Android官方内部的源代码中实现了一套层次状态机(Hierarchical State Machine)，总共有三个代码文件：IState.java ， State.java， StateMachine.java，目录位置在：
package com.android.internal.util;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.Message;
/**
* {@hide}
*
* The interface for implementing states in a {@link StateMachine}
*/
public interface IState {
/**
* Returned by processMessage to indicate the the message was processed.
*/
static final boolean HANDLED = true;
/**
* Returned by processMessage to indicate the the message was NOT processed.
*/
static final boolean NOT_HANDLED = false;
/**
* Called when a state is entered.
*/
void enter();
/**
* Called when a state is exited.
*/
void exit();
/**
* Called when a message is to be processed by the
* state machine.
*
* This routine is never reentered thus no synchronization
* is needed as only one processMessage method will ever be
* executing within a state machine at any given time. This
* does mean that processing by this routine must be completed
* as expeditiously as possible as no subsequent messages will
* be processed until this routine returns.
*
* @param msg to process
* @return HANDLED if processing has completed and NOT_HANDLED
* if the message wasn't processed.
*/
boolean processMessage(Message msg);
/**
* Name of State for debugging purposes.
*
* @return name of state.
*/
@UnsupportedAppUsage
String getName();
}
package com.android.internal.util;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.Message;
/**
* {@hide}
*
* The class for implementing states in a StateMachine
*/
public class State implements IState {
/**
* Constructor
*/
@UnsupportedAppUsage
protected State() {
}
/* (non-Javadoc)
* @see com.android.internal.util.IState#enter()
*/
@UnsupportedAppUsage
@Override
public void enter() {
}
/* (non-Javadoc)
* @see com.android.internal.util.IState#exit()
*/
@UnsupportedAppUsage
@Override
public void exit() {
}
/* (non-Javadoc)
* @see com.android.internal.util.IState#processMessage(android.os.Message)
*/
@UnsupportedAppUsage
@Override
public boolean processMessage(Message msg) {
return false;
}
/**
* Name of State for debugging purposes.
*
* This default implementation returns the class name, returning
* the instance name would better in cases where a State class
* is used for multiple states. But normally there is one class per
* state and the class name is sufficient and easy to get. You may
* want to provide a setName or some other mechanism for setting
* another name if the class name is not appropriate.
*
* @see com.android.internal.util.IState#processMessage(android.os.Message)
*/
@UnsupportedAppUsage
@Override
public String getName() {
String name = getClass().getName();
int lastDollar = name.lastIndexOf('$');
return name.substring(lastDollar + 1);
}
}
package com.android.internal.util;
import android.compat.annotation.UnsupportedAppUsage;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.text.TextUtils;
import android.util.Log;
import com.android.internal.annotations.VisibleForTesting;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Vector;
/**
* {@hide}
*
* <p>The state machine defined here is a hierarchical state machine which processes messages
* and can have states arranged hierarchically.</p>
*
* <p>A state is a <code>State</code> object and must implement
* <code>processMessage</code> and optionally <code>enter/exit/getName</code>.
* The enter/exit methods are equivalent to the construction and destruction
* in Object Oriented programming and are used to perform initialization and
* cleanup of the state respectively. The <code>getName</code> method returns the
* name of the state; the default implementation returns the class name. It may be
* desirable to have <code>getName</code> return the the state instance name instead,
* in particular if a particular state class has multiple instances.</p>
*
* <p>When a state machine is created, <code>addState</code> is used to build the
* hierarchy and <code>setInitialState</code> is used to identify which of these
* is the initial state. After construction the programmer calls <code>start</code>
* which initializes and starts the state machine. The first action the StateMachine
* is to the invoke <code>enter</code> for all of the initial state's hierarchy,
* starting at its eldest parent. The calls to enter will be done in the context
* of the StateMachine's Handler, not in the context of the call to start, and they
