Follow Material spec for icons when adding web apps to home screen.

chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
index 3df4198f801d93f73568c09760bfeb5318d5dc37..d05a0329201b7d59eb967e7a05f0ebd32c2ce832 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
@@ -26,8 +26,6 @@ import android.os.Handler;
 import android.os.Looper;
 import android.text.TextUtils;
 import android.util.Base64;
-import android.util.DisplayMetrics;
-import android.util.TypedValue;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.ApplicationStatus;
@@ -77,11 +75,13 @@ public class ShortcutHelper {
     // 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";
-    private static final int INSET_DIMENSION_FOR_TOUCHICON = 1;
-    private static final int TOUCHICON_BORDER_RADII_DP = 4;
-    private static final int GENERATED_ICON_SIZE_DP = 40;
-    private static final int GENERATED_ICON_ROUNDED_CORNERS_DP = 2;
-    private static final int GENERATED_ICON_FONT_SIZE_DP = 16;
+
+    // These sizes are from the Material spec for icons:
+    // https://www.google.com/design/spec/style/icons.html#icons-product-icons
+    private static final float ICON_PADDING_RATIO = 2.0f / 44.0f;
+    private static final float ICON_CORNER_RADIUS_RATIO = 1.0f / 16.0f;
+    private static final float GENERATED_ICON_PADDING_RATIO = 1.0f / 12.0f;
+    private static final float GENERATED_ICON_FONT_SIZE_RATIO = 1.0f / 3.0f;
 
     /** Broadcasts Intents out Android for adding the shortcut. */
     public static class Delegate {
@@ -237,66 +237,112 @@ public class ShortcutHelper {
     /**
      * Returns whether the given icon matches the size requirements to be used on the homescreen.
      * @param context Context used to create the intent.
-     * @param icon Image representing the shortcut.
+     * @param width Icon width, in pixels.
+     * @param height Icon height, in pixels.
      * @return whether the given icon matches the size requirements to be used on the homescreen.
      */
     @CalledByNative
-    public static boolean isIconLargeEnoughForLauncher(Context context, Bitmap icon) {
+    public static boolean isIconLargeEnoughForLauncher(Context context, int width, int height) {
         ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
         final int minimalSize = am.getLauncherLargeIconSize() / 2;
-        return icon.getWidth() >= minimalSize && icon.getHeight() >= minimalSize;
+        return width >= minimalSize && height >= minimalSize;
     }
 
     /**
-     * Returns the given icon after applying same changes to match the launcher design
-     * requirements.
+     * Adapts a website's icon (e.g. favicon or touch icon) to the Material design style guidelines
+     * for home screen icons. This involves adding some padding and rounding the corners.
+     *
      * @param context Context used to create the intent.
-     * @param icon Image representing the shortcut.
+     * @param webIcon The website's favicon or touch icon.
      * @return Bitmap Either the touch-icon or the newly created favicon.
      */
     @CalledByNative
-    public static Bitmap modifyIconForLauncher(Context context, Bitmap icon) {
-        assert isIconLargeEnoughForLauncher(context, icon);
+    public static Bitmap generateHomescreenIconFromWebIcon(Context context, Bitmap webIcon) {

[gone, 2015/10/29 20:51:25]

nit: generateHomeScreenIcon because Android laughed/yelled at us for calling it
a "Homescreen"

[newt (away), 2015/10/29 21:30:25]

Replaced most instances of "homescreen" with "home screen", but didn't change
anything though would require changes to other files.

+        // getLauncherLargeIconSize() is just a guess at the launcher icon size, and is often
+        // wrong -- the launcher can shows icons at any size it pleases. Instead of resizing the

[gone, 2015/10/29 20:51:25]

nit: can show

[newt (away), 2015/10/29 21:30:24]

Done.

+        // icon to the supposed launcher size and then having the launcher resize the icon again,
+        // just leave the icon at its original size and let the launcher do a single rescaling.
+        // Unless the icon is much too big; then scale it down here too.
+        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
+        int maxInnerSize = Math.round(am.getLauncherLargeIconSize() * 1.25f);

[gone, 2015/10/29 20:51:25]

nit: make a constant

[newt (away), 2015/10/29 21:30:24]

Done.

