org.fife.ui.rtextarea.SmartHighlightPainter Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rsyntaxtextarea Show documentation

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.

There is a newer version: 3.5.1

Show newest version

/*
 * 10/01/2009
 *
 * SmartHighlightPainter.java - A highlight painter whose rendered highlights
 * don't "grow" when the user appends text to the end of them.
 *
 * This library is distributed under a modified BSD license.  See the included
 * LICENSE file for details.
 */
package org.fife.ui.rtextarea;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Paint;
import java.awt.Rectangle;
import java.awt.Shape;

import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
import javax.swing.text.Position;
import javax.swing.text.View;


/**
 * A "smart" highlight painter designed for use in RSyntaxTextArea.  Adds the
 * following features:
 *
 * 
 *    Rendered highlights don't "grow" when users append text to the "end"
 *        of them.  This is implemented by assuming that the highlights
 *        themselves specify their end offset as one offset "too short".  This
 *        behavior is baked into various RSTA highlights (mark all, mark
 *        occurrences, etc.).
 *    
Ability to paint a border line around highlights.
 * 
 *
 * @author Robert Futrell
 * @version 1.0
 */
public class SmartHighlightPainter extends ChangeableHighlightPainter {

	private Color borderColor;
	private boolean paintBorder;


	/**
	 * Creates a highlight painter that defaults to blue.
	 */
	public SmartHighlightPainter() {
		super(Color.BLUE);
	}


	/**
	 * Constructor.
	 *
	 * @param paint The color or paint to use for this painter.
	 */
	public SmartHighlightPainter(Paint paint) {
		super(paint);
	}


	/**
	 * Returns whether a border is painted around marked occurrences.
	 *
	 * @return Whether a border is painted.
	 * @see #setPaintBorder(boolean)
	 * @see #getPaint()
	 */
	public boolean getPaintBorder() {
		return paintBorder;
	}


	/**
	 * {@inheritDoc}
	 */
	@Override
	public Shape paintLayer(Graphics g, int p0, int p1, Shape viewBounds,
								JTextComponent c, View view) {

		g.setColor((Color)getPaint());

		// 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 (p0==p1) {
			try {
				Shape s = view.modelToView(p0, viewBounds,
											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;
			}
		}

		if (p0 == view.getStartOffset() && p1 == view.getEndOffset()) {
			// Contained in view, can just use bounds.
			Rectangle alloc;
			if (viewBounds instanceof Rectangle) {
				alloc = (Rectangle) viewBounds;
			} else {
				alloc = viewBounds.getBounds();
			}
			g.fillRect(alloc.x, alloc.y, alloc.width, alloc.height);
			return alloc;
		}

		// Should only render part of View.
		try {
			// --- determine locations ---
			Shape shape = view.modelToView(p0, Position.Bias.Forward, p1,
					Position.Bias.Backward, viewBounds);
			Rectangle r = shape instanceof Rectangle ? (Rectangle) shape :
														shape.getBounds();
			g.fillRect(r.x, r.y, r.width, r.height);
			if (paintBorder) {
				g.setColor(borderColor);
				g.drawRect(r.x,r.y, r.width-1,r.height-1);
			}
			return r;
		} catch (BadLocationException e) { // Never happens
			e.printStackTrace();
			return null;
		}

	}


	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setPaint(Paint paint) {
		super.setPaint(paint);
		if (paint instanceof Color) {
			borderColor = ((Color)paint).darker();
		}
	}


	/**
	 * Toggles whether a border is painted around highlights.
	 *
	 * @param paint Whether to paint a border.
	 * @see #getPaintBorder()
	 * @see #setPaint(Paint)
	 */
	public void setPaintBorder(boolean paint) {
		this.paintBorder = paint;
	}


}