| 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.TerminalPosition; |
| 22 | import com.googlecode.lanterna.TerminalSize; |
| 23 | |
| 24 | /** |
| 25 | * AbstractComponent provides some good default behaviour for a {@code Component}, all components in Lanterna extends |
| 26 | * from this class in some way. If you want to write your own component that isn't interactable or theme:able, you |
| 27 | * probably want to extend from this class. |
| 28 | * <p> |
| 29 | * The way you want to declare your new {@code Component} is to pass in itself as the generic parameter, like this: |
| 30 | * <pre> |
| 31 | * {@code |
| 32 | * public class MyComponent extends AbstractComponent<MyComponent> { |
| 33 | * ... |
| 34 | * } |
| 35 | * } |
| 36 | * </pre> |
| 37 | * This was, the component renderer will be correctly setup type-wise and you will need to do fewer typecastings when |
| 38 | * you implement the drawing method your new component. |
| 39 | * |
| 40 | * @author Martin |
| 41 | * @param <T> Should always be itself, this value will be used for the {@code ComponentRenderer} declaration |
| 42 | */ |
| 43 | public abstract class AbstractComponent<T extends Component> implements Component { |
| 44 | private ComponentRenderer<T> renderer; |
| 45 | private Container parent; |
| 46 | private TerminalSize size; |
| 47 | private TerminalSize explicitPreferredSize; //This is keeping the value set by the user (if setPreferredSize() is used) |
| 48 | private TerminalPosition position; |
| 49 | private LayoutData layoutData; |
| 50 | private boolean invalid; |
| 51 | |
| 52 | /** |
| 53 | * Default constructor |
| 54 | */ |
| 55 | public AbstractComponent() { |
| 56 | size = TerminalSize.ZERO; |
| 57 | position = TerminalPosition.TOP_LEFT_CORNER; |
| 58 | explicitPreferredSize = null; |
| 59 | layoutData = null; |
| 60 | invalid = true; |
| 61 | parent = null; |
| 62 | renderer = null; //Will be set on the first call to getRenderer() |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * When you create a custom component, you need to implement this method and return a Renderer which is responsible |
| 67 | * for taking care of sizing the component, rendering it and choosing where to place the cursor (if Interactable). |
| 68 | * This value is intended to be overridden by custom themes. |
| 69 | * @return Renderer to use when sizing and drawing this component |
| 70 | */ |
| 71 | protected abstract ComponentRenderer<T> createDefaultRenderer(); |
| 72 | |
| 73 | /** |
| 74 | * This will attempt to dynamically construct a {@code ComponentRenderer} class from a string, assumed to be passed |
| 75 | * in from a theme. This makes it possible to create themes that supplies their own {@code ComponentRenderers} that |
| 76 | * can even replace the ones built into lanterna and used for the bundled components. |
| 77 | * |
| 78 | * @param className Fully qualified name of the {@code ComponentRenderer} we want to instatiate |
| 79 | * @return {@code null} if {@code className} was null, otherwise the {@code ComponentRenderer} instance |
| 80 | * @throws RuntimeException If there were any problems instatiating the class |
| 81 | */ |
| 82 | @SuppressWarnings("unchecked") |
| 83 | protected ComponentRenderer<T> getRendererFromTheme(String className) { |
| 84 | if(className == null) { |
| 85 | return null; |
| 86 | } |
| 87 | try { |
| 88 | return (ComponentRenderer<T>)Class.forName(className).newInstance(); |
| 89 | } catch (InstantiationException e) { |
| 90 | throw new RuntimeException(e); |
| 91 | } catch (IllegalAccessException e) { |
| 92 | throw new RuntimeException(e); |
| 93 | } catch (ClassNotFoundException e) { |
| 94 | throw new RuntimeException(e); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Takes a {@code Runnable} and immediately executes it if this is called on the designated GUI thread, otherwise |
| 100 | * schedules it for later invocation. |
| 101 | * @param runnable {@code Runnable} to execute on the GUI thread |
