Expose disabled color filter for drawable

Fix: 192333050
Test: Manual
Change-Id: I8ef548b934183f152d0df1c80998d85202fd0e8a
diff --git a/iconloaderlib/src/com/android/launcher3/icons/FastBitmapDrawable.java b/iconloaderlib/src/com/android/launcher3/icons/FastBitmapDrawable.java
index 96ee291..4aa2846 100644
--- a/iconloaderlib/src/com/android/launcher3/icons/FastBitmapDrawable.java
+++ b/iconloaderlib/src/com/android/launcher3/icons/FastBitmapDrawable.java
@@ -253,22 +253,7 @@
 
     private ColorFilter getDisabledColorFilter() {
         if (sDisabledFColorFilter == null) {
-            ColorMatrix tempBrightnessMatrix = new ColorMatrix();
-            ColorMatrix tempFilterMatrix = new ColorMatrix();
-
-            tempFilterMatrix.setSaturation(1f - DISABLED_DESATURATION);
-            float scale = 1 - DISABLED_BRIGHTNESS;
-            int brightnessI =   (int) (255 * DISABLED_BRIGHTNESS);
-            float[] mat = tempBrightnessMatrix.getArray();
-            mat[0] = scale;
-            mat[6] = scale;
-            mat[12] = scale;
-            mat[4] = brightnessI;
-            mat[9] = brightnessI;
-            mat[14] = brightnessI;
-            mat[18] = mDisabledAlpha;
-            tempFilterMatrix.preConcat(tempBrightnessMatrix);
-            sDisabledFColorFilter = new ColorMatrixColorFilter(tempFilterMatrix);
+            sDisabledFColorFilter = getDisabledFColorFilter(mDisabledAlpha);
         }
         return sDisabledFColorFilter;
     }
@@ -286,6 +271,25 @@
         return new FastBitmapConstantState(mBitmap, mIconColor, mIsDisabled);
     }
 
+    public static ColorFilter getDisabledFColorFilter(float disabledAlpha) {
+        ColorMatrix tempBrightnessMatrix = new ColorMatrix();
+        ColorMatrix tempFilterMatrix = new ColorMatrix();
+
+        tempFilterMatrix.setSaturation(1f - DISABLED_DESATURATION);
+        float scale = 1 - DISABLED_BRIGHTNESS;
+        int brightnessI =   (int) (255 * DISABLED_BRIGHTNESS);
+        float[] mat = tempBrightnessMatrix.getArray();
+        mat[0] = scale;
+        mat[6] = scale;
+        mat[12] = scale;
+        mat[4] = brightnessI;
+        mat[9] = brightnessI;
+        mat[14] = brightnessI;
+        mat[18] = disabledAlpha;
+        tempFilterMatrix.preConcat(tempBrightnessMatrix);
+        return new ColorMatrixColorFilter(tempBrightnessMatrix);
+    }
+
     protected static class FastBitmapConstantState extends ConstantState {
         protected final Bitmap mBitmap;
         protected final int mIconColor;