Merge "Enables scroll capture for WebView" into sc-v2-dev am: 9bcef36827 (4e013d4f) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/view/ScrollCaptureInternal.java

+26 −12

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@ import android.util.Log;
		import android.view.ScrollCaptureCallback;
		import android.view.View;
		import android.view.ViewGroup;
		import android.webkit.WebView;
		import android.widget.ListView;

		/**
		@@ -43,7 +44,7 @@ public class ScrollCaptureInternal {
		private static final int DOWN = 1;

		/**
		* Not a ViewGroup, or cannot scroll according to View APIs.
		* Cannot scroll according to {@link View#canScrollVertically}.
		*/
		public static final int TYPE_FIXED = 0;

		@@ -60,7 +61,7 @@ public class ScrollCaptureInternal {
		public static final int TYPE_RECYCLING = 2;

		/**
		* The ViewGroup scrolls, but has no child views in
		* Unknown scrollable view with no child views (or not a subclass of ViewGroup).
		*/
		private static final int TYPE_OPAQUE = 3;

		@@ -73,16 +74,6 @@ public class ScrollCaptureInternal {
		* as excluded during scroll capture search.
		*/
		private static int detectScrollingType(View view) {
		// Must be a ViewGroup
		if (!(view instanceof ViewGroup)) {
		if (DEBUG_VERBOSE) {
		Log.v(TAG, "hint: not a subclass of ViewGroup");
		}
		return TYPE_FIXED;
		}
		if (DEBUG_VERBOSE) {
		Log.v(TAG, "hint: is a subclass of ViewGroup");
		}
		// Confirm that it can scroll.
		if (!(view.canScrollVertically(DOWN) \|\| view.canScrollVertically(UP))) {
		// Nothing to scroll here, move along.
		@@ -94,6 +85,17 @@ public class ScrollCaptureInternal {
		if (DEBUG_VERBOSE) {
		Log.v(TAG, "hint: can be scrolled up or down");
		}
		// Must be a ViewGroup
		if (!(view instanceof ViewGroup)) {
		if (DEBUG_VERBOSE) {
		Log.v(TAG, "hint: not a subclass of ViewGroup");
		}
		return TYPE_OPAQUE;
		}
		if (DEBUG_VERBOSE) {
		Log.v(TAG, "hint: is a subclass of ViewGroup");
		}

		// ScrollViews accept only a single child.
		if (((ViewGroup) view).getChildCount() > 1) {
		if (DEBUG_VERBOSE) {
		@@ -188,6 +190,18 @@ public class ScrollCaptureInternal {
		}
		return new ScrollCaptureViewSupport<>((ViewGroup) view,
		new RecyclerViewCaptureHelper());
		case TYPE_OPAQUE:
		if (DEBUG) {
		Log.d(TAG, "scroll capture: FOUND " + view.getClass().getName()
		+ "[" + resolveId(view.getContext(), view.getId()) + "]"
		+ " -> TYPE_OPAQUE");
		}
		if (view instanceof WebView) {
		Log.d(TAG, "scroll capture: Using WebView support");
		return new ScrollCaptureViewSupport<>((WebView) view,
		new WebViewCaptureHelper());
		}
		break;
		case TYPE_FIXED:
		// ignore
		break;

core/java/com/android/internal/view/WebViewCaptureHelper.java

0 → 100644

+100 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 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 com.android.internal.view;

		import static android.util.MathUtils.constrain;

		import static java.lang.Math.max;
		import static java.lang.Math.min;

		import android.annotation.NonNull;
		import android.graphics.Rect;
		import android.webkit.WebView;

		/**
		* ScrollCapture for WebView.
		*/
		class WebViewCaptureHelper implements ScrollCaptureViewHelper<WebView> {
		private static final String TAG = "WebViewScrollCapture";

		private final Rect mRequestWebViewLocal = new Rect();
		private final Rect mWebViewBounds = new Rect();

		private int mOriginScrollY;
		private int mOriginScrollX;

		@Override
		public boolean onAcceptSession(@NonNull WebView view) {
		return view.isVisibleToUser()
		&& (view.getContentHeight() * view.getScale()) > view.getHeight();
		}

		@Override
		public void onPrepareForStart(@NonNull WebView view, @NonNull Rect scrollBounds) {
		mOriginScrollX = view.getScrollX();
		mOriginScrollY = view.getScrollY();
		}

		@NonNull
		@Override
		public ScrollResult onScrollRequested(@NonNull WebView view, @NonNull Rect scrollBounds,
		@NonNull Rect requestRect) {

		int scrollDelta = view.getScrollY() - mOriginScrollY;

		ScrollResult result = new ScrollResult();
		result.requestedArea = new Rect(requestRect);
		result.availableArea = new Rect();
		result.scrollDelta = scrollDelta;

		mWebViewBounds.set(0, 0, view.getWidth(), view.getHeight());

		if (!view.isVisibleToUser()) {
		return result;
		}

		// Map the request into local coordinates
		mRequestWebViewLocal.set(requestRect);
		mRequestWebViewLocal.offset(0, -scrollDelta);

		// Offset to center the rect vertically, clamp to available content
		int upLimit = min(0, -view.getScrollY());
		int contentHeightPx = (int) (view.getContentHeight() * view.getScale());
		int downLimit = max(0, (contentHeightPx - view.getHeight()) - view.getScrollY());
		int scrollToCenter = mRequestWebViewLocal.centerY() - mWebViewBounds.centerY();
		int scrollMovement = constrain(scrollToCenter, upLimit, downLimit);

		// Scroll and update relative based on the new position
		view.scrollBy(mOriginScrollX, scrollMovement);
		scrollDelta = view.getScrollY() - mOriginScrollY;
		mRequestWebViewLocal.offset(0, -scrollMovement);
		result.scrollDelta = scrollDelta;

		if (mRequestWebViewLocal.intersect(mWebViewBounds)) {
		result.availableArea = new Rect(mRequestWebViewLocal);
		result.availableArea.offset(0, result.scrollDelta);
		}
		return result;
		}

		@Override
		public void onPrepareForEnd(@NonNull WebView view) {
		view.scrollTo(mOriginScrollX, mOriginScrollY);
		}

		}