com.yworks.yfiles.view

Class ViewportLimiter

java.lang.Object

com.yworks.yfiles.view.ViewportLimiter

public class ViewportLimiter
extends Object

Helper class used by CanvasControl to limit the interactive movement of the viewport.

The ViewportLimiter instance should be consulted whenever the user tries to change the viewport. Using method limitViewport(CanvasControl, RectD) the desired viewport can be validated by the implementation. Note that setting the Zoom property or ViewPoint property will not be influenced by implementations of this class. It is up to the caller to perform verification.

See Also:

getBounds()

Constructor Summary

Constructors

Constructor and Description
ViewportLimiter() Initializes a new instance of the ViewportLimiter class.

Method Summary

Modifier and Type	Method and Description
RectD	getBounds() Gets the maximal allowed navigable bounds for the viewport.
protected RectD	getCurrentBounds(CanvasControl canvas, RectD suggestedViewport) Gets the to bounds that should be honored for the upcoming call.
boolean	isHonoringBothDimensionsEnabled() Gets a value indicating whether both dimensions of Bounds need to be honored.
RectD	limitViewport(CanvasControl canvas, RectD suggestedViewport) Inspects the desired or suggested new viewport for the given control and returns a valid viewport to use.
void	setBounds(RectD value) Sets the maximal allowed navigable bounds for the viewport.
void	setHonoringBothDimensionsEnabled(boolean value) Sets a value indicating whether both dimensions of Bounds need to be honored.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ViewportLimiter

public ViewportLimiter()

Initializes a new instance of the ViewportLimiter class.

Method Detail

getBounds

public final RectD getBounds()

Gets the maximal allowed navigable bounds for the viewport.

Returns:

The bounds or null. This value will be used by the default implementation of limitViewport(CanvasControl, RectD) to crop the desired viewport to.

See Also:

setBounds(RectD)

getCurrentBounds

protected RectD getCurrentBounds(CanvasControl canvas,
                                 RectD suggestedViewport)

Gets the to bounds that should be honored for the upcoming call.

This method is used as callback by limitViewport(CanvasControl, RectD) for each request. The default implementation just yields Bounds.

Parameters:

canvas - The canvas control.

suggestedViewport - The suggested viewport.

Returns:

The bounds to honor or null.

isHonoringBothDimensionsEnabled

public final boolean isHonoringBothDimensionsEnabled()

Gets a value indicating whether both dimensions of Bounds need to be honored.

Returns:

true if both dimensions need to be honored, otherwise false.

See Also:

setHonoringBothDimensionsEnabled(boolean)

limitViewport

public RectD limitViewport(CanvasControl canvas,
                           RectD suggestedViewport)

Inspects the desired or suggested new viewport for the given control and returns a valid viewport to use.

Parameters:

canvas - The canvas control on which the viewport should be applied.

suggestedViewport - The suggested viewport.

Returns:

The viewport that should be used.

setBounds

public final void setBounds(RectD value)

Sets the maximal allowed navigable bounds for the viewport.

Parameters:

value - The bounds or null. This value will be used by the default implementation of limitViewport(CanvasControl, RectD) to crop the desired viewport to.

See Also:

getBounds()

setHonoringBothDimensionsEnabled

public final void setHonoringBothDimensionsEnabled(boolean value)

Sets a value indicating whether both dimensions of Bounds need to be honored.

Parameters:

value - true if both dimensions need to be honored, otherwise false.

See Also:

isHonoringBothDimensionsEnabled()