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    1   /*
    2    * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   package javax.swing.text;
   26   
   27   import sun.swing.SwingUtilities2;
   28   import java.awt;
   29   import javax.swing.JPasswordField;
   30   
   31   /**
   32    * Implements a View suitable for use in JPasswordField
   33    * UI implementations.  This is basically a field ui that
   34    * renders its contents as the echo character specified
   35    * in the associated component (if it can narrow the
   36    * component to a JPasswordField).
   37    *
   38    * @author  Timothy Prinzing
   39    * @see     View
   40    */
   41   public class PasswordView extends FieldView {
   42   
   43       /**
   44        * Constructs a new view wrapped on an element.
   45        *
   46        * @param elem the element
   47        */
   48       public PasswordView(Element elem) {
   49           super(elem);
   50       }
   51   
   52       /**
   53        * Renders the given range in the model as normal unselected
   54        * text.  This sets the foreground color and echos the characters
   55        * using the value returned by getEchoChar().
   56        *
   57        * @param g the graphics context
   58        * @param x the starting X coordinate >= 0
   59        * @param y the starting Y coordinate >= 0
   60        * @param p0 the starting offset in the model >= 0
   61        * @param p1 the ending offset in the model >= p0
   62        * @return the X location of the end of the range >= 0
   63        * @exception BadLocationException if p0 or p1 are out of range
   64        */
   65       protected int drawUnselectedText(Graphics g, int x, int y,
   66                                        int p0, int p1) throws BadLocationException {
   67   
   68           Container c = getContainer();
   69           if (c instanceof JPasswordField) {
   70               JPasswordField f = (JPasswordField) c;
   71               if (! f.echoCharIsSet()) {
   72                   return super.drawUnselectedText(g, x, y, p0, p1);
   73               }
   74               if (f.isEnabled()) {
   75                   g.setColor(f.getForeground());
   76               }
   77               else {
   78                   g.setColor(f.getDisabledTextColor());
   79               }
   80               char echoChar = f.getEchoChar();
   81               int n = p1 - p0;
   82               for (int i = 0; i < n; i++) {
   83                   x = drawEchoCharacter(g, x, y, echoChar);
   84               }
   85           }
   86           return x;
   87       }
   88   
   89       /**
   90        * Renders the given range in the model as selected text.  This
   91        * is implemented to render the text in the color specified in
   92        * the hosting component.  It assumes the highlighter will render
   93        * the selected background.  Uses the result of getEchoChar() to
   94        * display the characters.
   95        *
   96        * @param g the graphics context
   97        * @param x the starting X coordinate >= 0
   98        * @param y the starting Y coordinate >= 0
   99        * @param p0 the starting offset in the model >= 0
  100        * @param p1 the ending offset in the model >= p0
  101        * @return the X location of the end of the range >= 0
  102        * @exception BadLocationException if p0 or p1 are out of range
  103        */
  104       protected int drawSelectedText(Graphics g, int x,
  105                                      int y, int p0, int p1) throws BadLocationException {
  106           g.setColor(selected);
  107           Container c = getContainer();
  108           if (c instanceof JPasswordField) {
  109               JPasswordField f = (JPasswordField) c;
  110               if (! f.echoCharIsSet()) {
  111                   return super.drawSelectedText(g, x, y, p0, p1);
  112               }
  113               char echoChar = f.getEchoChar();
  114               int n = p1 - p0;
  115               for (int i = 0; i < n; i++) {
  116                   x = drawEchoCharacter(g, x, y, echoChar);
  117               }
  118           }
  119           return x;
  120       }
  121   
  122       /**
  123        * Renders the echo character, or whatever graphic should be used
  124        * to display the password characters.  The color in the Graphics
  125        * object is set to the appropriate foreground color for selected
  126        * or unselected text.
