Restore the layout when onStart(), ensuring that View will not be added repeatedly when PIP mode is turned on

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

@@ -474,6 +474,15 @@ public void attachToActivity(Activity activity) {
         decor.addView(this);
     }
 
+    public void detachFromActivity(Activity activity) {
+        ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
+        decorView.removeView(this);
+        View decorChild = getChildAt(0);
+        removeView(decorChild);
+        decorView.addView(decorChild,0);
+        setContentView(decorChild);
+    }
+
     @Override
     public void computeScroll() {
         mScrimOpacity = 1 - mScrollPercent;

library/src/main/java/me/imid/swipebacklayout/lib/app/SwipeBackActivity.java

@@ -2,7 +2,6 @@
 package me.imid.swipebacklayout.lib.app;
 
 import android.os.Bundle;
-import android.support.v4.app.FragmentActivity;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 
@@ -22,10 +21,19 @@ protected void onCreate(Bundle savedInstanceState) {
     @Override
     protected void onPostCreate(Bundle savedInstanceState) {
         super.onPostCreate(savedInstanceState);
-        mHelper.onPostCreate();
     }
 
-    @Override
+    @Override protected void onStart() {
+      super.onStart();
+      mHelper.onPostCreate();
+    }
+
+    @Override protected void onStop() {
+      super.onStop();
+      mHelper.onStop();
+    }
+
+  @Override
     public View findViewById(int id) {
         View v = super.findViewById(id);
         if (v == null && mHelper != null)

library/src/main/java/me/imid/swipebacklayout/lib/app/SwipeBackActivityHelper.java

@@ -33,6 +33,10 @@ public void onPostCreate() {
         mSwipeBackLayout.attachToActivity(mActivity);
     }
 
+    public void onStop() {
+        mSwipeBackLayout.detachFromActivity(mActivity);
+    }
+
     public View findViewById(int id) {
         if (mSwipeBackLayout != null) {
             return mSwipeBackLayout.findViewById(id);