* will be invoked before any messages are processed. For example, given the simple
* state machine below, mP1.enter will be invoked and then mS1.enter. Finally,
* messages sent to the state machine will be processed by the current state;
* in our simple state machine below that would initially be mS1.processMessage.</p>
<pre>
mP1
/ \
mS2 mS1 ----> initial state
</pre>
* <p>After the state machine is created and started, messages are sent to a state
* machine using <code>sendMessage</code> and the messages are created using
* <code>obtainMessage</code>. When the state machine receives a message the
* current state's <code>processMessage</code> is invoked. In the above example
* mS1.processMessage will be invoked first. The state may use <code>transitionTo</code>
* to change the current state to a new state.</p>
*
* <p>Each state in the state machine may have a zero or one parent states. If
* a child state is unable to handle a message it may have the message processed
* by its parent by returning false or NOT_HANDLED. If a message is not handled by
* a child state or any of its ancestors, <code>unhandledMessage</code> will be invoked
* to give one last chance for the state machine to process the message.</p>
*
* <p>When all processing is completed a state machine may choose to call
* <code>transitionToHaltingState</code>. When the current <code>processingMessage</code>
* returns the state machine will transfer to an internal <code>HaltingState</code>
* and invoke <code>halting</code>. Any message subsequently received by the state
* machine will cause <code>haltedProcessMessage</code> to be invoked.</p>
*
* <p>If it is desirable to completely stop the state machine call <code>quit</code> or
* <code>quitNow</code>. These will call <code>exit</code> of the current state and its parents,
* call <code>onQuitting</code> and then exit Thread/Loopers.</p>
*
* <p>In addition to <code>processMessage</code> each <code>State</code> has
* an <code>enter</code> method and <code>exit</code> method which may be overridden.</p>
*
* <p>Since the states are arranged in a hierarchy transitioning to a new state
* causes current states to be exited and new states to be entered. To determine
* the list of states to be entered/exited the common parent closest to
* the current state is found. We then exit from the current state and its
* parent's up to but not including the common parent state and then enter all
* of the new states below the common parent down to the destination state.
* If there is no common parent all states are exited and then the new states
* are entered.</p>
*
* <p>Two other methods that states can use are <code>deferMessage</code> and
* <code>sendMessageAtFrontOfQueue</code>. The <code>sendMessageAtFrontOfQueue</code> sends
* a message but places it on the front of the queue rather than the back. The
* <code>deferMessage</code> causes the message to be saved on a list until a
* transition is made to a new state. At which time all of the deferred messages
* will be put on the front of the state machine queue with the oldest message
* at the front. These will then be processed by the new current state before
* any other messages that are on the queue or might be added later. Both of
* these are protected and may only be invoked from within a state machine.</p>
*
* <p>To illustrate some of these properties we'll use state machine with an 8
* state hierarchy:</p>
<pre>
mP0
/ \
mP1 mS0
/ \
mS2 mS1
/ \ \
mS3 mS4 mS5 ---> initial state
</pre>
* <p>After starting mS5 the list of active states is mP0, mP1, mS1 and mS5.
* So the order of calling processMessage when a message is received is mS5,
* mS1, mP1, mP0 assuming each processMessage indicates it can't handle this
* message by returning false or NOT_HANDLED.</p>
*
* <p>Now assume mS5.processMessage receives a message it can handle, and during
* the handling determines the machine should change states. It could call
* transitionTo(mS4) and return true or HANDLED. Immediately after returning from
* processMessage the state machine runtime will find the common parent,
* which is mP1. It will then call mS5.exit, mS1.exit, mS2.enter and then
* mS4.enter. The new list of active states is mP0, mP1, mS2 and mS4. So
* when the next message is received mS4.processMessage will be invoked.</p>
*
* <p>Now for some concrete examples, here is the canonical HelloWorld as a state machine.
