StateMachine.java revision 8d3ed21583a8d83047cee1735cf669e131809e73
1/** 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.android.internal.util; 18 19import android.os.Handler; 20import android.os.HandlerThread; 21import android.os.Looper; 22import android.os.Message; 23import android.text.TextUtils; 24import android.util.Log; 25 26import java.io.FileDescriptor; 27import java.io.PrintWriter; 28import java.io.StringWriter; 29import java.util.ArrayList; 30import java.util.Calendar; 31import java.util.Collection; 32import java.util.HashMap; 33import java.util.Iterator; 34import java.util.Vector; 35 36/** 37 * {@hide} 38 * 39 * <p>The state machine defined here is a hierarchical state machine which processes messages 40 * and can have states arranged hierarchically.</p> 41 * 42 * <p>A state is a <code>State</code> object and must implement 43 * <code>processMessage</code> and optionally <code>enter/exit/getName</code>. 44 * The enter/exit methods are equivalent to the construction and destruction 45 * in Object Oriented programming and are used to perform initialization and 46 * cleanup of the state respectively. The <code>getName</code> method returns the 47 * name of the state; the default implementation returns the class name. It may be 48 * desirable to have <code>getName</code> return the the state instance name instead, 49 * in particular if a particular state class has multiple instances.</p> 50 * 51 * <p>When a state machine is created, <code>addState</code> is used to build the 52 * hierarchy and <code>setInitialState</code> is used to identify which of these 53 * is the initial state. After construction the programmer calls <code>start</code> 54 * which initializes and starts the state machine. The first action the StateMachine 55 * is to the invoke <code>enter</code> for all of the initial state's hierarchy, 56 * starting at its eldest parent. The calls to enter will be done in the context 57 * of the StateMachine's Handler, not in the context of the call to start, and they 58 * will be invoked before any messages are processed. For example, given the simple 59 * state machine below, mP1.enter will be invoked and then mS1.enter. Finally, 60 * messages sent to the state machine will be processed by the current state; 61 * in our simple state machine below that would initially be mS1.processMessage.</p> 62<pre> 63 mP1 64 / \ 65 mS2 mS1 ----> initial state 66</pre> 67 * <p>After the state machine is created and started, messages are sent to a state 68 * machine using <code>sendMessage</code> and the messages are created using 69 * <code>obtainMessage</code>. When the state machine receives a message the 70 * current state's <code>processMessage</code> is invoked. In the above example 71 * mS1.processMessage will be invoked first. The state may use <code>transitionTo</code> 72 * to change the current state to a new state.</p> 73 * 74 * <p>Each state in the state machine may have a zero or one parent states. If 75 * a child state is unable to handle a message it may have the message processed 76 * by its parent by returning false or NOT_HANDLED. If a message is not handled by 77 * a child state or any of its ancestors, <code>unhandledMessage</code> will be invoked 78 * to give one last chance for the state machine to process the message.</p> 79 * 80 * <p>When all processing is completed a state machine may choose to call 81 * <code>transitionToHaltingState</code>. When the current <code>processingMessage</code> 82 * returns the state machine will transfer to an internal <code>HaltingState</code> 83 * and invoke <code>halting</code>. Any message subsequently received by the state 84 * machine will cause <code>haltedProcessMessage</code> to be invoked.</p> 85 * 86 * <p>If it is desirable to completely stop the state machine call <code>quit</code> or 87 * <code>quitNow</code>. These will call <code>exit</code> of the current state and its parents, 88 * call <code>onQuitting</code> and then exit Thread/Loopers.</p> 89 * 90 * <p>In addition to <code>processMessage</code> each <code>State</code> has 91 * an <code>enter</code> method and <code>exit</code> method which may be overridden.</p> 92 * 93 * <p>Since the states are arranged in a hierarchy transitioning to a new state 94 * causes current states to be exited and new states to be entered. To determine 95 * the list of states to be entered/exited the common parent closest to 96 * the current state is found. We then exit from the current state and its 97 * parent's up to but not including the common parent state and then enter all 98 * of the new states below the common parent down to the destination state. 99 * If there is no common parent all states are exited and then the new states 100 * are entered.</p> 101 * 102 * <p>Two other methods that states can use are <code>deferMessage</code> and 103 * <code>sendMessageAtFrontOfQueue</code>. The <code>sendMessageAtFrontOfQueue</code> sends 104 * a message but places it on the front of the queue rather than the back. The 105 * <code>deferMessage</code> causes the message to be saved on a list until a 106 * transition is made to a new state. At which time all of the deferred messages 107 * will be put on the front of the state machine queue with the oldest message 108 * at the front. These will then be processed by the new current state before 109 * any other messages that are on the queue or might be added later. Both of 110 * these are protected and may only be invoked from within a state machine.</p> 111 * 112 * <p>To illustrate some of these properties we'll use state machine with an 8 113 * state hierarchy:</p> 114<pre> 115 mP0 116 / \ 117 mP1 mS0 118 / \ 119 mS2 mS1 120 / \ \ 121 mS3 mS4 mS5 ---> initial state 122</pre> 123 * <p>After starting mS5 the list of active states is mP0, mP1, mS1 and mS5. 124 * So the order of calling processMessage when a message is received is mS5, 125 * mS1, mP1, mP0 assuming each processMessage indicates it can't handle this 126 * message by returning false or NOT_HANDLED.</p> 127 * 128 * <p>Now assume mS5.processMessage receives a message it can handle, and during 129 * the handling determines the machine should change states. It could call 130 * transitionTo(mS4) and return true or HANDLED. Immediately after returning from 131 * processMessage the state machine runtime will find the common parent, 132 * which is mP1. It will then call mS5.exit, mS1.exit, mS2.enter and then 133 * mS4.enter. The new list of active states is mP0, mP1, mS2 and mS4. So 134 * when the next message is received mS4.processMessage will be invoked.</p> 135 * 136 * <p>Now for some concrete examples, here is the canonical HelloWorld as a state machine. 137 * It responds with "Hello World" being printed to the log for every message.</p> 138<pre> 139class HelloWorld extends StateMachine { 140 HelloWorld(String name) { 141 super(name); 142 addState(mState1); 143 setInitialState(mState1); 144 } 145 146 public static HelloWorld makeHelloWorld() { 147 HelloWorld hw = new HelloWorld("hw"); 148 hw.start(); 149 return hw; 150 } 151 152 class State1 extends State { 153 @Override public boolean processMessage(Message message) { 154 log("Hello World"); 155 return HANDLED; 156 } 157 } 158 State1 mState1 = new State1(); 159} 160 161void testHelloWorld() { 162 HelloWorld hw = makeHelloWorld(); 163 hw.sendMessage(hw.obtainMessage()); 164} 165</pre> 166 * <p>A more interesting state machine is one with four states 167 * with two independent parent states.</p> 168<pre> 169 mP1 mP2 170 / \ 171 mS2 mS1 172</pre> 173 * <p>Here is a description of this state machine using pseudo code.