ConvWndPos is the conversion window position which is mapped to the Focus Window or the Frame Window coordinate upon usDispMode.

When IM_CNV_FOCUS_COORD is set in usDispMode, ConvWndPos and ConvWndBegin are mapped to the Focus Window coordinate. If IM_CNV_WND_NULL is specified, applicaitons put NULL in ConvWndPos. When IM_CNV_WND_FOCUS or IM_CNV_WND_FRAME is set, an application fills the Focus and the Frame Window coordinates respectively. When IM_CNV_WND_XFCS_YFRM is set, an application fills the Focus Window - X coordinate and the Frame Window - Y coordinate.

ConvWndBegin specifies a starting point in the conversion window from where the IM displays the intermediate string. In most cases, it is same as the cursor position obtained in pCursorPos with the WM_QUERYCONVERTPOS message.

Note: The application must set IM_CNV_MSG_FROMAPPL in usDispMode. Once the applications send this message, the GTR stops to send IM_CONVPOSITION periodically for the Frame window.