Update swipe-back Demo

Author: YoKeyword

demo/src/main/java/me/yokeyword/sample/flow/SwipeBackSampleActivity.java

@@ -26,6 +26,16 @@ protected void onCreate(Bundle savedInstanceState) {
         getSwipeBackLayout().setEdgeOrientation(SwipeBackLayout.EDGE_ALL);
     }
 
+    /**
+     * 限制SwipeBack的条件,默认栈内Fragment数 <= 1时 , 优先滑动退出Activity , 而不是Fragment
+     *
+     * @return true: Activity可以滑动退出, 并且总是优先;  false: Activity不允许滑动退出
+     */
+    @Override
+    public boolean swipeBackPriority() {
+        return super.swipeBackPriority();
+    }
+
     public FragmentAnimator onCreateFragmentAnimator() {
         return new DefaultHorizontalAnimator();
     }