Update the AppBannerView appearance

chrome/android/java/src/org/chromium/chrome/browser/banners/RatingView.java

Index: chrome/android/java/src/org/chromium/chrome/browser/banners/RatingView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/banners/RatingView.java b/chrome/android/java/src/org/chromium/chrome/browser/banners/RatingView.java
new file mode 100644
index 0000000000000000000000000000000000000000..0fd296944b167cbfb6e317e4538cf9c54c3453b1
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/banners/RatingView.java
@@ -0,0 +1,94 @@
+// 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.chrome.browser.banners;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Matrix;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.View;
+
+import org.chromium.chrome.R;
+import org.chromium.ui.base.LocalizationUtils;
+
+/**
+ * Displays a set of stars representing a rating for an app.
+ */
+public class RatingView extends View {
+    private static final int MAX_INCREMENT = 10;
+
+    // Bitmaps used to draw the ratings.
+    private final Bitmap mStarFull;
+    private final Bitmap mStarHalf;
+    private final Bitmap mStarEmpty;
+
+    /** Stores whether or not the layout is left-to-right. */
+    private final boolean mIsLayoutLTR;
+
+    /** Variables used for drawing. */
+    private final Rect mDrawingRect;
+
+    /** Each increment represents 0.5 stars. */
+    private int mIncrements;
+
+    public RatingView(Context context, AttributeSet params) {
+        super(context, params);
+        mIsLayoutLTR = !LocalizationUtils.isSystemLayoutDirectionRtl();
+        mDrawingRect = new Rect();
+
+        // Cache the Bitmaps.
+        Resources res = getResources();
+        Bitmap starHalf = BitmapFactory.decodeResource(res, R.drawable.btn_star_mini_half);
+        if (!mIsLayoutLTR) {
+            // RTL mode requires flipping the Bitmap.
+            int width = starHalf.getWidth();
+            int height = starHalf.getHeight();
+            Matrix m = new Matrix();
+            m.preScale(-1, 1);
+            starHalf = Bitmap.createBitmap(starHalf, 0, 0, width, height, m, false);
+        }
+        mStarHalf = starHalf;
+        mStarFull = BitmapFactory.decodeResource(res, R.drawable.btn_star_mini_full);
+        mStarEmpty = BitmapFactory.decodeResource(res, R.drawable.btn_star_mini_empty);
+    }
+
+    /**
+     * Initializes the RatingView.
+     * @param rating How many stars to display.
+     */
+    void initialize(float rating) {
+        // Ratings are rounded to the nearest 0.5 increment, like in the Play Store.
+        mIncrements = Math.round(rating * 2);
+    }
+
+    @Override
+    public void onDraw(Canvas canvas) {
+        int starSize = canvas.getHeight();
+
+        // Start off on the left for LTR mode, on the right for RTL.
+        mDrawingRect.top = 0;
+        mDrawingRect.bottom = starSize;
+        mDrawingRect.left = mIsLayoutLTR ? 0 : (canvas.getWidth() - starSize);
+        mDrawingRect.right = mDrawingRect.left + starSize;
+
+        // Draw all the stars.
+        for (int i = 0; i < MAX_INCREMENT; i += 2) {
+            Bitmap toShow = mStarEmpty;
+            if (i < mIncrements) {
+                boolean isFullStar = (mIncrements - i) >= 2;
+                toShow = isFullStar ? mStarFull : mStarHalf;
+            }
+            canvas.drawBitmap(toShow, null, mDrawingRect, null);
+
+            // Scooch over to show the next star.
+            mDrawingRect.left += (mIsLayoutLTR ? 1 : -1) * starSize;
+            mDrawingRect.right = mDrawingRect.left + starSize;
+        }
+    }
+}