Package noaa.coastwatch.render

Class LineOverlay

java.lang.Object

noaa.coastwatch.render.EarthDataOverlay

noaa.coastwatch.render.LineOverlay

All Implemented Interfaces:

Serializable, Cloneable, Comparable

Direct Known Subclasses:

LabeledLineOverlay, LineFeatureOverlay, PoliticalOverlay, PolygonOverlay, ShapeOverlay, SurveyOverlay, TopographyOverlay

public abstract class LineOverlay
extends EarthDataOverlay

A vector overlay annotes a data view with vector-specified lines and shapes. The vector overlay adds the concept of a stroke to the parent class.

An implementation note: The normal BasicStroke object that would be used to define a stroke for vector overlays is not serializable. So we add some special serialization methods here to handle saving and restoring stroke objects. The alternative is to create a new serializable stroke class, which may be required if there are other classes that use a stroke and need serialization. For now, we keep it simple.

Since:

3.1.1

Author:

Peter Hollemans

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	drawingShadow	The shadow rendering flag, true if we are rendering a shadow.

Fields inherited from class noaa.coastwatch.render.EarthDataOverlay

alpha, lastTrans, prepared

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	LineOverlay(Color color)	Constructs a new vector overlay.
protected	LineOverlay(Color color, int layer, Stroke stroke)	Constructs a new vector overlay.

Method Summary

Modifier and Type	Method	Description
static Line2D	clip(Line2D line, Rectangle2D rect)	Clips the line segment to the specified rectangle.
protected void	drawShadow(Graphics2D g, EarthDataView view)	Draws a drop shadow version of this overlay.
boolean	getDropShadow()	Gets the drop shadow flag.
static Color	getShadowColor(Color foreground)	Gets the shadow color that will have the greatest contrast to the specified foreground color.
Stroke	getStroke()	Gets the vector path stroke.
void	render(Graphics2D g, EarthDataView view)	Renders the overlay graphics.
void	setDropShadow(boolean flag)	Sets the drop shadow flag.
void	setStroke(Stroke stroke)	Sets the vector path stroke.

Methods inherited from class noaa.coastwatch.render.EarthDataOverlay

clone, compareTo, draw, getAlphaVersion, getColor, getColors, getColorWithAlpha, getLayer, getMetadataAtPoint, getName, getTransparency, getVisible, hasMetadata, invalidate, isPrepared, needsPrepare, prepare, setColor, setLayer, setName, setTransparency, setVisible, toString

Methods inherited from class java.lang.Object

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

Field Details

drawingShadow

protected boolean drawingShadow

The shadow rendering flag, true if we are rendering a shadow.

Constructor Details

LineOverlay

protected LineOverlay(Color color,
 int layer,
 Stroke stroke)

Constructs a new vector overlay.

Parameters:

color - the overlay color.

layer - the overlay layer number.

stroke - the stroke to use for vector paths.

LineOverlay

protected LineOverlay(Color color)

Constructs a new vector overlay. The layer number is initialized to 0, and the stroke to the default BasicStroke with beveled joins.

Parameters:

color - the overlay color.

Method Details

getDropShadow

public boolean getDropShadow()

Gets the drop shadow flag.

setDropShadow

public void setDropShadow(boolean flag)

Sets the drop shadow flag. When drop shadow mode is on, a shadow is drawn behind the lines. By default, drop shadow mode is off.

drawShadow

protected void drawShadow(Graphics2D g,
 EarthDataView view)

Draws a drop shadow version of this overlay.

Parameters:

g - the graphics device to draw to.

view - the data for drawing.

render

public void render(Graphics2D g,
 EarthDataView view)

Description copied from class: EarthDataOverlay

Renders the overlay graphics.

Overrides:

render in class EarthDataOverlay

Parameters:

g - the graphics object for drawing.

view - the earth data view.

getShadowColor

public static Color getShadowColor(Color foreground)

Gets the shadow color that will have the greatest contrast to the specified foreground color.

Parameters:

foreground - the foreground color in question.

Returns:

the shadow color, white if the foreground is dark or black if the foreground is light.

setStroke

public void setStroke(Stroke stroke)

Sets the vector path stroke.

getStroke

public Stroke getStroke()

Gets the vector path stroke.

clip

public static Line2D clip(Line2D line,
 Rectangle2D rect)

Clips the line segment to the specified rectangle. This method implements the Cohen-Sutherland line clipping algorithm as specified in:

Foley, J.D., A. van Dam, S.K. Feiner, and J.F. Hughes, "Computer Graphics: Principles and Practice, Second edition in C", Addison-Wesley, July 1997, pp 117-124, 274.

Parameters:

line - the line for clipping.

rect - the clipping rectangle.

Returns:

the clipped line, or null if the line is entirely outside the rectangle. The same set of points is returned if no modifications to the points were performed, or a new set of points otherwise.