Adding support for dynamically adding shadows to the icon

Change-Id: I94d98750aea1faef8879e25990aa5c41a4894708

4 files changed, 158 insertions, 3 deletions

diff --git a/src/com/android/launcher3/ShortcutInfo.java b/src/com/android/launcher3/ShortcutInfo.java
index b8f0ec9c4..a9f73c261 100644
--- a/src/com/android/launcher3/ShortcutInfo.java
+++ b/src/com/android/launcher3/ShortcutInfo.java
@@ -307,7 +307,7 @@ public class ShortcutInfo extends ItemInfo {
                 .getShortcutIconDrawable(shortcutInfo,
                         launcherAppState.getInvariantDeviceProfile().fillResIconDpi);
         Bitmap icon = unbadgedIcon == null ? null
-                : Utilities.createBadgedIconBitmap(unbadgedIcon, user, context);
+                : Utilities.createBadgedIconBitmapWithShadow(unbadgedIcon, user, context);
         setIcon(icon != null ? icon : launcherAppState.getIconCache().getDefaultIcon(user));
     }
 
diff --git a/src/com/android/launcher3/Utilities.java b/src/com/android/launcher3/Utilities.java
index cedbe74c7..7b1a16c5f 100644
--- a/src/com/android/launcher3/Utilities.java
+++ b/src/com/android/launcher3/Utilities.java
@@ -40,6 +40,7 @@ import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.PaintFlagsDrawFilter;
 import android.graphics.Rect;
+import android.graphics.RectF;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.PaintDrawable;
@@ -64,6 +65,7 @@ import android.widget.Toast;
 import com.android.launcher3.compat.UserHandleCompat;
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.config.ProviderConfig;
+import com.android.launcher3.graphics.ShadowGenerator;
 import com.android.launcher3.util.IconNormalizer;
 
 import java.io.ByteArrayOutputStream;
@@ -244,7 +246,7 @@ public final class Utilities {
     public static Bitmap createBadgedIconBitmap(
             Drawable icon, UserHandleCompat user, Context context) {
         float scale = FeatureFlags.LAUNCHER3_DISABLE_ICON_NORMALIZATION ?
-                1 : IconNormalizer.getInstance().getScale(icon);
+                1 : IconNormalizer.getInstance().getScale(icon, null);
         Bitmap bitmap = createIconBitmap(icon, context, scale);
         if (Utilities.ATLEAST_LOLLIPOP && user != null
                 && !UserHandleCompat.myUserHandle().equals(user)) {
@@ -262,6 +264,34 @@ public final class Utilities {
     }
 