  127        *
  128        * @param g the graphics context
  129        * @param x the starting X coordinate >= 0
  130        * @param y the starting Y coordinate >= 0
  131        * @param c the echo character
  132        * @return the updated X position >= 0
  133        */
  134       protected int drawEchoCharacter(Graphics g, int x, int y, char c) {
  135           ONE[0] = c;
  136           SwingUtilities2.drawChars(Utilities.getJComponent(this),
  137                                     g, ONE, 0, 1, x, y);
  138           return x + g.getFontMetrics().charWidth(c);
  139       }
  140   
  141       /**
  142        * Provides a mapping from the document model coordinate space
  143        * to the coordinate space of the view mapped to it.
  144        *
  145        * @param pos the position to convert >= 0
  146        * @param a the allocated region to render into
  147        * @return the bounding box of the given position
  148        * @exception BadLocationException  if the given position does not
  149        *   represent a valid location in the associated document
  150        * @see View#modelToView
  151        */
  152       public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {
  153           Container c = getContainer();
  154           if (c instanceof JPasswordField) {
  155               JPasswordField f = (JPasswordField) c;
  156               if (! f.echoCharIsSet()) {
  157                   return super.modelToView(pos, a, b);
  158               }
  159               char echoChar = f.getEchoChar();
  160               FontMetrics m = f.getFontMetrics(f.getFont());
  161   
  162               Rectangle alloc = adjustAllocation(a).getBounds();
  163               int dx = (pos - getStartOffset()) * m.charWidth(echoChar);
  164               alloc.x += dx;
  165               alloc.width = 1;
  166               return alloc;
  167           }
  168           return null;
  169       }
  170   
  171       /**
  172        * Provides a mapping from the view coordinate space to the logical
  173        * coordinate space of the model.
  174        *
  175        * @param fx the X coordinate >= 0.0f
  176        * @param fy the Y coordinate >= 0.0f
  177        * @param a the allocated region to render into
  178        * @return the location within the model that best represents the
  179        *  given point in the view
  180        * @see View#viewToModel
  181        */
  182       public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {
  183           bias[0] = Position.Bias.Forward;
  184           int n = 0;
  185           Container c = getContainer();
  186           if (c instanceof JPasswordField) {
  187               JPasswordField f = (JPasswordField) c;
  188               if (! f.echoCharIsSet()) {
  189                   return super.viewToModel(fx, fy, a, bias);
  190               }
  191               char echoChar = f.getEchoChar();
  192               int charWidth = f.getFontMetrics(f.getFont()).charWidth(echoChar);
  193               a = adjustAllocation(a);
  194               Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a :
  195                                 a.getBounds();
  196               n = (charWidth > 0 ?
  197                    ((int)fx - alloc.x) / charWidth : Integer.MAX_VALUE);
  198               if (n < 0) {
  199                   n = 0;
  200               }
  201               else if (n > (getStartOffset() + getDocument().getLength())) {
  202                   n = getDocument().getLength() - getStartOffset();
  203               }
  204           }
  205           return getStartOffset() + n;
  206       }
  207   
  208       /**
  209        * Determines the preferred span for this view along an
  210        * axis.
  211        *
  212        * @param axis may be either View.X_AXIS or View.Y_AXIS
  213        * @return   the span the view would like to be rendered into >= 0.
  214        *           Typically the view is told to render into the span
  215        *           that is returned, although there is no guarantee.
  216        *           The parent may choose to resize or break the view.
  217        */
  218       public float getPreferredSpan(int axis) {
  219           switch (axis) {
  220           case View.X_AXIS:
  221               Container c = getContainer();
  222               if (c instanceof JPasswordField) {
  223                   JPasswordField f = (JPasswordField) c;
  224                   if (f.echoCharIsSet()) {
  225                       char echoChar = f.getEchoChar();
  226                       FontMetrics m = f.getFontMetrics(f.getFont());
  227                       Document doc = getDocument();
  228                       return m.charWidth(echoChar) * getDocument().getLength();
  229                   }
  230               }
  231           }
  232           return super.getPreferredSpan(axis);
  233       }
  234   
  235       static char[] ONE = new char[1];
  236   }

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