| 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 | } |