net.alantea.swing.ui.TextTool Maven / Gradle / Ivy

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package net.alantea.swing.ui;

import java.awt.Font;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.HashMap;
import java.util.Map;

import javax.swing.JComponent;

public class TextTool
{
   private static Map fontMap = new HashMap<>();
   
   public static void drawString(JComponent comp, Graphics g, String text, Rectangle view)
   {
      Font fontToUse = getBestFontFor(comp, text, view);
      g.setFont(fontToUse);

      int refWidth = comp.getFontMetrics(fontToUse).stringWidth(text);
      int refHeight = comp.getFontMetrics(fontToUse).getHeight();
      
      int x = view.x + ((view.width - refWidth) / 2);
      int y = view.y + ((view.height - refHeight) / 2 + comp.getFontMetrics(fontToUse).getAscent());
      
      g.drawString(text, x, y);
   }
   
   public static Font getBestFontFor(JComponent comp, String text, Rectangle view)
   {
      Font font = comp.getFont();
      int refWidth = comp.getFontMetrics(font).stringWidth(text);
      int refHeight = comp.getFontMetrics(font).getHeight();
      
      double hRatio = view.width / ((double) refWidth);
      double vRatio = view.height / ((double) refHeight);
      double ratio = Math.min(hRatio, vRatio);
      
      int targetHeight = (int) (font.getSize() * ratio);
      Font targetFont = getResizedFont(font, targetHeight);
      
      int calcWidth = comp.getFontMetrics(targetFont).stringWidth(text);
      int calcHeight = comp.getFontMetrics(targetFont).getHeight();
      
      while ((calcWidth < view.width) && (calcHeight < view.height))
      {
         targetFont = getResizedFont(font, targetHeight + 1);
         
         calcWidth = comp.getFontMetrics(targetFont).stringWidth(text);
         calcHeight = comp.getFontMetrics(targetFont).getHeight();
         if ((calcWidth < view.width) && (calcHeight < view.height))
         {
            targetHeight++;
         }
      }
      
      while ((calcWidth > view.width) && (calcHeight > view.height))
      {
         targetFont = getResizedFont(font, targetHeight - 1);
         
         calcWidth = comp.getFontMetrics(targetFont).stringWidth(text);
         calcHeight = comp.getFontMetrics(targetFont).getHeight();
         if ((calcWidth > view.width) && (calcHeight > view.height))
         {
            targetHeight--;
         }
      }
      return targetFont;
   }
   
   private static Font getResizedFont(Font font, int height)
   {
      Font targetFont = fontMap.get(font.getFamily() + "-" + font.getStyle() + "-" + height);
      if (targetFont == null)
      {
         targetFont = font.deriveFont((float)height);
         fontMap.put(font.getFamily() + "-" + font.getStyle() + "-" + height, targetFont);
      }
      return targetFont;
   }
}