| 102 | */ |
| 103 | protected void runOnGUIThreadIfExistsOtherwiseRunDirect(Runnable runnable) { |
| 104 | if(getTextGUI() != null && getTextGUI().getGUIThread() != null) { |
| 105 | getTextGUI().getGUIThread().invokeLater(runnable); |
| 106 | } |
| 107 | else { |
| 108 | runnable.run(); |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Explicitly sets the {@code ComponentRenderer} to be used when drawing this component. |
| 114 | * @param renderer {@code ComponentRenderer} to be used when drawing this component |
| 115 | * @return Itself |
| 116 | */ |
| 117 | public T setRenderer(ComponentRenderer<T> renderer) { |
| 118 | this.renderer = renderer; |
| 119 | return self(); |
| 120 | } |
| 121 | |
| 122 | @Override |
| 123 | public synchronized ComponentRenderer<T> getRenderer() { |
| 124 | if(renderer == null) { |
| 125 | renderer = createDefaultRenderer(); |
| 126 | if(renderer == null) { |
| 127 | throw new IllegalStateException(getClass() + " returns a null default renderer"); |
| 128 | } |
| 129 | } |
| 130 | return renderer; |
| 131 | } |
| 132 | |
| 133 | @Override |
| 134 | public void invalidate() { |
| 135 | invalid = true; |
| 136 | } |
| 137 | |
| 138 | @Override |
| 139 | public synchronized T setSize(TerminalSize size) { |
| 140 | this.size = size; |
| 141 | return self(); |
| 142 | } |
| 143 | |
| 144 | @Override |
| 145 | public TerminalSize getSize() { |
| 146 | return size; |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | public final TerminalSize getPreferredSize() { |
| 151 | if(explicitPreferredSize != null) { |
| 152 | return explicitPreferredSize; |
| 153 | } |
| 154 | else { |
| 155 | return calculatePreferredSize(); |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | @Override |
| 160 | public final synchronized T setPreferredSize(TerminalSize explicitPreferredSize) { |
| 161 | this.explicitPreferredSize = explicitPreferredSize; |
| 162 | return self(); |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * Invokes the component renderer's size calculation logic and returns the result. This value represents the |
| 167 | * preferred size and isn't necessarily what it will eventually be assigned later on. |
| 168 | * @return Size that the component renderer believes the component should be |
| 169 | */ |
| 170 | protected synchronized TerminalSize calculatePreferredSize() { |
| 171 | return getRenderer().getPreferredSize(self()); |
| 172 | } |
| 173 | |
| 174 | @Override |
| 175 | public synchronized T setPosition(TerminalPosition position) { |
| 176 | this.position = position; |
| 177 | return self(); |
| 178 | } |
| 179 | |
| 180 | @Override |
| 181 | public TerminalPosition getPosition() { |
| 182 | return position; |
| 183 | } |
| 184 | |
| 185 | @Override |
| 186 | public boolean isInvalid() { |
| 187 | return invalid; |
| 188 | } |
| 189 | |
| 190 | @Override |
| 191 | public final synchronized void draw(final TextGUIGraphics graphics) { |
| 192 | if(getRenderer() == null) { |
| 193 | ComponentRenderer<T> renderer = getRendererFromTheme(graphics.getThemeDefinition(getClass()).getRenderer()); |
| 194 | if(renderer == null) { |
| 195 | renderer = createDefaultRenderer(); |
| 196 | if(renderer == null) { |
| 197 | throw new IllegalStateException(getClass() + " returned a null default renderer"); |
| 198 | } |
| 199 | } |
| 200 | setRenderer(renderer); |
| 201 | } |
| 202 | //Delegate drawing the component to the renderer |
| 203 | setSize(graphics.getSize()); |
| 204 | onBeforeDrawing(); |
| 205 | getRenderer().drawComponent(graphics, self()); |
| 206 | onAfterDrawing(graphics); |
| 207 | invalid = false; |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * This method is called just before the component's renderer is invoked for the drawing operation. You can use this |
| 212 | * hook to do some last-minute adjustments to the component, as an alternative to coding it into the renderer |
