Event when Menu is Opened - Is a Menu Dropped?

CarlBarnes · April 13, 2021, 3:02am

The recent discussion of knowing when a Combo is dropped reminded me of the question of getting an Event before the Menus open so they can be modified based on the current state.

There are Windows Messages for this so SV could setup Modal Events like a LIST Tree has Event:Expanding and Event:Contracting.


WM_ENTERMENULOOP                EQUATE(0211h)   !1st message,once, wParm=1 if TrackPopupMenu i.e. POPUP() http://msdn.microsoft.com/en-us/library/ms647595(VS.85).aspx
                                                !   The WM_ENTERMENULOOP message informs an application's main window procedure that a menu modal loop has been entered. 

WM_INITMENU                     EQUATE(0116h)   !next,once, passes wParam as hMenu to menubar   http://msdn.microsoft.com/en-us/library/ms646344(VS.85).aspx
                                                !   The WM_INITMENU message is sent when a menu is about to become active. It occurs when the user clicks an item on the menu bar or presses a menu key. This allows the application to modify the menu before it is displayed. 

WM_INITMENUPOPUP                EQUATE(0117h)   !next,each, passed hSubMenu to menu activated   http://msdn.microsoft.com/en-us/library/ms646347(VS.85).aspx

WM_EXITMENULOOP                 EQUATE(0212h)   !last message,once

CarlBarnes · April 13, 2021, 3:10am

I posted an example program here:

gist.github.com

https://gist.github.com/CarlTBarnes/e2902bb0280fe25554aa67b2e9292c51

MenuOpenMessage.clw

!Often right when Menus are being opened you want to change the Menus
!based on the other variables and things.
!Simple example of SubClass Window to get a WM_INITMENU Message before Menus display
!This adds Time to an Item text to show it changing at time it opens
!It also adds Time when closed, you get a Message when window close also WM_EXITMENULOOP

    PROGRAM  
    INCLUDE 'TplEqu.CLW'
    INCLUDE 'KeyCodes.CLW'
    MAP

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MenuWinAPI_INC.clw

!Windows Menu API Functions

MENUITEMINFO        GROUP,TYPE      !http://msdn.microsoft.com/en-us/library/ms647578(VS.85).aspx
cbSize                UNSIGNED      !Size of structure, in bytes. Caller must = size(MENUITEMINFO)
fMask                 UNSIGNED      !Mask of Members to retrieve or set. MIIM_XXXX equates  MIIM_STATE MIIM_TYPE MIIM_FTYPE
fType                 UNSIGNED      !Menu item type MFT_XXXX some require fMask to be MIIM_FTYPE
fState                UNSIGNED      !Menu item state MFS_CHECKED MFS_DISABLED+MFS_GRAYED  MFS_ENABLED
wID                   UNSIGNED      !Application-defined 16-bit value that identifies the menu item. Set fMask to MIIM_ID to use wID.
hSubMenu              UNSIGNED      !Handle to the drop-down menu or submenu associated with the menu item. Null if not a SubMenu
hBmpChecked           UNSIGNED      !Handle to the bitmap to display next to the item if it is selected.

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When the menu is opened the current time is placed in the first menu item and a counter as proof the menu was updated right when opened.

  OF WM_INITMENU 
     ?Menu1Item1{PROP:Text}='Menu Opened ' & FORMAT(CLOCK(),@t4) |
                            &' - LT#'&  LongThread 
          LongThread + =1

The Sheet Menu is adjusted based on the currently selected tab:

 DISABLE(?SheeMenuTab1,?SheeMenuTab3)
 CASE ?SHEET1{PROP:ChoiceFEQ}
 OF ?Tab1 ; Enable(?SheeMenuTab1)
 OF ?Tab2 ; Enable(?SheeMenuTab2)
 OF ?Tab3 ; Enable(?SheeMenuTab3)
 END

The Sheet / Menu sync is just a simple example. I would code that in the Sheet’s Event:NewSelection.