Add DeJellyUtils.java

Adds Android-specific customization of de-jelly effect based on display
properties.

Bug: 995965
Change-Id: Ie48ddf1e3f61d601e05522cf1f7b99a3dc25f012
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1837115
Commit-Queue: Eric Karl <ericrk@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: enne <enne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705760}

android_webview/BUILD.gn

@@ -632,6 +632,7 @@ android_library("browser_java") {
     "//components/variations:load_seed_result_enum_java",
     "//components/variations/android:variations_java",
     "//components/version_info/android:version_constants_java",
+    "//components/viz/common:common_java",
     "//content/public/android:content_java",
     "//device/gamepad:java",
     "//mojo/public/java:system_java",

chrome/android/BUILD.gn

@@ -325,6 +325,7 @@ android_library("chrome_java") {
     "//components/url_formatter/android:url_formatter_java",
     "//components/variations/android:variations_java",
     "//components/version_info/android:version_constants_java",
+    "//components/viz/common:common_java",
     "//components/viz/service:service_java",
     "//content/public/android:content_java",
     "//device/gamepad:java",

components/viz/common/BUILD.gn

@@ -278,7 +278,10 @@ viz_component("common") {
   }
 
   if (is_android) {
-    deps += [ "//gpu/config" ]
+    deps += [
+      ":common_jni_headers",
+      "//gpu/config",
+    ]
   }
 
   if (is_chromecast) {
@@ -396,3 +399,20 @@ viz_source_set("perf_tests") {
     "//testing/perf",
   ]
 }
+
+if (is_android) {
+  android_library("common_java") {
+    deps = [
+      "//base:base_java",
+    ]
+    java_files = [
+      "java/src/org/chromium/components/viz/common/display/DeJellyUtils.java",
+    ]
+  }
+
+  generate_jni("common_jni_headers") {
+    sources = [
+      "java/src/org/chromium/components/viz/common/display/DeJellyUtils.java",
+    ]
+  }
+}

components/viz/common/display/de_jelly.cc

@@ -5,8 +5,16 @@
 #include "components/viz/common/display/de_jelly.h"
 
 #include "base/command_line.h"
+#include "build/build_config.h"
 #include "components/viz/common/switches.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/jni_android.h"
+#include "base/android/jni_string.h"
+#include "base/time/time.h"
+#include "components/viz/common/common_jni_headers/DeJellyUtils_jni.h"
+#endif
+
 namespace viz {
 
 bool DeJellyEnabled() {
@@ -15,8 +23,14 @@ bool DeJellyEnabled() {
 }
 
 bool DeJellyActive() {
-  // TODO(ericrk): Android specific bits to be added in a follow-up CL.
-  return DeJellyEnabled();
+  if (!DeJellyEnabled())
+    return false;
+
+#if defined(OS_ANDROID)
+  return Java_DeJellyUtils_useDeJelly(base::android::AttachCurrentThread());
+#endif
+
+  return true;
 }
 
 float DeJellyScreenWidth() {
@@ -26,8 +40,10 @@ float DeJellyScreenWidth() {
   if (!value.empty())
     return std::atoi(value.c_str());
 
-  // TODO(ericrk): We can automatically handle this on Android. For now return
-  // a reasonable default.
+#if defined(OS_ANDROID)
+  return Java_DeJellyUtils_screenWidth(base::android::AttachCurrentThread());
+#endif
+
   return 1440.0f;
 }
 

