Question

I have added minimize & restore cases to my even processing, but I found out they are never hit.

Only on startup of the program does Size_Minimized get hit. Afterwards, minimize case never happens.
The Size_Restore case never happens either.

Debug stopping at Size_Minimize only on startup of program:

My other cases work, so I have no idea why minimize & restore dont trigger my code or break points.
I conclude that Size_Minimized & Size_Restore are not related to what I need.

What is it I need to know to handle minimize/restore?

Code, in case I did it wrong:

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam){
    PAINTSTRUCT ps;
    HDC hdc;



    switch(message){
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);
        EndPaint(hWnd, &ps);
        break;

    case SIZE_MINIMIZED:
        break;

    case SIZE_RESTORED:
        break;

    case WM_SIZING:
    case WM_SIZE:
        if(engine.isReady()) engine.resizeDevice();
        if(engine.isReady()) engine.draw();
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }

    return 0;
}

Answer 1

SIZE_MINIMIZED and SIZE_RESTORED are constants passed to you through the WM_SIZE message; they are not window messages. Your breakpoint is getting hit whenever your window receives a window message with the same id as SIZE_MINIMIZED and/or SIZE_RESTORED.

You would need to have your code look something like this:

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam){
    PAINTSTRUCT ps;
    HDC hdc;
    switch(message){
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);
        EndPaint(hWnd, &ps);
        break;


    case WM_SIZE:
        switch(wParam) {
        case SIZE_MINIMIZED:
          // Do whatever
          break;
        case SIZE_RESTORED:
          // Do whatever
          break;
        }
    case WM_SIZING:
        if(engine.isReady()) engine.resizeDevice();
        if(engine.isReady()) engine.draw();
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }

    return 0;
}