IMC_GETCOMPOSITIONWINDOW

An application sends the IMC_GETCOMPOSITIONWINDOW message to the IME window to get the position of the composition window. An IME may adjust the position of a composition window regarding some concerns. An application can get the real position of composition window to decide whether it wants to reposition it to another position.

If successful, the return value is zero. Otherwise, it is nonzero.

lParam

Address of a COMPOSITIONFORM structure that receives the position of the composition window.

The return value in the buffer is in the client coordinates of the focus window of an application. The UI window receives this message.