</p> 174 <pre> 175state mP1 { 176 enter { log("mP1.enter"); } 177 exit { log("mP1.exit"); } 178 on msg { 179 CMD_2 { 180 send(CMD_3); 181 defer(msg); 182 transitionTo(mS2); 183 return HANDLED; 184 } 185 return NOT_HANDLED; 186 } 187} 188 189INITIAL 190state mS1 parent mP1 { 191 enter { log("mS1.enter"); } 192 exit { log("mS1.exit"); } 193 on msg { 194 CMD_1 { 195 transitionTo(mS1); 196 return HANDLED; 197 } 198 return NOT_HANDLED; 199 } 200} 201 202state mS2 parent mP1 { 203 enter { log("mS2.enter"); } 204 exit { log("mS2.exit"); } 205 on msg { 206 CMD_2 { 207 send(CMD_4); 208 return HANDLED; 209 } 210 CMD_3 { 211 defer(msg); 212 transitionTo(mP2); 213 return HANDLED; 214 } 215 return NOT_HANDLED; 216 } 217} 218 219state mP2 { 220 enter { 221 log("mP2.enter"); 222 send(CMD_5); 223 } 224 exit { log("mP2.exit"); } 225 on msg { 226 CMD_3, CMD_4 { return HANDLED; } 227 CMD_5 { 228 transitionTo(HaltingState); 229 return HANDLED; 230 } 231 return NOT_HANDLED; 232 } 233} 234</pre> 235 * <p>The implementation is below and also in StateMachineTest:</p> 236<pre> 237class Hsm1 extends StateMachine { 238 public static final int CMD_1 = 1; 239 public static final int CMD_2 = 2; 240 public static final int CMD_3 = 3; 241 public static final int CMD_4 = 4; 242 public static final int CMD_5 = 5; 243 244 public static Hsm1 makeHsm1() { 245 log("makeHsm1 E"); 246 Hsm1 sm = new Hsm1("hsm1"); 247 sm.start(); 248 log("makeHsm1 X"); 249 return sm; 250 } 251 252 Hsm1(String name) { 253 super(name); 254 log("ctor E"); 255 256 // Add states, use indentation to show hierarchy 257 addState(mP1); 258 addState(mS1, mP1); 259 addState(mS2, mP1); 260 addState(mP2); 261 262 // Set the initial state 263 setInitialState(mS1); 264 log("ctor X"); 265 } 266 267 class P1 extends State { 268 @Override public void enter() { 269 log("mP1.enter"); 270 } 271 @Override public boolean processMessage(Message message) { 272 boolean retVal; 273 log("mP1.processMessage what=" + message.what); 274 switch(message.what) { 275 case CMD_2: 276 // CMD_2 will arrive in mS2 before CMD_3 277 sendMessage(obtainMessage(CMD_3)); 278 deferMessage(message); 279 transitionTo(mS2); 280 retVal = HANDLED; 281 break; 282 default: 283 // Any message we don't understand in this state invokes unhandledMessage 284 retVal = NOT_HANDLED; 285 break; 286 } 287 return retVal; 288 } 289 @Override public void exit() { 290 log("mP1.exit"); 291 } 292 } 293 294 class S1 extends State { 295 @Override public void enter() { 296 log("mS1.enter"); 297 } 298 @Override public boolean processMessage(Message message) { 299 log("S1.processMessage what=" + message.what); 300 if (message.what == CMD_1) { 301 // Transition to ourself to show that enter/exit is called 302 transitionTo(mS1); 303 return HANDLED; 304 } else { 305 // Let parent process all other messages 306 return NOT_HANDLED; 307 } 308 } 309 @Override public void exit() { 310 log("mS1.exit"); 311 } 312 } 313 314 class S2 extends State { 315 @Override public void enter() { 316 log("mS2.enter"); 317 } 318 @Override public boolean processMessage(Message message) { 319 boolean retVal; 320 log("mS2.processMessage what=" + message.what); 321 switch(message.what) { 322 case(CMD_2): 323 sendMessage(obtainMessage(CMD_4)); 324 retVal = HANDLED; 325 break; 326 case(CMD_3): 327 deferMessage(message); 328 transitionTo(mP2); 329 retVal = HANDLED; 330 break; 331 default: 332 retVal = NOT_HANDLED; 333 break; 334 } 335 return retVal; 336 } 337 @Override public void exit() { 338 log("mS2.exit"); 339 } 340 } 341 342 class P2 extends State { 343 @Override public void enter() { 344 log("mP2.enter"); 345 sendMessage(obtainMessage(CMD_5)); 346 } 347 @Override public boolean processMessage(Message message) { 348 log("P2.processMessage what=" + message.what); 349 switch(message.what) { 350 case(CMD_3): 351 break; 352 case(CMD_4): 353 break; 354 case(CMD_5): 355 transitionToHaltingState(); 356 break; 357 } 358 return HANDLED; 359 } 360 @Override public void exit() { 361 log("mP2.exit"); 362 } 363 } 364 365 @Override 366 void onHalting() { 367 log("halting"); 368 synchronized (this) { 369 this.notifyAll(); 370 } 371 } 372 373 P1 mP1 = new P1(); 374 S1 mS1 = new S1(); 375 S2 mS2 = new S2(); 376 P2 mP2 = new P2(); 377} 378</pre> 379 * <p>If this is executed by sending two messages CMD_1 and CMD_2 380 * (Note the synchronize is only needed because we use hsm.wait())</p> 381<pre> 382Hsm1 hsm = makeHsm1(); 383synchronize(hsm) { 384 hsm.sendMessage(obtainMessage(hsm.CMD_1)); 385 hsm.sendMessage(obtainMessage(hsm.CMD_2)); 386 try { 387 // wait for the messages to be handled 388 hsm.wait(); 389 } catch (InterruptedException e) { 390 loge("exception while waiting " + e.getMessage()); 391 } 392} 393</pre> 394 * <p>The output is:</p> 395<pre> 396D/hsm1 ( 1999): makeHsm1 E 397D/hsm1 ( 1999): ctor E 398D/hsm1 ( 1999): ctor X 399D/hsm1 ( 1999): mP1.enter 400D/hsm1 ( 1999): mS1.enter 401D/hsm1 ( 1999): makeHsm1 X 402D/hsm1 ( 1999): mS1.processMessage what=1 403D/hsm1 ( 1999): mS1.exit 404D/hsm1 ( 1999): mS1.enter 405D/hsm1 ( 1999): mS1.processMessage what=2 406D/hsm1 ( 1999): mP1.processMessage what=2 407D/hsm1 ( 1999): mS1.exit 408D/hsm1 ( 1999): mS2.enter 409D/hsm1 ( 1999): mS2.processMessage what=2 410D/hsm1 ( 1999): mS2.processMessage what=3 411D/hsm1 ( 1999): mS2.exit 412D/hsm1 ( 1999): mP1.exit 413D/hsm1 ( 1999): mP2.enter 414D/hsm1 ( 1999): mP2.processMessage what=3 415D/hsm1 ( 1999): mP2.processMessage what=4 416D/hsm1 ( 1999): mP2.processMessage what=5 417D/hsm1 ( 1999): mP2.exit 418D/hsm1 ( 1999): halting 419</pre> 420 */ 421public class StateMachine { 422 // Name of the state machine and used as logging tag 423 private String mName; 424 425 /** Message.what value when quitting */ 426 private static final int SM_QUIT_CMD = -1; 427 428 /** Message.what value when initializing */ 429 private static final int SM_INIT_CMD = -2; 430 431 /** 432 * Convenience constant that maybe returned by processMessage 433 * to indicate the the message was processed and is not to be 434 * processed by parent states 435 */ 436 public static final boolean HANDLED = true; 437 438 /** 439 * Convenience constant that maybe returned by processMessage 440 * to indicate the the message was NOT processed and is to be 441 * processed by parent states 442 */ 443 public static final boolean NOT_HANDLED = false; 444 445 /** 446 * StateMachine logging record. 447 * {@hide} 448 */ 449 public static class LogRec { 450 private StateMachine mSm; 451 private long mTime; 452 private int mWhat; 453 private String mInfo; 454 private IState mState; 455 private IState mOrgState; 456 private IState mDstState; 457 458 /** 459 * Constructor 460 * 461 * @param msg 462 * @param state the state which handled the message 463 * @param orgState is the first state the received the message but 464 * did not processes the message. 465 * @param transToState is the state that was transitioned to after the message was 466 * processed. 467 */ 468 LogRec(StateMachine sm, Message msg, String info, IState state, IState orgState, 469 IState transToState) { 470 update(sm, msg, info, state, orgState, transToState); 471 } 472 473 /** 474 * Update the information in the record. 475 * @param state that handled the message 476 * @param orgState is the first state the received the message 477 * @param dstState is the state that was the transition target when logging 478 */ 479 public void update(StateMachine sm, Message msg, String info, IState state, IState orgState, 480 IState dstState) { 481 mSm = sm; 482 mTime = System.currentTimeMillis(); 483 mWhat = (msg != null) ? msg.what : 0; 484 mInfo = info; 485 mState = state; 486 mOrgState = orgState; 487 mDstState = dstState; 488 } 489 490 /** 491 * @return time stamp 492 */ 493 public long getTime() { 494 return mTime; 495 } 496 497 /** 498 * @return msg.what 499 */ 500 public long getWhat() { 501 return mWhat; 502 } 503 504 /** 505 * @return the command that was executing 506 */ 507 public String getInfo() { 508 return mInfo; 509 } 510 511 /** 512 * @return the state that handled this message 513 */ 514 public IState getState() { 515 return mState; 516 } 517 518 /** 519 * @return the state destination state if a transition is occurring or null if none. 520 */ 521 public IState getDestState() { 522 return mDstState; 523 } 524 525 /** 526 * @return the original state that received the message. 527 */ 528 public IState getOriginalState() { 529 return mOrgState; 530 } 531 532 @Override 533 public String toString() { 534 StringBuilder sb = new StringBuilder(); 535 sb.append("time="); 536 Calendar c = Calendar.getInstance(); 537 c.setTimeInMillis(mTime); 538 sb.append(String.format("%tm-%td %tH:%tM:%tS.