1 files changed, 63 insertions, 0 deletions
diff --git a/tool/src/org/antlr/v4/gui/SystemFontMetrics.java b/tool/src/org/antlr/v4/gui/SystemFontMetrics.java
new file mode 100644
index 0000000..fb2b17a
--- /dev/null
+++ b/tool/src/org/antlr/v4/gui/SystemFontMetrics.java
@@ -0,0 +1,63 @@
+/*
+ * [The "BSD license"]
+ *  Copyright (c) 2012 Terence Parr
+ *  Copyright (c) 2012 Sam Harwell
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.antlr.v4.gui;
+
+import java.awt.*;
+import java.awt.font.FontRenderContext;
+import java.awt.font.TextLayout;
+import java.awt.image.BufferedImage;
+
+/**
+ *
+ * @author Sam Harwell
+ */
+public class SystemFontMetrics extends BasicFontMetrics {
+	protected final Font font;
+
+	public SystemFontMetrics(String fontName) {
+		BufferedImage img = new BufferedImage(40, 40, BufferedImage.TYPE_4BYTE_ABGR);
+		Graphics2D graphics = GraphicsEnvironment.getLocalGraphicsEnvironment().createGraphics(img);
+		FontRenderContext fontRenderContext = graphics.getFontRenderContext();
+		this.font = new Font(fontName, Font.PLAIN, 1000);
+		double maxHeight = 0;
+		for (int i = 0; i < 255; i++) {
+			TextLayout layout = new TextLayout(Character.toString((char)i), font, fontRenderContext);
+			maxHeight = Math.max(maxHeight, layout.getBounds().getHeight());
+			super.widths[i] = (int)layout.getAdvance();
+		}
+
+		super.maxCharHeight = (int)Math.round(maxHeight);
+	}
+
+	public Font getFont() {
+		return font;
+	}
+}