Using IlvAbstractMenu
The class IlvAbstractMenu, a subclass of IlvGadget, defines a common interface for menu bars, toolbars, and pop-up menus. IlvAbstractMenu also inherits from the class IlvListGadgetItemHolder, which handles lists of gadget items. IlvAbstractMenu handles a list of IlvMenuItem objects, a subclass of IlvGadgetItem.
Manipulating Menu Items
Member functions for manipulating menu items are defined in the class IlvListGadgetItemHolder.
Callbacks
When the user highlights a menu item, the Highlight callback is invoked. This callback allows actions to take place according to the user selection. For example, the Highlight callback can be used to display a small help message when the user highlights an item in a pop-up menu.
You can set a Highlight callback with the symbol returned by the member function IlvAbstractMenu::HighlightCBSymbol. Callbacks” in the chapter “Graphic Objects” of the Views Foundation User’s Manual
Here is an example of Highlight callback that simply writes the index of the highlighted item:
static void
Highlight(IlvGraphic* g, IlvAny any)
{
// Highlighted item position.
IlvShort pos = *(IlvShort*)any;
IlvAbstractMenu* menu = (IlvAbstractMenu*)g;
if (pos != -1)
IlvPrint("Item %d highlighted", pos);
else
IlvPrint("No item highlighted");
}
Note: Once it has been cast to IlvShort, the value of the any parameter is the position of the highlighted menu item, or -1 if no item is highlighted. |
Handling Events
The class IlvAbstractMenu includes the following virtual member functions that you can redefine in subclasses:
IlvAbstractMenu::isSelectable specifies whether a menu item can be selected.IlvAbstractMenu::selectNext and IlvAbstractMenu::selectPrevious return the next or previous selectable item when the user moves in the menu using the arrow keys. Published date: 05/24/2022
Last modified date: 02/24/2022
