1 /*

     2  * Copyright (c) 1997, 2013, 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 java.awt.*;

    28 import javax.swing.*;

    29 import javax.swing.event.*;

    30 

    31 /**

    32  * Extends the multi-line plain text view to be suitable

    33  * for a single-line editor view.  If the view is

    34  * allocated extra space, the field must adjust for it.

    35  * If the hosting component is a JTextField, this view

    36  * will manage the ranges of the associated BoundedRangeModel

    37  * and will adjust the horizontal allocation to match the

    38  * current visibility settings of the JTextField.

    39  *

    40  * @author  Timothy Prinzing

    41  * @see     View

    42  */

    43 public class FieldView extends PlainView {

    44 

    45     /**

    46      * Constructs a new FieldView wrapped on an element.

    47      *

    48      * @param elem the element

    49      */

    50     public FieldView(Element elem) {

    51         super(elem);

    52     }

    53 

    54     /**

    55      * Fetches the font metrics associated with the component hosting

    56      * this view.

    57      *

    58      * @return the metrics

    59      */

    60     protected FontMetrics getFontMetrics() {

    61         Component c = getContainer();

    62         return c.getFontMetrics(c.getFont());

    63     }

    64 

    65     /**

    66      * Adjusts the allocation given to the view

    67      * to be a suitable allocation for a text field.

    68      * If the view has been allocated more than the

    69      * preferred span vertically, the allocation is

    70      * changed to be centered vertically.  Horizontally

    71      * the view is adjusted according to the horizontal

    72      * alignment property set on the associated JTextField

    73      * (if that is the type of the hosting component).

    74      *

    75      * @param a the allocation given to the view, which may need

    76      *  to be adjusted.

    77      * @return the allocation that the superclass should use.

    78      */

    79     protected Shape adjustAllocation(Shape a) {

    80         if (a != null) {

    81             Rectangle bounds = a.getBounds();

    82             int vspan = (int) getPreferredSpan(Y_AXIS);

    83             int hspan = (int) getPreferredSpan(X_AXIS);

    84             if (bounds.height != vspan) {

    85                 int slop = bounds.height - vspan;

    86                 bounds.y += slop / 2;

    87                 bounds.height -= slop;

    88             }

    89 

    90             // horizontal adjustments

    91             Component c = getContainer();

    92             if (c instanceof JTextField) {

    93                 JTextField field = (JTextField) c;

    94                 BoundedRangeModel vis = field.getHorizontalVisibility();

    95                 int max = Math.max(hspan, bounds.width);

    96                 int value = vis.getValue();

    97                 int extent = Math.min(max, bounds.width - 1);

    98                 if ((value + extent) > max) {

    99                     value = max - extent;

   100                 }

   101                 vis.setRangeProperties(value, extent, vis.getMinimum(),

   102                                        max, false);

   103                 if (hspan < bounds.width) {

   104                     // horizontally align the interior

   105                     int slop = bounds.width - 1 - hspan;

   106 

   107                     int align = ((JTextField)c).getHorizontalAlignment();

   108                     if(Utilities.isLeftToRight(c)) {

   109                         if(align==LEADING) {

   110                             align = LEFT;

   111                         }

   112                         else if(align==TRAILING) {

   113                             align = RIGHT;

   114                         }

   115                     }

   116                     else {

   117                         if(align==LEADING) {

   118                             align = RIGHT;

   119                         }

   120                         else if(align==TRAILING) {

   121                             align = LEFT;

   122                         }

   123                     }

   124 

   125                     switch (align) {

   126                     case SwingConstants.CENTER:

   127                         bounds.x += slop / 2;

   128                         bounds.width -= slop;

   129                         break;

   130                     case SwingConstants.RIGHT:

   131                         bounds.x += slop;

   132                         bounds.width -= slop;

   133                         break;

   134                     }

   135                 } else {

   136                     // adjust the allocation to match the bounded range.

   137                     bounds.width = hspan;

   138                     bounds.x -= vis.getValue();

   139                 }

   140             }

   141             return bounds;

   142         }

   143         return null;

   144     }

   145 

   146     /**

   147      * Update the visibility model with the associated JTextField

   148      * (if there is one) to reflect the current visibility as a

   149      * result of changes to the document model.  The bounded

   150      * range properties are updated.  If the view hasn't yet been

   151      * shown the extent will be zero and we just set it to be full

   152      * until determined otherwise.

   153      */

   154     void updateVisibilityModel() {

   155         Component c = getContainer();

   156         if (c instanceof JTextField) {

   157             JTextField field = (JTextField) c;

   158             BoundedRangeModel vis = field.getHorizontalVisibility();

   159             int hspan = (int) getPreferredSpan(X_AXIS);

   160             int extent = vis.getExtent();

   161             int maximum = Math.max(hspan, extent);

   162             extent = (extent == 0) ? maximum : extent;

   163             int value = maximum - extent;

   164             int oldValue = vis.getValue();

   165             if ((oldValue + extent) > maximum) {

   166                 oldValue = maximum - extent;

   167             }

   168             value = Math.max(0, Math.min(value, oldValue));

   169             vis.setRangeProperties(value, extent, 0, maximum, false);

   170         }

   171     }

   172 

   173     // --- View methods -------------------------------------------

   174 

   175     /**

   176      * Renders using the given rendering surface and area on that surface.