%tL", c, c, c, c, c, c)); 539 sb.append(" processed="); 540 sb.append(mState == null ? "<null>" : mState.getName()); 541 sb.append(" org="); 542 sb.append(mOrgState == null ? "<null>" : mOrgState.getName()); 543 sb.append(" dest="); 544 sb.append(mDstState == null ? "<null>" : mDstState.getName()); 545 sb.append(" what="); 546 String what = mSm != null ? mSm.getWhatToString(mWhat) : ""; 547 if (TextUtils.isEmpty(what)) { 548 sb.append(mWhat); 549 sb.append("(0x"); 550 sb.append(Integer.toHexString(mWhat)); 551 sb.append(")"); 552 } else { 553 sb.append(what); 554 } 555 if (!TextUtils.isEmpty(mInfo)) { 556 sb.append(" "); 557 sb.append(mInfo); 558 } 559 return sb.toString(); 560 } 561 } 562 563 /** 564 * A list of log records including messages recently processed by the state machine. 565 * 566 * The class maintains a list of log records including messages 567 * recently processed. The list is finite and may be set in the 568 * constructor or by calling setSize. The public interface also 569 * includes size which returns the number of recent records, 570 * count which is the number of records processed since the 571 * the last setSize, get which returns a record and 572 * add which adds a record. 573 */ 574 private static class LogRecords { 575 576 private static final int DEFAULT_SIZE = 20; 577 578 private Vector<LogRec> mLogRecVector = new Vector<LogRec>(); 579 private int mMaxSize = DEFAULT_SIZE; 580 private int mOldestIndex = 0; 581 private int mCount = 0; 582 private boolean mLogOnlyTransitions = false; 583 584 /** 585 * private constructor use add 586 */ 587 private LogRecords() { 588 } 589 590 /** 591 * Set size of messages to maintain and clears all current records. 592 * 593 * @param maxSize number of records to maintain at anyone time. 594 */ 595 synchronized void setSize(int maxSize) { 596 // TODO: once b/28217358 is fixed, add unit tests to verify that these variables are 597 // cleared after calling this method, and that subsequent calls to get() function as 598 // expected. 599 mMaxSize = maxSize; 600 mOldestIndex = 0; 601 mCount = 0; 602 mLogRecVector.clear(); 603 } 604 605 synchronized void setLogOnlyTransitions(boolean enable) { 606 mLogOnlyTransitions = enable; 607 } 608 609 synchronized boolean logOnlyTransitions() { 610 return mLogOnlyTransitions; 611 } 612 613 /** 614 * @return the number of recent records. 615 */ 616 synchronized int size() { 617 return mLogRecVector.size(); 618 } 619 620 /** 621 * @return the total number of records processed since size was set. 622 */ 623 synchronized int count() { 624 return mCount; 625 } 626 627 /** 628 * Clear the list of records. 629 */ 630 synchronized void cleanup() { 631 mLogRecVector.clear(); 632 } 633 634 /** 635 * @return the information on a particular record. 0 is the oldest 636 * record and size()-1 is the newest record. If the index is to 637 * large null is returned. 638 */ 639 synchronized LogRec get(int index) { 640 int nextIndex = mOldestIndex + index; 641 if (nextIndex >= mMaxSize) { 642 nextIndex -= mMaxSize; 643 } 644 if (nextIndex >= size()) { 645 return null; 646 } else { 647 return mLogRecVector.get(nextIndex); 648 } 649 } 650 651 /** 652 * Add a processed message. 653 * 654 * @param msg 655 * @param messageInfo to be stored 656 * @param state that handled the message 657 * @param orgState is the first state the received the message but 658 * did not processes the message. 659 * @param transToState is the state that was transitioned to after the message was 660 * processed. 661 * 662 */ 663 synchronized void add(StateMachine sm, Message msg, String messageInfo, IState state, 664 IState orgState, IState transToState) { 665 mCount += 1; 666 if (mLogRecVector.size() < mMaxSize) { 667 mLogRecVector.add(new LogRec(sm, msg, messageInfo, state, orgState, transToState)); 668 } else { 669 LogRec pmi = mLogRecVector.get(mOldestIndex); 670 mOldestIndex += 1; 671 if (mOldestIndex >= mMaxSize) { 672 mOldestIndex = 0; 673 } 674 pmi.update(sm, msg, messageInfo, state, orgState, transToState); 675 } 676 } 677 } 678 679 private static class SmHandler extends Handler { 680 681 /** true if StateMachine has quit */ 682 private boolean mHasQuit = false; 683 684 /** The debug flag */ 685 private boolean mDbg = false; 686 687 /** The SmHandler object, identifies that message is internal */ 688 private static final Object mSmHandlerObj = new Object(); 689 690 /** The current message */ 691 private Message mMsg; 692 693 /** A list of log records including messages this state machine has processed */ 694 private LogRecords mLogRecords = new LogRecords(); 695 696 /** true if construction of the state machine has not been completed */ 697 private boolean mIsConstructionCompleted; 698 699 /** Stack used to manage the current hierarchy of states */ 700 private StateInfo mStateStack[]; 701 702 /** Top of mStateStack */ 703 private int mStateStackTopIndex = -1; 704 705 /** A temporary stack used to manage the state stack */ 706 private StateInfo mTempStateStack[]; 707 708 /** The top of the mTempStateStack */ 709 private int mTempStateStackCount; 710 711 /** State used when state machine is halted */ 712 private HaltingState mHaltingState = new HaltingState(); 713 714 /** State used when state machine is quitting */ 715 private QuittingState mQuittingState = new QuittingState(); 716 717 /** Reference to the StateMachine */ 718 private StateMachine mSm; 719 720 /** 721 * Information about a state. 722 * Used to maintain the hierarchy. 723 */ 724 private class StateInfo { 725 /** The state */ 726 State state; 727 728 /** The parent of this state, null if there is no parent */ 729 StateInfo parentStateInfo; 730 731 /** True when the state has been entered and on the stack */ 732 boolean active; 733 734 /** 735 * Convert StateInfo to string 736 */ 737 @Override 738 public String toString() { 739 return "state=" + state.getName() + ",active=" + active + ",parent=" 740 + ((parentStateInfo == null) ? "null" : parentStateInfo.state.getName()); 741 } 742 } 743 744 /** The map of all of the states in the state machine */ 745 private HashMap<State, StateInfo> mStateInfo = new HashMap<State, StateInfo>(); 746 747 /** The initial state that will process the first message */ 748 private State mInitialState; 749 750 /** The destination state when transitionTo has been invoked */ 751 private State mDestState; 752 753 /** 754 * Indicates if a transition is in progress 755 * 756 * This will be true for all calls of State.exit and all calls of State.enter except for the 757 * last enter call for the current destination state. 758 */ 759 private boolean mTransitionInProgress = false; 760 761 /** The list of deferred messages */ 762 private ArrayList<Message> mDeferredMessages = new ArrayList<Message>(); 763 764 /** 765 * State entered when transitionToHaltingState is called. 766 */ 767 private class HaltingState extends State { 768 @Override 769 public boolean processMessage(Message msg) { 770 mSm.haltedProcessMessage(msg); 771 return true; 772 } 773 } 774 775 /** 776 * State entered when a valid quit message is handled. 777 */ 778 private class QuittingState extends State { 779 @Override 780 public boolean processMessage(Message msg) { 781 return NOT_HANDLED; 782 } 783 } 784 785 /** 786 * Handle messages sent to the state machine by calling 787 * the current state's processMessage. It also handles 788 * the enter/exit calls and placing any deferred messages 789 * back onto the queue when transitioning to a new state. 790 */ 791 @Override 792 public final void handleMessage(Message msg) { 793 if (!mHasQuit) { 794 if (mSm != null && msg.what != SM_INIT_CMD && msg.what != SM_QUIT_CMD) { 795 mSm.onPreHandleMessage(msg); 796 } 797 798 if (mDbg) mSm.log("handleMessage: E msg.what=" + msg.what); 799 800 /** Save the current message */ 801 mMsg = msg; 802 803 /** State that processed the message */ 804 State msgProcessedState = null; 805 if (mIsConstructionCompleted) { 806 /** Normal path */ 807 msgProcessedState = processMsg(msg); 808 } else if (!mIsConstructionCompleted && (mMsg.what == SM_INIT_CMD) 809 && (mMsg.obj == mSmHandlerObj)) { 810 /** Initial one time path. */ 811 mIsConstructionCompleted = true; 812 invokeEnterMethods(0); 813 } else { 814 throw new RuntimeException("StateMachine.handleMessage: " 815 + "The start method not called, received msg: " + msg); 816 } 817 performTransitions(msgProcessedState, msg); 818 819 // We need to check if mSm == null here as we could be quitting. 