Functions
void	AreaDrag ()
	This event is triggered when a parallelogram is changed in the `LB_AREAMODE` mode (while the left mouse button is held down).

void	AreaDraged ()
	This event is triggered when modification of a parallelogram in the `LB_AREAMODE` mode has finished (the left mouse button has been released).

void	CSChanged ()
	This event is triggered when a coordinate system is changed in the `LB_SETORIGIN` mode.

void	CSClicked ()
	This event is triggered when the user clicks on a coordinate system with the mouse tool.

void	CVCError (ErrorCode ErrorCode, BSTR ErrorString, boolean *Continue)
	This event is fired if an error occurs in the Display Control. More...

void	EndDraw ()
	This event is triggered when the overlay drawings are finished.

void	ImageUpdated ()
	This event is triggered when the image object has changed. This is the case when a new image has been loaded from the hard disk or an image acquisition device driver.

void	LabelClicked (long ID)
	This event is triggered when there is a click on a label. More...

void	LabelDrag (long ID)
	This event is triggered when a label is dragged with the mouse. More...

void	LabelDraged (long ID)
	This event is triggeredhen the left mouse button is released after a label has been dragged with the mouse. More...

void	LayoutChanged ()
	This event tells the program that the display has changed as a result of zooming or scrolling. More...

void	OverlayObjectClick (long ID)
	This event is triggered when an overlay object has been clicked with the mouse. More...

void	OverlayObjectDrag (long ID)
	This event is triggered when an overlay object is dragged. More...

void	OverlayObjectDraged (long ID)
	This event is triggered when an overlay object was dragged and the left mouse button has been released. More...

void	RectDrag ()
	This event is triggered when a rectangle is modified in the `LB_FRAME` mode (while the left mouse button is held down).

void	RectDraged ()
	This event is triggered when modification of a rectangle the `LB_FRAME` mode has finished (the left mouse button is pressed again).

void	RubberDrag (long x0, long y0, long x1, long y1, double distance, double angle)
	Event that is raised while the user drags a rubber band on the display. More...

void	RubberDragged (long x0, long y0, long x1, long y1, double distance, double angle)
	Event that is raised when the user releases the left mouse button after having dragged a rubber band. More...

void	UserObjectClick (long ID)
	This event is triggered when a user-defined object is selected by a mouse click. More...

void	UserObjectDrag (long ID)
	This event is triggered when a user-defined object is dragged. More...

void	UserObjectDraged (long ID)
	This event is triggered when a user-defined object was dragged and the left mouse button was pressed again. More...

void	UserPaint (long ID, long NumVertices, __int3264 Vertices, boolean Dragging, __int3264 hDC)
	This event is triggered when a user-defined graphic objects have to be repainted. More...

Detailed Description

Function Documentation

◆ CVCError()

void CVCError	(	ErrorCode	ErrorCode,
		BSTR	ErrorString,
		boolean *	Continue
	)

This event is fired if an error occurs in the Display Control.

   For instance an error could occure trying to save an image but the folder is write protected.

Attention: Please include the appropriate header file for your compiler (cvcerror.*).

Parameters

[in]

ErrorCode

A unique number describing the error. The following error codes have been defined:

1	CVC_E_ERROR
	This error cannot be described more precisely.
2	CVC_E_PARAMETER
	Incorrect parameter in a function call.
3	CVC_E_FILEIO
	File I/O error, for example while saving or loading an image.
5	CVC_E_MEMORY
	Memory could not be allocated.
16	CVC_E_NOIMAGE
	No image at all.
17	CVC_E_NOINTERFACE
	No interface available.

[in] ErrorString Specifies the error text of the output.

[in] Continue This specifies whether execution should continue despite the error. The user can overwrite the value in order to change the default action. The default value depends on the function that caused the error.
TRUE specifies that a messate box will appear to inform the user of the error. FALSE means that it is possible to perform custom error handling, e.g. use a self-defined message-box.

Visual Basic Test Code:: The following example shows error handling during saving an image:
Private Sub cvDisp_CVCError(ByVal ErrorCode As CVDISPLAYLib.ErrorCode, ByVal ErrorString As String, Continue As Boolean)

// display error infos

If MsgBox(ErrorString & " Error Code: " & Str$(ErrorCode) & ". Continue?", vbYesNo) = vbYes Then

Continue = True // shows automatically Message Box with Error

Else

Continue = False // does not show automatically the Message Box

EndIf

// checking of error type

If ErrorCode = CVC_E_FILEIO Then // File Open/Save Problems

// Do what you like

labelResult.Caption = "Error - File save " + sFilename

Else

labelResult.Caption = "OK - File save " + sFilename

End

EndIf Sub

Examples:: Visual Basic - VB Fileformats Example

◆ LabelClicked()

void LabelClicked ( long ID )

This event is triggered when there is a click on a label.

Parameters

[in] ID ID of the selected label.

