001/*
002 * $Id: MultiSplitPane.java,v 1.15 2005/10/26 14:29:54 hansmuller Exp $
003 *
004 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
005 * Santa Clara, California 95054, U.S.A. All rights reserved.
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
015 * Lesser General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this library; if not, write to the Free Software
019 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
020 */
021package org.openstreetmap.josm.gui.widgets;
022
023import java.awt.Color;
024import java.awt.Cursor;
025import java.awt.Graphics;
026import java.awt.Graphics2D;
027import java.awt.Rectangle;
028import java.awt.event.KeyEvent;
029import java.awt.event.KeyListener;
030import java.awt.event.MouseEvent;
031
032import javax.accessibility.AccessibleContext;
033import javax.accessibility.AccessibleRole;
034import javax.swing.JPanel;
035import javax.swing.event.MouseInputAdapter;
036
037import org.openstreetmap.josm.gui.widgets.MultiSplitLayout.Divider;
038import org.openstreetmap.josm.gui.widgets.MultiSplitLayout.Node;
039
040/**
041 *
042 * <p>
043 * All properties in this class are bound: when a properties value
044 * is changed, all PropertyChangeListeners are fired.
045 *
046 * @author Hans Muller - SwingX
047 */
048public class MultiSplitPane extends JPanel {
049    private transient AccessibleContext accessibleContext;
050    private boolean continuousLayout = true;
051    private transient DividerPainter dividerPainter = new DefaultDividerPainter();
052
053    /**
054     * Creates a MultiSplitPane with it's LayoutManager set to
055     * to an empty MultiSplitLayout.
056     */
057    public MultiSplitPane() {
058        super(new MultiSplitLayout());
059        InputHandler inputHandler = new InputHandler();
060        addMouseListener(inputHandler);
061        addMouseMotionListener(inputHandler);
062        addKeyListener(inputHandler);
063        setFocusable(true);
064    }
065
066    /**
067     * A convenience method that returns the layout manager cast to MultiSplitLayout.
068     *
069     * @return this MultiSplitPane's layout manager
070     * @see java.awt.Container#getLayout
071     * @see #setModel
072     */
073    public final MultiSplitLayout getMultiSplitLayout() {
074        return (MultiSplitLayout) getLayout();
075    }
076
077    /**
078     * A convenience method that sets the MultiSplitLayout model.
079     * Equivalent to <code>getMultiSplitLayout.setModel(model)</code>
080     *
081     * @param model the root of the MultiSplitLayout model
082     * @see #getMultiSplitLayout
083     * @see MultiSplitLayout#setModel
084     */
085    public final void setModel(Node model) {
086        getMultiSplitLayout().setModel(model);
087    }
088
089    /**
090     * A convenience method that sets the MultiSplitLayout dividerSize
091     * property. Equivalent to
092     * <code>getMultiSplitLayout().setDividerSize(newDividerSize)</code>.
093     *
094     * @param dividerSize the value of the dividerSize property
095     * @see #getMultiSplitLayout
096     * @see MultiSplitLayout#setDividerSize
097     */
098    public final void setDividerSize(int dividerSize) {
099        getMultiSplitLayout().setDividerSize(dividerSize);
100    }
101
102    /**
103     * Sets the value of the <code>continuousLayout</code> property.
104     * If true, then the layout is revalidated continuously while
105     * a divider is being moved.  The default value of this property
106     * is true.
107     *
108     * @param continuousLayout value of the continuousLayout property
109     * @see #isContinuousLayout
110     */
111    public void setContinuousLayout(boolean continuousLayout) {
112        boolean oldContinuousLayout = continuousLayout;
113        this.continuousLayout = continuousLayout;
114        firePropertyChange("continuousLayout", oldContinuousLayout, continuousLayout);
115    }
116
117    /**
118     * Returns true if dragging a divider only updates
119     * the layout when the drag gesture ends (typically, when the
120     * mouse button is released).
121     *
122     * @return the value of the <code>continuousLayout</code> property
123     * @see #setContinuousLayout
124     */
125    public boolean isContinuousLayout() {
126        return continuousLayout;
127    }
128
129    /**
130     * Returns the Divider that's currently being moved, typically
131     * because the user is dragging it, or null.
132     *
133     * @return the Divider that's being moved or null.
134     */
135    public Divider activeDivider() {
136        return dragDivider;
137    }
138
139    /**
140     * Draws a single Divider.  Typically used to specialize the
141     * way the active Divider is painted.
