Upstream DeviceClassManager

chrome/android/java/src/org/chromium/chrome/browser/device/DeviceClassManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/device/DeviceClassManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/device/DeviceClassManager.java b/chrome/android/java/src/org/chromium/chrome/browser/device/DeviceClassManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..34ae41ac891f30d2b481111349a3115ed257034c
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/device/DeviceClassManager.java
@@ -0,0 +1,166 @@
+// Copyright 2013 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.chrome.browser.device;
+
+import android.content.Context;
+import android.view.accessibility.AccessibilityManager;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.CommandLine;
+import org.chromium.base.SysUtils;
+import org.chromium.base.TraceEvent;
+import org.chromium.chrome.ChromeSwitches;
+import org.chromium.ui.base.DeviceFormFactor;
+
+/**
+ * This class is used to turn on and off certain features for different types of
+ * devices.
+ */
+public class DeviceClassManager {
+    private static DeviceClassManager sInstance;
+
+    // Set of features that can be enabled/disabled
+    private boolean mEnableSnapshots;
+    private boolean mEnableLayerDecorationCache;
+    private boolean mEnableAccessibilityLayout;
+    private boolean mEnableAnimations;
+    private boolean mEnableInstantSearchClicks;
+    private boolean mEnablePrerendering;
+    private boolean mEnableToolbarSwipe;
+    private boolean mEnableToolbarSwipeInDocumentMode;
+    private boolean mEnableUndo;
+    private final boolean mEnableFullscreen;
+
+    private static DeviceClassManager getInstance() {
+        if (sInstance == null) {
+            sInstance = new DeviceClassManager();
+        }
+        return sInstance;
+    }
+
+    /**
+     * The {@link DeviceClassManager} constructor should be self contained and
+     * rely on system information and command line flags.
+     */
+    private DeviceClassManager() {
+        // Device based configurations.
+        if (SysUtils.isLowEndDevice()) {
+            mEnableSnapshots = false;
+            mEnableLayerDecorationCache = true;
+            mEnableAccessibilityLayout = true;
+            mEnableAnimations = false;
+            mEnablePrerendering = false;
+            mEnableToolbarSwipe = false;
+            mEnableInstantSearchClicks = false;
+        } else {
+            mEnableSnapshots = true;
+            mEnableLayerDecorationCache = true;
+            mEnableAccessibilityLayout = false;
+            mEnableAnimations = true;
+            mEnablePrerendering = true;
+            mEnableToolbarSwipe = true;
+            mEnableInstantSearchClicks = true;
+        }
+
+        if (DeviceFormFactor.isTablet(ApplicationStatus.getApplicationContext())) {
+            mEnableAccessibilityLayout = false;
+        }
+
+        // Flag based configurations.
+        CommandLine commandLine = CommandLine.getInstance();
+        mEnableAccessibilityLayout |= commandLine
+                .hasSwitch(ChromeSwitches.ENABLE_ACCESSIBILITY_TAB_SWITCHER);
+        mEnableFullscreen =
+                !commandLine.hasSwitch(ChromeSwitches.DISABLE_FULLSCREEN);
+        mEnableUndo = commandLine.hasSwitch(ChromeSwitches.ENABLE_HIGH_END_UI_UNDO);
+        mEnableToolbarSwipeInDocumentMode =
+                commandLine.hasSwitch(ChromeSwitches.ENABLE_TOOLBAR_SWIPE_IN_DOCUMENT_MODE);
+
+        // Related features.
+        if (mEnableAccessibilityLayout) {
+            mEnableAnimations = false;
+        }
+
+        if (SysUtils.isLowEndDevice() || mEnableAccessibilityLayout)  {
+            mEnableUndo = true;
+        }
+    }
+
+    /**
+     * @return Whether or not we can take screenshots.
+     */
+    public static boolean enableSnapshots() {
+        return getInstance().mEnableSnapshots;
+    }
+
+    /**
+     * @return Whether or not we can use the layer decoration cache.
+     */
+    public static boolean enableLayerDecorationCache() {
+        return getInstance().mEnableLayerDecorationCache;
+    }
+
+    /**
+     * @return Whether or not should use the accessibility tab switcher.
+     */
+    public static boolean enableAccessibilityLayout() {
+        return getInstance().mEnableAccessibilityLayout;
+    }
+
+    /**
+     * @return Whether or not full screen is enabled.
+     */
+    public static boolean enableFullscreen() {
+        return getInstance().mEnableFullscreen;
+    }
+
+    /**
+     * @param context A {@link Context} instance.
+     * @return        Whether or not we are showing animations.
+     */
+    public static boolean enableAnimations(Context context) {
+        return getInstance().mEnableAnimations && !isAccessibilityModeEnabled(context);
+    }
+
+    /**
+     * @return Whether or not prerendering is enabled.
+     */
+    public static boolean enablePrerendering() {
+        return getInstance().mEnablePrerendering;
+    }
+
+    /**
+     * @param isDocumentMode Whether or not chrome is in document mode.
+     * @return Whether or not we can use the toolbar swipe.
+     */
+    public static boolean enableToolbarSwipe(boolean isDocumentMode) {
+        return getInstance().mEnableToolbarSwipe
+                && !(isDocumentMode && !getInstance().mEnableToolbarSwipeInDocumentMode);
+    }
+
+    /**
+     * @return Whether or not instant search clicks is enabled.
+     */
+    public static boolean enableInstantSearchClicks() {
+        return getInstance().mEnableInstantSearchClicks;
+    }
+
+    /**
+     * @return Whether or not undo is enabled.
+     */
+    public static boolean enableUndo(Context context) {
+        return getInstance().mEnableUndo || isAccessibilityModeEnabled(context);
+    }
+
+    public static boolean isAccessibilityModeEnabled(Context context) {
+        TraceEvent.begin("DeviceClassManager::isAccessibilityModeEnabled");
+        AccessibilityManager manager = (AccessibilityManager)
+                context.getSystemService(Context.ACCESSIBILITY_SERVICE);
+        boolean enabled = manager != null && manager.isEnabled()
+                && manager.isTouchExplorationEnabled();
+        TraceEvent.end("DeviceClassManager::isAccessibilityModeEnabled");
+        return enabled;
+    }
+}