Identify display orientation (flipped or not) in Win32 app

Question

Hello,

In Win32 app, I want to capture event when display orientation is changed. below is the sample code snippet to get an idea:

LRESULT CALLBACK WindowProc(HWND hWnd, UINT messageCode, WPARAM wParam, LPARAM lParam)
{
    switch (messageCode)
    {

    case WM_DISPLAYCHANGE: {
        // Handle display orientation change
        int width = LOWORD(lParam);
        int height = HIWORD(lParam);

        if (width > height) {
            // ORIENTATION_LANDSCAPE
        }
        else {
            // ORIENTATION_PORTRAIT
        }

        break;
    }

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

    return 0;
}

Using this way, I'm able to identify whether new orientation is landscape or portrait. That is fine and working.

I wanted to know if there is any way to find out that current display orientation is 'landscape' or 'landscape_flipped'?

Similar for 'portrait' and 'portrait_flipped'.

Thanks.

Answer 1

See the dmDisplayOrientation member of the DEVMODE structure. You can use EnumDisplaySettings to get the structure.

Answer 2

Refer to the following -

Using the Display­Information class from a desktop Win32 application, part 1

Using the Display­Information class from a desktop Win32 application, part 2

Answer 3

Following worked for me.

DEVMODEW dm;

// Initialize the DEVMODE structure
ZeroMemory(&dm, sizeof(dm));
dm.dmSize = sizeof(dm);

// Retrieve display settings
if (EnumDisplaySettingsExW(NULL, ENUM_CURRENT_SETTINGS, &dm, 0)) {

    // Check the display orientation
    if (dm.dmDisplayOrientation == DMDO_DEFAULT) {
        printf("Display Orientation: Default\n");
    }
    else if (dm.dmDisplayOrientation == DMDO_90) {
        printf("Display Orientation: 90 degrees\n");
    }
    else if (dm.dmDisplayOrientation == DMDO_180) {
        printf("Display Orientation: 180 degrees\n");
    }
    else if (dm.dmDisplayOrientation == DMDO_270) {
        printf("Display Orientation: 270 degrees\n");
    }
}