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a3b510ab NR |
1 | /* |
2 | * This file is part of lanterna (http://code.google.com/p/lanterna/). | |
3 | * | |
4 | * lanterna is free software: you can redistribute it and/or modify | |
5 | * it under the terms of the GNU Lesser General Public License as published by | |
6 | * the Free Software Foundation, either version 3 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU Lesser General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public License | |
15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | * | |
17 | * Copyright (C) 2010-2015 Martin | |
18 | */ | |
19 | package com.googlecode.lanterna.gui2; | |
20 | ||
21 | import com.googlecode.lanterna.TerminalTextUtils; | |
22 | import com.googlecode.lanterna.TerminalPosition; | |
23 | import com.googlecode.lanterna.TerminalSize; | |
24 | import com.googlecode.lanterna.graphics.ThemeDefinition; | |
25 | import com.googlecode.lanterna.input.KeyStroke; | |
26 | import com.googlecode.lanterna.input.KeyType; | |
27 | ||
28 | import java.util.List; | |
29 | import java.util.concurrent.CopyOnWriteArrayList; | |
30 | ||
31 | /** | |
32 | * The checkbox component looks like a regular checkbox that you can find in modern graphics user interfaces, a label | |
33 | * and a space that the user can toggle on and off by using enter or space keys. | |
34 | * | |
35 | * @author Martin | |
36 | */ | |
37 | public class CheckBox extends AbstractInteractableComponent<CheckBox> { | |
38 | ||
39 | /** | |
40 | * Listener interface that can be used to catch user events on the check box | |
41 | */ | |
42 | public interface Listener { | |
43 | /** | |
44 | * This is fired when the user has altered the checked state of this {@code CheckBox} | |
45 | * @param checked If the {@code CheckBox} is now toggled on, this is set to {@code true}, otherwise | |
46 | * {@code false} | |
47 | */ | |
48 | void onStatusChanged(boolean checked); | |
49 | } | |
50 | ||
51 | private final List<Listener> listeners; | |
52 | private String label; | |
53 | private boolean checked; | |
54 | ||
55 | /** | |
56 | * Creates a new checkbox with no label, initially set to un-checked | |
57 | */ | |
58 | public CheckBox() { | |
59 | this(""); | |
60 | } | |
61 | ||
62 | /** | |
63 | * Creates a new checkbox with a specific label, initially set to un-checked | |
64 | * @param label Label to assign to the check box | |
65 | */ | |
66 | public CheckBox(String label) { | |
67 | if(label == null) { | |
68 | throw new IllegalArgumentException("Cannot create a CheckBox with null label"); | |
69 | } | |
70 | else if(label.contains("\n") || label.contains("\r")) { | |
71 | throw new IllegalArgumentException("Multiline checkbox labels are not supported"); | |
72 | } | |
73 | this.listeners = new CopyOnWriteArrayList<Listener>(); | |
74 | this.label = label; | |
75 | this.checked = false; | |
76 | } | |
77 | ||
78 | /** | |
79 | * Programmatically updated the check box to a particular checked state | |
80 | * @param checked If {@code true}, the check box will be set to toggled on, otherwise {@code false} | |
81 | * @return Itself | |
82 | */ | |
83 | public synchronized CheckBox setChecked(final boolean checked) { | |
84 | this.checked = checked; | |
85 | runOnGUIThreadIfExistsOtherwiseRunDirect(new Runnable() { | |
86 | @Override | |
87 | public void run() { | |
88 | for(Listener listener : listeners) { | |
89 | listener.onStatusChanged(checked); | |
90 | } | |
91 | } | |
92 | }); | |
93 | invalidate(); | |
94 | return this; | |
95 | } | |
96 | ||
97 | /** | |
98 | * Returns the checked state of this check box | |
99 | * @return {@code true} if the check box is toggled on, otherwise {@code false} | |
100 | */ | |
101 | public boolean isChecked() { | |
102 | return checked; | |
103 | } | |
104 | ||
105 | @Override | |
106 | public Result handleKeyStroke(KeyStroke keyStroke) { | |
