// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.android_webview;
import android.graphics.Rect;
import android.os.Build;
import android.view.DisplayCutout;
import android.view.View;
import android.view.WindowInsets;
import androidx.annotation.RequiresApi;
import androidx.annotation.VisibleForTesting;
import org.chromium.android_webview.common.Lifetime;
import org.chromium.base.Log;
/**
* Display cutout controller for WebView.
*
* This object should be constructed in WebView's constructor to support set listener logic for
* Android P and above.
*/
@Lifetime.WebView
@RequiresApi(Build.VERSION_CODES.P)
public class AwDisplayCutoutController {
private static final boolean DEBUG = false;
private static final String TAG = "DisplayCutout";
/** This is a delegate that the embedder needs to implement. */
public interface Delegate {
/** @return The DIP scale. */
float getDipScale();
/**
* Set display cutout safe area such that webpage can read safe-area-insets CSS properties.
* Note that this can be called with the same parameter repeatedly, and the embedder needs
* to check / throttle as necessary.
*
* @param insets A placeholder to store left, top, right, and bottom insets in regards to
* WebView. Note that DIP scale has been applied.
*/
void setDisplayCutoutSafeArea(Insets insets);
}
/**
* A placeholder for insets.
*
* android.graphics.Insets is available from Q, while we support display cutout from P and
* above, so adding a new class.
*/
public static final class Insets {
public int left;
public int top;
public int right;
public int bottom;
public Insets() {}
public Insets(int left, int top, int right, int bottom) {
set(left, top, right, bottom);
}
public Rect toRect(Rect rect) {
rect.set(left, top, right, bottom);
return rect;
}
public void set(Insets insets) {
left = insets.left;
top = insets.top;
right = insets.right;
bottom = insets.bottom;
}
public void set(int left, int top, int right, int bottom) {
this.left = left;
this.top = top;
this.right = right;
this.bottom = bottom;
}
@Override
public final boolean equals(Object o) {
if (!(o instanceof Insets)) return false;
Insets i = (Insets) o;
return left == i.left && top == i.top && right == i.right && bottom == i.bottom;
}
@Override
public final String toString() {
return "Insets: (" + left + ", " + top + ")-(" + right + ", " + bottom + ")";
}
@Override
public final int hashCode() {
return 3 * left + 5 * top + 7 * right + 11 * bottom;
}
}
private Delegate mDelegate;
private View mContainerView;
/**
* Constructor for AwDisplayCutoutController.
*
* @param delegate The delegate.
* @param containerView The container view (WebView).
*/
public AwDisplayCutoutController(Delegate delegate, View containerView) {
mDelegate = delegate;
mContainerView = containerView;
registerContainerView(containerView);
}
/**
* Register a container view to listen to window insets.
*
* Note that you do not need to register the containerView.
*
* @param containerView A container View, such as fullscreen view.
*/
public void registerContainerView(View containerView) {
if (DEBUG) Log.i(TAG, "registerContainerView");
// For Android P~R, we set the listener in WebView's constructor.
// Once we set the listener, we will no longer get View#onApplyWindowInsets(WindowInsets).
// If the app sets its own listener after WebView's constructor, then the app can override
// our logic, which seems like a natural behavior.
// For Android S, WebViewChromium can get onApplyWindowInsets(WindowInsets) call, so we do
// not need to set the listener.
// TODO(crbug.com/40699457): do not set listener and plumb WebViewChromium to handle
// onApplyWindowInsets in S and above.
containerView.setOnApplyWindowInsetsListener(
new View.OnApplyWindowInsetsListener() {
@Override
public WindowInsets onApplyWindowInsets(View view, WindowInsets insets) {
// Ignore if this is not the current container view.
if (view == mContainerView) {
return AwDisplayCutoutController.this.onApplyWindowInsets(insets);
} else {
if (DEBUG) Log.i(TAG, "Ignoring onApplyWindowInsets on View: " + view);
return insets;
}
}
});
}
/**
* Set the current container view.
*
* @param containerView The current container view.
*/
public void setCurrentContainerView(View containerView) {
if (DEBUG) Log.i(TAG, "setCurrentContainerView: " + containerView);
mContainerView = containerView;
// Ensure that we get new insets for the new container view.
mContainerView.requestApplyInsets();
}
/**
* Call this when window insets are first applied or changed.
*
* @see View#onApplyWindowInsets(WindowInsets)
* @param insets The window (display) insets.
*/
@VisibleForTesting
public WindowInsets onApplyWindowInsets(final WindowInsets insets) {
if (DEBUG) Log.i(TAG, "onApplyWindowInsets: " + insets.toString());
// TODO(crbug.com/40699457): add a throttling logic.
DisplayCutout cutout = insets.getDisplayCutout();
// DisplayCutout can be null if there is no notch, or layoutInDisplayCutoutMode is DEFAULT
// (before R) or consumed in the parent view.
if (cutout != null) {
Insets displayCutoutInsets =
new Insets(
cutout.getSafeInsetLeft(),
cutout.getSafeInsetTop(),
cutout.getSafeInsetRight(),
cutout.getSafeInsetBottom());
onApplyWindowInsetsInternal(displayCutoutInsets);
}
return insets;
}
/**
* Call this when window insets are first applied or changed.
*
* Similar to {@link onApplyWindowInsets(WindowInsets)}, but accepts
* Rect as input.
*
* @param displayCutoutInsets Insets to store left, top, right, bottom insets.
*/
@VisibleForTesting
public void onApplyWindowInsetsInternal(final Insets displayCutoutInsets) {
float dipScale = mDelegate.getDipScale();
// We only apply this logic when webview is occupying the entire screen.
adjustInsetsForScale(displayCutoutInsets, dipScale);
if (DEBUG) {
Log.i(
TAG,
"onApplyWindowInsetsInternal. insets: "
+ displayCutoutInsets
+ ", dip scale: "
+ dipScale);
}
// Note that internally we apply this logic only when the display is in fullscreen mode.
// See AwDisplayModeController for more details on how we check the fullscreen mode.
mDelegate.setDisplayCutoutSafeArea(displayCutoutInsets);
}
private void onUpdateWindowInsets() {
mContainerView.requestApplyInsets();
}
/** @see View#onSizeChanged(int, int, int, int) */
public void onSizeChanged() {
if (DEBUG) Log.i(TAG, "onSizeChanged");
onUpdateWindowInsets();
}
/** @see View#onAttachedToWindow() */
public void onAttachedToWindow() {
if (DEBUG) Log.i(TAG, "onAttachedToWindow");
onUpdateWindowInsets();
}
private static void adjustInsetsForScale(Insets insets, float dipScale) {
insets.left = adjustOneInsetForScale(insets.left, dipScale);
insets.top = adjustOneInsetForScale(insets.top, dipScale);
insets.right = adjustOneInsetForScale(insets.right, dipScale);
insets.bottom = adjustOneInsetForScale(insets.bottom, dipScale);
}
/**
* Adjusts a WindowInset inset to a CSS pixel value.
*
* @param inset The inset as an integer.
* @param dipScale The devices dip scale as an integer.
* @return The CSS pixel value adjusted for scale.
*/
private static int adjustOneInsetForScale(int inset, float dipScale) {
return (int) Math.ceil(inset / dipScale);
}
}
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