820 if (mDbg && mSm != null) mSm.log("handleMessage: X"); 821 822 if (mSm != null && msg.what != SM_INIT_CMD && msg.what != SM_QUIT_CMD) { 823 mSm.onPostHandleMessage(msg); 824 } 825 } 826 } 827 828 /** 829 * Do any transitions 830 * @param msgProcessedState is the state that processed the message 831 */ 832 private void performTransitions(State msgProcessedState, Message msg) { 833 /** 834 * If transitionTo has been called, exit and then enter 835 * the appropriate states. We loop on this to allow 836 * enter and exit methods to use transitionTo. 837 */ 838 State orgState = mStateStack[mStateStackTopIndex].state; 839 840 /** 841 * Record whether message needs to be logged before we transition and 842 * and we won't log special messages SM_INIT_CMD or SM_QUIT_CMD which 843 * always set msg.obj to the handler. 844 */ 845 boolean recordLogMsg = mSm.recordLogRec(mMsg) && (msg.obj != mSmHandlerObj); 846 847 if (mLogRecords.logOnlyTransitions()) { 848 /** Record only if there is a transition */ 849 if (mDestState != null) { 850 mLogRecords.add(mSm, mMsg, mSm.getLogRecString(mMsg), msgProcessedState, 851 orgState, mDestState); 852 } 853 } else if (recordLogMsg) { 854 /** Record message */ 855 mLogRecords.add(mSm, mMsg, mSm.getLogRecString(mMsg), msgProcessedState, orgState, 856 mDestState); 857 } 858 859 State destState = mDestState; 860 if (destState != null) { 861 /** 862 * Process the transitions including transitions in the enter/exit methods 863 */ 864 while (true) { 865 if (mDbg) mSm.log("handleMessage: new destination call exit/enter"); 866 867 /** 868 * Determine the states to exit and enter and return the 869 * common ancestor state of the enter/exit states. Then 870 * invoke the exit methods then the enter methods. 871 */ 872 StateInfo commonStateInfo = setupTempStateStackWithStatesToEnter(destState); 873 // flag is cleared in invokeEnterMethods before entering the target state 874 mTransitionInProgress = true; 875 invokeExitMethods(commonStateInfo); 876 int stateStackEnteringIndex = moveTempStateStackToStateStack(); 877 invokeEnterMethods(stateStackEnteringIndex); 878 879 /** 880 * Since we have transitioned to a new state we need to have 881 * any deferred messages moved to the front of the message queue 882 * so they will be processed before any other messages in the 883 * message queue. 884 */ 885 moveDeferredMessageAtFrontOfQueue(); 886 887 if (destState != mDestState) { 888 // A new mDestState so continue looping 889 destState = mDestState; 890 } else { 891 // No change in mDestState so we're done 892 break; 893 } 894 } 895 mDestState = null; 896 } 897 898 /** 899 * After processing all transitions check and 900 * see if the last transition was to quit or halt. 901 */ 902 if (destState != null) { 903 if (destState == mQuittingState) { 904 /** 905 * Call onQuitting to let subclasses cleanup. 906 */ 907 mSm.onQuitting(); 908 cleanupAfterQuitting(); 909 } else if (destState == mHaltingState) { 910 /** 911 * Call onHalting() if we've transitioned to the halting 912 * state. All subsequent messages will be processed in 913 * in the halting state which invokes haltedProcessMessage(msg); 914 */ 915 mSm.onHalting(); 916 } 917 } 918 } 919 920 /** 921 * Cleanup all the static variables and the looper after the SM has been quit. 922 */ 923 private final void cleanupAfterQuitting() { 924 if (mSm.mSmThread != null) { 925 // If we made the thread then quit looper which stops the thread. 926 getLooper().quit(); 927 mSm.mSmThread = null; 928 } 929 930 mSm.mSmHandler = null; 931 mSm = null; 932 mMsg = null; 933 mLogRecords.cleanup(); 934 mStateStack = null; 935 mTempStateStack = null; 936 mStateInfo.clear(); 937 mInitialState = null; 938 mDestState = null; 939 mDeferredMessages.clear(); 940 mHasQuit = true; 941 } 942 943 /** 944 * Complete the construction of the state machine. 945 */ 946 private final void completeConstruction() { 947 if (mDbg) mSm.log("completeConstruction: E"); 948 949 /** 950 * Determine the maximum depth of the state hierarchy 951 * so we can allocate the state stacks. 952 */ 953 int maxDepth = 0; 954 for (StateInfo si : mStateInfo.values()) { 955 int depth = 0; 956 for (StateInfo i = si; i != null; depth++) { 957 i = i.parentStateInfo; 958 } 959 if (maxDepth < depth) { 960 maxDepth = depth; 961 } 962 } 963 if (mDbg) mSm.log("completeConstruction: maxDepth=" + maxDepth); 964 965 mStateStack = new StateInfo[maxDepth]; 966 mTempStateStack = new StateInfo[maxDepth]; 967 setupInitialStateStack(); 968 969 /** Sending SM_INIT_CMD message to invoke enter methods asynchronously */ 970 sendMessageAtFrontOfQueue(obtainMessage(SM_INIT_CMD, mSmHandlerObj)); 971 972 if (mDbg) mSm.log("completeConstruction: X"); 973 } 974 975 /** 976 * Process the message. If the current state doesn't handle 977 * it, call the states parent and so on. If it is never handled then 978 * call the state machines unhandledMessage method. 979 * @return the state that processed the message 980 */ 981 private final State processMsg(Message msg) { 982 StateInfo curStateInfo = mStateStack[mStateStackTopIndex]; 983 if (mDbg) { 984 mSm.log("processMsg: " + curStateInfo.state.getName()); 985 } 986 987 if (isQuit(msg)) { 988 transitionTo(mQuittingState); 989 } else { 990 while (!curStateInfo.state.processMessage(msg)) { 991 /** 992 * Not processed 993 */ 994 curStateInfo = curStateInfo.parentStateInfo; 995 if (curStateInfo == null) { 996 /** 997 * No parents left so it's not handled 998 */ 999 mSm.unhandledMessage(msg); 1000 break; 1001 } 1002 if (mDbg) { 1003 mSm.log("processMsg: " + curStateInfo.state.getName()); 1004 } 1005 } 1006 } 1007 return (curStateInfo != null) ? curStateInfo.state : null; 1008 } 1009 1010 /** 1011 * Call the exit method for each state from the top of stack 1012 * up to the common ancestor state. 1013 */ 1014 private final void invokeExitMethods(StateInfo commonStateInfo) { 1015 while ((mStateStackTopIndex >= 0) 1016 && (mStateStack[mStateStackTopIndex] != commonStateInfo)) { 1017 State curState = mStateStack[mStateStackTopIndex].state; 1018 if (mDbg) mSm.log("invokeExitMethods: " + curState.getName()); 1019 curState.exit(); 1020 mStateStack[mStateStackTopIndex].active = false; 1021 mStateStackTopIndex -= 1; 1022 } 1023 } 1024 1025 /** 1026 * Invoke the enter method starting at the entering index to top of state stack 1027 */ 1028 private final void invokeEnterMethods(int stateStackEnteringIndex) { 1029 for (int i = stateStackEnteringIndex; i <= mStateStackTopIndex; i++) { 1030 if (stateStackEnteringIndex == mStateStackTopIndex) { 1031 // Last enter state for transition 1032 mTransitionInProgress = false; 1033 } 1034 if (mDbg) mSm.log("invokeEnterMethods: " + mStateStack[i].state.getName()); 1035 mStateStack[i].state.enter(); 1036 mStateStack[i].active = true; 1037 } 1038 mTransitionInProgress = false; // ensure flag set to false if no methods called 1039 } 1040 1041 /** 1042 * Move the deferred message to the front of the message queue. 1043 */ 1044 private final void moveDeferredMessageAtFrontOfQueue() { 1045 /** 1046 * The oldest messages on the deferred list must be at 1047 * the front of the queue so start at the back, which 1048 * as the most resent message and end with the oldest 1049 * messages at the front of the queue. 1050 */ 1051 for (int i = mDeferredMessages.size() - 1; i >= 0; i--) { 1052 Message curMsg = mDeferredMessages.get(i); 1053 if (mDbg) mSm.log("moveDeferredMessageAtFrontOfQueue; what=" + curMsg.what); 1054 sendMessageAtFrontOfQueue(curMsg); 1055 } 1056 mDeferredMessages.clear(); 1057 } 1058 1059 /** 1060 * Move the contents of the temporary stack to the state stack 1061 * reversing the order of the items on the temporary stack as 1062 * they are moved. 