Upstream ResourceManager

content/public/android/java/src/org/chromium/content_public/resources/system/SystemResourceLoader.java

Index: content/public/android/java/src/org/chromium/content_public/resources/system/SystemResourceLoader.java
diff --git a/content/public/android/java/src/org/chromium/content_public/resources/system/SystemResourceLoader.java b/content/public/android/java/src/org/chromium/content_public/resources/system/SystemResourceLoader.java
new file mode 100644
index 0000000000000000000000000000000000000000..16935bd2ebf687919bd231c2e657f979a6674e0d
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content_public/resources/system/SystemResourceLoader.java
@@ -0,0 +1,93 @@
+// Copyright 2014 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.content_public.resources.system;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Paint.Style;
+import android.graphics.RectF;
+
+import org.chromium.content_public.resources.Resource;
+import org.chromium.content_public.resources.async.AsyncPreloadResourceLoader;
+import org.chromium.content_public.resources.statics.StaticResource;
+import org.chromium.ui.base.SystemUIResourceType;
+import org.chromium.ui.gfx.DeviceDisplayInfo;
+
+/**
+ * Handles loading system specific resources like overscroll and edge glows.
+ */
+public class SystemResourceLoader extends AsyncPreloadResourceLoader {
+    private static final float SIN_PI_OVER_6 = 0.5f;
+    private static final float COS_PI_OVER_6 = 0.866f;
+
+    /**
+     * Creates an instance of a {@link SystemResourceLoader}.
+     * @param resourceType The resource type this loader is responsible for loading.
+     * @param callback     The {@link ResourceLoaderCallback} to notify when a {@link Resource} is
+     *                     done loading.
+     * @param resources    A {@link Resources} instance to load assets from.
+     */
+    public SystemResourceLoader(int resourceType, ResourceLoaderCallback callback,
+            final Context context) {
+        super(resourceType, callback, new ResourceCreator() {
+            @Override
+            public Resource create(int resId) {
+                return createResource(context, resId);
+            }
+        });
+    }
+
+    private static Resource createResource(Context context, int resId) {
+        switch (resId) {
+            case SystemUIResourceType.OVERSCROLL_EDGE:
+                return StaticResource.create(Resources.getSystem(),
+                        getResourceId("android:drawable/overscroll_edge"), 128, 12);
+            case SystemUIResourceType.OVERSCROLL_GLOW:
+                return StaticResource.create(Resources.getSystem(),
+                        getResourceId("android:drawable/overscroll_glow"), 128, 64);
+            case SystemUIResourceType.OVERSCROLL_GLOW_L:
+                return createOverscrollGlowLBitmap(context);
+        }
+        return null;
+    }
+
+    private static Resource createOverscrollGlowLBitmap(Context context) {
+        DeviceDisplayInfo displayInfo = DeviceDisplayInfo.create(context);
+        int screenWidth = displayInfo.getPhysicalDisplayWidth() != 0
+                ? displayInfo.getPhysicalDisplayWidth() : displayInfo.getDisplayWidth();
+        int screenHeight = displayInfo.getPhysicalDisplayHeight() != 0
+                ? displayInfo.getPhysicalDisplayHeight() : displayInfo.getDisplayHeight();
+
+        float arcWidth = Math.min(screenWidth, screenHeight) * 0.5f / SIN_PI_OVER_6;
+        float y = COS_PI_OVER_6 * arcWidth;
+        float height = arcWidth - y;
+
+        float arcRectX = -arcWidth / 2.f;
+        float arcRectY = -arcWidth - y;
+        float arcRectWidth = arcWidth * 2.f;
+        float arcRectHeight = arcWidth * 2.f;
+        RectF arcRect = new RectF(
+                arcRectX, arcRectY, arcRectX + arcRectWidth, arcRectY + arcRectHeight);
+
+        Paint arcPaint = new Paint();
+        arcPaint.setAntiAlias(true);
+        arcPaint.setAlpha(0xBB);
+        arcPaint.setStyle(Style.FILL);
+
+        Bitmap bitmap = Bitmap.createBitmap((int) arcWidth, (int) height, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(bitmap);
+        canvas.drawArc(arcRect, 45, 90, true, arcPaint);
+
+        return new StaticResource(bitmap);
+    }
+
+    private static int getResourceId(String name) {
+        Resources systemResources = Resources.getSystem();
+        return systemResources.getIdentifier(name, null, null);
+    }
+}