LAnnPolygon::IsFixedInRect

#include "ltwrappr.h"

virtual L_BOOL LAnnPolygon::IsFixedInRect(prc, uFlags)

LPRECT prc;

address of variable representing client area

L_UINT uFlags;

flags that determine which objects to process

Indicates whether there are any fixed annotations in the client rectangle prc.

Parameter Description
prc Address of a RECT variable representing a client area of a window. This can be NULL. For more information, see comments below.
uFlags Flags that determine which objects to process. Most of the flags apply only to container objects. You can combine values when appropriate by using a bitwise OR ( | ). The following are valid values:
  Value Meaning
  0 Process only the specified object.
  ANNFLAG_SELECTED [0x0001] Process only objects that have the selected property set to TRUE. For getting and setting the selected property, use the LAnnotation::IsSelected and LAnnotation::SetSelected functions.
  ANNFLAG_NOTTHIS [0x0004] Process only one level of objects within the specified container, not the container itself. If there are containers within the container, they are modified, but the objects within them are not.
  ANNFLAG_RECURSE [0x0008] Process objects within a container, and within any subcontainers, down to any level.
  ANNFLAG_NOTCONTAINER [0x0002] (Used with ANNFLAG_RECURSE) Process objects within containers, not the containers themselves.
  ANNFLAG_NOINVALIDATE [0x0010] Do not invalidate the affected rectangle in the window. Use this to avoid generating unwanted paint messages.
  ANNFLAG_CHECKMENU [0x0020] Process objects only if the ANNAUTOTEXT_MENU_TEXT menu item has been selected.

Returns

TRUE

There is a fixed annotation object in the client area.

FALSE

There are no fixed annotation objects in the client area.

Comments

This function is used primarily as an aid in scrolling annotations without using double buffering. For more information on double buffering, see the documentation for:

LDoubleBuffer::Begin

LDoubleBuffer::CreateHandle

LDoubleBuffer::DestroyHandle

LDoubleBuffer::EnableDoubleBuffer

LDoubleBuffer::End

A successful call to LAnnPolygon::IsFixedInRect will update pbFixedInRect with TRUE if hObject intersects with prc and hObject is fixed. If prc is NULL, then pbFixedInRect is updated with TRUE if hObject is fixed.

It is useful to pass an annotation container object for parameter hObject, along with the uFlags equal to ANNFLAG_RECURSE. Then pbFixedInRect is updated with TRUE if ANY annotation object intersects with prc. If prc is NULL in this case, then pbFixedInRect is updated with TRUE if ANY fixed object exists in the container.

Fixed annotations are independent of the annotation container scalarX, scalarY, offsetX and offsetY properties. The result is that they do not scroll or move with the underlying image. For more information, refer to LAnnotation::SetScalarX, LAnnotation::SetScalarY, LAnnotation::SetOffsetX, and LAnnotation::SetOffsetY. For more information, refer to Fixed Annotations.

Required DLLs and Libraries

LTANN

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

See Also

Topics:

Annotation Functions: Object Properties

 

Implementing Annotations

 

Automated User Interface for Annotations

 

Annotation Functions: Creating and Deleting Annotations

 

Types of Annotations

 

Annotation Functions: Implementing Custom Annotations

 

Annotation Functions: Creating Custom Annotations

 

Fixed Annotations

 

Minimizing Flicker With Double Buffering

Example

// This example displays a message box telling if there are any fixed annotations // visible in the client area of hWnd. This is useful for handling scrolling and zooming // of fixed annotations without double-buffering. // hWnd -- window displaying annotations // pLPolygon -- Pointer to LAnnPolygon annotation object. 

L_INT LAnnPolygon_IsFixedInRectExample(HWND hWnd, LAnnPolygon *pLPolygon)  
{ 
	 
   RECT rcClient;  
   L_BOOL bFixedInRect;  
   L_TCHAR *pszMsg;  
    
   GetClientRect(hWnd, &rcClient);  
   bFixedInRect = pLPolygon->IsFixedInRect(&rcClient,  ANNFLAG_RECURSE);  
   pszMsg = bFixedInRect ? TEXT("There are fixed annotations visible") : TEXT("There are NO fixed annotations visible"); 
   MessageBox(NULL, pszMsg, TEXT(""), MB_OK);  
	return SUCCESS; 
}

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