   177      * The view may need to do layout and create child views to enable

   178      * itself to render into the given allocation.

   179      *

   180      * @param g the rendering surface to use

   181      * @param a the allocated region to render into

   182      *

   183      * @see View#paint

   184      */

   185     public void paint(Graphics g, Shape a) {

   186         Rectangle r = (Rectangle) a;

   187         g.clipRect(r.x, r.y, r.width, r.height);

   188         super.paint(g, a);

   189     }

   190 

   191     /**

   192      * Adjusts <code>a</code> based on the visible region and returns it.

   193      */

   194     Shape adjustPaintRegion(Shape a) {

   195         return adjustAllocation(a);

   196     }

   197 

   198     /**

   199      * Determines the preferred span for this view along an

   200      * axis.

   201      *

   202      * @param axis may be either View.X_AXIS or View.Y_AXIS

   203      * @return   the span the view would like to be rendered into >= 0.

   204      *           Typically the view is told to render into the span

   205      *           that is returned, although there is no guarantee.

   206      *           The parent may choose to resize or break the view.

   207      */

   208     public float getPreferredSpan(int axis) {

   209         switch (axis) {

   210         case View.X_AXIS:

   211             Segment buff = SegmentCache.getSharedSegment();

   212             Document doc = getDocument();

   213             int width;

   214             try {

   215                 FontMetrics fm = getFontMetrics();

   216                 doc.getText(0, doc.getLength(), buff);

   217                 width = Utilities.getTabbedTextWidth(buff, fm, 0, this, 0);

   218                 if (buff.count > 0) {

   219                     Component c = getContainer();

   220                     firstLineOffset = sun.swing.SwingUtilities2.

   221                         getLeftSideBearing((c instanceof JComponent) ?

   222                                            (JComponent)c : null, fm,

   223                                            buff.array[buff.offset]);

   224                     firstLineOffset = Math.max(0, -firstLineOffset);

   225                 }

   226                 else {

   227                     firstLineOffset = 0;

   228                 }

   229             } catch (BadLocationException bl) {

   230                 width = 0;

   231             }

   232             SegmentCache.releaseSharedSegment(buff);

   233             return width + firstLineOffset;

   234         default:

   235             return super.getPreferredSpan(axis);

   236         }

   237     }

   238 

   239     /**

   240      * Determines the resizability of the view along the

   241      * given axis.  A value of 0 or less is not resizable.

   242      *

   243      * @param axis View.X_AXIS or View.Y_AXIS

   244      * @return the weight -> 1 for View.X_AXIS, else 0

   245      */

   246     public int getResizeWeight(int axis) {

   247         if (axis == View.X_AXIS) {

   248             return 1;

   249         }

   250         return 0;

   251     }

   252 

   253     /**

   254      * Provides a mapping from the document model coordinate space

   255      * to the coordinate space of the view mapped to it.

   256      *

   257      * @param pos the position to convert >= 0

   258      * @param a the allocated region to render into

   259      * @return the bounding box of the given position

   260      * @exception BadLocationException  if the given position does not

   261      *   represent a valid location in the associated document

   262      * @see View#modelToView

   263      */

   264     public Shape modelToView(int pos, Shape a, Position.Bias b) throws BadLocationException {

   265         return super.modelToView(pos, adjustAllocation(a), b);

   266     }

   267 

   268     /**

   269      * Provides a mapping from the view coordinate space to the logical

   270      * coordinate space of the model.

   271      *

   272      * @param fx the X coordinate >= 0.0f

   273      * @param fy the Y coordinate >= 0.0f

   274      * @param a the allocated region to render into

   275      * @return the location within the model that best represents the

   276      *  given point in the view

   277      * @see View#viewToModel

   278      */

   279     public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias) {

   280         return super.viewToModel(fx, fy, adjustAllocation(a), bias);

   281     }

   282 

   283     /**

   284      * Gives notification that something was inserted into the document

   285      * in a location that this view is responsible for.

   286      *

   287      * @param changes the change information from the associated document

   288      * @param a the current allocation of the view

   289      * @param f the factory to use to rebuild if the view has children

   290      * @see View#insertUpdate

   291      */

   292     public void insertUpdate(DocumentEvent changes, Shape a, ViewFactory f) {

   293         super.insertUpdate(changes, adjustAllocation(a), f);

   294         updateVisibilityModel();

   295     }

   296 

   297     /**

   298      * Gives notification that something was removed from the document

   299      * in a location that this view is responsible for.

   300      *

   301      * @param changes the change information from the associated document

   302      * @param a the current allocation of the view

   303      * @param f the factory to use to rebuild if the view has children

   304      * @see View#removeUpdate

   305      */

   306     public void removeUpdate(DocumentEvent changes, Shape a, ViewFactory f) {

   307         super.removeUpdate(changes, adjustAllocation(a), f);

   308         updateVisibilityModel();

   309     }

   310 

   311 }