com.bc.ceres.grender

Interface Viewport

All Superinterfaces:

Cloneable

All Known Implementing Classes:

DefaultViewport

public interface Viewport
extends Cloneable

A Viewport allows to view a certain part of graphical data representations given in coordinates defined in some model coordinate system. The Viewport assumes that there is an affine similiarity transformation (translation, rotation, scaling) from the view to the model coordiate system. Shearing transformations are not supported, but the coordinate system's Y-axes may point in different directions.

The view coordinate system is a cartesian coordinate system with the X-axis pointing to the right and the Y-axis pointing downwards.

The model coordinate system is assumed to be cartesian coordinate system with the X-axis pointing to the right and the Y-axis pointing either upwards or downwards. See method isModelYAxisDown().

Method Summary

Modifier and Type	Method and Description
void	addListener(ViewportListener listener) Adds a change listener to this viewport.
Viewport	clone() Creates a clone of this viewport.
ViewportListener[]	getListeners() Gets all listeners added to this viewport.
AffineTransform	getModelToViewTransform()
double	getOffsetX()
double	getOffsetY()
double	getOrientation()
Rectangle	getViewBounds()
AffineTransform	getViewToModelTransform()
double	getZoomFactor() Gets the zoom factor.
boolean	isModelYAxisDown()
void	moveViewDelta(double viewDeltaX, double viewDeltaY) Moves the model CS by translating it into the opposite direction of the given vector in view coordinates.
void	removeListener(ViewportListener listener) Removes a change listener from this viewport.
void	setModelYAxisDown(boolean modelYAxisDown)
void	setOffset(double offsetX, double offsetY) Sets the viewport's absolute offset in model coordinates.
void	setOrientation(double orientation) Sets the orientation angle relative to the viewport bound's center point.
void	setTransform(Viewport otherViewport) Modifies this viewport so that it matches the given one.
void	setViewBounds(Rectangle bounds)
void	setZoomFactor(double zoomFactor) Sets the zoom factor relative to the viewport bound's center point.
void	setZoomFactor(double zoomFactor, double modelCenterX, double modelCenterY) Zooms to the given point given in model coordinates.
void	zoom(Rectangle2D modelArea) Zooms to the given area given in model coordinates.

Method Detail

isModelYAxisDown

boolean isModelYAxisDown()

Returns:

If true, the model coordinate's Y-axis points downwards. Returns false by default.

setModelYAxisDown

void setModelYAxisDown(boolean modelYAxisDown)

Parameters:

modelYAxisDown - If true, the model coordinate's Y-axis points downwards.

getViewBounds

Rectangle getViewBounds()

Returns:

The bounds in view coordinates.

setViewBounds

void setViewBounds(Rectangle bounds)

Parameters:

bounds - The bounds in view coordinates.

getViewToModelTransform

AffineTransform getViewToModelTransform()

Returns:

The affine transformation from view to model coordinates.

getModelToViewTransform

AffineTransform getModelToViewTransform()

Returns:

The affine transformation from model to view coordinates.

getOffsetX

double getOffsetX()

Returns:

The viewport's absolute X-offset in model coordinates.

getOffsetY

double getOffsetY()

Returns:

The viewport's absolute Y-offset in model coordinates.

setOffset

void setOffset(double offsetX,
               double offsetY)

Sets the viewport's absolute offset in model coordinates.

Parameters:

offsetX - The X-offset in model coordinates.

offsetY - The Y-offset in model coordinates.

moveViewDelta

void moveViewDelta(double viewDeltaX,
                   double viewDeltaY)

Moves the model CS by translating it into the opposite direction of the given vector in view coordinates.

Parameters:

viewDeltaX - the X delta in view coordinates

viewDeltaY - the Y delta in view coordinates

getZoomFactor

double getZoomFactor()

Gets the zoom factor. The zoom factor is equal to the number of model units per view unit.

Returns:

The zoom factor.

setZoomFactor

void setZoomFactor(double zoomFactor)

Sets the zoom factor relative to the viewport bound's center point.

Parameters:

zoomFactor - The new zoom factor, must be greater than zero.

Throws:

IllegalArgumentException - if zoomFactor is less than or equal to zero

See Also:

getZoomFactor()

setZoomFactor

void setZoomFactor(double zoomFactor,
                   double modelCenterX,
                   double modelCenterY)

Zooms to the given point given in model coordinates.

Parameters:

zoomFactor - The new zoom factor, must be greater than zero.

modelCenterX - New X of the view's center point in model coordinates.

modelCenterY - New Y of the view's center point in model coordinates.

Throws:

IllegalArgumentException - if zoomFactor is less than or equal to zero

zoom

void zoom(Rectangle2D modelArea)

Zooms to the given area given in model coordinates.

Parameters:

modelArea - the area in model coordinates

getOrientation

double getOrientation()

Returns:

The rotation angle in radians.

setOrientation

void setOrientation(double orientation)

Sets the orientation angle relative to the viewport bound's center point.

Parameters:

orientation - the new orientation angle in radians

setTransform

void setTransform(Viewport otherViewport)

Modifies this viewport so that it matches the given one.

Parameters:

otherViewport - The view port to synchronize with.

addListener

void addListener(ViewportListener listener)

Adds a change listener to this viewport.

Parameters:

listener - The listener.

removeListener

void removeListener(ViewportListener listener)

Removes a change listener from this viewport.

Parameters:

listener - The listener.

getListeners

ViewportListener[] getListeners()

Gets all listeners added to this viewport.

Returns:

The listeners.

clone

Viewport clone()

Creates a clone of this viewport. The clone is a deep copy of this viewport but doesn't copy its listeners.

Returns:

The clone.