Added Support to WebView for Zoom Keyboard Shortcuts

Bug: 1412052
Change-Id: Ibe449946a7e5db53d38a5b92726f079fbe2f7e18
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4208795
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: James Maclean <wjmaclean@chromium.org>
Commit-Queue: Wayne Jackson Jr. <wbjacksonjr@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1104485}

android_webview/BUILD.gn

@@ -561,6 +561,7 @@ android_library("browser_java") {
     "java/src/org/chromium/android_webview/AwGeolocationPermissions.java",
     "java/src/org/chromium/android_webview/AwHistogramRecorder.java",
     "java/src/org/chromium/android_webview/AwHttpAuthHandler.java",
+    "java/src/org/chromium/android_webview/AwKeyboardShortcuts.java",
     "java/src/org/chromium/android_webview/AwLayoutSizer.java",
     "java/src/org/chromium/android_webview/AwNetworkChangeNotifierRegistrationPolicy.java",
     "java/src/org/chromium/android_webview/AwOriginVerificationScheduler.java",
@@ -676,6 +677,7 @@ android_library("browser_java") {
     "//components/variations/android:variations_java",
     "//components/version_info/android:version_constants_java",
     "//components/viz/service:service_java",
+    "//components/zoom/android:java",
     "//content/public/android:content_java",
     "//device/gamepad:java",
     "//mojo/public/java:system_java",

android_webview/browser/aw_feature_list.cc

@@ -36,6 +36,7 @@ const base::Feature* const kFeaturesExposedToJava[] = {
     &features::kWebViewRestrictSensitiveContent,
     &features::kWebViewUmaUploadQualityOfServiceSetToDefault,
     &metrics::kAndroidMetricsAsyncMetricLogging,
+    &features::kWebViewZoomKeyboardShortcuts,
 };
 
 const base::Feature* FindFeatureExposedToJava(const std::string& feature_name) {

android_webview/common/aw_features.cc

@@ -166,5 +166,10 @@ BASE_FEATURE(kWebViewUmaUploadQualityOfServiceSetToDefault,
              "WebViewUmaUploadQualityOfServiceSetToDefault",
              base::FEATURE_DISABLED_BY_DEFAULT);
 
+// This enables zoom keyboard shortcuts for zoom-in, zoom-out and zoom reset.
+BASE_FEATURE(kWebViewZoomKeyboardShortcuts,
+             "WebViewZoomKeyboardShortcuts",
+             base::FEATURE_DISABLED_BY_DEFAULT);
+
 }  // namespace features
 }  // namespace android_webview

android_webview/common/aw_features.h

@@ -42,6 +42,7 @@ BASE_DECLARE_FEATURE(kWebViewXRequestedWithHeaderControl);
 extern const base::FeatureParam<int> kWebViewXRequestedWithHeaderMode;
 BASE_DECLARE_FEATURE(kWebViewXRequestedWithHeaderManifestAllowList);
 BASE_DECLARE_FEATURE(kWebViewUmaUploadQualityOfServiceSetToDefault);
+BASE_DECLARE_FEATURE(kWebViewZoomKeyboardShortcuts);
 
 }  // namespace features
 }  // namespace android_webview

android_webview/java/DEPS

@@ -8,6 +8,7 @@ include_rules = [
   "+components/safe_browsing/android/java",
   "+components/stylus_handwriting/android/java",
   "+components/component_updater/android/java",
+  "+components/zoom/android/java",
 
   "-content/public/android/java",
   "+content/public/android/java/src/org/chromium/content_public",

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -85,6 +85,7 @@
 import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
 import org.chromium.components.stylus_handwriting.StylusWritingController;
 import org.chromium.components.url_formatter.UrlFormatter;
+import org.chromium.components.zoom.ZoomConstants;
 import org.chromium.content_public.browser.ChildProcessImportance;
 import org.chromium.content_public.browser.ContentViewStatics;
 import org.chromium.content_public.browser.GestureListenerManager;
@@ -2953,7 +2954,7 @@ public boolean zoomIn() {
         if (!canZoomIn()) {
             return false;
         }
-        zoomBy(1.25f);
+        zoomBy(ZoomConstants.ZOOM_IN_DELTA);
         return true;
     }
 
@@ -2966,7 +2967,17 @@ public boolean zoomOut() {
         if (!canZoomOut()) {
             return false;
         }
-        zoomBy(0.8f);
+        zoomBy(ZoomConstants.ZOOM_OUT_DELTA);
+        return true;
+    }
+
+    /**
+     * Resets the zoom to default
+     */
+    // This method uses the term 'zoom' for legacy reasons, but relates
+    // to what chrome calls the 'page scale factor'.
+    public boolean zoomReset() {
+        zoomByInternal(ZoomConstants.ZOOM_RESET_DELTA);
         return true;
     }
 
@@ -2976,11 +2987,15 @@ public boolean zoomOut() {
     // This method uses the term 'zoom' for legacy reasons, but relates
     // to what chrome calls the 'page scale factor'.
     public void zoomBy(float delta) {
-        if (TRACE) Log.i(TAG, "%s zoomBy=%f", this, delta);
-        if (isDestroyed(WARN)) return;
         if (delta < 0.01f || delta > 100.0f) {
             throw new IllegalStateException("zoom delta value outside [0.01, 100] range.");
         }
+        zoomByInternal(delta);
+    }
+
+    private void zoomByInternal(float delta) {
+        if (TRACE) Log.i(TAG, "%s zoomBy=%f", this, delta);
+        if (isDestroyed(WARN)) return;
         AwContentsJni.get().zoomBy(mNativeAwContents, delta);
     }
 
