ImageViewUtils.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.graphics.Matrix;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.util.Log;
import android.widget.ImageView;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
class ImageViewUtils {
private static final String TAG = "ImageViewUtils";
private static Method sAnimateTransformMethod;
private static boolean sAnimateTransformMethodFetched;
private static Field sDrawMatrixField;
private static boolean sDrawMatrixFieldFetched;
/**
* Sets the matrix to animate the content of the image view.
*/
static void animateTransform(ImageView view, Matrix matrix) {
if (matrix == null) {
// There is a bug in ImageView.animateTransform() prior to the current development
// version of Android so paddings are ignored when matrix is null.
Drawable drawable = view.getDrawable();
if (drawable != null) {
int vwidth = view.getWidth() - view.getPaddingLeft() - view.getPaddingRight();
int vheight = view.getHeight() - view.getPaddingTop() - view.getPaddingBottom();
drawable.setBounds(0, 0, vwidth, vheight);
view.invalidate();
}
} else if (Build.VERSION.SDK_INT >= 21) {
fetchAnimateTransformMethod();
if (sAnimateTransformMethod != null) {
try {
sAnimateTransformMethod.invoke(view, matrix);
} catch (IllegalAccessException e) {
// Do nothing
} catch (InvocationTargetException e) {
throw new RuntimeException(e.getCause());
}
}
} else {
Drawable drawable = view.getDrawable();
if (drawable != null) {
drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
drawable.getIntrinsicHeight());
Matrix drawMatrix = null;
fetchDrawMatrixField();
if (sDrawMatrixField != null) {
try {
drawMatrix = (Matrix) sDrawMatrixField.get(view);
if (drawMatrix == null) {
drawMatrix = new Matrix();
sDrawMatrixField.set(view, drawMatrix);
}
} catch (IllegalAccessException ignore) {
// Do nothing
}
}
if (drawMatrix != null) {
drawMatrix.set(matrix);
}
view.invalidate();
}
}
}
private static void fetchAnimateTransformMethod() {
if (!sAnimateTransformMethodFetched) {
try {
sAnimateTransformMethod = ImageView.class.getDeclaredMethod("animateTransform",
Matrix.class);
sAnimateTransformMethod.setAccessible(true);
} catch (NoSuchMethodException e) {
Log.i(TAG, "Failed to retrieve animateTransform method", e);
}
sAnimateTransformMethodFetched = true;
}
}
private static void fetchDrawMatrixField() {
if (!sDrawMatrixFieldFetched) {
try {
sDrawMatrixField = ImageView.class.getDeclaredField("mDrawMatrix");
sDrawMatrixField.setAccessible(true);
} catch (NoSuchFieldException ignore) {
// Do nothing
}
sDrawMatrixFieldFetched = true;
}
}
private ImageViewUtils() {
}
}