◆ LabelDrag()

void LabelDrag ( long ID )

This event is triggered when a label is dragged with the mouse.

Parameters

[in] ID ID of the selected label.

◆ LabelDraged()

void LabelDraged ( long ID )

This event is triggeredhen the left mouse button is released after a label has been dragged with the mouse.

Parameters

[in] ID ID of the label which has been dragged.

◆ LayoutChanged()

void LayoutChanged ( )

This event tells the program that the display has changed as a result of zooming or scrolling.

Attention: This requires the RightButtonMode property to have been set to RB_MENU or RB_ZOOM.

◆ OverlayObjectClick()

void OverlayObjectClick ( long ID )

This event is triggered when an overlay object has been clicked with the mouse.

Parameters

[in] ID ID of the object that was clicked.

Hints and Notes:: The click event is only available for non dragable Overlay Plug-In objects.
For a distinction between a click on the OPI and real dragging please check the coordinates in the OverlayObjectDraged-Event.

◆ OverlayObjectDrag()

void OverlayObjectDrag ( long ID )

This event is triggered when an overlay object is dragged.

Parameters

[in] ID ID of the object that is being dragged.

◆ OverlayObjectDraged()

void OverlayObjectDraged ( long ID )

This event is triggered when an overlay object was dragged and the left mouse button has been released.

Parameters

[in] ID ID of the object that was dragged.

◆ RubberDrag()

void RubberDrag	(	long	x0,
		long	y0,
		long	x1,
		long	y1,
		double	distance,
		double	angle
	)

Event that is raised while the user drags a rubber band on the display.

Note that you need to have set the display's #LeftBuffonMode property accordingly, otherwise no rubber band events will be raised.

Parameters

[in]	x0	X coordinate of the rubber band's starting point.
[in]	y0	Y coordinate of the rubber band's starting point.
[in]	x1	X coordinate of the rubber band's end point.
[in]	y1	Y coordinate of the rubber band's end point.
[in]	distance	Distance between vertex 1 and vertex 2.
[in]	angle	Angle between vertex 1 and vertex 2.

◆ RubberDragged()

void RubberDragged	(	long	x0,
		long	y0,
		long	x1,
		long	y1,
		double	distance,
		double	angle
	)

Event that is raised when the user releases the left mouse button after having dragged a rubber band.

Note that you need to have set the display's #LeftBuffonMode property accordingly, otherwise no rubber band events will be raised.

Parameters

[in]	x0	X coordinate of the rubber band's starting point.
[in]	y0	Y coordinate of the rubber band's starting point.
[in]	x1	X coordinate of the rubber band's end point.
[in]	y1	Y coordinate of the rubber band's end point.
[in]	distance	Distance between vertex 1 and vertex 2.
[in]	angle	Angle between vertex 1 and vertex 2.

◆ UserObjectClick()

void UserObjectClick ( long ID )

This event is triggered when a user-defined object is selected by a mouse click.

Attention: This event is not supported in Visual Basic.

Parameters

[in] ID ID of the selected object.

Examples:: Delphi - Delphi Overlay Example
Visual C++ - VC Image Overlay Example

◆ UserObjectDrag()

void UserObjectDrag ( long ID )

This event is triggered when a user-defined object is dragged.

Attention: This event is not supported in Visual Basic.

Parameters

[in] ID ID of the selected object.

Examples:: Delphi - Delphi Overlay Example
Visual C++ - VC Image Overlay Example

◆ UserObjectDraged()

void UserObjectDraged ( long ID )

This event is triggered when a user-defined object was dragged and the left mouse button was pressed again.

Attention: This event is not supported in Visual Basic.

Parameters

[in] ID ID of the selected object.

Examples:: Delphi - Delphi Overlay Example
Visual C++ - VC Image Overlay Example

◆ UserPaint()

void UserPaint	(	long	ID,
		long	NumVertices,
		__int3264	Vertices,
		boolean	Dragging,
		__int3264	hDC
	)

This event is triggered when a user-defined graphic objects have to be repainted.

Attention: This event is not supported in Visual Basic.

Parameters

[in]	ID	ID of the label to be repainted.
[in]	NumVertices	Number of vertices of the display object.
[in]	Vertices	A POINT-type listing containing the object vertices in windows coordinates.
[in]	Dragging	Specifies whether dragging is still in progress or not.
[in]	hDC	Handle for the DC which must be used for drawing.

Examples:: Delphi - Delphi Overlay Example
Visual C++ - VC Image Overlay Example


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Functions

Detailed Description

Function Documentation

◆ CVCError()

◆ LabelClicked()

◆ LabelDrag()

◆ LabelDraged()

◆ LayoutChanged()

◆ OverlayObjectClick()

◆ OverlayObjectDrag()

◆ OverlayObjectDraged()

◆ RubberDrag()

◆ RubberDragged()

◆ UserObjectClick()

◆ UserObjectDrag()

◆ UserObjectDraged()

◆ UserPaint()