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RSyntaxTextArea is the syntax highlighting text editor for Swing applications. Features include syntax highlighting for 40+ languages, code folding, code completion, regex find and replace, macros, code templates, undo/redo, line numbering and bracket matching.
/*
* 11/10/2004
*
* ChangeableHighlightPainter.java - A highlight painter whose color you can
* change.
*
* This library is distributed under a modified BSD license. See the included
* LICENSE file for details.
*/
package org.fife.ui.rtextarea;
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.SystemColor;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import javax.swing.plaf.TextUI;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
import javax.swing.text.LayeredHighlighter;
import javax.swing.text.Position;
import javax.swing.text.View;
/**
* An extension of LayerPainter that allows the user to
* change several of its properties:
*
*
* - Its color/fill style (can use a
GradientPaint, for
* example).
* - Whether the edges of a painted highlight are rounded.
* - Whether painted highlights have translucency.
*
*
* @author Robert Futrell
* @version 0.6
*/
public class ChangeableHighlightPainter
extends LayeredHighlighter.LayerPainter implements Serializable {
/**
* The Paint/Color of this highlight.
*/
private Paint paint;
/**
* Whether selections have rounded edges.
*/
private boolean roundedEdges;
/**
* The alpha composite used to render with translucency.
*/
private transient AlphaComposite alphaComposite;
/**
* The alpha value used in computing translucency. This should stay in the
* range 0.0f (completely invisible) to 1.0f
* (completely opaque).
*/
private float alpha;
private static final int ARCWIDTH = 8;
private static final int ARCHEIGHT = 8;
/**
* Creates a new ChangeableHighlightPainter that paints
* highlights with the text area's selection color (i.e., behaves exactly
* like
* javax.swing.text.DefaultHighlighter.DefaultHighlightPainter
* ).
*/
public ChangeableHighlightPainter() {
this(null);
}
/**
* Creates a new highlight painter using the specified Paint
* without rounded edges.
*
* @param paint The Paint (usually a
* java.awt.Color) with which to paint the
* highlights.
*/
public ChangeableHighlightPainter(Paint paint) {
this(paint, false);
}
/**
* Creates a new highlight painter.
*
* @param paint The Paint (usually a
* java.awt.Color) with which to paint the
* highlights.
* @param rounded Whether to use rounded edges on the highlights.
*/
public ChangeableHighlightPainter(Paint paint, boolean rounded) {
this(paint, rounded, 1.0f);
}
/**
* Creates a new highlight painter.
*
* @param paint The Paint (usually a
* java.awt.Color) with which to paint the
* highlights.
* @param rounded Whether to use rounded edges on the highlights.
* @param alpha The alpha value to use when painting highlights. This
* value should be in the range 0.0f (completely
* transparent) through 1.0f (opaque).
*/
public ChangeableHighlightPainter(Paint paint, boolean rounded,
float alpha) {
setPaint(paint);
setRoundedEdges(rounded);
setAlpha(alpha);
}
/**
* Returns the alpha value used in computing the translucency of these
* highlights. A value of 1.0f (the default) means that no
* translucency is used; there is no performance hit for this value. For
* all other values ([0.0f..1.0f)), there will be a
* performance hit.
*
* @return The alpha value.
* @see #setAlpha
*/
public float getAlpha() {
return alpha;
}
/**
* Returns the alpha composite to use when rendering highlights with this
* painter.
*
* @return The alpha composite.
*/
private AlphaComposite getAlphaComposite() {
if (alphaComposite==null) {
alphaComposite = AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, alpha);
}
return alphaComposite;
}
/**
* Returns the Paint (usually a java.awt.Color)
* being used to paint highlights.
*
* @return The Paint.
* @see #setPaint
*/
public Paint getPaint() {
return paint;
}
/**
* Returns whether rounded edges are used when painting selections with
* this highlight painter.
*
* @return Whether rounded edges are used.
* @see #setRoundedEdges
*/
public boolean getRoundedEdges() {
return roundedEdges;
}
/**
* Paints a highlight.
*
* @param g the graphics context
* @param offs0 the starting model offset >= 0
* @param offs1 the ending model offset >= offs1
* @param bounds the bounding box for the highlight
* @param c the editor
*/
@Override
public void paint(Graphics g, int offs0, int offs1, Shape bounds,
JTextComponent c) {
Rectangle alloc = bounds.getBounds();
// Set up translucency if necessary.
Graphics2D g2d = (Graphics2D)g;
Composite originalComposite = null;
if (getAlpha()<1.0f) {
originalComposite = g2d.getComposite();
g2d.setComposite(getAlphaComposite());
}
try {
// Determine locations.
TextUI mapper = c.getUI();
Rectangle p0 = mapper.modelToView(c, offs0);
Rectangle p1 = mapper.modelToView(c, offs1);
Paint paint = getPaint();
if (paint==null) {
g2d.setColor(c.getSelectionColor());
}
else {
g2d.setPaint(paint);
}
// Entire highlight is on one line.
if (p0.y == p1.y) {
// Standard Swing views return 0 width for chars, but ours
// returns the char's width. Set this to 0 here since p1 is
// technically an exclusive boundary.
p1.width = 0;
Rectangle r = p0.union(p1);
g2d.fillRect(r.x, r.y, r.width, r.height);
}
// Highlight spans lines.
else {
int p0ToMarginWidth = alloc.x + alloc.width - p0.x;
g2d.fillRect(p0.x, p0.y, p0ToMarginWidth, p0.height);
if ((p0.y + p0.height) != p1.y) {
g2d.fillRect(alloc.x, p0.y + p0.height, alloc.width,
p1.y - (p0.y + p0.height));
}
g2d.fillRect(alloc.x, p1.y, (p1.x - alloc.x), p1.height);
}
} catch (BadLocationException e) {
// Never happens.
e.printStackTrace();
} finally {
// Restore state from before translucency if necessary.
if (getAlpha()<1.0f) {
g2d.setComposite(originalComposite);
}
}
}
/**
* Paints a portion of a highlight.
