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21 
22 import java.util.*;
23 import java.awt.*;
24 import java.awt.event.*;
25 import javax.swing.*;
26 import javax.swing.tree.*;
27 import javax.swing.event.TreeSelectionListener;
28 import javax.swing.event.TreeSelectionEvent;
29 import java.awt.geom.Rectangle2D;
30 
31 import com.sun.star.accessibility.XAccessible;
32 import com.sun.star.accessibility.XAccessibleContext;
33 import com.sun.star.accessibility.XAccessibleComponent;
34 
35 /** This canvas displays accessible objects graphically.  Each accessible
36     object with graphical representation is represented by an
37     CanvasShape object and has to be added by the
38     <member>addAccessible</member> member function.
39 
40     <p>The canvas listens to selection events of the associated JTree and
41     highlights the first selected node of that tree.</p>
42 */
43 class Canvas
44     extends JPanel
45     implements MouseListener, MouseMotionListener, TreeSelectionListener//, Scrollable
46 {
47     // This constant can be passed to SetZoomMode to always show the whole screen.
48     public static final int WHOLE_SCREEN = -1;
49 
50     public Canvas ()
51     {
52         super (true);
53         maObjects = new java.util.HashMap ();
54         maNodes = new Vector ();
55         maObjectList = new Vector ();
56         maContexts = new Vector ();
57         addMouseListener (this);
58         addMouseMotionListener (this);
59         maBoundingBox = new Rectangle (0,0,100,100);
60         maTree = null;
61         mnHOffset = 0;
62         mnVOffset = 0;
63         mnScale = 1;
64         setShowText(false);
65         setShowDescriptions (true);
66         setShowNames (true);
67         setAntialiasing (true);
68         maLastWidgetSize = new Dimension (0,0);
69     }
70 
71     /** Tell the canvas which tree view to use to highlight accessible
72         objects.
73     */
74     public void setTree (JTree aTree)
75     {
76         if (maTree != null)
77             maTree.removeTreeSelectionListener (this);
78         maTree = aTree;
79         if (maTree != null)
80             maTree.addTreeSelectionListener (this);
81     }
82 
83 
84 
85 
86     public void addNode (AccTreeNode aNode)
87     {
88         if (maNodes.indexOf (aNode) == -1)
89         {
90             maNodes.add (aNode);
91 
92             CanvasShape aObject = (CanvasShape) maObjects.get (aNode);
93             if (aObject == null)
94             {
95                 aObject = new CanvasShape (aNode);
96                 // Update bounding box that includes all objects.
97                 if (maObjects.size() == 0)
98                     maBoundingBox = aObject.getBBox();
99                 else
100                     maBoundingBox = maBoundingBox.union (aObject.getBBox());
101 
102                 maObjects.put (aNode, aObject);
103                 maObjectList.add (aObject);
104 
105             }
106             repaint ();
107         }
108     }
109 
110     public void removeNode (AccTreeNode aNode)
111     {
112         int i = maNodes.indexOf (aNode);
113         if( i != -1 )
114         {
115             Object aObject = maObjects.get(aNode);
116             maObjectList.remove (aObject);
117             maObjects.remove (aObject);
118             maNodes.remove (aNode);
119             repaint ();
120         }
121     }
122 
123     public void updateNode (AccTreeNode aNode)
124     {
125         int i = maNodes.indexOf (aNode);
126         if (i != -1)
127         {
128             CanvasShape aObject = (CanvasShape)maObjects.get(aNode);
129             if (aObject != null)
130                 aObject.update();
131         }
132     }
133 
134     public void updateNodeGeometry (AccTreeNode aNode)
135     {
136         CanvasShape aObject = (CanvasShape)maObjects.get(aNode);
137         if (aObject != null)
138             aObject.updateGeometry();
139     }
140 
141     public void clear ()
142     {
143         while (maNodes.size() > 0)
144             removeNode ((AccTreeNode)maNodes.elementAt(0));
145 
146         maNodes.clear();
147         maObjects.clear();
148         maObjectList.clear();
149     }
150 
151     public boolean getShowDescriptions ()
152     {
153         return Options.GetBoolean ("ShowDescriptions");
154     }
155 
156     public void setShowDescriptions (boolean bNewValue)
157     {
158         Options.SetBoolean ("ShowDescriptions", bNewValue);
159         repaint ();
160     }
161 
162     public boolean getShowNames ()
163     {
164         return Options.GetBoolean ("ShowNames");
165     }
166 
167     public void setShowNames (boolean bNewValue)
168     {
169         Options.SetBoolean ("ShowNames", bNewValue);
170         repaint ();
171     }
172 
173     public boolean getAntialiasing ()
174     {
175         return Options.GetBoolean ("Antialiasing");
176     }
177 
178     public void setAntialiasing (boolean bNewValue)
179     {
180         Options.SetBoolean ("Antialiasing", bNewValue);
181         repaint ();
182     }
183 
184     public boolean getShowText ()
185     {
186         return Options.GetBoolean ("ShowText");
187     }
188 
189     public void setShowText (boolean bNewValue)
190     {
191         Options.SetBoolean ("ShowText", bNewValue);
192         repaint ();
193     }
194 
195     public void setZoomMode (int nZoomMode)
196     {
197         Options.SetInteger ("ZoomMode", nZoomMode);
198         repaint ();
199     }
200 
201     public int getZoomMode ()
202     {
203         return Options.GetInteger ("ZoomMode", WHOLE_SCREEN);
204     }
205 
206 
207     public void paintComponent (Graphics g)
208     {
209         synchronized (g)
210         {
211             super.paintComponent (g);
212 
213             Graphics2D g2 = (Graphics2D)g;
214             if (getAntialiasing())
215                 g2.setRenderingHint (RenderingHints.KEY_ANTIALIASING,
216                     RenderingHints.VALUE_ANTIALIAS_ON);
217             else
218                 g2.setRenderingHint (RenderingHints.KEY_ANTIALIASING,
219                     RenderingHints.VALUE_ANTIALIAS_OFF);
220 
221             setupTransformation ();
222 
223             // Draw the screen representation to give a hint of the location of the
224             // accessible object on the screen.
