Pop Up Menus
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Sometimes, it's nice to be able to activate a menu anywhere in the screen.
For example, the user may click on a gadget, intending to change some
parameter of it. A menu pops up right then and there and, since the mouse is
positioned over it, the user can quickly select the desired option.
Pop Up Menus are very easy to use, especially if you are familiar with
working with Intuition style Drop Down menus.
The only differences with Intuition style menus are:
* Only one Menu is accessed, and its title is not displayed. There is no
need for a title bar since the users knows which menu is selected
because they selected a specific menu by clicking on a particular
gadget or icon. However, submenus are supported.
* The user holds down on the left mouse button rather than the right.
* Only one item can be selected, since only one button is used.
As with Intuition Menus, you create your menu with Menu and MenuItem
structures. See the Intuition programming guide for more on how to do that.
When you wish to open a Pop Up Menu, call PopUpMenu and pass it pointers to
your Window and Menu structure. After it has put up the menu and the user
has selected one or none of the items, it will return a selection code,
which you can decipher with the Intuition ITEMNUM and SUBNUM macros. Note
that there is no point in deciphering MENUNUM because there is only one
Menu.
If a gadget is used to select your menu, make sure its highlight rendering
is set to GADGHNONE. Otherwise, it will change as the mouse pointer moves
over the menu, and when the menu is released, the section under the menu
will not have changed, leaving an unsightly blemish. The loss of GADGHCOMP
and GADGHBOX rendering is really no loss since you are now displaying the
selection of your gadget with a Pop Up Menu.