IlvChartZoomInteractor Class Reference

Implements interactive zooming of a chart. More...

#include <ilviews/charts/chartint.h>

Inheritance diagram for IlvChartZoomInteractor:

List of all members.

Public Types
enum	ZoomState { Zooming, UnZooming }
	This enumeration type defines the possible zooming states of the interactor. More...
Public Member Functions
	IlvChartZoomInteractor (IlUShort whichButton=IlvLeftButton)
	Constructor.
ZoomState	getState () const
	Returns the current zooming state.
IlUShort	getZoomSteps ()
	Returns the number of intermediate steps during a zooming operation.
virtual IlBoolean	handleEvent (IlvGraphic *chart, IlvEvent &ev, const IlvTransformer *t=0)
	Handles events received by the interactor.
virtual IlBoolean	isShowingAbscissaCursor () const
	Indicates whether the interactor uses a cursor on the abscissa.
virtual IlBoolean	isShowingOrdinateCursor () const
	Indicates whether the interactor uses a cursor on the ordinate.
void	setZoomSteps (IlUShort count)
	Sets the number of intermediate steps during the zooming operation.
Protected Member Functions
virtual void	adjustZoomRange (const IlvChartGraphic *chart, IlvCoordInterval &abscissaRange, IlvCoordInterval &ordinateRange)
	Adjusts the zooming range.
virtual void	doIt (IlvChartGraphic *chart, const IlvCoordInterval &abscissaRange, const IlvCoordInterval &ordinateRange)
	Action method called when the user releases the mouse button.
virtual void	drawGhost (const IlvChartGraphic *chart, const IlvCoordInterval &abscissaRange, const IlvCoordInterval &ordinateRange, const IlvTransformer *t) const
	Draws the graphical representation of the dragged rectangle.

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Detailed Description

Implements interactive zooming of a chart.

Library: ilvcharts

This class lets the user trigger a zoom-in or zoom-out command by dragging a rectangular region within the chart data display area.

The registered name of this interactor class is "ChartZoom".

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Member Enumeration Documentation

enum IlvChartZoomInteractor::ZoomState

This enumeration type defines the possible zooming states of the interactor.

Enumerator:

Zooming	The interactor is in a zooming state.
UnZooming	The interactor is in an unzooming state.

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Constructor & Destructor Documentation

IlvChartZoomInteractor::IlvChartZoomInteractor

(

IlUShort

whichButton = IlvLeftButton

)

Constructor.

Initializes a new IlvChartZoomInteractor object.

Parameters:

whichButton

The mouse button that should be used for the interaction.

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Member Function Documentation

virtual void IlvChartZoomInteractor::adjustZoomRange	(	const IlvChartGraphic *	chart,
		IlvCoordInterval &	abscissaRange,
		IlvCoordInterval &	ordinateRange
	)			[protected, virtual]

Adjusts the zooming range.

This method is called each time the mouse is dragged and lets you control the range selected by the user. The default implementation does nothing.

Parameters:

	chart	The considered chart.
	abscissaRange	The abscissa coordinate range corresponding to the dragged rectangle.
	ordinateRange	The ordinate coordinate range corresponding to the dragged rectangle.

See also:

IlvCoordInterval, IlvChartGraphic::zoomCharts.

virtual void IlvChartZoomInteractor::doIt	(	IlvChartGraphic *	chart,
		const IlvCoordInterval &	abscissaRange,
		const IlvCoordInterval &	ordinateRange
	)			[protected, virtual]

Action method called when the user releases the mouse button.

The default implementation computes the new coordinate ranges and then calls IlvChartGraphic::zoomCharts.

Parameters:

	chart	The considered chart.
	abscissaRange	The abscissa coordinate range corresponding to the dragged rectangle.
	ordinateRange	The ordinate coordinate range corresponding to the dragged rectangle.

See also:

IlvCoordInterval, IlvChartGraphic::zoomCharts.

virtual void IlvChartZoomInteractor::drawGhost	(	const IlvChartGraphic *	chart,
		const IlvCoordInterval &	abscissaRange,
		const IlvCoordInterval &	ordinateRange,
		const IlvTransformer *	t
	)			const [protected, virtual]

Draws the graphical representation of the dragged rectangle.

This method draws the dragged region in XOR mode.

Parameters:

	chart	The considered chart.
	abscissaRange	The abscissa coordinate range corresponding to the dragged rectangle.
	ordinateRange	The ordinate coordinate range corresponding to the dragged rectangle.
	t	The transformer applied to the view in which the event occurred.

See also:

IlvCoordInterval, IlvChartGraphic::zoomCharts.

ZoomState IlvChartZoomInteractor::getState

(

)

const

Returns the current zooming state.

During a drag operation, the interactor can either be in a Zooming or UnZooming state depending on the initial event. (The default implementation of this class uses IlvShiftModifier to discriminate between a zoom-in and a zoom-out command.) This method returns the current zooming state of the interactor and is typically used in methods such as IlvChartZoomInteractor::doIt, IlvChartZoomInteractor::drawGhost, and IlvChartZoomInteractor::adjustZoomRange.

Returns:

The current zooming state.

IlUShort IlvChartZoomInteractor::getZoomSteps

(

)

Returns the number of intermediate steps during a zooming operation.

Each zooming-in/zooming-out operation can be divided into several steps to render a smooth transition between the original and the final visual state of the displayed data. This method returns the number of steps for the current object. The default number of steps when an instance is created is 0.

Returns:

The number of steps.

virtual IlBoolean IlvChartZoomInteractor::handleEvent	(	IlvGraphic *	chart,
		IlvEvent &	event,
		const IlvTransformer *	t = 0
	)			[virtual]

Handles events received by the interactor.

This method is the entry point of all events dispatched to this interactor.

Parameters:

	chart	The chart object that received the event.
	event	The received event.
	t	The transformer applied to the view in which the event occurred.

Returns:

IlTrue if the event was successfully handled and IlFalse otherwise.

Implements IlvChartInteractor.

virtual IlBoolean IlvChartZoomInteractor::isShowingAbscissaCursor

(

)

const [virtual]

Indicates whether the interactor uses a cursor on the abscissa.

Interactor instances will use the API of IlvChartInteractorManager to display and move the corresponding cursor. If this method returns IlTrue and IlvChartInteractorManager::isShowingAbscissaCursor also returns IlTrue, the cursor will be displayed during the event sequence handled by this interactor. The default implementation returns IlFalse.

Returns:

IlTrue if the interactor uses an abscissa cursor and IlFalse otherwise.

See also:

IlvChartInteractorManager.

Reimplemented from IlvChartInteractor.

virtual IlBoolean IlvChartZoomInteractor::isShowingOrdinateCursor

(

)

const [virtual]

Indicates whether the interactor uses a cursor on the ordinate.

Interactor instances will use the API of IlvChartInteractorManager to display and move the corresponding cursor. If this method returns IlTrue and IlvChartInteractorManager::isShowingAbscissaCursor also returns IlTrue, the cursor will be displayed during the event sequence handled by this interactor.

Returns:

IlTrue if the interactor uses an ordinate cursor and IlFalse otherwise.

See also:

IlvChartInteractorManager.

Reimplemented from IlvChartInteractor.

void IlvChartZoomInteractor::setZoomSteps

(

IlUShort

count

)

Sets the number of intermediate steps during the zooming operation.

Parameters:

The

new number of steps.

See also:

getZoomSteps.