1063 * 1064 * @return index into mStateStack where entering needs to start 1065 */ 1066 private final int moveTempStateStackToStateStack() { 1067 int startingIndex = mStateStackTopIndex + 1; 1068 int i = mTempStateStackCount - 1; 1069 int j = startingIndex; 1070 while (i >= 0) { 1071 if (mDbg) mSm.log("moveTempStackToStateStack: i=" + i + ",j=" + j); 1072 mStateStack[j] = mTempStateStack[i]; 1073 j += 1; 1074 i -= 1; 1075 } 1076 1077 mStateStackTopIndex = j - 1; 1078 if (mDbg) { 1079 mSm.log("moveTempStackToStateStack: X mStateStackTop=" + mStateStackTopIndex 1080 + ",startingIndex=" + startingIndex + ",Top=" 1081 + mStateStack[mStateStackTopIndex].state.getName()); 1082 } 1083 return startingIndex; 1084 } 1085 1086 /** 1087 * Setup the mTempStateStack with the states we are going to enter. 1088 * 1089 * This is found by searching up the destState's ancestors for a 1090 * state that is already active i.e. StateInfo.active == true. 1091 * The destStae and all of its inactive parents will be on the 1092 * TempStateStack as the list of states to enter. 1093 * 1094 * @return StateInfo of the common ancestor for the destState and 1095 * current state or null if there is no common parent. 1096 */ 1097 private final StateInfo setupTempStateStackWithStatesToEnter(State destState) { 1098 /** 1099 * Search up the parent list of the destination state for an active 1100 * state. Use a do while() loop as the destState must always be entered 1101 * even if it is active. This can happen if we are exiting/entering 1102 * the current state. 1103 */ 1104 mTempStateStackCount = 0; 1105 StateInfo curStateInfo = mStateInfo.get(destState); 1106 do { 1107 mTempStateStack[mTempStateStackCount++] = curStateInfo; 1108 curStateInfo = curStateInfo.parentStateInfo; 1109 } while ((curStateInfo != null) && !curStateInfo.active); 1110 1111 if (mDbg) { 1112 mSm.log("setupTempStateStackWithStatesToEnter: X mTempStateStackCount=" 1113 + mTempStateStackCount + ",curStateInfo: " + curStateInfo); 1114 } 1115 return curStateInfo; 1116 } 1117 1118 /** 1119 * Initialize StateStack to mInitialState. 1120 */ 1121 private final void setupInitialStateStack() { 1122 if (mDbg) { 1123 mSm.log("setupInitialStateStack: E mInitialState=" + mInitialState.getName()); 1124 } 1125 1126 StateInfo curStateInfo = mStateInfo.get(mInitialState); 1127 for (mTempStateStackCount = 0; curStateInfo != null; mTempStateStackCount++) { 1128 mTempStateStack[mTempStateStackCount] = curStateInfo; 1129 curStateInfo = curStateInfo.parentStateInfo; 1130 } 1131 1132 // Empty the StateStack 1133 mStateStackTopIndex = -1; 1134 1135 moveTempStateStackToStateStack(); 1136 } 1137 1138 /** 1139 * @return current message 1140 */ 1141 private final Message getCurrentMessage() { 1142 return mMsg; 1143 } 1144 1145 /** 1146 * @return current state 1147 */ 1148 private final IState getCurrentState() { 1149 return mStateStack[mStateStackTopIndex].state; 1150 } 1151 1152 /** 1153 * Add a new state to the state machine. Bottom up addition 1154 * of states is allowed but the same state may only exist 1155 * in one hierarchy. 1156 * 1157 * @param state the state to add 1158 * @param parent the parent of state 1159 * @return stateInfo for this state 1160 */ 1161 private final StateInfo addState(State state, State parent) { 1162 if (mDbg) { 1163 mSm.log("addStateInternal: E state=" + state.getName() + ",parent=" 1164 + ((parent == null) ? "" : parent.getName())); 1165 } 1166 StateInfo parentStateInfo = null; 1167 if (parent != null) { 1168 parentStateInfo = mStateInfo.get(parent); 1169 if (parentStateInfo == null) { 1170 // Recursively add our parent as it's not been added yet. 1171 parentStateInfo = addState(parent, null); 1172 } 1173 } 1174 StateInfo stateInfo = mStateInfo.get(state); 1175 if (stateInfo == null) { 1176 stateInfo = new StateInfo(); 1177 mStateInfo.put(state, stateInfo); 1178 } 1179 1180 // Validate that we aren't adding the same state in two different hierarchies. 1181 if ((stateInfo.parentStateInfo != null) 1182 && (stateInfo.parentStateInfo != parentStateInfo)) { 1183 throw new RuntimeException("state already added"); 1184 } 1185 stateInfo.state = state; 1186 stateInfo.parentStateInfo = parentStateInfo; 1187 stateInfo.active = false; 1188 if (mDbg) mSm.log("addStateInternal: X stateInfo: " + stateInfo); 1189 return stateInfo; 1190 } 1191 1192 /** 1193 * Constructor 1194 * 1195 * @param looper for dispatching messages 1196 * @param sm the hierarchical state machine 1197 */ 1198 private SmHandler(Looper looper, StateMachine sm) { 1199 super(looper); 1200 mSm = sm; 1201 1202 addState(mHaltingState, null); 1203 addState(mQuittingState, null); 1204 } 1205 1206 /** @see StateMachine#setInitialState(State) */ 1207 private final void setInitialState(State initialState) { 1208 if (mDbg) mSm.log("setInitialState: initialState=" + initialState.getName()); 1209 mInitialState = initialState; 1210 } 1211 1212 /** @see StateMachine#transitionTo(IState) */ 1213 private final void transitionTo(IState destState) { 1214 if (mTransitionInProgress) { 1215 Log.wtf(mSm.mName, "transitionTo called while transition already in progress to " + 1216 mDestState + ", new target state=" + destState); 1217 } 1218 mDestState = (State) destState; 1219 if (mDbg) mSm.log("transitionTo: destState=" + mDestState.getName()); 1220 } 1221 1222 /** @see StateMachine#deferMessage(Message) */ 1223 private final void deferMessage(Message msg) { 1224 if (mDbg) mSm.log("deferMessage: msg=" + msg.what); 1225 1226 /* Copy the "msg" to "newMsg" as "msg" will be recycled */ 1227 Message newMsg = obtainMessage(); 1228 newMsg.copyFrom(msg); 1229 1230 mDeferredMessages.add(newMsg); 1231 } 1232 1233 /** @see StateMachine#quit() */ 1234 private final void quit() { 1235 if (mDbg) mSm.log("quit:"); 1236 sendMessage(obtainMessage(SM_QUIT_CMD, mSmHandlerObj)); 1237 } 1238 1239 /** @see StateMachine#quitNow() */ 1240 private final void quitNow() { 1241 if (mDbg) mSm.log("quitNow:"); 1242 sendMessageAtFrontOfQueue(obtainMessage(SM_QUIT_CMD, mSmHandlerObj)); 1243 } 1244 1245 /** Validate that the message was sent by quit or quitNow. */ 1246 private final boolean isQuit(Message msg) { 1247 return (msg.what == SM_QUIT_CMD) && (msg.obj == mSmHandlerObj); 1248 } 1249 1250 /** @see StateMachine#isDbg() */ 1251 private final boolean isDbg() { 1252 return mDbg; 1253 } 1254 1255 /** @see StateMachine#setDbg(boolean) */ 1256 private final void setDbg(boolean dbg) { 1257 mDbg = dbg; 1258 } 1259 1260 } 1261 1262 private SmHandler mSmHandler; 1263 private HandlerThread mSmThread; 1264 1265 /** 1266 * Initialize. 1267 * 1268 * @param looper for this state machine 1269 * @param name of the state machine 1270 */ 1271 private void initStateMachine(String name, Looper looper) { 1272 mName = name; 1273 mSmHandler = new SmHandler(looper, this); 1274 } 1275 1276 /** 1277 * Constructor creates a StateMachine with its own thread. 1278 * 1279 * @param name of the state machine 1280 */ 1281 protected StateMachine(String name) { 1282 mSmThread = new HandlerThread(name); 1283 mSmThread.start(); 1284 Looper looper = mSmThread.getLooper(); 1285 1286 initStateMachine(name, looper); 1287 } 1288 1289 /** 1290 * Constructor creates a StateMachine using the looper. 1291 * 1292 * @param name of the state machine 1293 */ 1294 protected StateMachine(String name, Looper looper) { 1295 initStateMachine(name, looper); 1296 } 1297 1298 /** 1299 * Constructor creates a StateMachine using the handler. 1300 * 1301 * @param name of the state machine 1302 */ 1303 protected StateMachine(String name, Handler handler) { 1304 initStateMachine(name, handler.getLooper()); 1305 } 1306 1307 /** 1308 * Notifies subclass that the StateMachine handler is about to process the Message msg 1309 * @param msg The message that is being handled 1310 */ 1311 protected void onPreHandleMessage(Message msg) { 1312 } 1313 1314 /** 1315 * Notifies subclass that the StateMachine handler has finished processing the Message msg and 1316 * has possibly transitioned to a new state. 1317 * @param msg The message that is being handled 1318 */ 1319 protected void onPostHandleMessage(Message msg) { 1320 } 1321 1322 /** 1323 * Add a new state to the state machine 1324 * @param state the state to add 1325 * @param parent the parent of state 1326 */ 1327 public final void addState(State state, State parent) { 1328 mSmHandler.addState(state, parent); 1329 } 1330 1331 /** 1332 * Add a new state to the state machine, parent will be null 1333 * @param state to add 1334 */ 1335 public final void addState(State state) { 1336 mSmHandler.addState(state, null); 1337 } 1338 1339 /** 1340 * Set the initial state. This must be invoked before 1341 * and messages are sent to the state machine. 1342 * 1343 * @param initialState is the state which will receive the first message. 1344 */ 1345 public final void setInitialState(State initialState) { 1346 mSmHandler.setInitialState(initialState); 1347 } 1348 1349 /** 1350 * @return current message 1351 */ 1352 public final Message getCurrentMessage() { 1353 // mSmHandler can be null if the state machine has quit. 1354 SmHandler smh = mSmHandler; 1355 if (smh == null) return null; 1356 return smh.getCurrentMessage(); 1357 } 1358 1359 /** 1360 * @return current state 1361 */ 1362 public final IState getCurrentState() { 1363 // mSmHandler can be null if the state machine has quit. 1364 SmHandler smh = mSmHandler; 1365 if (smh == null) return null; 1366 return smh.getCurrentState(); 1367 } 1368 1369 /** 1370 * transition to destination state. Upon returning 1371 * from processMessage the current state's exit will 1372 * be executed and upon the next message arriving 1373 * destState.enter will be invoked. 1374 * 1375 * this function can also be called inside the enter function of the 1376 * previous transition target, but the behavior is undefined when it is 1377 * called mid-way through a previous transition (for example, calling this 1378 * in the enter() routine of a intermediate node when the current transition 1379 * target is one of the nodes descendants). 1380 * 1381 * @param destState will be the state that receives the next message. 1382 */ 1383 public final void transitionTo(IState destState) { 1384 mSmHandler.transitionTo(destState); 1385 } 1386 1387 /** 1388 * transition to halt state. Upon returning 1389 * from processMessage we will exit all current 1390 * states, execute the onHalting() method and then 1391 * for all subsequent messages haltedProcessMessage 1392 * will be called. 1393 */ 1394 public final void transitionToHaltingState() { 1395 mSmHandler.transitionTo(mSmHandler.mHaltingState); 1396 } 1397 1398 /** 1399 * Defer this message until next state transition. 1400 * Upon transitioning all deferred messages will be 1401 * placed on the queue and reprocessed in the original 1402 * order. (i.e. The next state the oldest messages will 1403 * be processed first) 1404 * 1405 * @param msg is deferred until the next transition. 1406 */ 1407 public final void deferMessage(Message msg) { 1408 mSmHandler.deferMessage(msg); 1409 } 1410 1411 /** 1412 * Called when message wasn't handled 1413 * 1414 * @param msg that couldn't be handled. 1415 */ 1416 protected void unhandledMessage(Message msg) { 1417 if (mSmHandler.mDbg) loge(" - unhandledMessage: msg.what=" + msg.what); 1418 } 1419 1420 /** 1421 * Called for any message that is received after 1422 * transitionToHalting is called. 1423 */ 1424 protected void haltedProcessMessage(Message msg) { 1425 } 1426 1427 /** 1428 * This will be called once after handling a message that called 1429 * transitionToHalting. All subsequent messages will invoke 1430 * {@link StateMachine#haltedProcessMessage(Message)} 1431 */ 1432 protected void onHalting() { 1433 } 1434 1435 /** 1436 * This will be called once after a quit message that was NOT handled by 1437 * the derived StateMachine. The StateMachine will stop and any subsequent messages will be 1438 * ignored. In addition, if this StateMachine created the thread, the thread will 1439 * be stopped after this method returns. 1440 */ 1441 protected void onQuitting() { 1442 } 1443 1444 /** 1445 * @return the name 1446 */ 1447 public final String getName() { 1448 return mName; 1449 } 1450 1451 /** 1452 * Set number of log records to maintain and clears all current records. 1453 * 1454 * @param maxSize number of messages to maintain at anyone time. 1455 */ 1456 public final void setLogRecSize(int maxSize) { 1457 mSmHandler.mLogRecords.setSize(maxSize); 1458 } 1459 1460 /** 1461 * Set to log only messages that cause a state transition 1462 * 1463 * @param enable {@code true} to enable, {@code false} to disable 1464 */ 1465 public final void setLogOnlyTransitions(boolean enable) { 1466 mSmHandler.mLogRecords.setLogOnlyTransitions(enable); 1467 } 1468 1469 /** 1470 * @return number of log records 1471 */ 1472 public final int getLogRecSize() { 1473 // mSmHandler can be null if the state machine has quit. 1474 SmHandler smh = mSmHandler; 1475 if (smh == null) return 0; 1476 return smh.mLogRecords.size(); 1477 } 1478 1479 /** 1480 * @return the total number of records processed 1481 */ 1482 public final int getLogRecCount() { 1483 // mSmHandler can be null if the state machine has quit. 1484 SmHandler smh = mSmHandler; 1485 if (smh == null) return 0; 1486 return smh.mLogRecords.count(); 1487 } 1488 1489 /** 1490 * @return a log record, or null if index is out of range 1491 */ 1492 public final LogRec getLogRec(int index) { 1493 // mSmHandler can be null if the state machine has quit. 1494 SmHandler smh = mSmHandler; 1495 if (smh == null) return null; 1496 return smh.mLogRecords.get(index); 1497 } 1498 1499 /** 1500 * @return a copy of LogRecs as a collection 1501 */ 1502 public final Collection<LogRec> copyLogRecs() { 1503 Vector<LogRec> vlr = new Vector<LogRec>(); 1504 SmHandler smh = mSmHandler; 1505 if (smh != null) { 1506 for (LogRec lr : smh.mLogRecords.mLogRecVector) { 1507 vlr.add(lr); 1508 } 1509 } 1510 return vlr; 1511 } 1512 1513 /** 1514 * Add the string to LogRecords. 1515 * 1516 * @param string 1517 */ 1518 public void addLogRec(String string) { 1519 // mSmHandler can be null if the state machine has quit. 1520 SmHandler smh = mSmHandler; 1521 if (smh == null) return; 1522 smh.mLogRecords.add(this, smh.getCurrentMessage(), string, smh.getCurrentState(), 1523 smh.mStateStack[smh.mStateStackTopIndex].state, smh.mDestState); 1524 } 1525 1526 /** 1527 * @return true if msg should be saved in the log, default is true. 1528 */ 1529 protected boolean recordLogRec(Message msg) { 1530 return true; 1531 } 1532 1533 /** 1534 * Return a string to be logged by LogRec, default 1535 * is an empty string. Override if additional information is desired. 1536 * 1537 * @param msg that was processed 1538 * @return information to be logged as a String 1539 */ 1540 protected String getLogRecString(Message msg) { 1541 return ""; 1542 } 1543 1544 /** 1545 * @return the string for msg.what 1546 */ 1547 protected String getWhatToString(int what) { 1548 return null; 1549 } 1550 1551 /** 1552 * @return Handler, maybe null if state machine has quit. 1553 */ 1554 public final Handler getHandler() { 1555 return mSmHandler; 1556 } 1557 1558 /** 1559 * Get a message and set Message.target state machine handler. 1560 * 1561 * Note: The handler can be null if the state machine has quit, 1562 * which means target will be null and may cause a AndroidRuntimeException 1563 * in MessageQueue#enqueMessage if sent directly or if sent using 1564 * StateMachine#sendMessage the message will just be ignored. 1565 * 1566 * @return A Message object from the global pool 1567 */ 1568 public final Message obtainMessage() { 1569 return Message.obtain(mSmHandler); 1570 } 1571 1572 /** 1573 * Get a message and set Message.target state machine handler, what. 1574 * 1575 * Note: The handler can be null if the state machine has quit, 1576 * which means target will be null and may cause a AndroidRuntimeException 1577 * in MessageQueue#enqueMessage if sent directly or if sent using 1578 * StateMachine#sendMessage the message will just be ignored. 1579 * 1580 * @param what is the assigned to Message.what. 1581 * @return A Message object from the global pool 1582 */ 1583 public final Message obtainMessage(int what) { 1584 return Message.obtain(mSmHandler, what); 1585 } 1586 1587 /** 1588 * Get a message and set Message.target state machine handler, 1589 * what and obj. 1590 * 1591 * Note: The handler can be null if the state machine has quit, 1592 * which means target will be null and may cause a AndroidRuntimeException 1593 * in MessageQueue#enqueMessage if sent directly or if sent using 1594 * StateMachine#sendMessage the message will just be ignored. 1595 * 1596 * @param what is the assigned to Message.what. 1597 * @param obj is assigned to Message.obj. 1598 * @return A Message object from the global pool 1599 */ 1600 public final Message obtainMessage(int what, Object obj) { 1601 return Message.obtain(mSmHandler, what, obj); 1602 } 1603 1604 /** 1605 * Get a message and set Message.target state machine handler, 1606 * what, arg1 and arg2 1607 * 1608 * Note: The handler can be null if the state machine has quit, 1609 * which means target will be null and may cause a AndroidRuntimeException 1610 * in MessageQueue#enqueMessage if sent directly or if sent using 1611 * StateMachine#sendMessage the message will just be ignored. 1612 * 1613 * @param what is assigned to Message.what 1614 * @param arg1 is assigned to Message.arg1 1615 * @return A Message object from the global pool 1616 */ 1617 public final Message obtainMessage(int what, int arg1) { 1618 // use this obtain so we don't match the obtain(h, what, Object) method 1619 return Message.obtain(mSmHandler, what, arg1, 0); 1620 } 1621 1622 /** 1623 * Get a message and set Message.target state machine handler, 1624 * what, arg1 and arg2 1625 * 1626 * Note: The handler can be null if the state machine has quit, 1627 * which means target will be null and may cause a AndroidRuntimeException 1628 * in MessageQueue#enqueMessage if sent directly or if sent using 1629 * StateMachine#sendMessage the message will just be ignored. 1630 * 1631 * @param what is assigned to Message.what 1632 * @param arg1 is assigned to Message.arg1 1633 * @param arg2 is assigned to Message.arg2 1634 * @return A Message object from the global pool 1635 */ 1636 public final Message obtainMessage(int what, int arg1, int arg2) { 1637 return Message.obtain(mSmHandler, what, arg1, arg2); 1638 } 1639 1640 /** 1641 * Get a message and set Message.target state machine handler, 1642 * what, arg1, arg2 and obj 1643 * 1644 * Note: The handler can be null if the state machine has quit, 1645 * which means target will be null and may cause a AndroidRuntimeException 1646 * in MessageQueue#enqueMessage if sent directly or if sent using 1647 * StateMachine#sendMessage the message will just be ignored. 1648 * 1649 * @param what is assigned to Message.what 1650 * @param arg1 is assigned to Message.arg1 1651 * @param arg2 is assigned to Message.arg2 1652 * @param obj is assigned to Message.obj 1653 * @return A Message object from the global pool 1654 */ 1655 public final Message obtainMessage(int what, int arg1, int arg2, Object obj) { 1656 return Message.obtain(mSmHandler, what, arg1, arg2, obj); 1657 } 1658 1659 /** 1660 * Enqueue a message to this state machine. 1661 * 1662 * Message is ignored if state machine has quit. 1663 */ 1664 public void sendMessage(int what) { 1665 // mSmHandler can be null if the state machine has quit. 1666 SmHandler smh = mSmHandler; 1667 if (smh == null) return; 1668 1669 smh.sendMessage(obtainMessage(what)); 1670 } 1671 1672 /** 1673 * Enqueue a message to this state machine. 1674 * 1675 * Message is ignored if state machine has quit. 1676 */ 1677 public void sendMessage(int what, Object obj) { 1678 // mSmHandler can be null if the state machine has quit. 1679 SmHandler smh = mSmHandler; 1680 if (smh == null) return; 1681 1682 smh.sendMessage(obtainMessage(what, obj)); 1683 } 1684 1685 /** 1686 * Enqueue a message to this state machine. 1687 * 1688 * Message is ignored if state machine has quit. 1689 */ 1690 public void sendMessage(int what, int arg1) { 1691 // mSmHandler can be null if the state machine has quit. 1692 SmHandler smh = mSmHandler; 1693 if (smh == null) return; 1694 1695 smh.sendMessage(obtainMessage(what, arg1)); 1696 } 1697 1698 /** 1699 * Enqueue a message to this state machine. 1700 * 1701 * Message is ignored if state machine has quit. 1702 */ 1703 public void sendMessage(int what, int arg1, int arg2) { 1704 // mSmHandler can be null if the state machine has quit. 1705 SmHandler smh = mSmHandler; 1706 if (smh == null) return; 1707 1708 smh.sendMessage(obtainMessage(what, arg1, arg2)); 1709 } 1710 1711 /** 1712 * Enqueue a message to this state machine. 1713 * 1714 * Message is ignored if state machine has quit. 1715 */ 1716 public void sendMessage(int what, int arg1, int arg2, Object obj) { 1717 // mSmHandler can be null if the state machine has quit. 1718 SmHandler smh = mSmHandler; 1719 if (smh == null) return; 1720 1721 smh.sendMessage(obtainMessage(what, arg1, arg2, obj)); 1722 } 1723 1724 /** 1725 * Enqueue a message to this state machine. 1726 * 1727 * Message is ignored if state machine has quit. 1728 */ 1729 public void sendMessage(Message msg) { 1730 // mSmHandler can be null if the state machine has quit. 1731 SmHandler smh = mSmHandler; 1732 if (smh == null) return; 1733 1734 smh.sendMessage(msg); 1735 } 1736 1737 /** 1738 * Enqueue a message to this state machine after a delay. 1739 * 1740 * Message is ignored if state machine has quit. 1741 */ 1742 public void sendMessageDelayed(int what, long delayMillis) { 1743 // mSmHandler can be null if the state machine has quit. 1744 SmHandler smh = mSmHandler; 1745 if (smh == null) return; 1746 1747 smh.sendMessageDelayed(obtainMessage(what), delayMillis); 1748 } 1749 1750 /** 1751 * Enqueue a message to this state machine after a delay. 1752 * 1753 * Message is ignored if state machine has quit. 1754 */ 1755 public void sendMessageDelayed(int what, Object obj, long delayMillis) { 1756 // mSmHandler can be null if the state machine has quit. 1757 SmHandler smh = mSmHandler; 1758 if (smh == null) return; 1759 1760 smh.sendMessageDelayed(obtainMessage(what, obj), delayMillis); 1761 } 1762 1763 /** 1764 * Enqueue a message to this state machine after a delay. 1765 * 1766 * Message is ignored if state machine has quit. 1767 */ 1768 public void sendMessageDelayed(int what, int arg1, long delayMillis) { 1769 // mSmHandler can be null if the state machine has quit. 1770 SmHandler smh = mSmHandler; 1771 if (smh == null) return; 1772 1773 smh.sendMessageDelayed(obtainMessage(what, arg1), delayMillis); 1774 } 1775 1776 /** 1777 * Enqueue a message to this state machine after a delay. 1778 * 1779 * Message is ignored if state machine has quit. 1780 */ 1781 public void sendMessageDelayed(int what, int arg1, int arg2, long delayMillis) { 1782 // mSmHandler can be null if the state machine has quit. 1783 SmHandler smh = mSmHandler; 1784 if (smh == null) return; 1785 1786 smh.sendMessageDelayed(obtainMessage(what, arg1, arg2), delayMillis); 1787 } 1788 1789 /** 1790 * Enqueue a message to this state machine after a delay. 1791 * 1792 * Message is ignored if state machine has quit. 1793 */ 1794 public void sendMessageDelayed(int what, int arg1, int arg2, Object obj, 1795 long delayMillis) { 1796 // mSmHandler can be null if the state machine has quit. 1797 SmHandler smh = mSmHandler; 1798 if (smh == null) return; 1799 1800 smh.sendMessageDelayed(obtainMessage(what, arg1, arg2, obj), delayMillis); 1801 } 1802 1803 /** 1804 * Enqueue a message to this state machine after a delay. 1805 * 1806 * Message is ignored if state machine has quit. 1807 */ 1808 public void sendMessageDelayed(Message msg, long delayMillis) { 1809 // mSmHandler can be null if the state machine has quit. 1810 SmHandler smh = mSmHandler; 1811 if (smh == null) return; 1812 1813 smh.sendMessageDelayed(msg, delayMillis); 1814 } 1815 1816 /** 1817 * Enqueue a message to the front of the queue for this state machine. 1818 * Protected, may only be called by instances of StateMachine. 1819 * 1820 * Message is ignored if state machine has quit. 1821 */ 1822 protected final void sendMessageAtFrontOfQueue(int what) { 1823 // mSmHandler can be null if the state machine has quit. 1824 SmHandler smh = mSmHandler; 1825 if (smh == null) return; 1826 1827 smh.sendMessageAtFrontOfQueue(obtainMessage(what)); 1828 } 1829 1830 /** 1831 * Enqueue a message to the front of the queue for this state machine. 1832 * Protected, may only be called by instances of StateMachine. 1833 * 1834 * Message is ignored if state machine has quit. 1835 */ 1836 protected final void sendMessageAtFrontOfQueue(int what, Object obj) { 1837 // mSmHandler can be null if the state machine has quit. 1838 SmHandler smh = mSmHandler; 1839 if (smh == null) return; 1840 1841 smh.sendMessageAtFrontOfQueue(obtainMessage(what, obj)); 1842 } 1843 1844 /** 1845 * Enqueue a message to the front of the queue for this state machine. 1846 * Protected, may only be called by instances of StateMachine. 1847 * 1848 * Message is ignored if state machine has quit. 1849 */ 1850 protected final void sendMessageAtFrontOfQueue(int what, int arg1) { 1851 // mSmHandler can be null if the state machine has quit. 1852 SmHandler smh = mSmHandler; 1853 if (smh == null) return; 1854 1855 smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1)); 1856 } 1857 1858 1859 /** 1860 * Enqueue a message to the front of the queue for this state machine. 1861 * Protected, may only be called by instances of StateMachine. 1862 * 1863 * Message is ignored if state machine has quit. 1864 */ 1865 protected final void sendMessageAtFrontOfQueue(int what, int arg1, int arg2) { 1866 // mSmHandler can be null if the state machine has quit. 1867 SmHandler smh = mSmHandler; 1868 if (smh == null) return; 1869 1870 smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1, arg2)); 1871 } 1872 1873 /** 1874 * Enqueue a message to the front of the queue for this state machine. 1875 * Protected, may only be called by instances of StateMachine. 1876 * 1877 * Message is ignored if state machine has quit. 1878 */ 1879 protected final void sendMessageAtFrontOfQueue(int what, int arg1, int arg2, Object obj) { 1880 // mSmHandler can be null if the state machine has quit. 1881 SmHandler smh = mSmHandler; 1882 if (smh == null) return; 1883 1884 smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1, arg2, obj)); 1885 } 1886 1887 /** 1888 * Enqueue a message to the front of the queue for this state machine. 1889 * Protected, may only be called by instances of StateMachine. 1890 * 1891 * Message is ignored if state machine has quit. 1892 */ 1893 protected final void sendMessageAtFrontOfQueue(Message msg) { 1894 // mSmHandler can be null if the state machine has quit. 1895 SmHandler smh = mSmHandler; 1896 if (smh == null) return; 1897 1898 smh.sendMessageAtFrontOfQueue(msg); 1899 } 1900 1901 /** 1902 * Removes a message from the message queue. 1903 * Protected, may only be called by instances of StateMachine. 1904 */ 1905 protected final void removeMessages(int what) { 1906 // mSmHandler can be null if the state machine has quit. 1907 SmHandler smh = mSmHandler; 1908 if (smh == null) return; 1909 1910 smh.removeMessages(what); 1911 } 1912 1913 /** 1914 * Removes a message from the deferred messages queue. 1915 */ 1916 protected final void removeDeferredMessages(int what) { 1917 SmHandler smh = mSmHandler; 1918 if (smh == null) return; 1919 1920 Iterator<Message> iterator = smh.mDeferredMessages.iterator(); 1921 while (iterator.hasNext()) { 1922 Message msg = iterator.next(); 1923 if (msg.what == what) iterator.remove(); 1924 } 1925 } 1926 1927 /** 1928 * Check if there are any pending messages with code 'what' in deferred messages queue. 1929 */ 1930 protected final boolean hasDeferredMessages(int what) { 1931 SmHandler smh = mSmHandler; 1932 if (smh == null) return false; 1933 1934 Iterator<Message> iterator = smh.mDeferredMessages.iterator(); 1935 while (iterator.hasNext()) { 1936 Message msg = iterator.next(); 1937 if (msg.what == what) return true; 1938 } 1939 1940 return false; 1941 } 1942 1943 /** 1944 * Check if there are any pending posts of messages with code 'what' in 1945 * the message queue. This does NOT check messages in deferred message queue. 1946 */ 1947 protected final boolean hasMessages(int what) { 1948 SmHandler smh = mSmHandler; 1949 if (smh == null) return false; 1950 1951 return smh.hasMessages(what); 1952 } 1953 1954 /** 1955 * Validate that the message was sent by 1956 * {@link StateMachine#quit} or {@link StateMachine#quitNow}. 1957 * */ 1958 protected final boolean isQuit(Message msg) { 1959 // mSmHandler can be null if the state machine has quit. 1960 SmHandler smh = mSmHandler; 1961 if (smh == null) return msg.what == SM_QUIT_CMD; 1962 1963 return smh.isQuit(msg); 1964 } 1965 1966 /** 1967 * Quit the state machine after all currently queued up messages are processed. 1968 */ 1969 public final void quit() { 1970 // mSmHandler can be null if the state machine is already stopped. 1971 SmHandler smh = mSmHandler; 1972 if (smh == null) return; 1973 1974 smh.quit(); 1975 } 1976 1977 /** 1978 * Quit the state machine immediately all currently queued messages will be discarded. 1979 */ 1980 public final void quitNow() { 1981 // mSmHandler can be null if the state machine is already stopped. 1982 SmHandler smh = mSmHandler; 1983 if (smh == null) return; 1984 1985 smh.quitNow(); 1986 } 1987 1988 /** 1989 * @return if debugging is enabled 1990 */ 1991 public boolean isDbg() { 1992 // mSmHandler can be null if the state machine has quit. 1993 SmHandler smh = mSmHandler; 1994 if (smh == null) return false; 1995 1996 return smh.isDbg(); 1997 } 1998 1999 /** 2000 * Set debug enable/disabled. 2001 * 2002 * @param dbg is true to enable debugging. 2003 */ 2004 public void setDbg(boolean dbg) { 2005 // mSmHandler can be null if the state machine has quit. 2006 SmHandler smh = mSmHandler; 2007 if (smh == null) return; 2008 2009 smh.setDbg(dbg); 2010 } 2011 2012 /** 2013 * Start the state machine. 2014 */ 2015 public void start() { 2016 // mSmHandler can be null if the state machine has quit. 2017 SmHandler smh = mSmHandler; 2018 if (smh == null) return; 2019 2020 /** Send the complete construction message */ 2021 smh.completeConstruction(); 2022 } 2023 2024 /** 2025 * Dump the current state. 2026 * 2027 * @param fd 2028 * @param pw 2029 * @param args 2030 */ 2031 public void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 2032 // Cannot just invoke pw.println(this.toString()) because if the 2033 // resulting string is to long it won't be displayed. 2034 pw.println(getName() + ":"); 2035 pw.println(" total records=" + getLogRecCount()); 2036 for (int i = 0; i < getLogRecSize(); i++) { 2037 pw.println(" rec[" + i + "]: " + getLogRec(i).toString()); 2038 pw.flush(); 2039 } 2040 pw.println("curState=" + getCurrentState().getName()); 2041 } 2042 2043 @Override 2044 public String toString() { 2045 StringWriter sr = new StringWriter(); 2046 PrintWriter pr = new PrintWriter(sr); 2047 dump(null, pr, null); 2048 pr.flush(); 2049 pr.close(); 2050 return sr.toString(); 2051 } 2052 2053 /** 2054 * Log with debug and add to the LogRecords. 2055 * 2056 * @param s is string log 2057 */ 2058 protected void logAndAddLogRec(String s) { 2059 addLogRec(s); 2060 log(s); 2061 } 2062 2063 /** 2064 * Log with debug 2065 * 2066 * @param s is string log 2067 */ 2068 protected void log(String s) { 2069 Log.d(mName, s); 2070 } 2071 2072 /** 2073 * Log with debug attribute 2074 * 2075 * @param s is string log 2076 */ 2077 protected void logd(String s) { 2078 Log.d(mName, s); 2079 } 2080 2081 /** 2082 * Log with verbose attribute 2083 * 2084 * @param s is string log 2085 */ 2086 protected void logv(String s) { 2087 Log.v(mName, s); 2088 } 2089 2090 /** 2091 * Log with info attribute 2092 * 2093 * @param s is string log 2094 */ 2095 protected void logi(String s) { 2096 Log.i(mName, s); 2097 } 2098 2099 /** 2100 * Log with warning attribute 2101 * 2102 * @param s is string log 2103 */ 2104 protected void logw(String s) { 2105 Log.w(mName, s); 2106 } 2107 2108 /** 2109 * Log with error attribute 2110 * 2111 * @param s is string log 2112 */ 2113 protected void loge(String s) { 2114 Log.e(mName, s); 2115 } 2116 2117 /** 2118 * Log with error attribute 2119 * 2120 * @param s is string log 2121 * @param e is a Throwable which logs additional information. 2122 */ 2123 protected void loge(String s, Throwable e) { 2124 Log.e(mName, s, e); 2125 } 2126} 2127