* It responds with "Hello World" being printed to the log for every message.</p>
<pre>
class HelloWorld extends StateMachine {
HelloWorld(String name) {
super(name);
addState(mState1);
setInitialState(mState1);
}
public static HelloWorld makeHelloWorld() {
HelloWorld hw = new HelloWorld("hw");
hw.start();
return hw;
}
class State1 extends State {
@Override public boolean processMessage(Message message) {
log("Hello World");
return HANDLED;
}
}
State1 mState1 = new State1();
}
void testHelloWorld() {
HelloWorld hw = makeHelloWorld();
hw.sendMessage(hw.obtainMessage());
}
</pre>
* <p>A more interesting state machine is one with four states
* with two independent parent states.</p>
<pre>
mP1 mP2
/ \
mS2 mS1
</pre>
* <p>Here is a description of this state machine using pseudo code.</p>
<pre>
state mP1 {
enter { log("mP1.enter"); }
exit { log("mP1.exit"); }
on msg {
CMD_2 {
send(CMD_3);
defer(msg);
transitionTo(mS2);
return HANDLED;
}
return NOT_HANDLED;
}
}
INITIAL
state mS1 parent mP1 {
enter { log("mS1.enter"); }
exit { log("mS1.exit"); }
on msg {
CMD_1 {
transitionTo(mS1);
return HANDLED;
}
return NOT_HANDLED;
}
}
state mS2 parent mP1 {
enter { log("mS2.enter"); }
exit { log("mS2.exit"); }
on msg {
CMD_2 {
send(CMD_4);
return HANDLED;
}
CMD_3 {
defer(msg);
transitionTo(mP2);
return HANDLED;
}
return NOT_HANDLED;
}
}
state mP2 {
enter {
log("mP2.enter");
send(CMD_5);
}
exit { log("mP2.exit"); }
on msg {
CMD_3, CMD_4 { return HANDLED; }
CMD_5 {
transitionTo(HaltingState);
return HANDLED;
}
return NOT_HANDLED;
}
}
</pre>
* <p>The implementation is below and also in StateMachineTest:</p>
<pre>
class Hsm1 extends StateMachine {
public static final int CMD_1 = 1;
public static final int CMD_2 = 2;
public static final int CMD_3 = 3;
public static final int CMD_4 = 4;
public static final int CMD_5 = 5;
public static Hsm1 makeHsm1() {
log("makeHsm1 E");
Hsm1 sm = new Hsm1("hsm1");
sm.start();
log("makeHsm1 X");
return sm;
}
Hsm1(String name) {
super(name);
log("ctor E");
// Add states, use indentation to show hierarchy
addState(mP1);
addState(mS1, mP1);
addState(mS2, mP1);
addState(mP2);
// Set the initial state
setInitialState(mS1);
log("ctor X");
}
class P1 extends State {
@Override public void enter() {
log("mP1.enter");
}
@Override public boolean processMessage(Message message) {
boolean retVal;
log("mP1.processMessage what=" + message.what);
switch(message.what) {
case CMD_2:
// CMD_2 will arrive in mS2 before CMD_3
sendMessage(obtainMessage(CMD_3));
deferMessage(message);
transitionTo(mS2);
retVal = HANDLED;
break;
default:
// Any message we don't understand in this state invokes unhandledMessage
retVal = NOT_HANDLED;
break;
}
return retVal;
}
@Override public void exit() {
log("mP1.exit");
}
}
class S1 extends State {
@Override public void enter() {
log("mS1.enter");
}
@Override public boolean processMessage(Message message) {
log("S1.processMessage what=" + message.what);
if (message.what == CMD_1) {
// Transition to ourself to show that enter/exit is called
transitionTo(mS1);
return HANDLED;
} else {
// Let parent process all other messages
return NOT_HANDLED;
}
}
@Override public void exit() {
log("mS1.exit");
}
}
class S2 extends State {
@Override public void enter() {
log("mS2.enter");
}
@Override public boolean processMessage(Message message) {
boolean retVal;
log("mS2.processMessage what=" + message.what);
switch(message.what) {
case(CMD_2):
sendMessage(obtainMessage(CMD_4));
retVal = HANDLED;
break;
case(CMD_3):
deferMessage(message);
transitionTo(mP2);
retVal = HANDLED;
break;
default:
retVal = NOT_HANDLED;
break;
}
return retVal;
}
@Override public void exit() {
log("mS2.exit");
}
}
class P2 extends State {
@Override public void enter() {
log("mP2.enter");
sendMessage(obtainMessage(CMD_5));
}
@Override public boolean processMessage(Message message) {
log("P2.processMessage what=" + message.what);
switch(message.what) {
case(CMD_3):
break;
case(CMD_4):
break;
case(CMD_5):
transitionToHaltingState();
break;
}
return HANDLED;
}
@Override public void exit() {
log("mP2.exit");
}
}
@Override
void onHalting() {
log("halting");
synchronized (this) {
this.notifyAll();
}
}
P1 mP1 = new P1();
S1 mS1 = new S1();
S2 mS2 = new S2();
P2 mP2 = new P2();
}
</pre>
* <p>If this is executed by sending two messages CMD_1 and CMD_2
* (Note the synchronize is only needed because we use hsm.wait())</p>