*
* @param g the graphics context
* @param offs0 the starting model offset >= 0
* @param offs1 the ending model offset >= offs1
* @param bounds the bounding box of the view, which is not
* necessarily the region to paint.
* @param c the editor
* @param view View painting for
* @return region drawing occurred in
*/
@Override
public Shape paintLayer(Graphics g, int offs0, int offs1,
Shape bounds, JTextComponent c, View view) {
// Set up translucency if necessary.
Graphics2D g2d = (Graphics2D)g;
Composite originalComposite = null;
if (getAlpha()<1.0f) {
originalComposite = g2d.getComposite();
g2d.setComposite(getAlphaComposite());
}
// Set the color (our own if defined, otherwise text area's).
Paint paint = getPaint();
if (paint==null) {
g2d.setColor(c.getSelectionColor());
}
else {
g2d.setPaint(paint);
}
// This special case isn't needed for most standard Swing Views (which
// always return a width of 1 for modelToView() calls), but it is
// needed for RSTA views, which actually return the width of chars for
// modelToView calls. But this should be faster anyway, as we
// short-circuit and do only one modelToView() for one offset.
if (offs0==offs1) {
try {
Shape s = view.modelToView(offs0, bounds,
Position.Bias.Forward);
Rectangle r = s.getBounds();
g.drawLine(r.x, r.y, r.x, r.y+r.height);
return r;
} catch (BadLocationException ble) {
ble.printStackTrace(); // Never happens
return null;
}
}
// Contained in view, can just use bounds.
if (offs0==view.getStartOffset() && offs1==view.getEndOffset()) {
Rectangle alloc;
if (bounds instanceof Rectangle) {
alloc = (Rectangle)bounds;
}
else {
alloc = bounds.getBounds();
}
g2d.fillRect(alloc.x, alloc.y, alloc.width, alloc.height);
// Restore state from before translucency if necessary.
if (getAlpha()<1.0f) {
g2d.setComposite(originalComposite);
}
return alloc;
}
// Should only render part of View.
else {
try {
Shape shape = view.modelToView(offs0, Position.Bias.Forward,
offs1,Position.Bias.Backward,
bounds);
Rectangle r = (shape instanceof Rectangle) ?
(Rectangle)shape : shape.getBounds();
if (roundedEdges) {
g2d.fillRoundRect(r.x,r.y, r.width,r.height, ARCWIDTH,
ARCHEIGHT);
}
else {
g2d.fillRect(r.x, r.y, r.width, r.height);
}
// Restore state from before translucency if necessary.
if (getAlpha()<1.0f) {
g2d.setComposite(originalComposite);
}
return r;
} catch (BadLocationException ble) {
ble.printStackTrace();
} finally {
// Restore state from before translucency if necessary.
if (getAlpha()<1.0f) {
g2d.setComposite(originalComposite);
}
}
}
// Only if exception
return null;
}
/**
* Deserializes a painter.
*
* @param s The stream to read from.
* @throws ClassNotFoundException If something bad happens.
* @throws IOException If an IO error occurs.
*/
private void readObject(ObjectInputStream s)
throws ClassNotFoundException, IOException {
s.defaultReadObject();
// We cheat and always serialize the Paint as a Color. "-1" means
// no Paint (i.e. use system selection color when painting).
int rgb = s.readInt();
paint = rgb==-1 ? null : new Color(rgb);
alphaComposite = null; // Keep FindBugs happy. This will get set later
}
/**
* Sets the alpha value used in rendering highlights. If this value is
* 1.0f (the default), the highlights are rendered completely
* opaque. This behavior matches that of
* DefaultHighlightPainter and imposes no performance hit. If
* this value is below 1.0f, it represents how opaque the
* highlight will be. There will be a small performance hit for values
* less than 1.0f.
*
* @param alpha The new alpha value to use for transparency.
* @see #getAlpha
*/
public void setAlpha(float alpha) {
this.alpha = Math.max(alpha, 0.0f);
this.alpha = Math.min(1.0f, this.alpha);
alphaComposite = null; // So it is recreated with new alpha.
}
/**
* Sets the Paint (usually a java.awt.Color)
* used to paint this highlight.
*
* @param paint The new Paint.
* @see #getPaint
*/
public void setPaint(Paint paint) {
this.paint = paint;
}
/**
* Sets whether rounded edges are used when painting this highlight.
*
* @param rounded Whether rounded edges should be used.
* @see #getRoundedEdges
*/
public void setRoundedEdges(boolean rounded) {
roundedEdges = rounded;
}
/**
* Serializes this painter.
*
* @param s The stream to write to.
* @throws IOException If an IO error occurs.
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
int rgb = -1; // No Paint -> Use JTextComponent's selection color
if (paint!=null) {
// NOTE: We cheat and always serialize the Paint as a Color.
// This is (practically) always the case anyway.
Color c = (paint instanceof Color) ? ((Color)paint) :
SystemColor.textHighlight;
rgb = c.getRGB();
}
s.writeInt(rgb);
}
}