107 | if((keyStroke.getKeyType() == KeyType.Character && keyStroke.getCharacter() == ' ') || | |
108 | keyStroke.getKeyType() == KeyType.Enter) { | |
109 | setChecked(!isChecked()); | |
110 | return Result.HANDLED; | |
111 | } | |
112 | return super.handleKeyStroke(keyStroke); | |
113 | } | |
114 | ||
115 | /** | |
116 | * Updates the label of the checkbox | |
117 | * @param label New label to assign to the check box | |
118 | * @return Itself | |
119 | */ | |
120 | public synchronized CheckBox setLabel(String label) { | |
121 | if(label == null) { | |
122 | throw new IllegalArgumentException("Cannot set CheckBox label to null"); | |
123 | } | |
124 | this.label = label; | |
125 | invalidate(); | |
126 | return this; | |
127 | } | |
128 | ||
129 | /** | |
130 | * Returns the label of check box | |
131 | * @return Label currently assigned to the check box | |
132 | */ | |
133 | public String getLabel() { | |
134 | return label; | |
135 | } | |
136 | ||
137 | /** | |
138 | * Adds a listener to this check box so that it will be notificed on certain user actions | |
139 | * @param listener Listener to fire events on | |
140 | * @return Itself | |
141 | */ | |
142 | public CheckBox addListener(Listener listener) { | |
143 | if(listener != null && !listeners.contains(listener)) { | |
144 | listeners.add(listener); | |
145 | } | |
146 | return this; | |
147 | } | |
148 | ||
149 | /** | |
150 | * Removes a listener from this check box so that, if it was previously added, it will no long receive any events | |
151 | * @param listener Listener to remove from the check box | |
152 | * @return Itself | |
153 | */ | |
154 | public CheckBox removeListener(Listener listener) { | |
155 | listeners.remove(listener); | |
156 | return this; | |
157 | } | |
158 | ||
159 | @Override | |
160 | protected CheckBoxRenderer createDefaultRenderer() { | |
161 | return new DefaultCheckBoxRenderer(); | |
162 | } | |
163 | ||
164 | /** | |
165 | * Helper interface that doesn't add any new methods but makes coding new check box renderers a little bit more clear | |
166 | */ | |
167 | public static abstract class CheckBoxRenderer implements InteractableRenderer<CheckBox> { | |
168 | } | |
169 | ||
170 | /** | |
171 | * The default renderer that is used unless overridden. This renderer will draw the checkbox label on the right side | |
172 | * of a "[ ]" block which will contain a "X" inside it if the check box has toggle status on | |
173 | */ | |
174 | public static class DefaultCheckBoxRenderer extends CheckBoxRenderer { | |
175 | private static final TerminalPosition CURSOR_LOCATION = new TerminalPosition(1, 0); | |
176 | @Override | |
177 | public TerminalPosition getCursorLocation(CheckBox component) { | |
178 | return CURSOR_LOCATION; | |
179 | } | |
180 | ||
181 | @Override | |
182 | public TerminalSize getPreferredSize(CheckBox component) { | |
183 | int width = 3; | |
184 | if(!component.label.isEmpty()) { | |
185 | width += 1 + TerminalTextUtils.getColumnWidth(component.label); | |
186 | } | |
187 | return new TerminalSize(width, 1); | |
188 | } | |
189 | ||
190 | @Override | |
191 | public void drawComponent(TextGUIGraphics graphics, CheckBox component) { | |
192 | ThemeDefinition themeDefinition = graphics.getThemeDefinition(CheckBox.class); | |
193 | if(component.isFocused()) { | |
194 | graphics.applyThemeStyle(themeDefinition.getActive()); | |
195 | } | |
196 | else { | |
197 | graphics.applyThemeStyle(themeDefinition.getNormal()); | |
198 | } | |
199 | ||
200 | graphics.fill(' '); | |
201 | graphics.putString(4, 0, component.label); | |
202 | ||
203 | String head = "[" + (component.isChecked() ? themeDefinition.getCharacter("MARKER", 'x') : " ") + "]"; | |
204 | if(component.isFocused()) { | |
205 | graphics.applyThemeStyle(themeDefinition.getPreLight()); | |
206 | } | |
207 | else { | |
208 | graphics.applyThemeStyle(themeDefinition.getNormal()); | |
209 | } | |
210 | graphics.putString(0, 0, head); | |
211 | } | |
212 | } | |
213 | } |