Create BookmarkUtils class.

This factors out some bookmarks functionality that we would like to reuse when
impementing installable webapps.

Change-Id: Ia34d70b732c45220637767ddd0f05b280f0fc6bc
diff --git a/src/com/android/browser/BookmarkUtils.java b/src/com/android/browser/BookmarkUtils.java
new file mode 100644
index 0000000..0fdad15
--- /dev/null
+++ b/src/com/android/browser/BookmarkUtils.java
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.browser;
+
+import android.content.Context;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.graphics.PorterDuff;
+import android.graphics.PorterDuffXfermode;
+import android.graphics.Rect;
+import android.graphics.RectF;
+import android.net.Uri;
+import android.provider.Browser;
+import android.util.Log;
+
+class BookmarkUtils {
+    private final static String LOGTAG = "BookmarkUtils";
+
+    // XXX: There is no public string defining this intent so if Home changes the value, we
+    // have to update this string.
+    private static final String INSTALL_SHORTCUT = "com.android.launcher.action.INSTALL_SHORTCUT";
+
+    enum BookmarkIconType {
+        ICON_INSTALLABLE_WEB_APP, // Icon for an installable web app (launches WebAppRuntime).
+        ICON_HOME_SHORTCUT        // Icon for a shortcut on the home screen (launches Browser).
+    };
+
+    /**
+     * Creates an icon to be associated with this bookmark. If available, the apple touch icon
+     * will be used, else we draw our own depending on the type of "bookmark" being created.
+     */
+    static Bitmap createIcon(Context context, Bitmap touchIcon, Bitmap favicon,
+            BookmarkIconType type) {
+        int iconDimension = context.getResources().getDimensionPixelSize(
+                android.R.dimen.app_icon_size);
+
+        Bitmap bm = Bitmap.createBitmap(iconDimension, iconDimension, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(bm);
+        Rect iconBounds = new Rect(0, 0, bm.getWidth(), bm.getHeight());
+
+        // Use the apple-touch-icon if available
+        if (touchIcon != null) {
+            drawTouchIconToCanvas(touchIcon, canvas, iconBounds);
+        } else {
+            // No touch icon so create our own.
+            // Set the background based on the type of shortcut (either webapp or home shortcut).
+            Bitmap icon = getIconBackground(context, type);
+
+            if (icon != null) {
+                // Now draw the correct icon background into our new bitmap.
+                canvas.drawBitmap(icon, null, iconBounds, null);
+            }
+
+            // If we have a favicon, overlay it in a nice rounded white box on top of the
+            // background.
+            if (favicon != null) {
+                drawFaviconToCanvas(favicon, canvas, iconBounds,
+                        context.getResources().getDisplayMetrics().density);
+            }
+        }
+        return bm;
+    }
+
+    /**
+     * Convenience method for creating an intent that will add a shortcut to the home screen.
+     */
+    static Intent createAddToHomeIntent(Context context, String url, String title,
+            Bitmap touchIcon, Bitmap favicon) {
+        Intent i = new Intent(INSTALL_SHORTCUT);
+        Intent shortcutIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
+        long urlHash = url.hashCode();
+        long uniqueId = (urlHash << 32) | shortcutIntent.hashCode();
+        shortcutIntent.putExtra(Browser.EXTRA_APPLICATION_ID, Long.toString(uniqueId));
+        i.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);
+        i.putExtra(Intent.EXTRA_SHORTCUT_NAME, title);
+        i.putExtra(Intent.EXTRA_SHORTCUT_ICON, createIcon(context, touchIcon, favicon,
+                BookmarkIconType.ICON_HOME_SHORTCUT));
+
+        // Do not allow duplicate items
+        i.putExtra("duplicate", false);
+        return i;
+    }
+
+    private static Bitmap getIconBackground(Context context, BookmarkIconType type) {
+        if (type == BookmarkIconType.ICON_HOME_SHORTCUT) {
+            // Want to create a shortcut icon on the homescreen, so the icon
+            // background is the red bookmark.
+            return BitmapFactory.decodeResource(context.getResources(),
+                    R.drawable.ic_launcher_shortcut_browser_bookmark);
+        } else if (type == BookmarkIconType.ICON_INSTALLABLE_WEB_APP) {
+            // Use the web browser icon as the background for the icon for an installable
+            // web app.
+            return BitmapFactory.decodeResource(context.getResources(),
+                    R.drawable.ic_launcher_browser);
+        }
+        return null;
+    }
+
+    private static void drawTouchIconToCanvas(Bitmap touchIcon, Canvas canvas, Rect iconBounds) {
+        Rect src = new Rect(0, 0, touchIcon.getWidth(), touchIcon.getHeight());
+
+        // Paint used for scaling the bitmap and drawing the rounded rect.
+        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+        paint.setFilterBitmap(true);
+        canvas.drawBitmap(touchIcon, src, iconBounds, paint);
+
+        // Construct a path from a round rect. This will allow drawing with
+        // an inverse fill so we can punch a hole using the round rect.
+        Path path = new Path();
+        path.setFillType(Path.FillType.INVERSE_WINDING);
+        RectF rect = new RectF(iconBounds);
+        rect.inset(1, 1);
+        path.addRoundRect(rect, 8f, 8f, Path.Direction.CW);
+
+        // Reuse the paint and clear the outside of the rectangle.
+        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
+        canvas.drawPath(path, paint);
+    }
+
+    private static void drawFaviconToCanvas(Bitmap favicon, Canvas canvas, Rect iconBounds,
+            float density) {
+        // Make a Paint for the white background rectangle and for
+        // filtering the favicon.
+        Paint p = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+        p.setStyle(Paint.Style.FILL_AND_STROKE);
+        p.setColor(Color.WHITE);
+
+        // Create a rectangle that is slightly wider than the favicon
+        final float iconSize = 16 * density; // 16x16 favicon
+        final float padding = 2 * density; // white padding around icon
+        final float rectSize = iconSize + 2 * padding;
+        final float x = iconBounds.exactCenterX() - (rectSize / 2);
+        // Note: Subtract 2 dip from the y position since the box is
+        // slightly higher than center. Use padding since it is already
+        // 2 * density.
+        final float y = iconBounds.exactCenterY() - (rectSize / 2) - padding;
+        RectF r = new RectF(x, y, x + rectSize, y + rectSize);
+
+        // Draw a white rounded rectangle behind the favicon
+        canvas.drawRoundRect(r, 2, 2, p);
+
+        // Draw the favicon in the same rectangle as the rounded
+        // rectangle but inset by the padding
+        // (results in a 16x16 favicon).
+        r.inset(padding, padding);
+        canvas.drawBitmap(favicon, null, r, p);
+    }
+
+};