225             Dimension aScreenSize = Toolkit.getDefaultToolkit().getScreenSize();
226             Rectangle2D.Double aScreen = new Rectangle2D.Double (
227                 mnHOffset,
228                 mnVOffset,
229                 mnScale*aScreenSize.getWidth(),
230                 mnScale*aScreenSize.getHeight());
231             // Fill the screen rectangle and draw a frame arround it to increase its visibility.
232             g2.setColor (new Color (250,240,230));
233             g2.fill (aScreen);
234             g2.setColor (Color.BLACK);
235             g2.draw (aScreen);
236 
237             synchronized (maObjectList)
238             {
239                 int nCount = maObjectList.size();
240                 boolean bShowDescriptions = getShowDescriptions();
241                 boolean bShowNames = getShowNames();
242                 boolean bShowText = getShowText();
243                 for (int i=0; i<nCount; i++)
244                 {
245                     CanvasShape aCanvasShape = (CanvasShape)maObjectList.elementAt(i);
246                     aCanvasShape.paint (
247                         g2,
248                         mnHOffset, mnVOffset, mnScale,
249                         bShowDescriptions, bShowNames, bShowText);
250                 }
251             }
252 
253             // Paint highlighted frame around active object as the last thing.
254             if (maActiveObject != null)
255                 maActiveObject.paint_highlight (
256                     g2,
257                     mnHOffset, mnVOffset, mnScale);
258         }
259     }
260 
261 
262 
263 
264     /** Set up the transformation so that the graphical display can show a
265         centered representation of the whole screen.
266     */
267     private void setupTransformation ()
268     {
269         // Turn off scrollbars when showing the whole screen.  Otherwise show them when needed.
270         JViewport aViewport = (JViewport)getParent();
271         JScrollPane aScrollPane = (JScrollPane)aViewport.getParent();
272         int nZoomMode = getZoomMode();
273         if (nZoomMode == WHOLE_SCREEN)
274         {
275             if (aScrollPane.getHorizontalScrollBarPolicy()
276                 != JScrollPane.HORIZONTAL_SCROLLBAR_NEVER)
277                 aScrollPane.setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
278             if (aScrollPane.getVerticalScrollBarPolicy()
279                 != JScrollPane.VERTICAL_SCROLLBAR_NEVER)
280                 aScrollPane.setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_NEVER);
281         }
282         else
283         {
284             if (aScrollPane.getHorizontalScrollBarPolicy()
285                 != JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED)
286                 aScrollPane.setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
287             if (aScrollPane.getVerticalScrollBarPolicy()
288                 != JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED)
289                 aScrollPane.setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
290         }
291 
292         Dimension aScreenSize = Toolkit.getDefaultToolkit().getScreenSize();
293         Dimension aWidgetSize = aViewport.getSize();
294         {
295             if ((aScreenSize.getWidth() > 0) && (aScreenSize.getHeight() > 0))
296             {
297                 if (nZoomMode == WHOLE_SCREEN)
298                 {
299                     // Calculate the scales that would map the screen onto the
300                     // widget in both of the coordinate axes and select the
301                     // smaller
302                     // of the two: it maps the screen onto the widget in both
303                     // axes at the same time.
304                     double nHScale = (aWidgetSize.getWidth() - 10) / aScreenSize.getWidth();
305                     double nVScale = (aWidgetSize.getHeight() - 10) / aScreenSize.getHeight();
306                     if (nHScale < nVScale)
307                         mnScale = nHScale;
308                     else
309                         mnScale = nVScale;
310                 }
311                 else
312                 {
313                     mnScale = nZoomMode / 100.0;
314                 }
315 
316                 // Calculate offsets that center the scaled screen inside the widget.
