Package icyllis.modernui.view

Class ActionProvider

java.lang.Object
icyllis.modernui.view.ActionProvider
public abstract class ActionProvider extends Object
An ActionProvider defines rich menu interaction in a single component. ActionProvider can generate action views for use in the action bar, dynamically populate submenus of a MenuItem, and handle default menu item invocations.

An ActionProvider can be optionally specified for a MenuItem and will be responsible for creating the action view that appears in the ActionBar in place of a simple button in the bar. When the menu item is presented in a way that does not allow custom action views, (e.g. in an overflow menu,) the ActionProvider can perform a default action.

There are two ways to use an action provider:

See Also:

  • Constructor Details

    • ActionProvider

      public ActionProvider()
      Creates a new instance. ActionProvider classes should always implement a constructor that takes a single Context parameter for inflating from menu XML.

  • Method Details

    • onCreateActionView

      public abstract View onCreateActionView(MenuItem menuItem)
      Factory method called by the Android framework to create new action views. This method returns a new action view for the given MenuItem.
      Parameters:
      menuItem - MenuItem to create the action view for
      Returns:
      the new action view

    • overridesItemVisibility

      public boolean overridesItemVisibility()
      The result of this method determines whether or not isVisible() will be used by the MenuItem this ActionProvider is bound to help determine its visibility.
      Returns:
      true if this ActionProvider overrides the visibility of the MenuItem it is bound to, false otherwise. The default implementation returns false.
      See Also:

    • isVisible

      public boolean isVisible()
      If overridesItemVisibility() returns true, the return value of this method will help determine the visibility of the MenuItem this ActionProvider is bound to.

      If the MenuItem's visibility is explicitly set to false by the application, the MenuItem will not be shown, even if this method returns true.

      Returns:
      true if the MenuItem this ActionProvider is bound to is visible, false if it is invisible. The default implementation returns true.

    • refreshVisibility

      public void refreshVisibility()
      If this ActionProvider is associated with an item in a menu, refresh the visibility of the item based on overridesItemVisibility() and isVisible(). If overridesItemVisibility() returns false, this call will have no effect.

    • onPerformDefaultAction

      public boolean onPerformDefaultAction()
      Performs an optional default action.

      For the case of an action provider placed in a menu item not shown as an action this method is invoked if previous callbacks for processing menu selection has handled the event.

      A menu item selection is processed in the following order:

      The default implementation does not perform any action and returns false.

    • hasSubMenu

      public boolean hasSubMenu()
      Determines if this ActionProvider has a submenu associated with it.

      Associated submenus will be shown when an action view is not. This provider instance will receive a call to onPrepareSubMenu(SubMenu) after the call to onPerformDefaultAction() and before a submenu is displayed to the user.

      Returns:
      true if the item backed by this provider should have an associated submenu

    • onPrepareSubMenu

      public void onPrepareSubMenu(SubMenu subMenu)
      Called to prepare an associated submenu for the menu item backed by this ActionProvider.

      if hasSubMenu() returns true, this method will be called when the menu item is selected to prepare the submenu for presentation to the user. Apps may use this to create or alter submenu content right before display.

      Parameters:
      subMenu - Submenu that will be displayed

    • subUiVisibilityChanged

      public void subUiVisibilityChanged(boolean isVisible)
      Notify the system that the visibility of an action view's sub-UI such as an anchored popup has changed. This will affect how other system visibility notifications occur.

    • setSubUiVisibilityListener

      @Internal public void setSubUiVisibilityListener(ActionProvider.SubUiVisibilityListener listener)

    • setVisibilityListener

      public void setVisibilityListener(ActionProvider.VisibilityListener listener)
      Set a listener to be notified when this ActionProvider's overridden visibility changes. This should only be used by MenuItem implementations.
      Parameters:
      listener - listener to set

    • reset

      @Internal public void reset()