Child window inside child window

I'm having problems using child windows inside child windows. Thre creation works, but the window doesn't respond to any interaction. What I'm trying to do is a main window which has several child windows (like files, kinda) which have 1 text edit child window each. If I create the text edit as a normal window, or as a child to the main window it works fine, but when I create it as a child to a child window it doesn't work at all. Is this not even possible to do?

Code:

---

//Sets the text window styles
        Style = WS_BORDER | WS_CAPTION | WS_SIZEBOX | WS_SYSMENU | WS_VISIBLE;
        Style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
        Style |= WS_CHILD | WS_CLIPSIBLINGS;

        //Sets the starting location
        StartWidth = 300;
        StartHeight = 200;
        StartX = 10;
        StartY = 10;

        //Creates the text window
        TempWindow = CreateWindowEx(0, TextWindowClassName, "Unnamed", Style,
                                                                StartX, StartY, StartWidth, StartHeight,
                                                                MainWindow, NULL, GetModuleHandle(NULL), NULL);

        //Aborts on creation failure
        if(TempWindow == NULL)
        {
                Magos::Error.SetMessage("Unable to create text window!");
                return FALSE;
        }

        //Sets the text edit styles
        Style = ES_MULTILINE | ES_WANTRETURN | ES_LEFT | WS_VISIBLE;
        Style |= WS_CHILD | WS_HSCROLL | WS_VSCROLL | ES_AUTOHSCROLL | ES_AUTOVSCROLL;

        //Creates the text edit
        TempTextWindow.TextEdit = CreateWindowEx(0, "EDIT", "Testing...", Style, 0, 0,
                                                                                        StartWidth, StartHeight, TempWindow,
                                                                                        reinterpret_cast<HMENU>(TextEditId),
                                                                                        GetModuleHandle(NULL), NULL);

---

Perhaps your TextEditId is causing a problem?

Quote:

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hMenu

[in] Handle to a menu, or specifies a child-window identifier, depending on the window style. For an overlapped or pop-up window, hMenu identifies the menu to be used with the window; it can be NULL if the class menu is to be used. For a child window, hMenu specifies the child-window identifier, an integer value used by a dialog box control to notify its parent about events. The application determines the child-window identifier; it must be unique for all child windows with the same parent window.

---

[EDIT]
but you didn't say you have multiple edit's with the same parent....
I'm not aware of any "child-of-a-child" limitation on an edit control.
[/EDIT]

gg

Is DefWindowProc() being bypassed somewhere?

gg

There is only 1 text edit per window, so it *shouldn't* be any problems. Even with 1 window it doesn't work, so I doubt that is the (primary) problem.

I'm returning DefWindowProc in all cases where I don't handle the message myself, and 0 when I do. I dunno what more info I can give. I could post the message handler if you want.

Or just write a very simple app that creates an edit box as a child-of-a-child so we can have something to run and see how it isn't behaving right.

gg

Even simple apps in winprog takes tons of code ^^. Anyway, here's a nerfed version of my app. The text edit inside the child window is non-responding.

Code:

---

#include <windows.h>

HWND MainWindow = NULL;
HWND ChildWindow = NULL;
HWND ChildChildWindow = NULL;

//+-----------------------------------------------------------------------------

LRESULT MainMessageHandler(HWND Window, UINT Message, WPARAM wParam, LPARAM lParam)
{
        switch(Message)
        {
                case WM_CLOSE:
                {
                        PostQuitMessage(0);
                        return 0;
                }

                case WM_DESTROY:
                {
                        return 0;
                }
        }
        return DefWindowProc(Window, Message, wParam, lParam);
}

//+-----------------------------------------------------------------------------

BOOL Setup()
{
        DWORD Style;
        WNDCLASSEX ClassInfo;

        ClassInfo.cbSize = sizeof(WNDCLASSEX);
        ClassInfo.style = CS_HREDRAW | CS_VREDRAW;
        ClassInfo.cbClsExtra = 0;
        ClassInfo.cbWndExtra = 0;
        ClassInfo.hInstance = GetModuleHandle(NULL);
        ClassInfo.hCursor = LoadCursor(NULL, IDC_ARROW);
        ClassInfo.hIconSm = NULL;
        ClassInfo.lpfnWndProc = reinterpret_cast<WNDPROC>(MainMessageHandler);
        ClassInfo.hIcon = LoadIcon(NULL, IDI_APPLICATION);
        ClassInfo.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_APPWORKSPACE + 1);
        ClassInfo.lpszMenuName = NULL;
        ClassInfo.lpszClassName = "MainClass";

        if(!RegisterClassEx(&ClassInfo)) return FALSE;

