AspectRatioFrameLayout.java
/*
* Copyright (C) 2016 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.media3.ui;
import static java.lang.annotation.ElementType.TYPE_USE;
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.widget.FrameLayout;
import androidx.annotation.IntDef;
import androidx.annotation.Nullable;
import androidx.media3.common.util.UnstableApi;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/** A {@link FrameLayout} that resizes itself to match a specified aspect ratio. */
@UnstableApi
public final class AspectRatioFrameLayout extends FrameLayout {
/** Listener to be notified about changes of the aspect ratios of this view. */
public interface AspectRatioListener {
/**
* Called when either the target aspect ratio or the view aspect ratio is updated.
*
* @param targetAspectRatio The aspect ratio that has been set in {@link #setAspectRatio(float)}
* @param naturalAspectRatio The natural aspect ratio of this view (before its width and height
* are modified to satisfy the target aspect ratio).
* @param aspectRatioMismatch Whether the target and natural aspect ratios differ enough for
* changing the resize mode to have an effect.
*/
void onAspectRatioUpdated(
float targetAspectRatio, float naturalAspectRatio, boolean aspectRatioMismatch);
}
/**
* Resize modes for {@link AspectRatioFrameLayout}. One of {@link #RESIZE_MODE_FIT}, {@link
* #RESIZE_MODE_FIXED_WIDTH}, {@link #RESIZE_MODE_FIXED_HEIGHT}, {@link #RESIZE_MODE_FILL} or
* {@link #RESIZE_MODE_ZOOM}.
*/
@Documented
@Retention(RetentionPolicy.SOURCE)
@Target(TYPE_USE)
@IntDef({
RESIZE_MODE_FIT,
RESIZE_MODE_FIXED_WIDTH,
RESIZE_MODE_FIXED_HEIGHT,
RESIZE_MODE_FILL,
RESIZE_MODE_ZOOM
})
public @interface ResizeMode {}
/** Either the width or height is decreased to obtain the desired aspect ratio. */
public static final int RESIZE_MODE_FIT = 0;
/**
* The width is fixed and the height is increased or decreased to obtain the desired aspect ratio.
*/
public static final int RESIZE_MODE_FIXED_WIDTH = 1;
/**
* The height is fixed and the width is increased or decreased to obtain the desired aspect ratio.
*/
public static final int RESIZE_MODE_FIXED_HEIGHT = 2;
/** The specified aspect ratio is ignored. */
public static final int RESIZE_MODE_FILL = 3;
/** Either the width or height is increased to obtain the desired aspect ratio. */
public static final int RESIZE_MODE_ZOOM = 4;
/**
* The {@link FrameLayout} will not resize itself if the fractional difference between its natural
* aspect ratio and the requested aspect ratio falls below this threshold.
*
* <p>This tolerance allows the view to occupy the whole of the screen when the requested aspect
* ratio is very close, but not exactly equal to, the aspect ratio of the screen. This may reduce
* the number of view layers that need to be composited by the underlying system, which can help
* to reduce power consumption.
*/
private static final float MAX_ASPECT_RATIO_DEFORMATION_FRACTION = 0.01f;
private final AspectRatioUpdateDispatcher aspectRatioUpdateDispatcher;
@Nullable private AspectRatioListener aspectRatioListener;
private float videoAspectRatio;
private @ResizeMode int resizeMode;
public AspectRatioFrameLayout(Context context) {
this(context, /* attrs= */ null);
}
public AspectRatioFrameLayout(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
resizeMode = RESIZE_MODE_FIT;
if (attrs != null) {
TypedArray a =
context
.getTheme()
.obtainStyledAttributes(attrs, R.styleable.AspectRatioFrameLayout, 0, 0);
try {
resizeMode = a.getInt(R.styleable.AspectRatioFrameLayout_resize_mode, RESIZE_MODE_FIT);
} finally {
a.recycle();
}
}
aspectRatioUpdateDispatcher = new AspectRatioUpdateDispatcher();
}
/**
* Sets the aspect ratio that this view should satisfy.
*
* @param widthHeightRatio The width to height ratio.
*/
public void setAspectRatio(float widthHeightRatio) {
if (this.videoAspectRatio != widthHeightRatio) {
this.videoAspectRatio = widthHeightRatio;
requestLayout();
}
}
/**
* Sets the {@link AspectRatioListener}.
*
* @param listener The listener to be notified about aspect ratios changes, or null to clear a
* listener that was previously set.
*/
public void setAspectRatioListener(@Nullable AspectRatioListener listener) {
this.aspectRatioListener = listener;
}
/** Returns the {@link ResizeMode}. */
public @ResizeMode int getResizeMode() {
return resizeMode;
}
/**
* Sets the {@link ResizeMode}
*
* @param resizeMode The {@link ResizeMode}.
*/
public void setResizeMode(@ResizeMode int resizeMode) {
if (this.resizeMode != resizeMode) {
this.resizeMode = resizeMode;
requestLayout();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (videoAspectRatio <= 0) {
// Aspect ratio not set.
return;
}
int width = getMeasuredWidth();
int height = getMeasuredHeight();
float viewAspectRatio = (float) width / height;
float aspectDeformation = videoAspectRatio / viewAspectRatio - 1;
if (Math.abs(aspectDeformation) <= MAX_ASPECT_RATIO_DEFORMATION_FRACTION) {
// We're within the allowed tolerance.
aspectRatioUpdateDispatcher.scheduleUpdate(videoAspectRatio, viewAspectRatio, false);
return;
}
switch (resizeMode) {
case RESIZE_MODE_FIXED_WIDTH:
height = (int) (width / videoAspectRatio);
break;
case RESIZE_MODE_FIXED_HEIGHT:
width = (int) (height * videoAspectRatio);
break;
case RESIZE_MODE_ZOOM:
if (aspectDeformation > 0) {
width = (int) (height * videoAspectRatio);
} else {
height = (int) (width / videoAspectRatio);
}
break;
case RESIZE_MODE_FIT:
if (aspectDeformation > 0) {
height = (int) (width / videoAspectRatio);
} else {
width = (int) (height * videoAspectRatio);
}
break;
case RESIZE_MODE_FILL:
default:
// Ignore target aspect ratio
break;
}
aspectRatioUpdateDispatcher.scheduleUpdate(videoAspectRatio, viewAspectRatio, true);
super.onMeasure(
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
}
/** Dispatches updates to {@link AspectRatioListener}. */
private final class AspectRatioUpdateDispatcher implements Runnable {
private float targetAspectRatio;
private float naturalAspectRatio;
private boolean aspectRatioMismatch;
private boolean isScheduled;
public void scheduleUpdate(
float targetAspectRatio, float naturalAspectRatio, boolean aspectRatioMismatch) {
this.targetAspectRatio = targetAspectRatio;
this.naturalAspectRatio = naturalAspectRatio;
this.aspectRatioMismatch = aspectRatioMismatch;
if (!isScheduled) {
isScheduled = true;
post(this);
}
}
@Override
public void run() {
isScheduled = false;
if (aspectRatioListener == null) {
return;
}
aspectRatioListener.onAspectRatioUpdated(
targetAspectRatio, naturalAspectRatio, aspectRatioMismatch);
}
}
}