+        int innerSize = Math.min(maxInnerSize, Math.max(webIcon.getWidth(), webIcon.getHeight()));
+        int padding = Math.round(ICON_PADDING_RATIO * innerSize);
+        int outerSize = innerSize + 2 * padding;
 
         Bitmap bitmap = null;
-        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
-        final int iconSize = am.getLauncherLargeIconSize();
         try {
-            bitmap = Bitmap.createBitmap(iconSize, iconSize, Bitmap.Config.ARGB_8888);
-            Canvas canvas = new Canvas(bitmap);
-            drawTouchIconToCanvas(context, icon, canvas);
-            canvas.setBitmap(null);
+            bitmap = Bitmap.createBitmap(outerSize, outerSize, Bitmap.Config.ARGB_8888);
         } catch (OutOfMemoryError e) {
-            Log.w(TAG, "OutOfMemoryError while trying to draw bitmap on canvas.");
+            Log.w(TAG, "OutOfMemoryError while creating bitmap for home screen icon.");
+            return webIcon;
         }
+
+        // Draw the web icon with padding around it.
+        Canvas canvas = new Canvas(bitmap);
+        Rect innerBounds = new Rect(padding, padding, outerSize - padding, outerSize - padding);
+        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
+        paint.setFilterBitmap(true);
+        canvas.drawBitmap(webIcon, null, innerBounds, paint);
+
+        // Round the corners.
+        int cornerRadius = Math.round(ICON_CORNER_RADIUS_RATIO * outerSize);
+        Path path = new Path();
+        path.setFillType(Path.FillType.INVERSE_WINDING);
+        RectF innerBoundsF = new RectF(innerBounds);
+        path.addRoundRect(innerBoundsF, cornerRadius, cornerRadius, Path.Direction.CW);
+        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
+        canvas.drawPath(path, paint);
+
         return bitmap;
     }
 
     /**
-     * Generates an icon to be used on the launcher.
+     * Generates a generic icon to be used in the launcher. This is just a rounded rectangle with
+     * a letter in the middle taken from the website's domain name.
+     *
      * @param context Context used to create the intent.
      * @param url URL of the shortcut.
-     * @param rValue Red component of the dominant icon color.
-     * @param gValue Green component of the dominant icon color.
-     * @param bValue Blue component of the dominant icon color.
+     * @param red Red component of the dominant icon color.
+     * @param green Green component of the dominant icon color.
+     * @param blue Blue component of the dominant icon color.
      * @return Bitmap Either the touch-icon or the newly created favicon.
      */
     @CalledByNative
-    public static Bitmap generateLauncherIcon(Context context, String url, int rValue,
-            int gValue, int bValue) {
-        Bitmap bitmap = null;
+    public static Bitmap generateHomescreenIcon(Context context, String url, int red, int green,
+            int blue) {
         ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
-        final int iconSize = am.getLauncherLargeIconSize();
+        final int outerSize = am.getLauncherLargeIconSize();
         final int iconDensity = am.getLauncherLargeIconDensity();
+
+        Bitmap bitmap = null;
         try {
-            bitmap = Bitmap.createBitmap(iconSize, iconSize, Bitmap.Config.ARGB_8888);
-            Canvas canvas = new Canvas(bitmap);
-            drawWidgetBackgroundToCanvas(context, canvas, iconDensity, url,
-                    Color.rgb(rValue, gValue, bValue));
-            canvas.setBitmap(null);
+            bitmap = Bitmap.createBitmap(outerSize, outerSize, Bitmap.Config.ARGB_8888);
         } catch (OutOfMemoryError e) {
             Log.w(TAG, "OutOfMemoryError while trying to draw bitmap on canvas.");
+            return null;
         }
+
+        Canvas canvas = new Canvas(bitmap);
+
+        // Draw the drop shadow.
+        int padding = (int) (GENERATED_ICON_PADDING_RATIO * outerSize);
+        Rect outerBounds = new Rect(0, 0, outerSize, outerSize);
+        Bitmap bookmarkWidgetBg =
+                getBitmapFromResourceId(context, R.mipmap.bookmark_widget_bg, iconDensity);
+        Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG);
+        canvas.drawBitmap(bookmarkWidgetBg, null, outerBounds, paint);
+
+        // Draw the rounded rectangle and letter.
+        int innerSize = outerSize - 2 * padding;
+        int cornerRadius = Math.round(ICON_CORNER_RADIUS_RATIO * outerSize);
+        int fontSize = Math.round(GENERATED_ICON_FONT_SIZE_RATIO * outerSize);
+        int color = Color.rgb(red, green, blue);
+        RoundedIconGenerator generator = new RoundedIconGenerator(
+                innerSize, innerSize, cornerRadius, color, fontSize);
+        Bitmap icon = generator.generateIconForUrl(url);
+        if (icon == null) return null; // Bookmark URL does not have a domain.
+        canvas.drawBitmap(icon, padding, padding, null);
+
         return bitmap;
     }
 
