Win32 API: How to catch escape key in Edit control? - c++

Question

I found that for some unknown reason when focus is in Edit control, the Escape key never produces a messages.
Below is a code to create a parent window, and Edit control above it. In MyCallBckProcedure() I laid printf() under a *WM_COMMAND*, to catch a messages, produced by Edit. More over -- I even tried to print all the messages catched in MyCallBckProcedure(); but if focus on Edit, the escape key never produces any of messages.
What a weird problem could be here?
#include <iostream>
#include <windows.h>
#include <stdio.h>
#define IDC_MAIN_EDIT 101
LRESULT __stdcall MyCallBckProcedure( HWND window, unsigned msg, WPARAM wp, LPARAM lp ){
printf("%x ",msg);
switch(msg){
case WM_COMMAND://here should be catched the escape key of Edit
printf("%x ",msg);
break;
case WM_KEYDOWN:
printf("%x ",msg);
if(wp == VK_ESCAPE)PostQuitMessage(0);
break;
case WM_DESTROY:
std::cout << "\ndestroying window\n" ;
PostQuitMessage(0);
return 0;
default:
return DefWindowProc( window, msg, wp, lp ) ;
break;
case WM_SIZE:{
HWND hEdit;
RECT rcClient;
GetClientRect(window, &rcClient);
hEdit = GetDlgItem(window, IDC_MAIN_EDIT);
SetWindowPos(hEdit, NULL, 0, 0, rcClient.right, rcClient.bottom, SWP_NOZORDER);
}
break;
}
}
int main(){
const char* const myclass = "myclass";
WNDCLASSEX wndclass = { sizeof(WNDCLASSEX), CS_DBLCLKS, MyCallBckProcedure,
0, 0, GetModuleHandle(0), LoadIcon(0,IDI_APPLICATION),
LoadCursor(0,IDC_ARROW), HBRUSH(COLOR_WINDOW+1),
0, myclass, LoadIcon(0,IDI_APPLICATION) };
if(RegisterClassEx(&wndclass)<0){
printf("ERR: in registering window class\n");
return 1;
}
//Creating window
HWND window = CreateWindowEx( 0, myclass, "title",
WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT, 0, 0, GetModuleHandle(0), 0 );
if(!window){
printf("ERR: in creating window\n");
return 1;
}
ShowWindow( window, SW_SHOWDEFAULT );
MSG msg;
//creating TextBox on the window
HFONT hfDefault;
HWND hEdit;
hEdit = CreateWindowEx(0, "edit", "",
WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL,
CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
window, (HMENU)IDC_MAIN_EDIT, GetModuleHandle(NULL), NULL);
if(hEdit == NULL){
MessageBox(window, "Could not create edit box.", "Error", MB_OK | MB_ICONERROR);
return 1;
}
hfDefault = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
SendMessage(hEdit, WM_SETFONT, (WPARAM)hfDefault, MAKELPARAM(FALSE, 0));
//Now resize TextBox to fill whole parent window
RECT RectSize;
GetClientRect(window,&RectSize);
hEdit = GetDlgItem(window,IDC_MAIN_EDIT);
SetWindowPos(hEdit, 0,0,0,RectSize.right,RectSize.bottom,SWP_NOZORDER);
//Process messages
while(GetMessage(&msg,0,0,0) ){
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}

Answer 1

Pressing ESC while the Edit is in focus does not generate a WM_COMMAND message to the Edit's parent window. It generates WM_KEYDOWN, WM_KEYUP, WM_CHAR and WM_UNICHAR messages to the Edit window itself.
Update: You are only handling messages that are destined for the parent window. You need to assign a message procedure to the edit window instead, eg:
WNDPROC lpEditWndProc;
LRESULT CALLBACK MyEditCallBckProcedure(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
if( (uMsg == WM_CHAR) && (wParam == VK_ESCAPE) )
{
PostQuitMessage(0);
return 0;
}
return CallWindowProc(lpEditWndProc, hWnd, uMsg, wParam, lParam);
}
...
HWND hEdit = CreateWindowEx(...);
#ifdef _WIN64
lpEditWndProc = (WNDPROC) SetWindowLongPtr(hEdit, GWLP_WNDPROC, (LONG_PTR)&MyEditCallBckProcedure);
#else
lpEditWndProc = (WNDPROC) SetWindowLongPtr(hEdit, GWL_WNDPROC, (LONG_PTR)&MyEditCallBckProcedure);
#endif
Alternatively:
LRESULT CALLBACK MyEditCallBckProcedure(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
if( (uMsg == WM_CHAR) && (wParam == VK_ESCAPE) )
{
PostQuitMessage(0);
return 0;
}
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
...
HWND hEdit = CreateWindowEx(...);
SetWindowSubclass(hEdit, &MyEditCallBckProcedure, 0, 0);