142     *
143     * @see #getDividerPainter
144     * @see #setDividerPainter
145     */
146    @FunctionalInterface
147    public interface DividerPainter {
148        /**
149         * Paint a single Divider.
150         *
151         * @param g the Graphics object to paint with
152         * @param divider the Divider to paint
153         */
154        void paint(Graphics g, Divider divider);
155    }
156
157    private class DefaultDividerPainter implements DividerPainter {
158        @Override
159        public void paint(Graphics g, Divider divider) {
160            if ((divider == activeDivider()) && !isContinuousLayout()) {
161                Graphics2D g2d = (Graphics2D) g;
162                g2d.setColor(Color.black);
163                g2d.fill(divider.getBounds());
164            }
165        }
166    }
167
168    /**
169     * The DividerPainter that's used to paint Dividers on this MultiSplitPane.
170     * This property may be null.
171     *
172     * @return the value of the dividerPainter Property
173     * @see #setDividerPainter
174     */
175    public DividerPainter getDividerPainter() {
176        return dividerPainter;
177    }
178
179    /**
180     * Sets the DividerPainter that's used to paint Dividers on this
181     * MultiSplitPane.  The default DividerPainter only draws
182     * the activeDivider (if there is one) and then, only if
183     * continuousLayout is false.  The value of this property is
184     * used by the paintChildren method: Dividers are painted after
185     * the MultiSplitPane's children have been rendered so that
186     * the activeDivider can appear "on top of" the children.
187     *
188     * @param dividerPainter the value of the dividerPainter property, can be null
189     * @see #paintChildren
190     * @see #activeDivider
191     */
192    public void setDividerPainter(DividerPainter dividerPainter) {
193        this.dividerPainter = dividerPainter;
194    }
195
196    /**
197     * Uses the DividerPainter (if any) to paint each Divider that
198     * overlaps the clip Rectangle.  This is done after the call to
199     * <code>super.paintChildren()</code> so that Dividers can be
200     * rendered "on top of" the children.
201     * <p>
202     * {@inheritDoc}
203     */
204    @Override
205    protected void paintChildren(Graphics g) {
206        super.paintChildren(g);
207        DividerPainter dp = getDividerPainter();
208        Rectangle clipR = g.getClipBounds();
209        if ((dp != null) && (clipR != null)) {
210            Graphics dpg = g.create();
211            try {
212                MultiSplitLayout msl = getMultiSplitLayout();
213                for (Divider divider : msl.dividersThatOverlap(clipR)) {
214                    dp.paint(dpg, divider);
215                }
216            } finally {
217                dpg.dispose();
218            }
219        }
220    }
221
222    private boolean dragUnderway;
223    private transient MultiSplitLayout.Divider dragDivider;
224    private Rectangle initialDividerBounds;
225    private boolean oldFloatingDividers = true;
226    private int dragOffsetX;
227    private int dragOffsetY;
228    private int dragMin = -1;
229    private int dragMax = -1;
230
231    private void startDrag(int mx, int my) {
232        requestFocusInWindow();
233        MultiSplitLayout msl = getMultiSplitLayout();
234        MultiSplitLayout.Divider divider = msl.dividerAt(mx, my);
235        if (divider != null) {
236            MultiSplitLayout.Node prevNode = divider.previousSibling();
237            MultiSplitLayout.Node nextNode = divider.nextSibling();
238            if ((prevNode == null) || (nextNode == null)) {
239                dragUnderway = false;
240            } else {
241                initialDividerBounds = divider.getBounds();
242                dragOffsetX = mx - initialDividerBounds.x;
243                dragOffsetY = my - initialDividerBounds.y;
244                dragDivider = divider;
245                Rectangle prevNodeBounds = prevNode.getBounds();
246                Rectangle nextNodeBounds = nextNode.getBounds();
247                if (dragDivider.isVertical()) {
248                    dragMin = prevNodeBounds.x;
249                    dragMax = nextNodeBounds.x + nextNodeBounds.width;
250                    dragMax -= dragDivider.getBounds().width;
251                } else {
252                    dragMin = prevNodeBounds.y;
253                    dragMax = nextNodeBounds.y + nextNodeBounds.height;
254                    dragMax -= dragDivider.getBounds().height;
255                }
256                oldFloatingDividers = getMultiSplitLayout().getFloatingDividers();
257                getMultiSplitLayout().setFloatingDividers(false);
