Shadow fade out

Author: Issac

library/src/main/java/me/imid/swipebacklayout/lib/SwipeBackLayout.java

@@ -25,6 +25,8 @@ public class SwipeBackLayout extends FrameLayout {
 
     private static final int DEFAULT_SCRIM_COLOR = 0x99000000;
 
+    private static final int FULL_ALPHA = 255;
+
     /**
      * Edge flag indicating that the left edge should be affected.
      */
@@ -397,11 +399,11 @@ public void requestLayout() {
     @Override
     protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
         final boolean drawContent = child == mContentView;
-        drawShadow(canvas, child);
 
         boolean ret = super.drawChild(canvas, child, drawingTime);
         if (mScrimOpacity > 0 && drawContent
                 && mDragHelper.getViewDragState() != ViewDragHelper.STATE_IDLE) {
+            drawShadow(canvas, child);
             drawScrim(canvas, child);
         }
         return ret;
@@ -429,18 +431,21 @@ private void drawShadow(Canvas canvas, View child) {
         if ((mEdgeFlag & EDGE_LEFT) != 0) {
             mShadowLeft.setBounds(childRect.left - mShadowLeft.getIntrinsicWidth(), childRect.top,
                     childRect.left, childRect.bottom);
+            mShadowLeft.setAlpha((int) (mScrimOpacity * FULL_ALPHA));
             mShadowLeft.draw(canvas);
         }
 
         if ((mEdgeFlag & EDGE_RIGHT) != 0) {
             mShadowRight.setBounds(childRect.right, childRect.top,
                     childRect.right + mShadowRight.getIntrinsicWidth(), childRect.bottom);
+            mShadowRight.setAlpha((int) (mScrimOpacity * FULL_ALPHA));
             mShadowRight.draw(canvas);
         }
 
         if ((mEdgeFlag & EDGE_BOTTOM) != 0) {
             mShadowBottom.setBounds(childRect.left, childRect.bottom, childRect.right,
                     childRect.bottom + mShadowBottom.getIntrinsicHeight());
+            mShadowBottom.setAlpha((int) (mScrimOpacity * FULL_ALPHA));
             mShadowBottom.draw(canvas);
         }
     }