2
|
1 |
/*
|
|
2 |
* Copyright 2000-2007 Sun Microsystems, Inc. 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. Sun designates this
|
|
8 |
* particular file as subject to the "Classpath" exception as provided
|
|
9 |
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
22 |
* CA 95054 USA or visit www.sun.com if you need additional information or
|
|
23 |
* have any questions.
|
|
24 |
*/
|
|
25 |
|
|
26 |
package sun.awt;
|
|
27 |
|
|
28 |
import java.awt.ScrollPane;
|
|
29 |
import java.awt.Insets;
|
|
30 |
import java.awt.Adjustable;
|
|
31 |
import java.awt.event.MouseWheelEvent;
|
|
32 |
|
|
33 |
import java.util.logging.*;
|
|
34 |
|
|
35 |
/*
|
|
36 |
* ScrollPaneWheelScroller is a helper class for implmenenting mouse wheel
|
|
37 |
* scrolling on a java.awt.ScrollPane. It contains only static methods.
|
|
38 |
* No objects of this class may be instantiated, thus it is declared abstract.
|
|
39 |
*/
|
|
40 |
public abstract class ScrollPaneWheelScroller {
|
|
41 |
|
|
42 |
private static final Logger log = Logger.getLogger("sun.awt.ScrollPaneWheelScroller");
|
|
43 |
|
|
44 |
private ScrollPaneWheelScroller() {}
|
|
45 |
|
|
46 |
/*
|
|
47 |
* Called from ScrollPane.processMouseWheelEvent()
|
|
48 |
*/
|
|
49 |
public static void handleWheelScrolling(ScrollPane sp, MouseWheelEvent e) {
|
|
50 |
if (log.isLoggable(Level.FINER)) {
|
|
51 |
log.log(Level.FINER, "x = " + e.getX() + ", y = " + e.getY() + ", src is " + e.getSource());
|
|
52 |
}
|
|
53 |
int increment = 0;
|
|
54 |
|
|
55 |
if (sp != null && e.getScrollAmount() != 0) {
|
|
56 |
Adjustable adj = getAdjustableToScroll(sp);
|
|
57 |
if (adj != null) {
|
|
58 |
increment = getIncrementFromAdjustable(adj, e);
|
|
59 |
if (log.isLoggable(Level.FINER)) {
|
|
60 |
log.log(Level.FINER, "increment from adjustable(" + adj.getClass() + ") : " + increment);
|
|
61 |
}
|
|
62 |
scrollAdjustable(adj, increment);
|
|
63 |
}
|
|
64 |
}
|
|
65 |
}
|
|
66 |
|
|
67 |
/*
|
|
68 |
* Given a ScrollPane, determine which Scrollbar should be scrolled by the
|
|
69 |
* mouse wheel, if any.
|
|
70 |
*/
|
|
71 |
public static Adjustable getAdjustableToScroll(ScrollPane sp) {
|
|
72 |
int policy = sp.getScrollbarDisplayPolicy();
|
|
73 |
|
|
74 |
// if policy is display always or never, use vert
|
|
75 |
if (policy == ScrollPane.SCROLLBARS_ALWAYS ||
|
|
76 |
policy == ScrollPane.SCROLLBARS_NEVER) {
|
|
77 |
if (log.isLoggable(Level.FINER)) {
|
|
78 |
log.log(Level.FINER, "using vertical scrolling due to scrollbar policy");
|
|
79 |
}
|
|
80 |
return sp.getVAdjustable();
|
|
81 |
|
|
82 |
}
|
|
83 |
else {
|
|
84 |
|
|
85 |
Insets ins = sp.getInsets();
|
|
86 |
int vertScrollWidth = sp.getVScrollbarWidth();
|
|
87 |
|
|
88 |
if (log.isLoggable(Level.FINER)) {
|
|
89 |
log.log(Level.FINER, "insets: l = " + ins.left + ", r = " + ins.right +
|
|
90 |
", t = " + ins.top + ", b = " + ins.bottom);
|
|
91 |
log.log(Level.FINER, "vertScrollWidth = " + vertScrollWidth);
|
|
92 |
}
|
|
93 |
|
|
94 |
// Check if scrollbar is showing by examining insets of the
|
|
95 |
// ScrollPane
|
|
96 |
if (ins.right >= vertScrollWidth) {
