IViewObjectEx::QueryHitRect method

Indicates whether any point in a rectangle is within a given drawing aspect of an object.

Syntax


HRESULT QueryHitRect(
  [in]  DWORD   dwAspect,
  [in]  LPCRECT pRectBounds,
  [in]  LPCRECT pRectLoc,
  [in]  LONG    lCloseHint,
  [out] DWORD   *pHitResult
);

Parameters

dwAspect [in]

The requested drawing aspect.

pRectBounds [in]

An object bounding rectangle in client coordinates of the containing window. This rectangle is computed and passed by the container so that the object can meaningfully interpret the hit location.

pRectLoc [in]

The hit test rectangle, specified in HIMETRIC units, relative to the top-left corner of the object.

lCloseHint [in]

The suggested distance, in HIMETRIC units, that the container considers close. This value is a hint, and objects can interpret it in their own way. Objects can also use this hint to roughly infer output resolution to choose expansiveness of hit test implementation.

pHitResult [out]

A pointer to returned information about the hit expressed as the HITRESULT enumeration values.

Return value

This method returns S_OK on success. Other possible return values include the following.

Return codeDescription
E_FAIL

This method is not implemented for the requested aspect. Use DVASPECT_CONTENT instead.

 

Remarks

Containers may need to test whether an object overlaps a given drawing aspect of another object. They can determine whether the objects overlap by requesting a region or at least a bounding rectangle of the aspect in question. However, a quicker way to do this is to call IViewObjectEx::QueryHitRect to ask the object whether a given rectangle intersects one of its drawing aspects.

Note  Unlike IViewObjectEx::QueryHitPoint, this method does not return HITRESULT_TRANSPARENT or HITRESULT_CLOSE. It is strictly hit or miss, returning HITRESULT_OUTSIDE if no point in the rectangle is hit and HITRESULT_HIT if at least one point in the rectangle is a hit.
 

Notes to Implementers

An object supporting IViewObjectEx is required to implement this method at least for the DVASPECT_CONTENT aspect. The object should not take any other action in response to this method other than to return the information; there should be no side-effects. If there is any ambiguity about whether a point is a hit, for instance due to coordinates not converting exactly, the object should return HITRESULT_HIT whenever any point in the rectangle might be a hit on the object. That is, it is permissible to claim a hit for a point that is not actually rendered, but never correct to claim a miss for any point that is in the rendered image of the object.

Requirements

Minimum supported client

Windows 2000 Professional [desktop apps only]

Minimum supported server

Windows 2000 Server [desktop apps only]

Header

OCIdl.h

IDL

OCIdl.idl

IID

IID_IViewObjectEx is defined as 3AF24292-0C96-11CE-A0CF-00AA00600AB8

See also

IViewObjectEx
HITRESULT

 

 

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