        //+---------------------------------------------

        Style = WS_BORDER | WS_CAPTION | WS_SIZEBOX | WS_SYSMENU | WS_VISIBLE;
        Style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
        Style |= WS_CLIPCHILDREN;

        MainWindow = CreateWindowEx(0, "MainClass", "Main Window", Style,
                                                                100, 100, 500, 400,
                                                                NULL, NULL, GetModuleHandle(NULL), NULL);

        if(MainWindow == NULL) return FALSE;

        //+---------------------------------------------

        Style = WS_BORDER | WS_CAPTION | WS_SIZEBOX | WS_SYSMENU | WS_VISIBLE;
        Style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
        Style |= WS_CHILD | WS_CLIPSIBLINGS;

        ChildWindow = CreateWindowEx(0, "MainClass", "Child Window", Style,
                                                                50, 50, 200, 200,
                                                                MainWindow, NULL, GetModuleHandle(NULL), NULL);

        if(ChildWindow == NULL) return FALSE;

        //+---------------------------------------------

        Style = ES_MULTILINE | ES_WANTRETURN | ES_LEFT | WS_VISIBLE;
        Style |= WS_CHILD | WS_HSCROLL | WS_VSCROLL | ES_AUTOHSCROLL | ES_AUTOVSCROLL;

        ChildChildWindow = CreateWindowEx(0, "EDIT", "Child Child Window", Style,
                                                                          0, 0, 192, 166,
                                                                          ChildWindow, reinterpret_cast<HMENU>(1337),
                                                                          GetModuleHandle(NULL), NULL);

        if(ChildChildWindow == NULL) return FALSE;

        return TRUE;
}

//+-----------------------------------------------------------------------------

VOID Shutdown()
{
        if(ChildChildWindow != NULL) DestroyWindow(ChildChildWindow);
        if(ChildWindow != NULL) DestroyWindow(ChildWindow);
        if(MainWindow != NULL) DestroyWindow(MainWindow);
}

//+-----------------------------------------------------------------------------

INT WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, INT)
{
        MSG Message;

        if(!Setup())
        {
                Shutdown();
                return 0;
        }

        while(GetMessage(&Message, NULL, 0, 0))
        {
                TranslateMessage(&Message);
                DispatchMessage(&Message);
        }

        Shutdown();
        return 0;
}

---

Remove the WS_CAPTION style from child window (the parent of the edit) control and you can access/use the edit control but obviously lose the other style capabilities.

By the look of your layout I think a multiple document interface may be a better approach...

But removing WS_CAPTION removes the window looks of it, making it a stiff but resizeable frame. Also, WHY does it not work with WS_CAPTION?

I'll take a look at MDI...

Ken is right.
You will need MDI to achieve what you want.
It looks like the problem is that the main window doesn't want to give up being active (notice that the child window is always grayed) and the main window never gives up keyboard focus so the edit control looks stagnant.

gg

You can use SetParent to achieve what you want.
Also, WndProc uses the CALLBACK calling convention and you do not need to cast it unless you have done something wrong.
Corrected sample:

Code:

---

#include <windows.h>

HWND MainWindow = NULL;
HWND ChildWindow = NULL;
HWND ChildChildWindow = NULL;

//+-----------------------------------------------------------------------------

LRESULT CALLBACK MainMessageHandler(HWND Window, UINT Message, WPARAM wParam, LPARAM lParam)
{
        switch(Message)
        {
                case WM_CLOSE:
                {
                        PostQuitMessage(0);
                        return 0;
                }

                case WM_DESTROY:
                {
                        return 0;
                }
        }
        return DefWindowProc(Window, Message, wParam, lParam);
}

//+-----------------------------------------------------------------------------

BOOL Setup()
{
        DWORD Style;
        WNDCLASSEX ClassInfo;

