SAMPLE: ChildMnu.exe Implements a Child Window with Menus

ID: Q93199

The information in this article applies to:

SUMMARY

ChildMnu.exe demonstrates one way to embed a pop-up window with menus in a child window to simulate a child window with menus.Child windows by design do not have menus; however, some applications may require such child windows.

MORE INFORMATION

The following file is available for download from the Microsoft Software Library: 

 ~ ChildMnu.exe (size: 28690 bytes)
For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base: 

   ARTICLE-ID: Q119591
   TITLE     : How to Obtain Microsoft Support Files from
               Online Services
Child windows were not designed to have menus but under certain circumstances an application may require a child window with menus. Below are the steps to simulate a child window with menus:

1. Create the child for a main window using standard methods.

2. Create a pop-up window without a caption or border. The pop-up 

   window should take up the entire client area of the child window.
3. Moving: Set the child window as the parent of the pop-up window 
   using SetParent(). This method clips the pop-up window to the
   child's client and moves the pop-up window relative to the child
   window when the child moves.
4. Sizing: If the child window has sizing borders, then the pop-up 
   window must be adjusted as the child is sized.

   Correct sizing of the pop-up window can be accomplished by
   processing the child window's WM_SIZE message. When the child
   window receives a WM_SIZE message, the child's new client area is
   calculated and the pop-up window is adjusted.
5. Activation: Child windows are not activated by design. When the 
   user clicks the pop-up window, activation is taken away from the
   main window and is given to the pop-up window. To simulate the main
   window's activation, the pop-up's window procedure, upon receiving
   a WM_ACTIVATE message, posts a WM_NCACTIVATE message to the main
   window.

   Note: This step causes flashing because the caption is repainted
   when going back and forth between the pop-up window and the main
   window. Unfortunately, there is no sure way to accomplish the
   change of caption's activation.

Other Considerations

Maximizing: When a child window is maximized, it uses the screen's maximum size. To have the child window act similar to an MDI child, two messages need to be processed; WM_SIZE in the main parent's window procedure and WM_GETMINMAXINFO in the child's window procedure.

WM_SIZE of the child's parent window procedure checks for SIZE_MAXIMIZE and SIZE_RESTORE. Then, if the child window is maximized, call ShowWindow() with SW_MAXIMIZED. This method adjusts the child window's size to the new size of the parent's client area.

On WM_GETMINMAXINFO of the child's window procedure, calculate the size of the parent's client area. Use the newly calculated size and set the ptMaxSize variable of the MINMAXINFO structure. This ensures that the child is always fully contained within its parent client area when maximized.

Additional query words: Keywords : kbfile kbsample kb16bitonly kbMenu kbGrpUser kbWinOS310 kbWndw kbWndwProp

Last Reviewed: December 12, 1998