org.netbeans.editor.FontMetricsCache Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.netbeans.editor;
import java.awt.Component;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.font.LineMetrics;
import java.util.HashMap;
/** Static cache that holds the font metrics for the fonts.
* This can generally speed up drawing if the metrics are not cached
* directly by the system.
*
* @author Miloslav Metelka
* @version 1.00
*/
public class FontMetricsCache {
private static HashMap font2FM = new HashMap();
private static HashMap font2Info = new HashMap();
/** Get the font-metrics for the given font.
* @param font font for which the metrics is being retrieved.
* @param c component that is used to retrieve the metrics in case it's
* not yet in the cache.
*/
public static synchronized FontMetrics getFontMetrics(Font f, Component c) {
Object fm = font2FM.get(f);
if (fm == null) {
fm = c.getFontMetrics(f);
font2FM.put(f, fm);
}
return (FontMetrics)fm;
}
/** Get the font-metrics for the given font.
* @param font font for which the metrics is being retrieved.
* @param g graphics that is used to retrieve the metrics in case it's
* not yet in the cache.
*/
public static synchronized FontMetrics getFontMetrics(Font f, Graphics g) {
Object fm = font2FM.get(f);
if (fm == null) {
fm = g.getFontMetrics(f);
font2FM.put(f, fm);
}
return (FontMetrics)fm;
}
/** Get the info about the space-width and strike-through and underline
* constants.
* @param font font for which the info is being retrieved.
*/
public static synchronized Info getInfo(Font f) {
Info info = (Info)font2Info.get(f);
if (info == null) {
info = new InfoImpl(f);
font2Info.put(f, info);
}
return info;
}
/** Clear all the metrics from the cache. It's usually done
* when any of the editor ui is being garbage collected to
* ensure there will be no more unused metrics.
*/
public static synchronized void clear() {
font2FM.clear();
font2Info.clear();
}
public interface Info {
/** Returns the width of the space character */
public int getSpaceWidth(Graphics g);
/** Returns the width of the space character */
public int getSpaceWidth(Component c);
/** Returns the position of the strike-through line
* relative to the baseline.
*/
public float getStrikethroughOffset(Graphics g);
/** Returns the position of the strike-through line
* relative to the baseline.
*/
public float getStrikethroughOffset(Component c);
/** Returns the thickness of the strike-through line. */
public float getStrikethroughThickness(Graphics g);
/** Returns the thickness of the strike-through line. */
public float getStrikethroughThickness(Component c);
/** Returns the position of the underline relative to the baseline. */
public float getUnderlineOffset(Graphics g);
/** Returns the position of the underline relative to the baseline. */
public float getUnderlineOffset(Component c);
/** Returns the thickness of the underline. */
public float getUnderlineThickness(Graphics g);
/** Returns the thickness of the underline. */
public float getUnderlineThickness(Component c);
}
private static class InfoImpl implements Info {
private static final int SW_INITED = 1;
private static final int ST_INITED = 2;
private static final int UL_INITED = 4;
private Font font;
private int inited;
private int spaceWidth;
private float strikethroughOffset;
private float strikethroughThickness;
private float underlineOffset;
private float underlineThickness;
InfoImpl(Font font) {
this.font = font;
}
private synchronized void initSpaceWidth(Graphics g, Component c) {
FontMetrics fm = (g != null) ? getFontMetrics(font, g) : getFontMetrics(font, c);
spaceWidth = fm.stringWidth(" "); // NOI18N
if (spaceWidth <= 0) {
spaceWidth = fm.stringWidth("A") / 3; // NOI18N
}
inited |= SW_INITED;
}
private synchronized void initStrikethrough(Graphics g) {
LineMetrics lm = font.getLineMetrics("aAyY", ((Graphics2D)g).getFontRenderContext()); // NOI18N
strikethroughOffset = lm.getStrikethroughOffset();
strikethroughThickness = lm.getStrikethroughThickness();
inited |= ST_INITED;
}
private synchronized void initUnderline(Graphics g) {
LineMetrics lm = font.getLineMetrics("aAyY", ((Graphics2D)g).getFontRenderContext()); // NOI18N
underlineOffset = lm.getUnderlineOffset();
underlineThickness = lm.getUnderlineThickness();
inited |= UL_INITED;
}
/** Returns the width of the space character */
public int getSpaceWidth(Graphics g) {
if ((inited & SW_INITED) == 0) {
initSpaceWidth(g, null);
}
return spaceWidth;
}
/** Returns the width of the space character */
public int getSpaceWidth(Component c) {
if ((inited & SW_INITED) == 0) {
initSpaceWidth(null, c);
}
return spaceWidth;
}
/** Returns the position of the strike-through line
* relative to the baseline.
*/
public float getStrikethroughOffset(Graphics g) {
if ((inited & ST_INITED) == 0) {
initStrikethrough(g);
}
return strikethroughOffset;
}
/** Returns the position of the strike-through line
* relative to the baseline.
*/
public float getStrikethroughOffset(Component c) {
if ((inited & ST_INITED) == 0) {
initStrikethrough(c.getGraphics());
}
return strikethroughOffset;
}
/** Returns the thickness of the strike-through line. */
public float getStrikethroughThickness(Graphics g) {
if ((inited & ST_INITED) == 0) {
initStrikethrough(g);
}
return strikethroughThickness;
}
/** Returns the thickness of the strike-through line. */
public float getStrikethroughThickness(Component c) {
if ((inited & ST_INITED) == 0) {
initStrikethrough(c.getGraphics());
}
return strikethroughThickness;
}
/** Returns the position of the underline relative to the baseline. */
public float getUnderlineOffset(Graphics g) {
if ((inited & UL_INITED) == 0) {
initUnderline(g);
}
return underlineOffset;
}
/** Returns the position of the underline relative to the baseline. */
public float getUnderlineOffset(Component c) {
if ((inited & UL_INITED) == 0) {
initUnderline(c.getGraphics());
}
return underlineOffset;
}
/** Returns the thickness of the underline. */
public float getUnderlineThickness(Graphics g) {
if ((inited & UL_INITED) == 0) {
initUnderline(g);
}
return underlineThickness;
}
/** Returns the thickness of the underline. */
public float getUnderlineThickness(Component c) {
if ((inited & UL_INITED) == 0) {
initUnderline(c.getGraphics());
}
return underlineThickness;
}
}
}
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