     /**
+     * Same as {@link #createBadgedIconBitmap} but adds a shadow before badging the icon
+     */
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public static Bitmap createBadgedIconBitmapWithShadow(
+            Drawable icon, UserHandleCompat user, Context context) {
+        RectF iconBounds = new RectF();
+        float scale = FeatureFlags.LAUNCHER3_DISABLE_ICON_NORMALIZATION ?
+                1 : IconNormalizer.getInstance().getScale(icon, iconBounds);
+        scale = Math.min(scale, ShadowGenerator.getScaleForBounds(iconBounds));
+
+        Bitmap bitmap = createIconBitmap(icon, context, scale);
+        bitmap = ShadowGenerator.getInstance().recreateIcon(bitmap);
+        if (Utilities.ATLEAST_LOLLIPOP && user != null
+                && !UserHandleCompat.myUserHandle().equals(user)) {
+            BitmapDrawable drawable = new FixedSizeBitmapDrawable(bitmap);
+            Drawable badged = context.getPackageManager().getUserBadgedIcon(
+                    drawable, user.getUser());
+            if (badged instanceof BitmapDrawable) {
+                return ((BitmapDrawable) badged).getBitmap();
+            } else {
+                return createIconBitmap(badged, context);
+            }
+        } else {
+            return bitmap;
+        }
+    }
+
+    /**
      * Returns a bitmap suitable for the all apps view.
      */
     public static Bitmap createIconBitmap(Drawable icon, Context context) {
diff --git a/src/com/android/launcher3/graphics/ShadowGenerator.java b/src/com/android/launcher3/graphics/ShadowGenerator.java
new file mode 100644
index 000000000..2b24ec932
--- /dev/null
+++ b/src/com/android/launcher3/graphics/ShadowGenerator.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2016 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.launcher3.graphics;
+
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
+import android.graphics.BlurMaskFilter;
+import android.graphics.BlurMaskFilter.Blur;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.RectF;
+
+import com.android.launcher3.LauncherAppState;
+import com.android.launcher3.util.Preconditions;
+
+/**
+ * Utility class to add shadows to bitmaps.
+ */
+public class ShadowGenerator {
+
+    // Percent of actual icon size
+    private static final float HALF_DISTANCE = 0.5f;
+    private static final float BLUR_FACTOR = 0.5f/48;
+
+    // Percent of actual icon size
+    private static final float KEY_SHADOW_DISTANCE = 1f/48;
+    private static final int KEY_SHADOW_ALPHA = 61;
+
+    private static final int AMBIENT_SHADOW_ALPHA = 30;
+
+    private static final Object LOCK = new Object();
+    // Singleton object guarded by {@link #LOCK}
+    private static ShadowGenerator sShadowGenerator;
+
+    private final int mIconSize;
+
+    private final Canvas mCanvas;
+    private final Paint mBlurPaint;
+    private final Paint mDrawPaint;
+
+    private ShadowGenerator() {
+        mIconSize = LauncherAppState.getInstance().getInvariantDeviceProfile().iconBitmapSize;
+        mCanvas = new Canvas();
+        mBlurPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+        mBlurPaint.setMaskFilter(new BlurMaskFilter(mIconSize * BLUR_FACTOR, Blur.NORMAL));
+        mDrawPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+    }
+
+    public synchronized Bitmap recreateIcon(Bitmap icon) {
+        int[] offset = new int[2];
+        Bitmap shadow = icon.extractAlpha(mBlurPaint, offset);
+        Bitmap result = Bitmap.createBitmap(mIconSize, mIconSize, Config.ARGB_8888);
+        mCanvas.setBitmap(result);
+
+        // Draw ambient shadow
+        mDrawPaint.setAlpha(AMBIENT_SHADOW_ALPHA);
+        mCanvas.drawBitmap(shadow, offset[0], offset[1], mDrawPaint);
+
+        // Draw key shadow
+        mDrawPaint.setAlpha(KEY_SHADOW_ALPHA);
+        mCanvas.drawBitmap(shadow, offset[0], offset[1] + KEY_SHADOW_DISTANCE * mIconSize, mDrawPaint);
+
+        // Draw the icon
+        mDrawPaint.setAlpha(255);
+        mCanvas.drawBitmap(icon, 0, 0, mDrawPaint);
+
+        mCanvas.setBitmap(null);
+        return result;
+    }
+
+    public static ShadowGenerator getInstance() {
+        Preconditions.assertNonUiThread();
+        synchronized (LOCK) {
+            if (sShadowGenerator == null) {
+                sShadowGenerator = new ShadowGenerator();
+            }
+        }
+        return sShadowGenerator;
+    }
+
+    /**
+     * Returns the minimum amount by which an icon with {@param bounds} should be scaled
+     * so that the shadows do not get clipped.
+     */
+    public static float getScaleForBounds(RectF bounds) {
+        float scale = 1;
+
+        // For top, left & right, we need same space.
+        float minSide = Math.min(Math.min(bounds.left, bounds.right), bounds.top);
+        if (minSide < BLUR_FACTOR) {
+            scale = (HALF_DISTANCE - BLUR_FACTOR) / (HALF_DISTANCE - minSide);
+        }
+
+        float bottomSpace = BLUR_FACTOR + KEY_SHADOW_DISTANCE;
+        if (bounds.bottom < bottomSpace) {
+            scale = Math.min(scale, (HALF_DISTANCE - bottomSpace) / (HALF_DISTANCE - bounds.bottom));
+        }
+        return scale;
+    }
+}
diff --git a/src/com/android/launcher3/util/IconNormalizer.java b/src/com/android/launcher3/util/IconNormalizer.java
index 4087d7bcf..040a1b51a 100644
--- a/src/com/android/launcher3/util/IconNormalizer.java
+++ b/src/com/android/launcher3/util/IconNormalizer.java
@@ -19,6 +19,7 @@ package com.android.launcher3.util;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Color;
+import android.graphics.RectF;
 import android.graphics.drawable.Drawable;
 
 import com.android.launcher3.LauncherAppState;
@@ -74,8 +75,10 @@ public class IconNormalizer {
      *
      * This closeness is used to determine the ratio of hull area to the full icon size.
      * Refer {@link #MAX_CIRCLE_AREA_FACTOR} and {@link #MAX_SQUARE_AREA_FACTOR}
+     *
+     * @param outBounds optional rect to receive the fraction distance from each edge.
      */
-    public synchronized float getScale(Drawable d) {
+    public synchronized float getScale(Drawable d, RectF outBounds) {
         int width = d.getIntrinsicWidth();
         int height = d.getIntrinsicHeight();
         if (width <= 0 || height <= 0) {
@@ -168,6 +171,14 @@ public class IconNormalizer {
             scaleRequired = MAX_SQUARE_AREA_FACTOR + LINEAR_SCALE_SLOPE * (1  - hullByRect);
         }
 
+        if (outBounds != null) {
+            outBounds.left = ((float) leftX) / width;
+            outBounds.right = 1 - ((float) rightX) / width;
+
+            outBounds.top = ((float) topY) / height;
+            outBounds.bottom = 1 - ((float) bottomY) / height;
+        }
+
         float areaScale = area / (width * height);
         // Use sqrt of the final ratio as the images is scaled across both width and height.
         float scale = areaScale > scaleRequired ? (float) Math.sqrt(scaleRequired / areaScale) : 1;