|
|
97 |
if (log.isLoggable(Level.FINER)) {
|
|
98 |
log.log(Level.FINER, "using vertical scrolling because scrollbar is present");
|
|
99 |
}
|
|
100 |
return sp.getVAdjustable();
|
|
101 |
}
|
|
102 |
else {
|
|
103 |
int horizScrollHeight = sp.getHScrollbarHeight();
|
|
104 |
if (ins.bottom >= horizScrollHeight) {
|
|
105 |
if (log.isLoggable(Level.FINER)) {
|
|
106 |
log.log(Level.FINER, "using horiz scrolling because scrollbar is present");
|
|
107 |
}
|
|
108 |
return sp.getHAdjustable();
|
|
109 |
}
|
|
110 |
else {
|
|
111 |
if (log.isLoggable(Level.FINER)) {
|
|
112 |
log.log(Level.FINER, "using NO scrollbar becsause neither is present");
|
|
113 |
}
|
|
114 |
return null;
|
|
115 |
}
|
|
116 |
}
|
|
117 |
}
|
|
118 |
}
|
|
119 |
|
|
120 |
/*
|
|
121 |
* Given the info in a MouseWheelEvent and an Adjustable to scroll, return
|
|
122 |
* the amount by which the Adjustable should be adjusted. This value may
|
|
123 |
* be positive or negative.
|
|
124 |
*/
|
|
125 |
public static int getIncrementFromAdjustable(Adjustable adj,
|
|
126 |
MouseWheelEvent e) {
|
|
127 |
if (log.isLoggable(Level.FINE)) {
|
|
128 |
if (adj == null) {
|
|
129 |
log.log(Level.FINE, "Assertion (adj != null) failed");
|
|
130 |
}
|
|
131 |
}
|
|
132 |
|
|
133 |
int increment = 0;
|
|
134 |
|
|
135 |
if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {
|
|
136 |
increment = e.getUnitsToScroll() * adj.getUnitIncrement();
|
|
137 |
}
|
|
138 |
else if (e.getScrollType() == MouseWheelEvent.WHEEL_BLOCK_SCROLL) {
|
|
139 |
increment = adj.getBlockIncrement() * e.getWheelRotation();
|
|
140 |
}
|
|
141 |
return increment;
|
|
142 |
}
|
|
143 |
|
|
144 |
/*
|
|
145 |
* Scroll the given Adjustable by the given amount. Checks the Adjustable's
|
|
146 |
* bounds and sets the new value to the Adjustable.
|
|
147 |
*/
|
|
148 |
public static void scrollAdjustable(Adjustable adj, int amount) {
|
|
149 |
if (log.isLoggable(Level.FINE)) {
|
|
150 |
if (adj == null) {
|
|
151 |
log.log(Level.FINE, "Assertion (adj != null) failed");
|
|
152 |
}
|
|
153 |
if (amount == 0) {
|
|
154 |
log.log(Level.FINE, "Assertion (amount != 0) failed");
|
|
155 |
}
|
|
156 |
}
|
|
157 |
|
|
158 |
int current = adj.getValue();
|
|
159 |
int upperLimit = adj.getMaximum() - adj.getVisibleAmount();
|
|
160 |
if (log.isLoggable(Level.FINER)) {
|
|
161 |
log.log(Level.FINER, "doScrolling by " + amount);
|
|
162 |
}
|
|
163 |
|
|
164 |
if (amount > 0 && current < upperLimit) { // still some room to scroll
|
|
165 |
// down
|
|
166 |
if (current + amount < upperLimit) {
|
|
167 |
adj.setValue(current + amount);
|
|
168 |
return;
|
|
169 |
}
|
|
170 |
else {
|
|
171 |
adj.setValue(upperLimit);
|
|
172 |
return;
|
|
173 |
}
|
|
174 |
}
|
|
175 |
else if (amount < 0 && current > adj.getMinimum()) { // still some room
|
|
176 |
// to scroll up
|
|
177 |
if (current + amount > adj.getMinimum()) {
|
|
178 |
adj.setValue(current + amount);
|
|
179 |
return;
|
|
180 |
}
|
|
181 |
else {
|
|
182 |
adj.setValue(adj.getMinimum());
|
|
183 |
return;
|
|
184 |
}
|
|
185 |
}
|
|
186 |
}
|
|
187 |
}
|