Window to Window comms - Parent to Parent

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  • Window to Window comms - Parent to Parent

    Dear all
    I wondered if you could help me solve this puzzle. Scenario is as follows: there are two unrelated windows (i.e. both windows are parents to different children), defined in two different source files.
    For example, I have a main window and a footer window, both visible. Then how do I communicate to the main window that the footer window wants to, for example, display something else on the main window?

    I know I can use WM_SendMessageNoPara(hWinMain, WM_FOOTER_BUTTON_BACK); in the footer callback. However that relies on having the main window handle (hWinMain) declared as global. Is there a way to communicate between the two parents without using globals? What's the best way?

    Thanks

    The post was edited 1 time, last by mjanas10 ().

  • Hi,

    Yes, it is possible without global variables. You can simply react on WM_GET_ID in the callback of a window and write a unique ID into pMsg->Data.v. This way you can use WM_GetDialogItem() to get the window handle via the ID.

    Attached is an example on how to do this.

    As long you know the IDS you could also get the handle of a child window of another window, like:

    C Source Code

    1. hItem = WM_GetDialogItem(WM_HBKWIN, ID_MAINWIN);
    2. hItem = WM_GetDialogItem(hItem, ID_CHILD);
    3. hItem = WM_GetDialogItem(hItem, ID_CHILD_OF_CHILD);
    4. hItem = WM_GetDialogItem(hItem, ID_CHILD_OF_CHILD_OF_CHILD);


    Regards
    Sven
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