@@ -4076,10 +4091,10 @@ public void setLayerType(int layerType, Paint paint) {
         }
 
         private void updateHardwareAcceleratedFeaturesToggle() {
-            mSettings.setEnableSupportedHardwareAcceleratedFeatures(
-                    mIsAttachedToWindow && mContainerView.isHardwareAccelerated()
-                            && (mLayerType == View.LAYER_TYPE_NONE
-                                    || mLayerType == View.LAYER_TYPE_HARDWARE));
+            mSettings.setEnableSupportedHardwareAcceleratedFeatures(mIsAttachedToWindow
+                    && mContainerView.isHardwareAccelerated()
+                    && (mLayerType == View.LAYER_TYPE_NONE
+                            || mLayerType == View.LAYER_TYPE_HARDWARE));
         }
 
         @Override

android_webview/java/src/org/chromium/android_webview/AwKeyboardShortcuts.java

@@ -0,0 +1,75 @@
+// Copyright 2023 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.view.KeyEvent;
+
+import org.chromium.android_webview.common.AwFeatures;
+
+/**
+ * Handles WebView keyboard shortcut events that weren't handled in
+ * {@link AwWebContentsDelegateAdapter#handleKeyboardEvent(KeyEvent)}.
+ */
+/**
+ * TODO(wbjacksonjr) Possibly merge this class with {@link
+ * org.chromium.chrome.browser.KeyboardShortcuts}
+ */
+public class AwKeyboardShortcuts {
+    private static final int CTRL = 1 << 31;
+    private static final int ALT = 1 << 30;
+    private static final int SHIFT = 1 << 29;
+
+    private AwKeyboardShortcuts() {}
+
+    private static int getMetaState(KeyEvent event) {
+        return (event.isCtrlPressed() ? CTRL : 0) | (event.isAltPressed() ? ALT : 0)
+                | (event.isShiftPressed() ? SHIFT : 0);
+    }
+
+    public static boolean onKeyDown(KeyEvent event, AwContents awContents) {
+        int keyCode = event.getKeyCode();
+        if (event.getRepeatCount() != 0 || event.getAction() != KeyEvent.ACTION_DOWN
+                || KeyEvent.isModifierKey(keyCode)) {
+            return false;
+        }
+
+        int metaState = getMetaState(event);
+        int keyCodeAndMeta = keyCode | metaState;
+
+        if (AwFeatureList.isEnabled(AwFeatures.WEBVIEW_ZOOM_KEYBOARD_SHORTCUTS)) {
+            return handleZoomShortcut(awContents, keyCodeAndMeta);
+        }
+        return false;
+    }
+
+    private static boolean handleZoomShortcut(AwContents awContents, int keyCodeAndMeta) {
+        // We want to return true even if zoom is not supported as technically the keyboard shortcut
+        // was handled
+        boolean supportsZoom = awContents.getSettings().supportZoom();
+        switch (keyCodeAndMeta) {
+            case CTRL | KeyEvent.KEYCODE_PLUS:
+            case CTRL | KeyEvent.KEYCODE_EQUALS:
+            case CTRL | SHIFT | KeyEvent.KEYCODE_PLUS:
+            case CTRL | SHIFT | KeyEvent.KEYCODE_EQUALS:
+            case KeyEvent.KEYCODE_ZOOM_IN:
+                if (supportsZoom) {
+                    awContents.zoomIn();
+                }
+                return true;
+            case CTRL | KeyEvent.KEYCODE_MINUS:
+            case KeyEvent.KEYCODE_ZOOM_OUT:
+                if (supportsZoom) {
+                    awContents.zoomOut();
+                }
+                return true;
+            case CTRL | KeyEvent.KEYCODE_0:
+                if (supportsZoom) {
+                    awContents.zoomReset();
+                }
+                return true;
+        }
+        return false;
+    }
+}

android_webview/java/src/org/chromium/android_webview/AwWebContentsDelegateAdapter.java

@@ -80,6 +80,7 @@ public void handleKeyboardEvent(KeyEvent event) {
                     break;
             }
             if (direction != 0 && tryToMoveFocus(direction)) return;
+            if (AwKeyboardShortcuts.onKeyDown(event, mAwContents)) return;
         }
         handleMediaKey(event);
         mContentsClient.onUnhandledKeyEvent(event);

android_webview/java/src/org/chromium/android_webview/common/ProductionSupportedFlagList.java

@@ -381,6 +381,8 @@ private ProductionSupportedFlagList() {}
             Flag.baseFeature(BlinkFeatures.STYLUS_RICH_GESTURES,
                     "When enabled, stylus input can be used to draw rich gestures which "
                             + "affect text in editable web content."),
+            Flag.baseFeature(AwFeatures.WEBVIEW_ZOOM_KEYBOARD_SHORTCUTS,
+                    "Enables WebView to use zoom keyboard shortcuts on hardware keyboards."),
             // Add new commandline switches and features above. The final entry should have a
             // trailing comma for cleaner diffs.
     };