317                 mnHOffset = (aWidgetSize.getWidth() - mnScale*aScreenSize.getWidth()) / 2.0;
318                 mnVOffset = (aWidgetSize.getHeight() - mnScale*aScreenSize.getHeight()) / 2.0;
319                 if (mnHOffset < 0)
320                     mnHOffset = 0;
321                 if (mnVOffset < 0)
322                     mnVOffset = 0;
323 
324                 setPreferredSize (new Dimension (
325                     (int)(2*mnHOffset + mnScale * aScreenSize.getWidth()),
326                     (int)(2*mnVOffset + mnScale * aScreenSize.getHeight())));
327                 revalidate ();
328             }
329             else
330             {
331                 // In case of a degenerate (not yet initialized?) screen size
332                 // use some meaningless default values.
333                 mnScale = 1;
334                 mnHOffset = 0;
335                 mnVOffset = 0;
336             }
337         }
338         maLastWidgetSize = aWidgetSize;
339     }
340 
341 
342 
343     /**  Call getAccessibleAt to determine accessible object under mouse.
344     */
345     public void mouseClicked (MouseEvent e)
346     {
347     }
348 
349     public void mousePressed (MouseEvent e)
350     {
351         CanvasShape aObjectUnderMouse = FindCanvasShapeUnderMouse (e);
352         highlightObject (aObjectUnderMouse);
353         if ((e.getModifiers() & InputEvent.CTRL_MASK) != 0)
354         {
355             maTree.expandPath (aObjectUnderMouse.getPath());
356         }
357     }
358 
359     public void mouseReleased (MouseEvent e)
360     {
361     }
362 
363     public void mouseEntered (MouseEvent e)
364     {
365     }
366 
367     public void mouseExited (MouseEvent e)
368     {
369         // Deselect currently active object.
370         if (maActiveObject != null)
371         {
372             maActiveObject.unhighlight ();
373             maActiveObject = null;
374             repaint ();
375         }
376     }
377 
378     public void mouseDragged (MouseEvent e)
379     {
380     }
381 
382     public void mouseMoved (MouseEvent e)
383     {
384         if ((e.getModifiers() & InputEvent.SHIFT_MASK) != 0)
385             highlightObject (FindCanvasShapeUnderMouse (e));
386     }
387 
388     protected CanvasShape FindCanvasShapeUnderMouse (MouseEvent e)
389     {
390         int nObjects = maObjects.size();
391         CanvasShape aObjectUnderMouse = null;
392         int nCount = maObjectList.size();
393         for (int i=nCount-1; i>=0; --i)
394         {
395             CanvasShape aObject = (CanvasShape)maObjectList.elementAt(i);
396             if (aObject != null)
397                 if (aObject.contains (e.getX(),e.getY()))
398                 {
399                     aObjectUnderMouse = aObject;
400                     break;
401                 }
402         }
403         return aObjectUnderMouse;
404     }
405 
406     protected boolean highlightObject (CanvasShape aNewActiveObject)
407     {
408         if (aNewActiveObject != maActiveObject)
409         {
410             if (maActiveObject != null)
411                 maActiveObject.unhighlight();
412 
413             maActiveObject = aNewActiveObject;
414             if (maActiveObject != null)
415             {
416                 if (maTree != null)
417                 {
418                     maTree.scrollPathToVisible (maActiveObject.getPath());
419                     maTree.setSelectionPath (maActiveObject.getPath());
420                     maTree.repaint ();
421                 }
422                 maActiveObject.highlight ();
423                 repaint ();
424             }
425             return true;
426         }
427         else
428             return false;
429     }
430 
431     /** Called when the selection of the tree changes.  Highlight the
432         corresponding graphical representation of the first selected object.
433     */
434     public void valueChanged (javax.swing.event.TreeSelectionEvent event)
435     {
436         TreePath aPath = event.getPath();
437         Object aObject = aPath.getLastPathComponent();
438         if (aObject instanceof AccTreeNode)
439         {
440             CanvasShape aCanvasShape = (CanvasShape)maObjects.get ((AccTreeNode)aObject);
441             if (highlightObject (aCanvasShape))
442                 repaint();
443         }
444     }
445 
446     private int
447         mnXAnchor,
448         mnYAnchor,
449         maResizeFlag;
450     private double
451         mnHOffset,
452         mnVOffset,
453         mnScale;
454     private CanvasShape
455         maActiveObject;
456     private java.util.HashMap
457         maObjects;
458     private Vector
459         maObjectList,
460         maContexts,
461         maNodes;
462     private Rectangle
463         maBoundingBox;
464     private JTree
465         maTree;
466     // The size of the widget at the last call of setupTransformation()
467     private Dimension
468         maLastWidgetSize;
469 }
470