/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.resources;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.geom.Rectangle2D;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import org.geotools.io.ExpandedTabWriter;
/**
* A set of utilities methods for painting in a {@link Graphics2D} handle.
* Method in this class was used to be in {@link org.geotools.gui.swing.ExceptionMonitor}.
* We had to extract them in a separated class in order to avoid dependencies of renderer
* module toward the GUI one, especially since the extracted methods are not Swing specific.
*
* @since 2.0
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*/
public final class GraphicsUtilities {
/**
* Number of spaces to leave between each tab.
*/
private static final int TAB_WIDTH = 4;
/**
* The creation of {@code GraphicsUtilities} class objects is forbidden.
*/
private GraphicsUtilities() {
}
/**
* Writes the specified exception trace in the specified graphics
* context. This method is useful when an exception has occurred
* inside a {@link java.awt.Component#paint} method and we want to
* write it rather than leaving an empty window.
*
* @param exception Exception whose trace we want to write.
* @param graphics Graphics context in which to write exception. The
* graphics context should be in its initial state (default affine
* transform, default colour, etc...)
* @param widgetBounds Size of the trace which was being drawn.
*/
public static void paintStackTrace(final Graphics2D graphics,
final Rectangle widgetBounds,
final Throwable exception)
{
/*
* Obtains the exception trace in the form of a character chain.
* The carriage returns in this chain can be "\r", "\n" or "r\n".
*/
final String message = printStackTrace(exception);
/*
* Examines the character chain line by line.
* "Glyphs" will be created as we go along and we will take advantage
* of this to calculate the necessary space.
*/
double width = 0, height = 0;
final List<GlyphVector> glyphs = new ArrayList<GlyphVector>();
final List<Rectangle2D> bounds = new ArrayList<Rectangle2D>();
final int length = message.length();
final Font font = graphics.getFont();
final FontRenderContext context = graphics.getFontRenderContext();
for (int i = 0; i < length;) {
int ir = message.indexOf('\r', i);
int in = message.indexOf('\n', i);
if (ir < 0) ir = length;
if (in < 0) in = length;
final int irn = Math.min(ir, in);
final GlyphVector line = font.createGlyphVector(context, message.substring(i, irn));
final Rectangle2D rect = line.getVisualBounds();
final double w = rect.getWidth();
if (w > width) width = w;
height += rect.getHeight();
glyphs.add(line);
bounds.add(rect);
i = (Math.abs(ir - in) <= 1 ? Math.max(ir, in) : irn) + 1;
}
/*
* Proceeds to draw all the previously calculated glyphs.
*/
float xpos = (float) (0.5 * (widgetBounds.width - width));
float ypos = (float) (0.5 * (widgetBounds.height - height));
final int size = glyphs.size();
for (int i = 0; i < size; i++) {
final GlyphVector line = glyphs.get(i);
final Rectangle2D rect = bounds.get(i);
ypos += rect.getHeight();
graphics.drawGlyphVector(line, xpos, ypos);
}
}
/**
* Returns an exception trace. All tabs will have been replaced by 4 white spaces.
* This method was used to be a private one in {@link org.geotools.gui.swing.ExceptionMonitor}.
* Do not rely on it.
*/
public static String printStackTrace(final Throwable exception) {
final StringWriter writer = new StringWriter();
exception.printStackTrace(new PrintWriter(new ExpandedTabWriter(writer, TAB_WIDTH)));
return writer.toString();
}
}