TransitionUtils.java
/*
* Copyright (C) 2017 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 androidx.transition;
import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.TypeEvaluator;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Picture;
import android.graphics.RectF;
import android.os.Build;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroupOverlay;
import android.widget.ImageView;
import androidx.annotation.DoNotInline;
import androidx.annotation.RequiresApi;
class TransitionUtils {
private static final int MAX_IMAGE_SIZE = 1024 * 1024;
private static final boolean HAS_PICTURE_BITMAP =
Build.VERSION.SDK_INT >= Build.VERSION_CODES.P;
/**
* Creates a View using the bitmap copy of <code>view</code>. If <code>view</code> is large,
* the copy will use a scaled bitmap of the given view.
*
* @param sceneRoot The ViewGroup in which the view copy will be displayed.
* @param view The view to create a copy of.
* @param parent The parent of view.
*/
static View copyViewImage(ViewGroup sceneRoot, View view, View parent) {
Matrix matrix = new Matrix();
matrix.setTranslate(-parent.getScrollX(), -parent.getScrollY());
ViewUtils.transformMatrixToGlobal(view, matrix);
ViewUtils.transformMatrixToLocal(sceneRoot, matrix);
RectF bounds = new RectF(0, 0, view.getWidth(), view.getHeight());
matrix.mapRect(bounds);
int left = Math.round(bounds.left);
int top = Math.round(bounds.top);
int right = Math.round(bounds.right);
int bottom = Math.round(bounds.bottom);
ImageView copy = new ImageView(view.getContext());
copy.setScaleType(ImageView.ScaleType.CENTER_CROP);
Bitmap bitmap = createViewBitmap(view, matrix, bounds, sceneRoot);
if (bitmap != null) {
copy.setImageBitmap(bitmap);
}
int widthSpec = View.MeasureSpec.makeMeasureSpec(right - left, View.MeasureSpec.EXACTLY);
int heightSpec = View.MeasureSpec.makeMeasureSpec(bottom - top, View.MeasureSpec.EXACTLY);
copy.measure(widthSpec, heightSpec);
copy.layout(left, top, right, bottom);
return copy;
}
/**
* Creates a Bitmap of the given view, using the Matrix matrix to transform to the local
* coordinates. <code>matrix</code> will be modified during the bitmap creation.
*
* <p>If the bitmap is large, it will be scaled uniformly down to at most 1MB size.</p>
*
* @param view The view to create a bitmap for.
* @param matrix The matrix converting the view local coordinates to the coordinates that
* the bitmap will be displayed in. <code>matrix</code> will be modified before
* returning.
* @param bounds The bounds of the bitmap in the destination coordinate system (where the
* view should be presented. Typically, this is matrix.mapRect(viewBounds);
* @return A bitmap of the given view or null if bounds has no width or height.
*/
private static Bitmap createViewBitmap(View view, Matrix matrix, RectF bounds,
ViewGroup sceneRoot) {
final boolean addToOverlay;
final boolean sceneRootIsAttached;
addToOverlay = !view.isAttachedToWindow();
sceneRootIsAttached = sceneRoot != null && sceneRoot.isAttachedToWindow();
ViewGroup parent = null;
int indexInParent = 0;
if (addToOverlay) {
if (!sceneRootIsAttached) {
return null;
}
parent = (ViewGroup) view.getParent();
indexInParent = parent.indexOfChild(view);
ViewGroupOverlay result = sceneRoot.getOverlay();
result.add(view);
}
Bitmap bitmap = null;
int bitmapWidth = Math.round(bounds.width());
int bitmapHeight = Math.round(bounds.height());
if (bitmapWidth > 0 && bitmapHeight > 0) {
float scale = Math.min(1f, ((float) MAX_IMAGE_SIZE) / (bitmapWidth * bitmapHeight));
bitmapWidth = Math.round(bitmapWidth * scale);
bitmapHeight = Math.round(bitmapHeight * scale);
matrix.postTranslate(-bounds.left, -bounds.top);
matrix.postScale(scale, scale);
if (HAS_PICTURE_BITMAP) {
// Hardware rendering
final Picture picture = new Picture();
final Canvas canvas = picture.beginRecording(bitmapWidth, bitmapHeight);
canvas.concat(matrix);
view.draw(canvas);
picture.endRecording();
bitmap = Api28Impl.createBitmap(picture);
} else {
// Software rendering
bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
canvas.concat(matrix);
view.draw(canvas);
}
}
if (addToOverlay) {
ViewGroupOverlay result = sceneRoot.getOverlay();
result.remove(view);
parent.addView(view, indexInParent);
}
return bitmap;
}
static Animator mergeAnimators(Animator animator1, Animator animator2) {
if (animator1 == null) {
return animator2;
} else if (animator2 == null) {
return animator1;
} else {
AnimatorSet animatorSet = new AnimatorSet();
animatorSet.playTogether(animator1, animator2);
return animatorSet;
}
}
static class MatrixEvaluator implements TypeEvaluator<Matrix> {
final float[] mTempStartValues = new float[9];
final float[] mTempEndValues = new float[9];
final Matrix mTempMatrix = new Matrix();
@Override
public Matrix evaluate(float fraction, Matrix startValue, Matrix endValue) {
startValue.getValues(mTempStartValues);
endValue.getValues(mTempEndValues);
for (int i = 0; i < 9; i++) {
float diff = mTempEndValues[i] - mTempStartValues[i];
mTempEndValues[i] = mTempStartValues[i] + (fraction * diff);
}
mTempMatrix.setValues(mTempEndValues);
return mTempMatrix;
}
}
private TransitionUtils() { }
@RequiresApi(28)
static class Api28Impl {
private Api28Impl() {
// This class is not instantiable.
}
@DoNotInline
static Bitmap createBitmap(Picture source) {
return Bitmap.createBitmap(source);
}
}
}