From d6296fa6fb95443ce59a3d8f35303be7366d7b00 Mon Sep 17 00:00:00 2001
From: cgspine <cgspine@gmail.com>
Date: Thu, 22 Nov 2018 14:52:44 +0800
Subject: [PATCH] bugfix: Swipe back will flash at the end. #443

---
 .../qmui/layout/QMUILayoutHelper.java         | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/qmui/src/main/java/com/qmuiteam/qmui/layout/QMUILayoutHelper.java b/qmui/src/main/java/com/qmuiteam/qmui/layout/QMUILayoutHelper.java
index f33f64aeb..728a3c275 100644
--- a/qmui/src/main/java/com/qmuiteam/qmui/layout/QMUILayoutHelper.java
+++ b/qmui/src/main/java/com/qmuiteam/qmui/layout/QMUILayoutHelper.java
@@ -80,7 +80,7 @@ public class QMUILayoutHelper implements IQMUILayout {
     // shadow
     private boolean mIsShowBorderOnlyBeforeL = true;
     private int mShadowElevation = 0;
-    private float mShadowAlpha = 0f;
+    private float mShadowAlpha;
     private int mShadowColor = Color.BLACK;
 
     // outline inset
@@ -280,15 +280,15 @@ public void setShadowAlpha(float shadowAlpha) {
 
     @Override
     public void setShadowColor(int shadowColor) {
-        if(mShadowColor == shadowColor){
+        if (mShadowColor == shadowColor) {
             return;
         }
         mShadowColor = shadowColor;
         setShadowColorInner(mShadowColor);
     }
 
-    private void setShadowColorInner(int shadowColor){
-        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.P){
+    private void setShadowColorInner(int shadowColor) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
             View owner = mOwner.get();
             if (owner == null) {
                 return;
@@ -358,7 +358,7 @@ public void setRadiusAndShadow(int radius, @IQMUILayout.HideRadiusSide int hideR
 
     @Override
     public void setRadiusAndShadow(int radius, int hideRadiusSide, int shadowElevation, int shadowColor, float shadowAlpha) {
-        View owner = mOwner.get();
+        final View owner = mOwner.get();
         if (owner == null) {
             return;
         }
@@ -424,7 +424,15 @@ public void getOutline(View view, Outline outline) {
                         right = Math.max(left + 1, right - view.getPaddingRight());
                         bottom = Math.max(top + 1, bottom - view.getPaddingBottom());
                     }
-                    outline.setAlpha(mShadowAlpha);
+
+                    float shadowAlpha = mShadowAlpha;
+                    if (mShadowElevation == 0) {
+                        // outline.setAlpha will work even if shadowElevation == 0
+                        shadowAlpha = 1f;
+                    }
+
+                    outline.setAlpha(shadowAlpha);
+
                     if (mRadius <= 0) {
                         outline.setRect(left, top,
                                 right, bottom);
@@ -434,7 +442,6 @@ public void getOutline(View view, Outline outline) {
                     }
                 }
             });
-
             owner.setClipToOutline(mRadius > 0);
 
         }