platform/util/src/com/intellij/util/ui/GraphicsUtil.java

/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * Licensed 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 com.intellij.util.ui;

import com.intellij.openapi.ui.GraphicsConfig;
import org.jetbrains.annotations.NotNull;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Map;

/**
 * @author Konstantin Bulenkov
 */
public class GraphicsUtil {
  @SuppressWarnings("UndesirableClassUsage")
  private static final Graphics2D ourGraphics = new BufferedImage(1,1,BufferedImage.TYPE_INT_ARGB).createGraphics();
  static {
    setupFractionalMetrics(ourGraphics);
    setupAntialiasing(ourGraphics, true, true);
  }

  public static void setupFractionalMetrics(Graphics g) {
    ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
  }

  public static void setupAntialiasing(@NotNull Graphics g2) {
    setupAntialiasing(g2, true, false);
  }

  public static int stringWidth(String text, Font font) {
    setupAntialiasing(ourGraphics, true, true);
    return ourGraphics.getFontMetrics(font).stringWidth(text);
  }

  public static int charsWidth(char[] data, int off, int len, Font font) {
    return ourGraphics.getFontMetrics(font).charsWidth(data, off, len);
  }

  public static int charWidth(char ch,Font font) {
    return ourGraphics.getFontMetrics(font).charWidth(ch);
  }

  public static int charWidth(int ch,Font font) {
    return ourGraphics.getFontMetrics(font).charWidth(ch);
  }

  public static void setupAntialiasing(Graphics g2, boolean enableAA, boolean ignoreSystemSettings) {
    if (g2 instanceof Graphics2D) {
      Graphics2D g = (Graphics2D)g2;
      Toolkit tk = Toolkit.getDefaultToolkit();
      //noinspection HardCodedStringLiteral
      Map map = (Map)tk.getDesktopProperty("awt.font.desktophints");

      if (map != null && !ignoreSystemSettings) {
        g.addRenderingHints(map);
      } else {
        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
                           enableAA ? RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HBGR : RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);
      }
    }
  }

  public static GraphicsConfig setupAAPainting(Graphics g) {
    final GraphicsConfig config = new GraphicsConfig(g);
    final Graphics2D g2 = (Graphics2D)g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_NORMALIZE);
    return config;
  }

  public static GraphicsConfig paintWithAlpha(Graphics g, float alpha) {
    assert 0.0f <= alpha && alpha <= 1.0f : "alpha should be in range 0.0f .. 1.0f";
    final GraphicsConfig config = new GraphicsConfig(g);
    final Graphics2D g2 = (Graphics2D)g;

    g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
    return config;
  }
}