258                dragUnderway = true;
259            }
260        } else {
261            dragUnderway = false;
262        }
263    }
264
265    private void repaintDragLimits() {
266        Rectangle damageR = dragDivider.getBounds();
267        if (dragDivider.isVertical()) {
268            damageR.x = dragMin;
269            damageR.width = dragMax - dragMin;
270        } else {
271            damageR.y = dragMin;
272            damageR.height = dragMax - dragMin;
273        }
274        repaint(damageR);
275    }
276
277    private void updateDrag(int mx, int my) {
278        if (!dragUnderway) {
279            return;
280        }
281        Rectangle oldBounds = dragDivider.getBounds();
282        Rectangle bounds = new Rectangle(oldBounds);
283        if (dragDivider.isVertical()) {
284            bounds.x = mx - dragOffsetX;
285            bounds.x = Math.max(bounds.x, dragMin);
286            bounds.x = Math.min(bounds.x, dragMax);
287        } else {
288            bounds.y = my - dragOffsetY;
289            bounds.y = Math.max(bounds.y, dragMin);
290            bounds.y = Math.min(bounds.y, dragMax);
291        }
292        dragDivider.setBounds(bounds);
293        if (isContinuousLayout()) {
294            revalidate();
295            repaintDragLimits();
296        } else {
297            repaint(oldBounds.union(bounds));
298        }
299    }
300
301    private void clearDragState() {
302        dragDivider = null;
303        initialDividerBounds = null;
304        oldFloatingDividers = true;
305        dragOffsetX = dragOffsetY = 0;
306        dragMin = dragMax = -1;
307        dragUnderway = false;
308    }
309
310    private void finishDrag() {
311        if (dragUnderway) {
312            clearDragState();
313            if (!isContinuousLayout()) {
314                revalidate();
315                repaint();
316            }
317        }
318    }
319
320    private void cancelDrag() {
321        if (dragUnderway) {
322            dragDivider.setBounds(initialDividerBounds);
323            getMultiSplitLayout().setFloatingDividers(oldFloatingDividers);
324            setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
325            repaint();
326            revalidate();
327            clearDragState();
328        }
329    }
330
331    private void updateCursor(int x, int y, boolean show) {
332        if (dragUnderway) {
333            return;
334        }
335        int cursorID = Cursor.DEFAULT_CURSOR;
336        if (show) {
337            MultiSplitLayout.Divider divider = getMultiSplitLayout().dividerAt(x, y);
338            if (divider != null) {
339                cursorID = divider.isVertical() ?
340                    Cursor.E_RESIZE_CURSOR :
341                    Cursor.N_RESIZE_CURSOR;
342            }
343        }
344        setCursor(Cursor.getPredefinedCursor(cursorID));
345    }
346
347    private class InputHandler extends MouseInputAdapter implements KeyListener {
348
349        @Override
350        public void mouseEntered(MouseEvent e) {
351            updateCursor(e.getX(), e.getY(), true);
352        }
353
354        @Override
355        public void mouseMoved(MouseEvent e) {
356            updateCursor(e.getX(), e.getY(), true);
357        }
358
359        @Override
360        public void mouseExited(MouseEvent e) {
361            updateCursor(e.getX(), e.getY(), false);
362        }
363
364        @Override
365        public void mousePressed(MouseEvent e) {
366            startDrag(e.getX(), e.getY());
367        }
368
369        @Override
370        public void mouseReleased(MouseEvent e) {
371            finishDrag();
372        }
373
374        @Override
375        public void mouseDragged(MouseEvent e) {
376            updateDrag(e.getX(), e.getY());
377        }
378
379        @Override
380        public void keyPressed(KeyEvent e) {
381            if (e.getKeyCode() == KeyEvent.VK_ESCAPE) {
382                cancelDrag();
383            }
384        }
385
386        @Override
387        public void keyReleased(KeyEvent e) {
388            // Do nothing
389        }
390
391        @Override
392        public void keyTyped(KeyEvent e) {
393            // Do nothing
394        }
395    }
396
397    @Override
398    public AccessibleContext getAccessibleContext() {
399        if (accessibleContext == null) {
400            accessibleContext = new AccessibleMultiSplitPane();
401        }
402        return accessibleContext;
403    }
404
405    protected class AccessibleMultiSplitPane extends AccessibleJPanel {
406        @Override
407        public AccessibleRole getAccessibleRole() {
408            return AccessibleRole.SPLIT_PANE;
409        }
410    }
411}