components/viz/common/java/src/org/chromium/components/viz/common/display/DeJellyUtils.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.viz.common.display;
+
+import android.content.ComponentCallbacks;
+import android.content.Context;
+import android.content.res.Configuration;
+import android.graphics.Point;
+import android.hardware.display.DisplayManager;
+import android.provider.Settings.Global;
+import android.view.Display;
+import android.view.Surface;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.annotations.MainDex;
+
+import java.lang.reflect.Field;
+
+/**
+ * Provides static utility functions to query de-jelly settings.
+ */
+@JNINamespace("viz")
+@MainDex
+public class DeJellyUtils implements DisplayManager.DisplayListener, ComponentCallbacks {
+    /** Singleton DeJellyUtils instance */
+    private static DeJellyUtils sInstance;
+
+    /**
+     * @return The DeJellyUtils singleton.
+     */
+    private static DeJellyUtils getInstance() {
+        if (sInstance == null) sInstance = new DeJellyUtils();
+        return sInstance;
+    }
+
+    /** Whether the last processed rotation should have de-jelly applied. */
+    private boolean mRotationOk;
+    /** Whether the last processed configuration should have de-jelly applied. */
+    private boolean mConfigurationOk;
+    /** The last processed screen width. */
+    private float mScreenWidth;
+    /** Cached DisplayManager. */
+    private DisplayManager mManager;
+    /** Field used to identify in-use screen on some devices. */
+    private Field mDisplayDeviceType;
+
+    /** Int representing the sub-display, used with mDisplayDeviceType. */
+    private static final int SEM_DISPLAY_DEVICE_TYPE_SUB = 5;
+
+    private DeJellyUtils() {
+        // TODO(ericrk): We should probably plumb display information from the
+        // browser process, rather than re-querying it here.
+        mManager = (DisplayManager) ContextUtils.getApplicationContext().getSystemService(
+                Context.DISPLAY_SERVICE);
+        // Register callbacks which will notify of future changes.
+        mManager.registerDisplayListener(this, null);
+        ContextUtils.getApplicationContext().registerComponentCallbacks(this);
+
+        // Get current state, as we may need these values and callbacks will not yet have fired.
+        onDisplayChanged(0);
+        onConfigurationChanged(
+                ContextUtils.getApplicationContext().getResources().getConfiguration());
+
+        // See if we have a display device type field to query.
+        try {
+            Class configurationClass = Configuration.class;
+            mDisplayDeviceType = configurationClass.getDeclaredField("semDisplayDeviceType");
+        } catch (Exception e) {
+            // We do not require mDisplayDeviceType to exist. Continue.
+        }
+    }
+
+    // DisplayManager.DisplayListener implementation.
+    @Override
+    public void onDisplayAdded(int displayId) {}
+    @Override
+    public void onDisplayChanged(int displayId) {
+        // Ignore non-default display.
+        if (displayId != Display.DEFAULT_DISPLAY) return;
+
+        Display display = mManager.getDisplay(displayId);
+
+        // For now only support ROTATION_0.
+        // TODO(ericrk): Allow this to be customized.
+        int rotation = display.getRotation();
+        mRotationOk = rotation == Surface.ROTATION_0;
+
+        Point realSize = new Point();
+        display.getRealSize(realSize);
+        mScreenWidth = realSize.x;
+    }
+    @Override
+    public void onDisplayRemoved(int displayId) {}
+
+    // ComponentCallbacks implementation.
+    @Override
+    public void onConfigurationChanged(Configuration configuration) {
+        if (mDisplayDeviceType != null) {
+            try {
+                mConfigurationOk =
+                        mDisplayDeviceType.getInt(configuration) != SEM_DISPLAY_DEVICE_TYPE_SUB;
+                return;
+            } catch (Exception e) {
+                // We don't require that this field exists, continue.
+            }
+        }
+        // Configuration is always ok if we can't query mDisplayDeviceType.
+        mConfigurationOk = true;
+    }
+    @Override
+    public void onLowMemory() {}
+
+    /**
+     * @return Whether the current screen / configuration should use the de-jelly effect.
+     */
+    @CalledByNative
+    private static boolean useDeJelly() {
+        DeJellyUtils utils = getInstance();
+
+        // Device specific flag which force-disables jelly scroll on a per-frame basis.
+        if (Global.getInt(ContextUtils.getApplicationContext().getContentResolver(),
+                    "sem_support_scroll_filter", 1)
+                == 0) {
+            return false;
+        }
+
+        return utils.mRotationOk && utils.mConfigurationOk;
+    }
+
+    /**
+     * @return the current screen width.
+     */
+    @CalledByNative
+    private static float screenWidth() {
+        return getInstance().mScreenWidth;
+    }
+};