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EvaluateProximityToRect function (winuser.h)

  • Article

Returns the score of a rectangle as the probable touch target, compared to all other rectangles that intersect the touch contact area, and an adjusted touch point within the rectangle.

Syntax

C++ 
BOOL EvaluateProximityToRect(
  [in]  const RECT                             *controlBoundingBox,
  [in]  const TOUCH_HIT_TESTING_INPUT          *pHitTestingInput,
  [out] TOUCH_HIT_TESTING_PROXIMITY_EVALUATION *pProximityEval
);

Parameters

[in] controlBoundingBox

The RECT structure that defines the bounding box of the UI element.

[in] pHitTestingInput

The TOUCH_HIT_TESTING_INPUT structure that holds the data for the touch contact area.

[out] pProximityEval

The TOUCH_HIT_TESTING_PROXIMITY_EVALUATION structure that holds the score and adjusted touch-point data.

Return value

If this function succeeds, it returns TRUE.

Otherwise, it returns FALSE. To retrieve extended error information, call the GetLastError function.

Remarks

For consistency with Windows, frameworks that handle WM_TOUCHHITTESTING should use the following principles for targeting:

  • Inclusion: If the touch point is within the boundaries of a control, the touch point is not changed.
  • Intersection: Include only controls that intersect the contact geometry.
  • Z-order: If more than one control intersects the contact geometry, and the controls overlap, the control that's highest in the z-order receives priority.
  • Ambiguity: If more than one control intersects the contact geometry, and the controls don't overlap, the control that's closest to the original touch point receives priority.

Requirements

Requirement Value
Minimum supported client Windows 8 [desktop apps only]
Minimum supported server None supported
Target Platform Windows
Header winuser.h
Library User32.lib
DLL User32.dll

See also

Functions