Package io.flutter.util

Class ViewUtils

java.lang.Object
io.flutter.util.ViewUtils
public final class ViewUtils extends Object

  • Constructor Details

    • ViewUtils

      public ViewUtils()

  • Method Details

    • calculateMaximumDisplayMetrics

      public static void calculateMaximumDisplayMetrics(@Nullable Context context, @NonNull ViewUtils.DisplayUpdater updater)
      Calculates the maximum display metrics for the given context, and pushes the metric data to the updater.

    • getActivity

      @Nullable public static Activity getActivity(@Nullable Context context)
      Retrieves the Activity from a given Context.

      This method will recursively traverse up the context chain if it is a ContextWrapper until it finds the first instance of the base context that is an Activity.

    • generateViewId

      public static int generateViewId(int fallbackId)
      Generates a view id.

      In API level 17 and above, this ID is unique. Below 17, the fallback id is used instead.

      Parameters:
      fallbackId - the fallback id.
      Returns:
      the view id.

    • childHasFocus

      public static boolean childHasFocus(@Nullable View root)
      Determines if the current view or any descendant view has focus.
      Parameters:
      root - The root view.
      Returns:
      True if the current view or any descendant view has focus.

    • hasChildViewOfType

      public static boolean hasChildViewOfType(@Nullable View root, Class<? extends View>[] viewTypes)
      Returns true if the root or any child view is an instance of the given types.
      Parameters:
      root - The root view.
      viewTypes - The types of views.
      Returns:
      true if any child view is an instance of any of the given types.

    • traverseHierarchy

      public static boolean traverseHierarchy(@Nullable View root, @NonNull ViewUtils.ViewVisitor visitor)
      Traverses the view hierarchy in pre-order and runs the visitor for each child view including the root view.

      If the visitor returns true, the traversal stops, and the method returns true.

      If the visitor returns false, the traversal continues until all views are visited.

      Parameters:
      root - The root view.
      visitor - The visitor.
      Returns:
      true if the visitor returned true for a given view.