Minimized, Maximized, and Restored Windows

A maximized window is a window that has the WS_MAXIMIZE style. By default, Windows enlarges a maximized window so that it fills the screen or, in the case of a child window, the parent window's client area. Although a window's size can be set to the same size of a maximized window, a maximized window is slightly different. Windows automatically moves the window's title bar to the top of the screen or to the top of the parent window's client area. Also, Windows disables the window's sizing border and the window-positioning capability of the title bar (so that the user cannot move the window by dragging the title bar).

A minimized window is a window that has the WS_MINIMIZE style. By default, Windows reduces a minimized window to the size of its taskbar button and moves the minimized window to the taskbar. A restored window is a window that has been returned to its preminimized or premaximized size and position.

If an application specifies the WS_MAXIMIZE or WS_MINIMIZE style in the CreateWindowEx function, the window is initially maximized or minimized. After creating a window, an application can use the CloseWindow function to minimize the window. The ArrangeIconicWindows function arranges the icons on the desktop, or it arranges a parent window's minimized child windows in the parent window. The OpenIcon function restores a minimized window to its previous size and position.

The ShowWindow function can minimize, maximize, or restore a window. It can also set the window's visibility and activation states. The SetWindowPlacement function includes the same functionality as ShowWindow, but it can override the window's default minimized, maximized, and restored positions.

The IsZoomed and IsIconic functions determine whether a given window is maximized or minimized, respectively. The GetWindowPlacement function retrieves the minimized, maximized, and restored positions for the window, and also determines the window's show state.

When Windows receives a command to maximize or restore a minimized window, Windows sends the window a WM_QUERYOPEN message. If the window procedure returns FALSE, Windows ignores the Maximize or Restore command.

Windows automatically sets the size and position of a maximized window to the system-defined defaults for a maximized window. To override these defaults, an application can either call the SetWindowPlacement function or process the WM_GETMINMAXINFO message that is received by a window when Windows is about to maximize the window. WM_GETMINMAXINFO includes a pointer to a MINMAXINFO structure containing values Windows uses to set the maximized size and position. Replacing these values overrides the defaults.