将Snackbar置于最高z顺序,以避免被AutoCompleteTextView下拉阻止

Question

我有一个Snackbar如下:

但是,如果下拉的AutoCompleteTextView时间过长,则下拉将阻止Snackbar.

正如您在上图中看到的那样,Snackbar实际上正在显示.然而,长期下降阻碍了它的可见性.您可以从上面的图像中看到

我尝试使用以下内容Snackbar code.添加bringToFront()没有多大帮助.

private void showSnackbar(String message) {
    Snackbar snackbar
            = Snackbar.make(getActivity().findViewById(R.id.content), message, Snackbar.LENGTH_LONG);
    snackbar.getView().bringToFront();
    snackbar.show();
}

R.id.content是一个CoordinatorLayout:

    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/content"
        android:background="?attr/MyActivityBackground"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:foreground="?attr/headerShadow" />

有没有什么好办法可以避免Snackbar被AutoCompleteTextView摔倒？

Answer 1

对于那种情况,我可能有一个解决方案.当然,有一些假设,但也许解决方案适合你.

这里的关键是放入AutoCompleteTextView内部CoordinatorLayout并CoordinatorLayout.Behavior为其添加自定义.

1. 适合Behavior您的班级:

   public class AutoCompleteTextViewBehaviour extends CoordinatorLayout.Behavior<AutoCompleteTextView> {
   
       public AutoCompleteTextViewBehaviour(Context context, AttributeSet attrs) {
           super(context, attrs);
       }
   
       @Override
       public boolean layoutDependsOn(CoordinatorLayout parent, AutoCompleteTextView child, View dependency) {
           return dependency instanceof Snackbar.SnackbarLayout;
       }
   }
   

2. 覆盖方法layoutDependsOn:

   @Override
   public boolean layoutDependsOn(CoordinatorLayout parent, AutoCompleteTextView child, View dependency) {
       return dependency instanceof Snackbar.SnackbarLayout;
   }
   

3. 获取对AutoCompleteTextView弹出视图的引用:

   不幸的是,我还没有找到一个简单的解决方案.但是可以通过反射来完成.

   @Nullable
   private View getPopupList(AutoCompleteTextView child) {
       try {
           Field popupField;
           Class clazz;
           if (child instanceof AppCompatAutoCompleteTextView) {
               clazz = child.getClass().getSuperclass();
           } else {
               clazz = child.getClass();
           }
           popupField = clazz.getDeclaredField("mPopup");
           popupField.setAccessible(true);
           ListPopupWindow popup = (ListPopupWindow) popupField.get(child);
           Field popupListViewField = popup.getClass().getDeclaredField("mDropDownList");
           popupListViewField.setAccessible(true);
           return (View) popupListViewField.get(popup);
       } catch (NoSuchFieldException e) {
           e.printStackTrace();
       } catch (IllegalAccessException e) {
           e.printStackTrace();
       }
       return null;
   }
   

4. 覆盖onDependentViewChanged方法:

   @Override
   public boolean onDependentViewChanged(CoordinatorLayout parent, final AutoCompleteTextView child, View dependency) {
       if (popupList == null) {
           popupList = getPopupList(child);
           if (popupList == null) {
               return super.onDependentViewChanged(parent, child, dependency);
           }
       }
       int dropdownBottom = child.getBottom() + child.getDropDownVerticalOffset() + popupList.getHeight();
       int snackBarTop = dependency.getTop();
       int difference = dropdownBottom - snackBarTop;
       if (difference > 0) {
           child.setDropDownHeight(popupList.getHeight() - difference);
           return true;
       } else {
           child.setDropDownHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
       }
       return super.onDependentViewChanged(parent, child, dependency);
   }
   

5. 应用行为AutocompleteTextView中.xml:

   app:layout_behavior="com.example.package.AutoCompleteTextViewBehaviour"/>
   

当然这是一个非常基本的解决方案,例如没有动画列表高度,但我认为这是一个好的开始.这是完整的要点.

Answer 2

您可以计算并调整弹出窗口的高度作为替代.在下图中,我将下拉高度设置为:

textView.viewTreeObserver.addOnGlobalLayoutListener {
  textView.dropDownHeight = snackbarView.top - textView.bottom
}

此计算适用于建议列表的高度足够长的情况.您可能希望将该属性设置为WRAP_CONTENT.

据我所知,除非你直接添加SnackBar,否则无法更改"z-order" WindowManager.AutoCompleteTextView内部ListPopupWindow用于显示建议弹出ListPopupWindow窗口并且窗口类型为WindowManager.LayoutParams.TYPE_APPLICATION_PANEL= 1000,高于活动窗口类型WindowManager.LayoutParams.TYPE_APPLICATION= 2.