libjava/javax/swing/text/PasswordView.java

   1 /* PasswordView.java --
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.swing.text;
  40
  41 import java.awt.Color;
  42 import java.awt.Graphics;
  43
  44 import javax.swing.JPasswordField;
  45
  46 public class PasswordView extends FieldView
  47 {
  48   /**
  49    * Buffer for putting the echo char into it and
  50    * then using it to draw it into the view.
  51    */
  52   private char[] oneCharBuffer = new char[1];
  53
  54   public PasswordView(Element elem)
  55   {
  56     super(elem);
  57   }
  58
  59   /**
  60    * Draws one echo character at a given position.
  61    *
  62    * @param g the <code>Graphics</code> object to draw to
  63    * @param x the x-position
  64    * @param y the y-position
  65    * @param ch the echo character
  66    *
  67    * @return the next x position right of the drawn character
  68    */
  69   protected int drawEchoCharacter(Graphics g, int x, int y, char ch)
  70   {
  71     // Update font metrics.
  72     updateMetrics();
  73
  74     // Draw character.
  75     oneCharBuffer[0] = ch;
  76     g.drawChars(oneCharBuffer, 0, 1, x, y);
  77
  78     // Return new x position right of drawn character.
  79     return x + metrics.charWidth(ch);
  80   }
  81
  82   private char getEchoChar()
  83   {
  84     char ch = ((JPasswordField) getContainer()).getEchoChar();
  85
  86     if (ch == 0)
  87       ch = '*';
  88
  89     return ch;
  90   }
  91
  92   /**
  93    * Draws selected text at a given position.
  94    *
  95    * @param g the <code>Graphics</code> object to draw to
  96    * @param x the x-position
  97    * @param y the y-position
  98    * @param p0 the position of the first character to draw
  99    * @param p1 the position of the first character not to draw
 100    *
 101    * @return the next x position right of the drawn character
 102    */
 103   protected int drawSelectedText(Graphics g, int x, int y, int p0, int p1)
 104     throws BadLocationException
 105   {
 106     // FIXME: Throw BadLocationException somehow.
 107
 108     // Update font metrics.
 109     updateMetrics();
 110
 111     // Get echo character.
 112     char ch = getEchoChar();
 113
 114     // Set color for selected text.
 115     g.setColor(selectedColor);
 116     g.setColor(Color.BLACK);
 117
 118     // Initialize buffer for faster drawing of all characters.
 119     int len = p1 - p0;
 120     char[] buffer = new char[len];
 121     for (int index = 0; index < len; ++index)
 122       buffer[index] = ch;
 123
 124     // Draw echo charaters.
 125     g.drawChars(buffer, 0, len, x, y);
 126
 127     // Return new x position right of all drawn characters.
 128     return x + len * metrics.charWidth(ch);
 129   }
 130
 131   /**
 132    * Draws unselected text at a given position.
 133    *
 134    * @param g the <code>Graphics</code> object to draw to
 135    * @param x the x-position
 136    * @param y the y-position
 137    * @param p0 the position of the first character to draw
 138    * @param p1 the position of the first character not to draw
 139    *
 140    * @return the next x position right of the drawn character
 141    */
 142   protected int drawUnselectedText(Graphics g, int x, int y, int p0, int p1)
 143     throws BadLocationException
 144   {
 145     // FIXME: Throw BadLocationException somehow.
 146
 147     // Update font metrics.
 148     updateMetrics();
 149
 150     // Get echo character.
 151     char ch = getEchoChar();
 152
 153     // Set color for unselected text.
 154     g.setColor(unselectedColor);
 155     g.setColor(Color.BLACK);
 156
 157     // Initialize buffer for faster drawing of all characters.
 158     int len = p1 - p0;
 159     char[] buffer = new char[len];
 160     for (int index = 0; index < len; ++index)
 161       buffer[index] = ch;
 162
 163     // Draw echo charaters.
 164     g.drawChars(buffer, 0, len, x, y);
 165
 166     // Return new x position right of all drawn characters.
 167     return x + len * metrics.charWidth(ch);
 168   }
 169 }
 170