Mercurial > projects > dwt-addons

comparison dwtx/draw2d/AncestorHelper.d @ 98:95307ad235d9

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added Draw2d code, still work in progress
author Frank Benoit <benoit@tionex.de>
date Sun, 03 Aug 2008 00:52:14 +0200
parents
children
comparison
equal deleted inserted replaced
96:b492ba44e44d 98:95307ad235d9
1 /*******************************************************************************
2 * Copyright (c) 2000, 2005 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
12 *******************************************************************************/
13 module dwtx.draw2d.AncestorHelper;
14
15 import dwt.dwthelper.utils;
16 import dwtx.dwtxhelper.Bean;
17
18 import dwtx.draw2d.IFigure;
19 import dwtx.draw2d.FigureListener;
20 import dwtx.draw2d.AncestorListener;
21
22 /**
23 * A helper object which tracks the parent chain hierarchy.
24 * @since 2.1
25 */
26 class AncestorHelper
27 : PropertyChangeListener, FigureListener
28 {
29
30 /**
31 * The base figure whose ancestor chain is being observed.
32 */
33 protected final IFigure base;
34 /**
35 * The array of ancestor listeners.
36 */
37 protected AncestorListener[] listeners;
38
39 /**
40 * Constructs a new helper on the given base figure and starts listening to figure and
41 * property changes on the base figure's parent chain. When no longer needed, the helper
42 * should be disposed.
43 * @since 2.1
44 * @param baseFigure
45 */
46 public this(IFigure baseFigure) {
47 this.base = baseFigure;
48 addAncestors(baseFigure);
49 }
50
51 /**
52 * Appends a new listener to the list of listeners.
53 * @param listener the listener
54 */
55 public void addAncestorListener(AncestorListener listener) {
56 if (listeners is null) {
57 listeners = new AncestorListener[1];
58 listeners[0] = listener;
59 } else {
60 int oldSize = listeners.length;
61 AncestorListener newListeners[] = new AncestorListener[oldSize + 1];
62 SimpleType!(AncestorListener).arraycopy(listeners, 0, newListeners, 0, oldSize);
63 newListeners[oldSize] = listener;
64 listeners = newListeners;
65 }
66 }
67
68 /**
69 * Hooks up internal listeners used for maintaining the proper figure listeners.
70 * @param rootFigure the root figure
71 */
72 protected void addAncestors(IFigure rootFigure) {
73 for (IFigure ancestor = rootFigure;
74 ancestor !is null;
75 ancestor = ancestor.getParent()) {
76 ancestor.addFigureListener(this);
77 ancestor.addPropertyChangeListener("parent", this); //$NON-NLS-1$
78 }
79 }
80
81 /**
82 * Removes all internal listeners.
83 */
84 public void dispose() {
85 removeAncestors(base);
86 listeners = null;
87 }
88
89 /**
90 * @see dwtx.draw2d.FigureListener#figureMoved(dwtx.draw2d.IFigure)
91 */
92 public void figureMoved(IFigure ancestor) {
93 fireAncestorMoved(ancestor);
94 }
95
96 /**
97 * Fires notification to the listener list
98 * @param ancestor the figure which moved
99 */
100 protected void fireAncestorMoved(IFigure ancestor) {
101 if (listeners is null)
102 return;
103 for (int i = 0; i < listeners.length; i++)
104 listeners[i].ancestorMoved(ancestor);
105 }
106
107 /**
108 * Fires notification to the listener list
109 * @param ancestor the figure which moved
110 */
111 protected void fireAncestorAdded(IFigure ancestor) {
112 if (listeners is null)
113 return;
114 for (int i = 0; i < listeners.length; i++)
115 listeners[i].ancestorAdded(ancestor);
116 }
117
118 /**
119 * Fires notification to the listener list
120 * @param ancestor the figure which moved
121 */
122 protected void fireAncestorRemoved(IFigure ancestor) {
123 if (listeners is null)
124 return;
125 for (int i = 0; i < listeners.length; i++)
126 listeners[i].ancestorRemoved(ancestor);
127 }
128
129 /**
130 * Returns the total number of listeners.
131 * @return the number of listeners
132 */
133 public bool isEmpty() {
134 return listeners is null;
135 }
136
137 /**
138 * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)
139 */
140 public void propertyChange(PropertyChangeEvent event) {
141 if (event.getPropertyName().equals("parent")) { //$NON-NLS-1$
142 IFigure oldParent = cast(IFigure)event.getOldValue();
143 IFigure newParent = cast(IFigure)event.getNewValue();
144 if (oldParent !is null) {
145 removeAncestors(oldParent);
146 fireAncestorRemoved(oldParent);
147 }
148 if (newParent !is null) {
149 addAncestors(newParent);
150 fireAncestorAdded(newParent);
151 }
152 }
153 }
154
155 /**
156 * Removes the first occurence of the given listener
157 * @param listener the listener to remove
158 */
159 public void removeAncestorListener(AncestorListener listener) {
160 if (listeners is null)
161 return;
162 for (int index = 0; index < listeners.length; index++)
163 if (listeners[index] is listener) {
164 int newSize = listeners.length - 1;
165 AncestorListener newListeners[] = null;
166 if (newSize !is 0) {
167 newListeners = new AncestorListener[newSize];
168 SimpleType!(AncestorListener).arraycopy(listeners, 0, newListeners, 0, index);
169 SimpleType!(AncestorListener).arraycopy(listeners, index + 1, newListeners, index, newSize - index);
170 }
171 listeners = newListeners;
172 return;
173 }
174 }
175
176 /**
177 * Unhooks listeners starting at the given figure
178 * @param rootFigure
179 */
180 protected void removeAncestors(IFigure rootFigure) {
181 for (IFigure ancestor = rootFigure;
182 ancestor !is null;
183 ancestor = ancestor.getParent()) {
184 ancestor.removeFigureListener(this);
185 ancestor.removePropertyChangeListener("parent", this); //$NON-NLS-1$
186 }
187 }
188
189 }