| 213 | * itself. The component should have the correct size and position at this point, if you call {@code getSize()} and |
| 214 | * {@code getPosition()}. |
| 215 | */ |
| 216 | protected void onBeforeDrawing() { |
| 217 | //No operation by default |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * This method is called immediately after the component's renderer has finished the drawing operation. You can use |
| 222 | * this hook to do some post-processing if you need, as an alternative to coding it into the renderer. The |
| 223 | * {@code TextGUIGraphics} supplied is the same that was fed into the renderer. |
| 224 | * @param graphics Graphics object you can use to manipulate the appearance of the component |
| 225 | */ |
| 226 | protected void onAfterDrawing(TextGUIGraphics graphics) { |
| 227 | //No operation by default |
| 228 | } |
| 229 | |
| 230 | @Override |
| 231 | public synchronized T setLayoutData(LayoutData data) { |
| 232 | if(layoutData != data) { |
| 233 | layoutData = data; |
| 234 | invalidate(); |
| 235 | } |
| 236 | return self(); |
| 237 | } |
| 238 | |
| 239 | @Override |
| 240 | public LayoutData getLayoutData() { |
| 241 | return layoutData; |
| 242 | } |
| 243 | |
| 244 | @Override |
| 245 | public Container getParent() { |
| 246 | return parent; |
| 247 | } |
| 248 | |
| 249 | @Override |
| 250 | public boolean hasParent(Container parent) { |
| 251 | if(this.parent == null) { |
| 252 | return false; |
| 253 | } |
| 254 | Container recursiveParent = this.parent; |
| 255 | while(recursiveParent != null) { |
| 256 | if(recursiveParent == parent) { |
| 257 | return true; |
| 258 | } |
| 259 | recursiveParent = recursiveParent.getParent(); |
| 260 | } |
| 261 | return false; |
| 262 | } |
| 263 | |
| 264 | @Override |
| 265 | public TextGUI getTextGUI() { |
| 266 | if(parent == null) { |
| 267 | return null; |
| 268 | } |
| 269 | return parent.getTextGUI(); |
| 270 | } |
| 271 | |
| 272 | @Override |
| 273 | public boolean isInside(Container container) { |
| 274 | Component test = this; |
| 275 | while(test.getParent() != null) { |
| 276 | if(test.getParent() == container) { |
| 277 | return true; |
| 278 | } |
| 279 | test = test.getParent(); |
| 280 | } |
| 281 | return false; |
| 282 | } |
| 283 | |
| 284 | @Override |
| 285 | public BasePane getBasePane() { |
| 286 | if(parent == null) { |
| 287 | return null; |
| 288 | } |
| 289 | return parent.getBasePane(); |
| 290 | } |
| 291 | |
| 292 | @Override |
| 293 | public TerminalPosition toBasePane(TerminalPosition position) { |
| 294 | Container parent = getParent(); |
| 295 | if(parent == null) { |
| 296 | return null; |
| 297 | } |
| 298 | return parent.toBasePane(getPosition().withRelative(position)); |
| 299 | } |
| 300 | |
| 301 | @Override |
| 302 | public TerminalPosition toGlobal(TerminalPosition position) { |
| 303 | Container parent = getParent(); |
| 304 | if(parent == null) { |
| 305 | return null; |
| 306 | } |
| 307 | return parent.toGlobal(getPosition().withRelative(position)); |
| 308 | } |
| 309 | |
| 310 | @Override |
| 311 | public synchronized Border withBorder(Border border) { |
| 312 | border.setComponent(this); |
| 313 | return border; |
| 314 | } |
| 315 | |
| 316 | @Override |
| 317 | public synchronized T addTo(Panel panel) { |
| 318 | panel.addComponent(this); |
| 319 | return self(); |
| 320 | } |
| 321 | |
| 322 | @Override |
| 323 | public synchronized void onAdded(Container container) { |
| 324 | parent = container; |
| 325 | } |
| 326 | |
| 327 | @Override |
| 328 | public synchronized void onRemoved(Container container) { |
| 329 | parent = null; |
| 330 | } |
| 331 | |
| 332 | /** |
| 333 | * This is a little hack to avoid doing typecasts all over the place when having to return {@code T}. Credit to |
| 334 | * avl42 for this one! |
| 335 | * @return Itself, but as type T |
| 336 | */ |
| 337 | @SuppressWarnings("unchecked") |
| 338 | protected T self() { |
| 339 | return (T)this; |
| 340 | } |
| 341 | } |