<pre>
Hsm1 hsm = makeHsm1();
synchronize(hsm) {
hsm.sendMessage(obtainMessage(hsm.CMD_1));
hsm.sendMessage(obtainMessage(hsm.CMD_2));
try {
// wait for the messages to be handled
hsm.wait();
} catch (InterruptedException e) {
loge("exception while waiting " + e.getMessage());
}
}
</pre>
* <p>The output is:</p>
<pre>
D/hsm1 ( 1999): makeHsm1 E
D/hsm1 ( 1999): ctor E
D/hsm1 ( 1999): ctor X
D/hsm1 ( 1999): mP1.enter
D/hsm1 ( 1999): mS1.enter
D/hsm1 ( 1999): makeHsm1 X
D/hsm1 ( 1999): mS1.processMessage what=1
D/hsm1 ( 1999): mS1.exit
D/hsm1 ( 1999): mS1.enter
D/hsm1 ( 1999): mS1.processMessage what=2
D/hsm1 ( 1999): mP1.processMessage what=2
D/hsm1 ( 1999): mS1.exit
D/hsm1 ( 1999): mS2.enter
D/hsm1 ( 1999): mS2.processMessage what=2
D/hsm1 ( 1999): mS2.processMessage what=3
D/hsm1 ( 1999): mS2.exit
D/hsm1 ( 1999): mP1.exit
D/hsm1 ( 1999): mP2.enter
D/hsm1 ( 1999): mP2.processMessage what=3
D/hsm1 ( 1999): mP2.processMessage what=4
D/hsm1 ( 1999): mP2.processMessage what=5
D/hsm1 ( 1999): mP2.exit
D/hsm1 ( 1999): halting
</pre>
*/
public class StateMachine {
// Name of the state machine and used as logging tag
private String mName;
/** Message.what value when quitting */
private static final int SM_QUIT_CMD = -1;
/** Message.what value when initializing */
private static final int SM_INIT_CMD = -2;
/**
* Convenience constant that maybe returned by processMessage
* to indicate the the message was processed and is not to be
* processed by parent states
*/
public static final boolean HANDLED = true;
/**
* Convenience constant that maybe returned by processMessage
* to indicate the the message was NOT processed and is to be
* processed by parent states
*/
public static final boolean NOT_HANDLED = false;
/**
* StateMachine logging record.
* {@hide}
*/
public static class LogRec {
private StateMachine mSm;
private long mTime;
private int mWhat;
private String mInfo;
private IState mState;
private IState mOrgState;
private IState mDstState;
/**
* Constructor
*
* @param msg
* @param state the state which handled the message
* @param orgState is the first state the received the message but
* did not processes the message.
* @param transToState is the state that was transitioned to after the message was
* processed.
*/
LogRec(StateMachine sm, Message msg, String info, IState state, IState orgState,
IState transToState) {
update(sm, msg, info, state, orgState, transToState);
}
/**
* Update the information in the record.
* @param state that handled the message
* @param orgState is the first state the received the message
* @param dstState is the state that was the transition target when logging
*/
public void update(StateMachine sm, Message msg, String info, IState state, IState orgState,
IState dstState) {
mSm = sm;
mTime = System.currentTimeMillis();
mWhat = (msg != null) ? msg.what : 0;
mInfo = info;
mState = state;
mOrgState = orgState;
mDstState = dstState;
}
/**
* @return time stamp
*/
public long getTime() {
return mTime;
}
/**
* @return msg.what
*/
public long getWhat() {
return mWhat;
}
/**
* @return the command that was executing
*/
public String getInfo() {
return mInfo;
}
/**
* @return the state that handled this message
*/
public IState getState() {
return mState;
}
/**
* @return the state destination state if a transition is occurring or null if none.
*/
public IState getDestState() {
return mDstState;
}
/**
* @return the original state that received the message.
*/
public IState getOriginalState() {
return mOrgState;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("time=");
Calendar c = Calendar.getInstance();
c.setTimeInMillis(mTime);
sb.append(String.format("%tm-%td %tH:%tM:%tS.%tL", c, c, c, c, c, c));
sb.append(" processed=");
sb.append(mState == null ? "<null>" : mState.getName());
sb.append(" org=");
sb.append(mOrgState == null ? "<null>" : mOrgState.getName());
sb.append(" dest=");
sb.append(mDstState == null ? "<null>" : mDstState.getName());
sb.append(" what=");
String what = mSm != null ? mSm.getWhatToString(mWhat) : "";
if (TextUtils.isEmpty(what)) {
sb.append(mWhat);
sb.append("(0x");
sb.append(Integer.toHexString(mWhat));
sb.append(")");
} else {
sb.append(what);
}
if (!TextUtils.isEmpty(mInfo)) {
sb.append(" ");
sb.append(mInfo);
}
return sb.toString();
}
}
/**
* A list of log records including messages recently processed by the state machine.
