CalculatePopupWindowPosition function (winuser.h)

Article
10/13/2021

Calculates an appropriate pop-up window position using the specified anchor point, pop-up window size, flags, and the optional exclude rectangle. When the specified pop-up window size is smaller than the desktop window size, use the CalculatePopupWindowPosition function to ensure that the pop-up window is fully visible on the desktop window, regardless of the specified anchor point.

Syntax

BOOL CalculatePopupWindowPosition(
  [in]           const POINT *anchorPoint,
  [in]           const SIZE  *windowSize,
  [in]           UINT        flags,
  [in, optional] RECT        *excludeRect,
  [out]          RECT        *popupWindowPosition
);

Parameters

[in] anchorPoint

Type: const POINT*

The specified anchor point.

[in] windowSize

Type: const SIZE*

The specified window size.

[in] flags

Type: UINT

Use one of the following flags to specify how the function positions the pop-up window horizontally and vertically. The flags are the same as the vertical and horizontal positioning flags of the TrackPopupMenuEx function.

Use one of the following flags to specify how the function positions the pop-up window horizontally.

Value	Meaning
TPM_CENTERALIGN 0x0004L	Centers pop-up window horizontally relative to the coordinate specified by the anchorPoint->x parameter.
TPM_LEFTALIGN 0x0000L	Positions the pop-up window so that its left edge is aligned with the coordinate specified by the anchorPoint->x parameter.
TPM_RIGHTALIGN 0x0008L	Positions the pop-up window so that its right edge is aligned with the coordinate specified by the anchorPoint->x parameter.

Uses one of the following flags to specify how the function positions the pop-up window vertically.

Value	Meaning
TPM_BOTTOMALIGN 0x0020L	Positions the pop-up window so that its bottom edge is aligned with the coordinate specified by the anchorPoint->y parameter.
TPM_TOPALIGN 0x0000L	Positions the pop-up window so that its top edge is aligned with the coordinate specified by the anchorPoint->y parameter.
TPM_VCENTERALIGN 0x0010L	Centers the pop-up window vertically relative to the coordinate specified by the anchorPoint->y parameter.

Use one of the following flags to specify whether to accommodate horizontal or vertical alignment.

Value	Meaning
TPM_HORIZONTAL 0x0000L	If the pop-up window cannot be shown at the specified location without overlapping the excluded rectangle, the system tries to accommodate the requested horizontal alignment before the requested vertical alignment.
TPM_VERTICAL 0x0040L	If the pop-up window cannot be shown at the specified location without overlapping the excluded rectangle, the system tries to accommodate the requested vertical alignment before the requested horizontal alignment.

The following flag is available starting with Windows 7.

Value	Meaning
TPM_WORKAREA 0x10000L	Restricts the pop-up window to within the work area. If this flag is not set, the pop-up window is restricted to the work area only if the input point is within the work area. For more information, see the rcWork and rcMonitor members of the MONITORINFO structure.

[in, optional] excludeRect

Type: RECT*

A pointer to a structure that specifies the exclude rectangle. It can be NULL.

[out] popupWindowPosition

Type: RECT*

A pointer to a structure that specifies the pop-up window position.

Return value

Type: BOOL

If the function succeeds, it returns TRUE; otherwise, it returns FALSE. To get extended error information, call GetLastError.

Remarks

TPM_WORKAREA is supported for the TrackPopupMenu and TrackPopupMenuEx functions.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll