1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 | 1128× 1128× 1128× 1128× 1128× 1128× 1128× 1128× 2227× 1× 1× 5904× 5904× 5904× 5904× 5904× 1× 1140× 1140× 1140× 1140× 217× 217× 1140× 1× 2227× 2227× 2227× 1× 178× 178× 178× 178× 1091× 1091× 1091× 178× 913× 178× 1× 74× 74× 74× 74× 566× 566× 566× 74× 492× 74× 1× 36096× 1× 36096× 36096× 36096× 1× 1× 1× 640× 1× 1269× 1× 1091× 1091× 1091× 1091× 1091× 1091× 1091× 984× 1091× 1091× 1× 41114× 1236× 1236× 41114× 41114× 41114× 80069× 80069× 923× 41114× 1× 984× 1× 7561× 7561× 7561× 7561× 7561× 1× 6470× 6470× 6470× 6470× 6470× 6470× 6470× 5904× 5904× 1167× 5904× 6470× 6470× 6470× 5805× 6470× 6470× 6470× 5904× 5904× 2471× 5904× 6470× 1× 12626× 12626× 12626× 12626× 12626× 5904× 12626× 1× 12626× 12626× 12626× 12626× 12626× 1236× 1236× 1236× 1× 6789× 6789× 2103× 4686× 4686× 1× 6470× 6470× 5904× 1× 1091× 1× 8701× 1× 36096× 36096× 36096× | import { uniqueBy, isArray } from 'min-dash'; /** * A service that offers un- and redoable execution of commands. * * The command stack is responsible for executing modeling actions * in a un- and redoable manner. To do this it delegates the actual * command execution to {@link CommandHandler}s. * * Command handlers provide {@link CommandHandler#execute(ctx)} and * {@link CommandHandler#revert(ctx)} methods to un- and redo a command * identified by a command context. * * * ## Life-Cycle events * * In the process the command stack fires a number of life-cycle events * that other components to participate in the command execution. * * * preExecute * * preExecuted * * execute * * executed * * postExecute * * postExecuted * * revert * * reverted * * A special event is used for validating, whether a command can be * performed prior to its execution. * * * canExecute * * Each of the events is fired as `commandStack.{eventName}` and * `commandStack.{commandName}.{eventName}`, respectively. This gives * components fine grained control on where to hook into. * * The event object fired transports `command`, the name of the * command and `context`, the command context. * * * ## Creating Command Handlers * * Command handlers should provide the {@link CommandHandler#execute(ctx)} * and {@link CommandHandler#revert(ctx)} methods to implement * redoing and undoing of a command. * * A command handler _must_ ensure undo is performed properly in order * not to break the undo chain. It must also return the shapes that * got changed during the `execute` and `revert` operations. * * Command handlers may execute other modeling operations (and thus * commands) in their `preExecute` and `postExecute` phases. The command * stack will properly group all commands together into a logical unit * that may be re- and undone atomically. * * Command handlers must not execute other commands from within their * core implementation (`execute`, `revert`). * * * ## Change Tracking * * During the execution of the CommandStack it will keep track of all * elements that have been touched during the command's execution. * * At the end of the CommandStack execution it will notify interested * components via an 'elements.changed' event with all the dirty * elements. * * The event can be picked up by components that are interested in the fact * that elements have been changed. One use case for this is updating * their graphical representation after moving / resizing or deletion. * * @see CommandHandler * * @param {EventBus} eventBus * @param {Injector} injector */ export default function CommandStack(eventBus, injector) { /** * A map of all registered command handlers. * * @type {Object} */ this._handlerMap = {}; /** * A stack containing all re/undoable actions on the diagram * * @type {Array<Object>} */ this._stack = []; /** * The current index on the stack * * @type {Number} */ this._stackIdx = -1; /** * Current active commandStack execution * * @type {Object} */ this._currentExecution = { actions: [], dirty: [] }; this._injector = injector; this._eventBus = eventBus; this._uid = 1; eventBus.on([ 'diagram.destroy', 'diagram.clear' ], function() { this.clear(false); }, this); } CommandStack.$inject = [ 'eventBus', 'injector' ]; /** * Execute a command * * @param {String} command the command to execute * @param {Object} context the environment to execute the command in */ CommandStack.prototype.execute = function(command, context) { Iif (!command) { throw new Error('command required'); } var action = { command: command, context: context }; this._pushAction(action); this._internalExecute(action); this._popAction(action); }; /** * Ask whether a given command can be executed. * * Implementors may hook into the mechanism on two ways: * * * in event listeners: * * Users may prevent the execution via an event listener. * It must prevent the default action for `commandStack.(<command>.)canExecute` events. * * * in command handlers: * * If the method {@link CommandHandler#canExecute} is implemented in a handler * it will be called to figure out whether the execution is allowed. * * @param {String} command the command to execute * @param {Object} context the environment to execute the command in * * @return {Boolean} true if the command can be executed */ CommandStack.prototype.canExecute = function(command, context) { var action = { command: command, context: context }; var handler = this._getHandler(command); var result = this._fire(command, 'canExecute', action); // handler#canExecute will only be called if no listener // decided on a result already if (result === undefined) { Iif (!handler) { return false; } Iif (handler.canExecute) { result = handler.canExecute(context); } } return result; }; /** * Clear the command stack, erasing all undo / redo history */ CommandStack.prototype.clear = function(emit) { this._stack.length = 0; this._stackIdx = -1; Iif (emit !== false) { this._fire('changed'); } }; /** * Undo last command(s) */ CommandStack.prototype.undo = function() { var action = this._getUndoAction(), next; Eif (action) { this._pushAction(action); while (action) { this._internalUndo(action); next = this._getUndoAction(); if (!next || next.id !== action.id) { break; } action = next; } this._popAction(); } }; /** * Redo last command(s) */ CommandStack.prototype.redo = function() { var action = this._getRedoAction(), next; Eif (action) { this._pushAction(action); while (action) { this._internalExecute(action, true); next = this._getRedoAction(); if (!next || next.id !== action.id) { break; } action = next; } this._popAction(); } }; /** * Register a handler instance with the command stack * * @param {String} command * @param {CommandHandler} handler */ CommandStack.prototype.register = function(command, handler) { this._setHandler(command, handler); }; /** * Register a handler type with the command stack * by instantiating it and injecting its dependencies. * * @param {String} command * @param {Function} a constructor for a {@link CommandHandler} */ CommandStack.prototype.registerHandler = function(command, handlerCls) { Iif (!command || !handlerCls) { throw new Error('command and handlerCls must be defined'); } var handler = this._injector.instantiate(handlerCls); this.register(command, handler); }; CommandStack.prototype.canUndo = function() { return !!this._getUndoAction(); }; CommandStack.prototype.canRedo = function() { return !!this._getRedoAction(); }; // stack access ////////////////////// CommandStack.prototype._getRedoAction = function() { return this._stack[this._stackIdx + 1]; }; CommandStack.prototype._getUndoAction = function() { return this._stack[this._stackIdx]; }; // internal functionality ////////////////////// CommandStack.prototype._internalUndo = function(action) { var self = this; var command = action.command, context = action.context; var handler = this._getHandler(command); // guard against illegal nested command stack invocations this._atomicDo(function() { self._fire(command, 'revert', action); if (handler.revert) { self._markDirty(handler.revert(context)); } self._revertedAction(action); self._fire(command, 'reverted', action); }); }; CommandStack.prototype._fire = function(command, qualifier, event) { if (arguments.length < 3) { event = qualifier; qualifier = null; } var names = qualifier ? [ command + '.' + qualifier, qualifier ] : [ command ], i, name, result; event = this._eventBus.createEvent(event); for (i = 0; (name = names[i]); i++) { result = this._eventBus.fire('commandStack.' + name, event); if (event.cancelBubble) { break; } } return result; }; CommandStack.prototype._createId = function() { return this._uid++; }; CommandStack.prototype._atomicDo = function(fn) { var execution = this._currentExecution; execution.atomic = true; try { fn(); } finally { execution.atomic = false; } }; CommandStack.prototype._internalExecute = function(action, redo) { var self = this; var command = action.command, context = action.context; var handler = this._getHandler(command); Iif (!handler) { throw new Error('no command handler registered for <' + command + '>'); } this._pushAction(action); if (!redo) { this._fire(command, 'preExecute', action); if (handler.preExecute) { handler.preExecute(context); } this._fire(command, 'preExecuted', action); } // guard against illegal nested command stack invocations this._atomicDo(function() { self._fire(command, 'execute', action); if (handler.execute) { // actual execute + mark return results as dirty self._markDirty(handler.execute(context)); } // log to stack self._executedAction(action, redo); self._fire(command, 'executed', action); }); if (!redo) { this._fire(command, 'postExecute', action); if (handler.postExecute) { handler.postExecute(context); } this._fire(command, 'postExecuted', action); } this._popAction(action); }; CommandStack.prototype._pushAction = function(action) { var execution = this._currentExecution, actions = execution.actions; var baseAction = actions[0]; Iif (execution.atomic) { throw new Error('illegal invocation in <execute> or <revert> phase (action: ' + action.command + ')'); } if (!action.id) { action.id = (baseAction && baseAction.id) || this._createId(); } actions.push(action); }; CommandStack.prototype._popAction = function() { var execution = this._currentExecution, actions = execution.actions, dirty = execution.dirty; actions.pop(); if (!actions.length) { this._eventBus.fire('elements.changed', { elements: uniqueBy('id', dirty) }); dirty.length = 0; this._fire('changed'); } }; CommandStack.prototype._markDirty = function(elements) { var execution = this._currentExecution; if (!elements) { return; } elements = isArray(elements) ? elements : [ elements ]; execution.dirty = execution.dirty.concat(elements); }; CommandStack.prototype._executedAction = function(action, redo) { var stackIdx = ++this._stackIdx; if (!redo) { this._stack.splice(stackIdx, this._stack.length, action); } }; CommandStack.prototype._revertedAction = function(action) { this._stackIdx--; }; CommandStack.prototype._getHandler = function(command) { return this._handlerMap[command]; }; CommandStack.prototype._setHandler = function(command, handler) { Iif (!command || !handler) { throw new Error('command and handler required'); } Iif (this._handlerMap[command]) { throw new Error('overriding handler for command <' + command + '>'); } this._handlerMap[command] = handler; }; |