| 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 | /** |
| 29 | * Simple labeled button with an optional action attached to it, you trigger the action by pressing the Enter key on the |
| 30 | * keyboard when the component is in focus. |
| 31 | * @author Martin |
| 32 | */ |
| 33 | public class Button extends AbstractInteractableComponent<Button> { |
| 34 | private final Runnable action; |
| 35 | private String label; |
| 36 | |
| 37 | /** |
| 38 | * Creates a new button with a specific label and no attached action. Why would you need this? I have no idea. |
| 39 | * @param label Label to put on the button |
| 40 | */ |
| 41 | public Button(String label) { |
| 42 | this(label, new Runnable() { |
| 43 | @Override |
| 44 | public void run() { |
| 45 | } |
| 46 | }); |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Creates a new button with a label and an associated action to fire when triggered by the user |
| 51 | * @param label Label to put on the button |
| 52 | * @param action What action to fire when the user triggers the button by pressing the enter key |
| 53 | */ |
| 54 | public Button(String label, Runnable action) { |
| 55 | this.action = action; |
| 56 | setLabel(label); |
| 57 | } |
| 58 | |
| 59 | @Override |
| 60 | protected ButtonRenderer createDefaultRenderer() { |
| 61 | return new DefaultButtonRenderer(); |
| 62 | } |
| 63 | |
| 64 | @Override |
| 65 | public synchronized TerminalPosition getCursorLocation() { |
| 66 | return getRenderer().getCursorLocation(this); |
| 67 | } |
| 68 | |
| 69 | @Override |
| 70 | public synchronized Result handleKeyStroke(KeyStroke keyStroke) { |
| 71 | if(keyStroke.getKeyType() == KeyType.Enter) { |
| 72 | action.run(); |
| 73 | return Result.HANDLED; |
| 74 | } |
| 75 | return super.handleKeyStroke(keyStroke); |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | * Updates the label on the button to the specified string |
| 80 | * @param label New label to use on the button |
| 81 | */ |
| 82 | public final synchronized void setLabel(String label) { |
| 83 | if(label == null) { |
| 84 | throw new IllegalArgumentException("null label to a button is not allowed"); |
| 85 | } |
| 86 | if(label.isEmpty()) { |
| 87 | label = " "; |
| 88 | } |
| 89 | this.label = label; |
| 90 | invalidate(); |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * Returns the label current assigned to the button |
| 95 | * @return Label currently used by the button |
| 96 | */ |
| 97 | public String getLabel() { |
| 98 | return label; |
| 99 | } |
| 100 | |
| 101 | @Override |
| 102 | public String toString() { |
| 103 | return "Button{" + label + "}"; |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Helper interface that doesn't add any new methods but makes coding new button renderers a little bit more clear |
| 108 | */ |
| 109 | public interface ButtonRenderer extends InteractableRenderer<Button> { |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * This is the default button renderer that is used if you don't override anything. With this renderer, buttons are |
| 114 | * drawn on a single line, with the label inside of "<" and ">". |
| 115 | */ |
| 116 | public static class DefaultButtonRenderer implements ButtonRenderer { |
| 117 | @Override |
| 118 | public TerminalPosition getCursorLocation(Button button) { |
| 119 | return new TerminalPosition(1 + getLabelShift(button, button.getSize()), 0); |
| 120 | } |
| 121 | |
| 122 | @Override |
| 123 | public TerminalSize getPreferredSize(Button button) { |
| 124 | return new TerminalSize(Math.max(8, TerminalTextUtils.getColumnWidth(button.getLabel()) + 2), 1); |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public void drawComponent(TextGUIGraphics graphics, Button button) { |
| 129 | if(button.isFocused()) { |
| 130 | graphics.applyThemeStyle(getThemeDefinition(graphics).getActive()); |
| 131 | } |
| 132 | else { |
| 133 | graphics.applyThemeStyle(getThemeDefinition(graphics).getInsensitive()); |
| 134 | } |
| 135 | graphics.fill(' '); |
| 136 | graphics.setCharacter(0, 0, getThemeDefinition(graphics).getCharacter("LEFT_BORDER", '<')); |
| 137 | graphics.setCharacter(graphics.getSize().getColumns() - 1, 0, getThemeDefinition(graphics).getCharacter("RIGHT_BORDER", '>')); |
| 138 | |
| 139 | if(button.isFocused()) { |
| 140 | graphics.applyThemeStyle(getThemeDefinition(graphics).getActive()); |
| 141 | } |
| 142 | else { |
| 143 | graphics.applyThemeStyle(getThemeDefinition(graphics).getPreLight()); |
| 144 | } |
| 145 | int labelShift = getLabelShift(button, graphics.getSize()); |
| 146 | graphics.setCharacter(1 + labelShift, 0, button.getLabel().charAt(0)); |
| 147 | |
| 148 | if(TerminalTextUtils.getColumnWidth(button.getLabel()) == 1) { |
| 149 | return; |
| 150 | } |
| 151 | if(button.isFocused()) { |
| 152 | graphics.applyThemeStyle(getThemeDefinition(graphics).getSelected()); |
| 153 | } |
| 154 | else { |
| 155 | graphics.applyThemeStyle(getThemeDefinition(graphics).getNormal()); |
| 156 | } |
| 157 | graphics.putString(1 + labelShift + 1, 0, button.getLabel().substring(1)); |
| 158 | } |
| 159 | |
| 160 | private int getLabelShift(Button button, TerminalSize size) { |
| 161 | int availableSpace = size.getColumns() - 2; |
| 162 | if(availableSpace <= 0) { |
| 163 | return 0; |
| 164 | } |
| 165 | int labelShift = 0; |
| 166 | int widthInColumns = TerminalTextUtils.getColumnWidth(button.getLabel()); |
| 167 | if(availableSpace > widthInColumns) { |
| 168 | labelShift = (size.getColumns() - 2 - widthInColumns) / 2; |
| 169 | } |
| 170 | return labelShift; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Alternative button renderer that displays buttons with just the label and minimal decoration |
| 176 | */ |
| 177 | public static class FlatButtonRenderer implements ButtonRenderer { |
| 178 | @Override |
| 179 | public TerminalPosition getCursorLocation(Button component) { |
| 180 | return null; |
| 181 | } |
| 182 | |
| 183 | @Override |
| 184 | public TerminalSize getPreferredSize(Button component) { |
| 185 | return new TerminalSize(TerminalTextUtils.getColumnWidth(component.getLabel()), 1); |
| 186 | } |
| 187 | |
| 188 | @Override |
| 189 | public void drawComponent(TextGUIGraphics graphics, Button button) { |
| 190 | if(button.isFocused()) { |
| 191 | graphics.applyThemeStyle(getThemeDefinition(graphics).getActive()); |
| 192 | } |
| 193 | else { |
| 194 | graphics.applyThemeStyle(getThemeDefinition(graphics).getInsensitive()); |
| 195 | } |
| 196 | graphics.fill(' '); |
| 197 | if(button.isFocused()) { |
| 198 | graphics.applyThemeStyle(getThemeDefinition(graphics).getSelected()); |
| 199 | } |
| 200 | else { |
| 201 | graphics.applyThemeStyle(getThemeDefinition(graphics).getNormal()); |
| 202 | } |
| 203 | graphics.putString(0, 0, button.getLabel()); |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | private static ThemeDefinition getThemeDefinition(TextGUIGraphics graphics) { |
| 208 | return graphics.getThemeDefinition(Button.class); |
| 209 | } |
| 210 | } |