Should be called once per frame.

Manages startup and sync (e.g. hiding/unhiding the frame as the game enters/exits fullscreen).

Returns whether the frame is currently being shown.

Turns the frame on/off.

Enables or disables fullscreen.

You must use this in place of regular window_set_fullscreen or you may land yourself or your project's users in an unusual situation involving a fullscreen window that is click-through and cannot be minimized.

Counterpart of above function.

Equivalent to built-in window_has_focus, but counts the frame too.

Returns X of either the frame (if visible) or the game window.

Returns Y of either the frame (if visible) or the game window.

Returns width of either the frame (if visible) or the game window.

Returns height of either the frame (if visible) or the game window.

Returns a 4-element array containing x/y/width/height of either the frame (if visible) or the game window.

Equivalent to window_set_rectangle.

Will move either the frame (if active) or the actual game window.

If the frame is resizable, this function allows to specify minimum user-defined size.

For example,

window_frame_set_min_size(224, 192);

If the frame is resizable, this function allows to specify maximum user-defined size.

For example,

window_frame_set_max_size(1600, 900);

If the frame is active, this moves and/or resizes the game window inside the frame.

From the sample project:

// resize the game to fit the container window if it's visible
// (if you don't do window resizing, you don't need this)
if (window_frame_get_visible()) {
    var w = window_frame_get_width();
    var h = window_frame_get_height();
    if (w > 0 && h > 0 && surface_exists(application_surface)
    && (window_get_width() != w || window_get_height() != h)
    ) {
        // resize room (since we don't use views):
        room_width = w; room_height = h;
        // resize the game inside the frame-window to fit it's size:
        window_frame_set_region(0, 0, w, h);
        // also resize application_surface:
        surface_resize(application_surface, w, h);
    }
}

Sets the background color shown on the portions of the frame window not occupied by your game. Can be set to -1 to not draw anything there.

window_frame_set_background(make_color_rgb(136, 158, 197));

Like window_set_caption, but for the frame.

This function does not seem to work correctly, but you might find yourself amused by Windows' indecisiveness in whether it wants to draw the window caption or not.

The button for un-maximizing the window.

Disabling this can be generally considered somewhat evil.

If disabled, the window cannot be resized.

If disabled, the window cannot be dragged around.

Enables or disables a command.
For example, for buttons this grays out the button.

Returns the new value or -1 if the command cannot be manipulated.

So

window_command_set_active(window_command_minimize, 0);

would disable the ability to minimize the window

Returns whether a command is currently enabled, or -1 if unknown.

Hooks the specified command, intercepting the action and allowing you to check for it using window_command_check. Only button-commands can be hooked.

Un-hooks the specified command, allowing it to be performed as usual.

Returns whether the given command's button was pressed since the last call to this function.

Runs the specified command, regardless of whether it is currently hooked.

This essentially invokes WM_SYSCOMMAND on the frame.

param, if specified, is a raw lParam value, while index is wParam.

So

window_command_run(window_command_minimize);

would minimize the window when invoked.