001 /*
002 * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025 package javax.swing.text;
026
027 import java.awt.*;
028 import javax.swing.*;
029 import javax.swing.event.*;
030
031 /**
032 * Extends the multi-line plain text view to be suitable
033 * for a single-line editor view. If the view is
034 * allocated extra space, the field must adjust for it.
035 * If the hosting component is a JTextField, this view
036 * will manage the ranges of the associated BoundedRangeModel
037 * and will adjust the horizontal allocation to match the
038 * current visibility settings of the JTextField.
039 *
040 * @author Timothy Prinzing
041 * @version 1.33 05/05/07
042 * @see View
043 */
044 public class FieldView extends PlainView {
045
046 /**
047 * Constructs a new FieldView wrapped on an element.
048 *
049 * @param elem the element
050 */
051 public FieldView(Element elem) {
052 super (elem);
053 }
054
055 /**
056 * Fetches the font metrics associated with the component hosting
057 * this view.
058 *
059 * @return the metrics
060 */
061 protected FontMetrics getFontMetrics() {
062 Component c = getContainer();
063 return c.getFontMetrics(c.getFont());
064 }
065
066 /**
067 * Adjusts the allocation given to the view
068 * to be a suitable allocation for a text field.
069 * If the view has been allocated more than the
070 * preferred span vertically, the allocation is
071 * changed to be centered vertically. Horizontally
072 * the view is adjusted according to the horizontal
073 * alignment property set on the associated JTextField
074 * (if that is the type of the hosting component).
075 *
076 * @param a the allocation given to the view, which may need
077 * to be adjusted.
078 * @return the allocation that the superclass should use.
079 */
080 protected Shape adjustAllocation(Shape a) {
081 if (a != null) {
082 Rectangle bounds = a.getBounds();
083 int vspan = (int) getPreferredSpan(Y_AXIS);
084 int hspan = (int) getPreferredSpan(X_AXIS);
085 if (bounds.height != vspan) {
086 int slop = bounds.height - vspan;
087 bounds.y += slop / 2;
088 bounds.height -= slop;
089 }
090
091 // horizontal adjustments
092 Component c = getContainer();
093 if (c instanceof JTextField) {
094 JTextField field = (JTextField) c;
095 BoundedRangeModel vis = field.getHorizontalVisibility();
096 int max = Math.max(hspan, bounds.width);
097 int value = vis.getValue();
098 int extent = Math.min(max, bounds.width - 1);
099 if ((value + extent) > max) {
100 value = max - extent;
101 }
102 vis.setRangeProperties(value, extent, vis.getMinimum(),
103 max, false);
104 if (hspan < bounds.width) {
105 // horizontally align the interior
106 int slop = bounds.width - 1 - hspan;
107
108 int align = ((JTextField) c)
109 .getHorizontalAlignment();
110 if (Utilities.isLeftToRight(c)) {
111 if (align == LEADING) {
112 align = LEFT;
113 } else if (align == TRAILING) {
114 align = RIGHT;
115 }
116 } else {
117 if (align == LEADING) {
118 align = RIGHT;
119 } else if (align == TRAILING) {
120 align = LEFT;
121 }
122 }
123
124 switch (align) {
125 case SwingConstants.CENTER:
126 bounds.x += slop / 2;
127 bounds.width -= slop;
128 break;
129 case SwingConstants.RIGHT:
130 bounds.x += slop;
131 bounds.width -= slop;
132 break;
133 }
134 } else {
135 // adjust the allocation to match the bounded range.
136 bounds.width = hspan;
137 bounds.x -= vis.getValue();
138 }
139 }
140 return bounds;
141 }
142 return null;
143 }
144
145 /**
146 * Update the visibility model with the associated JTextField
147 * (if there is one) to reflect the current visibility as a
148 * result of changes to the document model. The bounded
149 * range properties are updated. If the view hasn't yet been
150 * shown the extent will be zero and we just set it to be full
151 * until determined otherwise.