@@ -411,58 +457,4 @@ public class ShortcutHelper {
         assert false : "The drawable was not a bitmap drawable as expected";
         return null;
     }
-
-    /**
-     * Use touch-icon or higher-resolution favicon and round the corners.
-     * @param context    Context used to get resources.
-     * @param touchIcon  Touch icon bitmap.
-     * @param canvas     Canvas that holds the touch icon.
-     */
-    private static void drawTouchIconToCanvas(Context context, Bitmap touchIcon, Canvas canvas) {
-        Rect iconBounds = new Rect(0, 0, canvas.getWidth(), canvas.getHeight());
-        Rect src = new Rect(0, 0, touchIcon.getWidth(), touchIcon.getHeight());
-        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
-        paint.setFilterBitmap(true);
-        canvas.drawBitmap(touchIcon, src, iconBounds, paint);
-        // Convert dp to px.
-        int borderRadii = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
-                TOUCHICON_BORDER_RADII_DP, context.getResources().getDisplayMetrics());
-        Path path = new Path();
-        path.setFillType(Path.FillType.INVERSE_WINDING);
-        RectF rect = new RectF(iconBounds);
-        rect.inset(INSET_DIMENSION_FOR_TOUCHICON, INSET_DIMENSION_FOR_TOUCHICON);
-        path.addRoundRect(rect, borderRadii, borderRadii, Path.Direction.CW);
-        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
-        canvas.drawPath(path, paint);
-    }
-
-    /**
-     * Draw document icon to canvas.
-     * @param context     Context used to get bitmap resources.
-     * @param canvas      Canvas that holds the document icon.
-     * @param iconDensity Density information to get bitmap resources.
-     * @param url         URL of the shortcut.
-     * @param color       Color for the document icon's folding and the bottom strip.
-     */
-    private static void drawWidgetBackgroundToCanvas(
-            Context context, Canvas canvas, int iconDensity, String url, int color) {
-        Rect iconBounds = new Rect(0, 0, canvas.getWidth(), canvas.getHeight());
-        Bitmap bookmarkWidgetBg =
-                getBitmapFromResourceId(context, R.mipmap.bookmark_widget_bg, iconDensity);
-
-        Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG);
-        canvas.drawBitmap(bookmarkWidgetBg, null, iconBounds, paint);
-
-        float density = (float) iconDensity / DisplayMetrics.DENSITY_MEDIUM;
-        int iconSize = (int) (GENERATED_ICON_SIZE_DP * density);
-        int iconRoundedEdge = (int) (GENERATED_ICON_ROUNDED_CORNERS_DP * density);
-        int iconFontSize = (int) (GENERATED_ICON_FONT_SIZE_DP * density);
-
-        RoundedIconGenerator generator = new RoundedIconGenerator(
-                iconSize, iconSize, iconRoundedEdge, color, iconFontSize);
-        Bitmap icon = generator.generateIconForUrl(url);
-        if (icon == null) return; // Bookmark URL does not have a domain.
-        canvas.drawBitmap(icon, iconBounds.exactCenterX() - icon.getWidth() / 2.0f,
-                iconBounds.exactCenterY() - icon.getHeight() / 2.0f, null);
-    }
 }