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/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
package org.mozilla.geckoview;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.BlendMode;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.os.Build;
import android.widget.EdgeEffect;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.UiThread;
import java.lang.reflect.Field;
import org.mozilla.gecko.util.ThreadUtils;
@UiThread
public final class OverscrollEdgeEffect {
// Used to index particular edges in the edges array
private static final int TOP = 0;
private static final int BOTTOM = 1;
private static final int LEFT = 2;
private static final int RIGHT = 3;
/* package */ static final int AXIS_X = 0;
/* package */ static final int AXIS_Y = 1;
// All four edges of the screen
private final EdgeEffect[] mEdges = new EdgeEffect[4];
private GeckoSession mSession;
private Runnable mInvalidationCallback;
private int mWidth;
private int mHeight;
/* package */ OverscrollEdgeEffect() {}
private static Field sPaintField;
@SuppressLint("DiscouragedPrivateApi")
private void setBlendMode(final EdgeEffect edgeEffect) {
if (Build.VERSION.SDK_INT < 29) {
// setBlendMode is only supported on SDK_INT >= 29 and above.
if (sPaintField == null) {
try {
sPaintField = EdgeEffect.class.getDeclaredField("mPaint");
sPaintField.setAccessible(true);
} catch (final NoSuchFieldException e) {
// Cannot get the field, nothing we can do here
return;
}
}
try {
final Paint paint = (Paint) sPaintField.get(edgeEffect);
final PorterDuffXfermode mode = new PorterDuffXfermode(PorterDuff.Mode.SRC);
paint.setXfermode(mode);
} catch (final IllegalAccessException ex) {
// Nothing we can do
}
return;
}
edgeEffect.setBlendMode(BlendMode.SRC);
}
/**
* Set the theme to use for overscroll from a given Context.
*
* @param context Context to use for the overscroll theme.
*/
public void setTheme(final @NonNull Context context) {
ThreadUtils.assertOnUiThread();
for (int i = 0; i < mEdges.length; i++) {
final EdgeEffect edgeEffect = new EdgeEffect(context);
if (mWidth != 0 || mHeight != 0) {
edgeEffect.setSize(mWidth, mHeight);
}
setBlendMode(edgeEffect);
mEdges[i] = edgeEffect;
}
}
/* package */ void setSession(final @Nullable GeckoSession session) {
mSession = session;
}
/**
* Set a Runnable that acts as a callback to invalidate the overscroll effect (for example, as a
* response to user fling for example). The Runnbale should schedule a future call to {@link
* #draw(Canvas)} as a result of the invalidation.
*
* @param runnable Invalidation Runnable.
* @see #getInvalidationCallback()
*/
public void setInvalidationCallback(final @Nullable Runnable runnable) {
ThreadUtils.assertOnUiThread();
mInvalidationCallback = runnable;
}
/**
* Get the current invalidatation Runnable.
*
* @return Invalidation Runnable.
* @see #setInvalidationCallback(Runnable)
*/
public @Nullable Runnable getInvalidationCallback() {
ThreadUtils.assertOnUiThread();
return mInvalidationCallback;
}
/* package */ void setSize(final int width, final int height) {
mEdges[LEFT].setSize(height, width);
mEdges[RIGHT].setSize(height, width);
mEdges[TOP].setSize(width, height);
mEdges[BOTTOM].setSize(width, height);
mWidth = width;
mHeight = height;
}
private EdgeEffect getEdgeForAxisAndSide(final int axis, final float side) {
if (axis == AXIS_Y) {
if (side < 0) {
return mEdges[TOP];
} else {
return mEdges[BOTTOM];
}
} else {
if (side < 0) {
return mEdges[LEFT];
} else {
return mEdges[RIGHT];
}
}
}
/* package */ void setVelocity(final float velocity, final int axis) {
if (velocity == 0.0f) {
if (axis == AXIS_Y) {
mEdges[TOP].onRelease();
mEdges[BOTTOM].onRelease();
} else {
mEdges[LEFT].onRelease();
mEdges[RIGHT].onRelease();
}
if (mInvalidationCallback != null) {
mInvalidationCallback.run();
}
return;
}
final EdgeEffect edge = getEdgeForAxisAndSide(axis, velocity);
// If we're showing overscroll already, start fading it out.
if (!edge.isFinished()) {
edge.onRelease();
} else {
// Otherwise, show an absorb effect
edge.onAbsorb((int) velocity);
}
if (mInvalidationCallback != null) {
mInvalidationCallback.run();
}
}
/* package */ void setDistance(final float distance, final int axis) {
// The first overscroll event often has zero distance. Throw it out
if (distance == 0.0f) {
return;
}
final EdgeEffect edge = getEdgeForAxisAndSide(axis, (int) distance);
edge.onPull(distance / (axis == AXIS_X ? mWidth : mHeight));
if (mInvalidationCallback != null) {
mInvalidationCallback.run();
}
}
/**
* Draw the overscroll effect on a Canvas.
*
* @param canvas Canvas to draw on.
*/
public void draw(final @NonNull Canvas canvas) {
ThreadUtils.assertOnUiThread();
if (mSession == null) {
return;
}
final Rect pageRect = new Rect();
mSession.getSurfaceBounds(pageRect);
// If we're pulling an edge, or fading it out, draw!
boolean invalidate = false;
if (!mEdges[TOP].isFinished()) {
invalidate |= draw(mEdges[TOP], canvas, pageRect.left, pageRect.top, 0);
}
if (!mEdges[BOTTOM].isFinished()) {
invalidate |= draw(mEdges[BOTTOM], canvas, pageRect.right, pageRect.bottom, 180);
}
if (!mEdges[LEFT].isFinished()) {
invalidate |= draw(mEdges[LEFT], canvas, pageRect.left, pageRect.bottom, 270);
}
if (!mEdges[RIGHT].isFinished()) {
invalidate |= draw(mEdges[RIGHT], canvas, pageRect.right, pageRect.top, 90);
}
// If the edge effect is animating off screen, invalidate.
if (invalidate && mInvalidationCallback != null) {
mInvalidationCallback.run();
}
}
private static boolean draw(
final EdgeEffect edge,
final Canvas canvas,
final float translateX,
final float translateY,
final float rotation) {
final int state = canvas.save();
canvas.translate(translateX, translateY);
canvas.rotate(rotation);
final boolean invalidate = edge.draw(canvas);
canvas.restoreToCount(state);
return invalidate;
}
}