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.
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.
select and
unSelect are called when the specified item is selected or deselected.
Version 6.0
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