ImageView) sharedElement);
Drawable d = imageView.getDrawable();
Drawable bg = imageView.getBackground();
if (d != null && (bg == null || bg.getAlpha() == 0)) {
Bitmap bitmap = TransitionUtils.createDrawableBitmap(d);
if (bitmap != null) {
Bundle bundle = new Bundle();
bundle.putParcelable(BUNDLE_SNAPSHOT_BITMAP, bitmap);
bundle.putString(BUNDLE_SNAPSHOT_IMAGE_SCALETYPE,
imageView.getScaleType().toString());
if (imageView.getScaleType() == ScaleType.MATRIX) {
Matrix matrix = imageView.getImageMatrix();
float[] values = new float[9];
matrix.getValues(values);
bundle.putFloatArray(BUNDLE_SNAPSHOT_IMAGE_MATRIX, values);
}
return bundle;
}
}
}
if (mTempMatrix == null) {
mTempMatrix = new Matrix(viewToGlobalMatrix);
} else {
mTempMatrix.set(viewToGlobalMatrix);
}
return TransitionUtils.createViewBitmap(sharedElement, mTempMatrix, screenBounds);
}
/**
* Reconstitutes a snapshot View from a Parcelable returned in
* {@link #onCaptureSharedElementSnapshot(android.view.View, android.graphics.Matrix,
* android.graphics.RectF)} to be used in {@link #onSharedElementStart(java.util.List,
* java.util.List, java.util.List)} and {@link #onSharedElementEnd(java.util.List,
* java.util.List, java.util.List)}. The returned View will be sized and positioned after
* this call so that it is ready to be added to the decor View's overlay.
*
* <p>This is not called for Fragment Transitions.</p>
*
* @param context The Context used to create the snapshot View.
* @param snapshot The Parcelable returned by {@link #onCaptureSharedElementSnapshot(
* android.view.View, android.graphics.Matrix, android.graphics.RectF)}.
* @return A View to be sent in {@link #onSharedElementStart(java.util.List, java.util.List,
* java.util.List)} and {@link #onSharedElementEnd(java.util.List, java.util.List,
* java.util.List)}. A null value will produce a null snapshot value for those two methods.
*/
public View onCreateSnapshotView(Context context, Parcelable snapshot) {
View view = null;
if (snapshot instanceof Bundle) {
Bundle bundle = (Bundle) snapshot;
Bitmap bitmap = (Bitmap) bundle.getParcelable(BUNDLE_SNAPSHOT_BITMAP);
if (bitmap == null) {
return null;
}
ImageView imageView = new ImageView(context);
view = imageView;
imageView.setImageBitmap(bitmap);
imageView.setScaleType(
ScaleType.valueOf(bundle.getString(BUNDLE_SNAPSHOT_IMAGE_SCALETYPE)));
if (imageView.getScaleType() == ScaleType.MATRIX) {
float[] values = bundle.getFloatArray(BUNDLE_SNAPSHOT_IMAGE_MATRIX);
Matrix matrix = new Matrix();
matrix.setValues(values);
imageView.setImageMatrix(matrix);
}
} else if (snapshot instanceof Bitmap) {
Bitmap bitmap = (Bitmap) snapshot;
view = new View(context);
Resources resources = context.getResources();
view.setBackground(new BitmapDrawable(resources, bitmap));
}
return view;
}
}
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