Can someone please tell me why this application is not returning correctly from my sub-classed child EDIT control.
The code shown is the bare minimum to demonstrate my problem. The code I am working on has multiple child windows.
My aim in the eventual application is to set conditions in a child EDIT window procedure, then to call a function to re-size multiple child windows.
My aim in the test application is for the child window to re-size when the mouse is clicked in the child window. The re-size only occurs when the mouse is then clicked in the parent window.
The code includes both old and new sub-class methods. These can be switched from one to the other by making changes in four places within the code. The code compiles successfully with both methods and gives the same result with both methods.
I know the application is not returning correctly from the EDIT window because I have found that a symptom of this is the LPCTSTR entry "hwnd_2" not displaying in the EDIT window. Turning sub-classing off by commenting out the calls to the Old_Subclass_hwnd_2 and New_Subclass_hwnd_2 functions will result in "hwnd_2" being displayed.
I am very new to C source code and have only just begun using the Pelles IDE. I obviously do not have the sub-class code correct.
Help would be appreciated please.
#include <windows.h>
#include <commctrl.h>
WNDPROC hwnd_2_RtnProc; //Global - Used for old and new sub-classing methods
ULONG_PTR ul_ptr; //Global - Used for the new sub-classing method
int hwnd_2_width = 0; //Global - Used to change the size of hwnd_2
int hwnd_2_height = 0; //Global - Used to change the size of hwnd_2
#define IDC_HWND_2 152
//=============================================================
//Old Subclass procedure CALLBACK
//LRESULT CALLBACK hwnd_2_SubProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
//New Subclass procedure CALLBACK
LRESULT CALLBACK hwnd_2_SubProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (msg)
{
case WM_LBUTTONUP:
MessageBox(hwnd, "WM_LBUTTONUP", "hwnd_2_SubProc",
MB_OK | MB_ICONINFORMATION);
hwnd_2_width = 100;
hwnd_2_height = 100;
HWND hwnd_2;
hwnd_2 = GetDlgItem(hwnd, IDC_HWND_2);//Not required for the old subclass method
//Old Subclass return
//return CallWindowProc(hwnd_2_RtnProc, hwnd_2, msg, wParam, lParam);
//New Subclass return
return DefSubclassProc(hwnd_2, msg, wParam, lParam);
break;
case WM_SIZE:
{
//Old Subclass return
//return CallWindowProc(hwnd_2_RtnProc, hwnd_2, msg, wParam, lParam);
//New Subclass return
return DefSubclassProc(hwnd_2, msg, wParam, lParam);
}
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
//=============================================================
void Old_Subclass_hwnd_2(HWND hwnd)
{
HWND hwnd_2;
hwnd_2 = GetDlgItem(hwnd, IDC_HWND_2);
hwnd_2_RtnProc = (WNDPROC)GetWindowLong(hwnd_2, GWLP_WNDPROC);//get the default procedure
SetWindowLong(hwnd_2, GWLP_WNDPROC, (LONG)hwnd_2_SubProc);//set the custom procedure
}
//=============================================================
void New_Subclass_hwnd_2(HWND hwnd)
{
HWND hwnd_2;
hwnd_2 = GetDlgItem(hwnd, IDC_HWND_2);
SetWindowSubclass(hwnd_2, &hwnd_2_SubProc, 1, (DWORD_PTR)ul_ptr); //Note the first parameter is the window being sub-classed
}
//=============================================================
//Step 7: The main Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CREATE:
{
HWND hwnd_2;
hwnd_2 = CreateWindowEx(
WS_EX_CLIENTEDGE,
"EDIT",
"hwnd_2",
WS_CHILD | WS_VISIBLE | WS_SIZEBOX | ES_MULTILINE,
0, 0, 300, 300,
hwnd,
(HMENU)IDC_HWND_2,
GetModuleHandle(NULL),
NULL);
if(hwnd_2 == NULL)
MessageBox(NULL, "hwnd_2 Creation Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
//Old Subclass hwnd_2
//Old_Subclass_hwnd_2(hwnd);
//New Subclass hwnd_2
New_Subclass_hwnd_2(hwnd);
}
break;
case WM_LBUTTONUP:
MessageBox(hwnd, "WM_LBUTTONUP", "WndProc",
MB_OK | MB_ICONINFORMATION);
HWND hwnd_2;
hwnd_2 = GetDlgItem(hwnd, IDC_HWND_2);
SetWindowPos(hwnd_2, NULL, 0, 0, hwnd_2_width, hwnd_2_height, SWP_NOZORDER);
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_SIZE:
{
}
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
//=============================================================
//Step 1: The application entry (winmain)
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
// Step 2: Create the main window class
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = "WindowClass_Main";
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
// Step 3: Register the class and check for registration
if(!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
// Step 4: Create the main Window
hwnd = CreateWindowEx(
WS_EX_CLIENTEDGE,
"WindowClass_Main",
"Test application",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT, 500, 400,
NULL, NULL, hInstance, NULL);
//Step 4: Check that the main window was created
if(hwnd == NULL)
{
MessageBox(NULL, "Window Creation Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
return 0;
}
// Step 5: Show the main window
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// Step 6: The Message Loop
while(GetMessage(&Msg, NULL, 0, 0) > 0)
{
TranslateMessage(&Msg);
DispatchMessage(&Msg);
}
return Msg.wParam;
}