        ClassInfo.cbSize = sizeof(WNDCLASSEX);
        ClassInfo.style = CS_HREDRAW | CS_VREDRAW;
        ClassInfo.cbClsExtra = 0;
        ClassInfo.cbWndExtra = 0;
        ClassInfo.hInstance = GetModuleHandle(NULL);
        ClassInfo.hCursor = LoadCursor(NULL, IDC_ARROW);
        ClassInfo.hIconSm = NULL;
        ClassInfo.lpfnWndProc = MainMessageHandler;
        ClassInfo.hIcon = LoadIcon(NULL, IDI_APPLICATION);
        ClassInfo.hbrBackground = reinterpret_cast<HBRUSH>(COLOR_APPWORKSPACE + 1);
        ClassInfo.lpszMenuName = NULL;
        ClassInfo.lpszClassName = "MainClass";

        if(!RegisterClassEx(&ClassInfo)) return FALSE;

        //+---------------------------------------------

        Style = WS_BORDER | WS_CAPTION | WS_SIZEBOX | WS_SYSMENU | WS_VISIBLE;
        Style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
        Style |= WS_CLIPCHILDREN;

        MainWindow = CreateWindowEx(0, "MainClass", "Main Window", Style,
                                                                100, 100, 500, 400,
                                                                NULL, NULL, GetModuleHandle(NULL), NULL);

        if(MainWindow == NULL) return FALSE;

        //+---------------------------------------------

        Style = WS_BORDER | WS_CAPTION  | WS_SIZEBOX | WS_SYSMENU | 0;
        Style |= WS_MINIMIZEBOX | WS_MAXIMIZEBOX;
        Style |= 0 | WS_CLIPSIBLINGS | WS_SYSMENU;

        ChildWindow = CreateWindowEx(0, "MainClass", "Child Window", Style,
                                                                50, 50, 200, 200,
                                                                MainWindow, NULL, GetModuleHandle(NULL), NULL);
        SetParent(ChildWindow, MainWindow);
        ShowWindow(ChildWindow, SW_SHOW);


        if(ChildWindow == NULL) return FALSE;

        //+---------------------------------------------

        Style = ES_MULTILINE | ES_WANTRETURN | ES_LEFT | WS_VISIBLE;
        Style |= WS_CHILD | WS_HSCROLL | WS_VSCROLL | ES_AUTOHSCROLL | ES_AUTOVSCROLL;

        ChildChildWindow = CreateWindowEx(0, "EDIT", "Child Child Window", Style,
                                                                          0, 0, 192, 166,
                                                                          ChildWindow, reinterpret_cast<HMENU>(1337),
                                                                          GetModuleHandle(NULL), NULL);


        if(ChildChildWindow == NULL) return FALSE;

        return TRUE;
}

//+-----------------------------------------------------------------------------

VOID Shutdown()
{
        if(ChildChildWindow != NULL) DestroyWindow(ChildChildWindow);
        if(ChildWindow != NULL) DestroyWindow(ChildWindow);
        if(MainWindow != NULL) DestroyWindow(MainWindow);
}

//+-----------------------------------------------------------------------------

INT WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, INT)
{
        MSG Message;

        if(!Setup())
        {
                Shutdown();
                return 0;
        }

        while(GetMessage(&Message, NULL, 0, 0))
        {
                TranslateMessage(&Message);
                DispatchMessage(&Message);
        }

        Shutdown();
        return 0;
}

---

http://groups.google.com/groups?thre...defix.eunet.fi

Thank you very much. Apart from the text edit bug, that solved 2 other things I've had problems with too.

*leaps away singing*

EDIT: Correction. 3 (!) other things, namely child window overlaps, active child windows (they were always grayed) and a slight rendering problem (bottom right wasn't re-rendered).

It's amaizing how something like that can escape you for years......thanks MFC!

gg

On a related note, is it possible to have a child window non-grayed when you select the main window (so both the main and the child stays non-grayed)?

Just eat the WM_NCACTIVATE message when appropriate:

Code:

---

LRESULT CALLBACK MainMessageHandler(HWND Window, UINT Message, WPARAM wParam, LPARAM lParam)
{
        switch(Message)
        {
                case WM_CLOSE:
                {
                        PostQuitMessage(0);
                        return 0;
                }

                case WM_DESTROY:
                {
                        return 0;
                }

                case WM_NCACTIVATE:
                        if (Window == ChildWindow && wParam == FALSE) return TRUE;
        }
        return DefWindowProc(Window, Message, wParam, lParam);
}

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