152 */
153 void updateVisibilityModel() {
154 Component c = getContainer();
155 if (c instanceof JTextField) {
156 JTextField field = (JTextField) c;
157 BoundedRangeModel vis = field.getHorizontalVisibility();
158 int hspan = (int) getPreferredSpan(X_AXIS);
159 int extent = vis.getExtent();
160 int maximum = Math.max(hspan, extent);
161 extent = (extent == 0) ? maximum : extent;
162 int value = maximum - extent;
163 int oldValue = vis.getValue();
164 if ((oldValue + extent) > maximum) {
165 oldValue = maximum - extent;
166 }
167 value = Math.max(0, Math.min(value, oldValue));
168 vis.setRangeProperties(value, extent, 0, maximum, false);
169 }
170 }
171
172 // --- View methods -------------------------------------------
173
174 /**
175 * Renders using the given rendering surface and area on that surface.
176 * The view may need to do layout and create child views to enable
177 * itself to render into the given allocation.
178 *
179 * @param g the rendering surface to use
180 * @param a the allocated region to render into
181 *
182 * @see View#paint
183 */
184 public void paint(Graphics g, Shape a) {
185 Rectangle r = (Rectangle) a;
186 g.clipRect(r.x, r.y, r.width, r.height);
187 super .paint(g, a);
188 }
189
190 /**
191 * Adjusts <code>a</code> based on the visible region and returns it.
192 */
193 Shape adjustPaintRegion(Shape a) {
194 return adjustAllocation(a);
195 }
196
197 /**
198 * Determines the preferred span for this view along an
199 * axis.
200 *
201 * @param axis may be either View.X_AXIS or View.Y_AXIS
202 * @return the span the view would like to be rendered into >= 0.
203 * Typically the view is told to render into the span
204 * that is returned, although there is no guarantee.
205 * The parent may choose to resize or break the view.
206 */
207 public float getPreferredSpan(int axis) {
208 switch (axis) {
209 case View.X_AXIS:
210 Segment buff = SegmentCache.getSharedSegment();
211 Document doc = getDocument();
212 int width;
213 try {
214 FontMetrics fm = getFontMetrics();
215 doc.getText(0, doc.getLength(), buff);
216 width = Utilities.getTabbedTextWidth(buff, fm, 0, this ,
217 0);
218 if (buff.count > 0) {
219 Component c = getContainer();
220 firstLineOffset = sun.swing.SwingUtilities2
221 .getLeftSideBearing(
222 (c instanceof JComponent) ? (JComponent) c
223 : null, fm,
224 buff.array[buff.offset]);
225 firstLineOffset = Math.max(0, -firstLineOffset);
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)
265 throws BadLocationException {
266 return super .modelToView(pos, adjustAllocation(a), b);
267 }
268
269 /**
270 * Provides a mapping from the view coordinate space to the logical
271 * coordinate space of the model.
272 *
273 * @param fx the X coordinate >= 0.0f
274 * @param fy the Y coordinate >= 0.0f
275 * @param a the allocated region to render into
276 * @return the location within the model that best represents the
277 * given point in the view
278 * @see View#viewToModel
279 */
280 public int viewToModel(float fx, float fy, Shape a,
281 Position.Bias[] bias) {
282 return super .viewToModel(fx, fy, adjustAllocation(a), bias);
283 }
284
285 /**
286 * Gives notification that something was inserted into the document
287 * in a location that this view is responsible for.
288 *
289 * @param changes the change information from the associated document
290 * @param a the current allocation of the view
291 * @param f the factory to use to rebuild if the view has children
292 * @see View#insertUpdate
293 */
294 public void insertUpdate(DocumentEvent changes, Shape a,
295 ViewFactory f) {
296 super .insertUpdate(changes, adjustAllocation(a), f);
297 updateVisibilityModel();
298 }
299
300 /**
301 * Gives notification that something was removed from the document
302 * in a location that this view is responsible for.
303 *
304 * @param changes the change information from the associated document
305 * @param a the current allocation of the view
306 * @param f the factory to use to rebuild if the view has children
307 * @see View#removeUpdate
308 */
309 public void removeUpdate(DocumentEvent changes, Shape a,
310 ViewFactory f) {
311 super.removeUpdate(changes, adjustAllocation(a), f);
312 updateVisibilityModel();
313 }
314
315 }
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