Q71061: MenuBmp.exe Contains Owner-Draw Menus with Bitmaps

Article: Q71061
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s): 
Keyword(s): _IK kbfile kbsample kbMenu kbOSWin2000 kbGrpDSUser kbOSWin310 kbOSWin300
Last Modified: 09-JUL-2000

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1 
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SUMMARY
=======

When an application creates an owner-draw menu item with the MF_OWNERDRAW style,
the application receives a WM_MEASUREITEM message for that item. The application
is required to fill the MEASUREITEMSTRUCT pointed to by the lParam of this
message.

The itemWidth field of the MEASUREITEMSTRUCT is normally filled with the actual
width of the item. However, when Windows displays that menu item, the width is
increased by the width of a check mark; that is, Windows automatically expands
the item to leave space for a check mark.

To make the menu item only as wide as the actual item, fill the itemWidth field
with the width of the item, minus the width of a check mark, as returned by
GetMenuCheckMarkDimensions().

MenuBmp.exe is a sample that contains an example of owner-draw menus with bitmaps
where each item is only as large as the bitmap.

MORE INFORMATION
================

The following files are available for download from the Microsoft Download
Center:

  MenuBmp.exe

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

  Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
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The following code fragment demonstrates processing a WM_MEASUREITEM message that
results in a menu item only as wide as the actual item. In this case, the menu
is being made with bitmaps. The handle to the bitmap is stored as part of the
item data.

  // Local variables.
     LPMEASUREITEMSTRUCT     lpItem;
     HBITMAP                 hBitmap;
     BITMAP                  bm;
     WORD                    cxCheck;

     ...

     case WM_MEASUREITEM:
         // lParam is a pointer to the structure.
         lpItem = (LPMEASUREITEMSTRUCT)lParam;

         // A bitmap handle was stored in the item data.
         hBitmap = LOWORD(lpItem->itemData);

         /*
          * The width of a check mark is automatically added to
          * menu items so we need to subtract it to make the
          * menu the minimum size.
          */ 
         cxCheck = LOWORD(GetMenuCheckMarkDimensions());

         // Get the bitmap dimensions
         GetObject(hBitmap, sizeof(BITMAP), (LPVOID)&bm);

         // Set the width to the width of the bitmap - cxCheck
         lpItem->itemWidth = bm.bmWidth - cxCheck;

         // Add one to the bitmap height for some spacing.
         lpItem->itemHeight = bm.bmHeight + 1;

         break;

     ...

Additional query words:

======================================================================
Keywords          : _IK kbfile kbsample kbMenu kbOSWin2000 kbGrpDSUser kbOSWin310 kbOSWin300 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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