*
* The class maintains a list of log records including messages
* recently processed. The list is finite and may be set in the
* constructor or by calling setSize. The public interface also
* includes size which returns the number of recent records,
* count which is the number of records processed since the
* the last setSize, get which returns a record and
* add which adds a record.
*/
private static class LogRecords {
private static final int DEFAULT_SIZE = 20;
private Vector<LogRec> mLogRecVector = new Vector<LogRec>();
private int mMaxSize = DEFAULT_SIZE;
private int mOldestIndex = 0;
private int mCount = 0;
private boolean mLogOnlyTransitions = false;
/**
* private constructor use add
*/
private LogRecords() {
}
/**
* Set size of messages to maintain and clears all current records.
*
* @param maxSize number of records to maintain at anyone time.
*/
synchronized void setSize(int maxSize) {
// TODO: once b/28217358 is fixed, add unit tests to verify that these variables are
// cleared after calling this method, and that subsequent calls to get() function as
// expected.
mMaxSize = maxSize;
mOldestIndex = 0;
mCount = 0;
mLogRecVector.clear();
}
synchronized void setLogOnlyTransitions(boolean enable) {
mLogOnlyTransitions = enable;
}
synchronized boolean logOnlyTransitions() {
return mLogOnlyTransitions;
}
/**
* @return the number of recent records.
*/
synchronized int size() {
return mLogRecVector.size();
}
/**
* @return the total number of records processed since size was set.
*/
synchronized int count() {
return mCount;
}
/**
* Clear the list of records.
*/
synchronized void cleanup() {
mLogRecVector.clear();
}
/**
* @return the information on a particular record. 0 is the oldest
* record and size()-1 is the newest record. If the index is to
* large null is returned.
*/
synchronized LogRec get(int index) {
int nextIndex = mOldestIndex + index;
if (nextIndex >= mMaxSize) {
nextIndex -= mMaxSize;
}
if (nextIndex >= size()) {
return null;
} else {
return mLogRecVector.get(nextIndex);
}
}
/**
* Add a processed message.
*
* @param msg
* @param messageInfo to be stored
* @param state that handled the message
* @param orgState is the first state the received the message but
* did not processes the message.
* @param transToState is the state that was transitioned to after the message was
* processed.
*
*/
synchronized void add(StateMachine sm, Message msg, String messageInfo, IState state,
IState orgState, IState transToState) {
mCount += 1;
if (mLogRecVector.size() < mMaxSize) {
mLogRecVector.add(new LogRec(sm, msg, messageInfo, state, orgState, transToState));
} else {
LogRec pmi = mLogRecVector.get(mOldestIndex);
mOldestIndex += 1;
if (mOldestIndex >= mMaxSize) {
mOldestIndex = 0;
}
pmi.update(sm, msg, messageInfo, state, orgState, transToState);
}
}
}
private static class SmHandler extends Handler {
/** true if StateMachine has quit */
private boolean mHasQuit = false;
/** The debug flag */
private boolean mDbg = false;
/** The SmHandler object, identifies that message is internal */
private static final Object mSmHandlerObj = new Object();
/** The current message */
private Message mMsg;
/** A list of log records including messages this state machine has processed */
private LogRecords mLogRecords = new LogRecords();
/** true if construction of the state machine has not been completed */
private boolean mIsConstructionCompleted;
/** Stack used to manage the current hierarchy of states */
private StateInfo mStateStack[];
/** Top of mStateStack */
private int mStateStackTopIndex = -1;
/** A temporary stack used to manage the state stack */
private StateInfo mTempStateStack[];
/** The top of the mTempStateStack */
private int mTempStateStackCount;
/** State used when state machine is halted */
private HaltingState mHaltingState = new HaltingState();
/** State used when state machine is quitting */
private QuittingState mQuittingState = new QuittingState();
/** Reference to the StateMachine */
private StateMachine mSm;
/**
* Information about a state.
* Used to maintain the hierarchy.
*/
private class StateInfo {
/** The state */
State state;
/** The parent of this state, null if there is no parent */
StateInfo parentStateInfo;
/** True when the state has been entered and on the stack */
boolean active;
/**
* Convert StateInfo to string
*/
@Override
public String toString() {
return "state=" + state.getName() + ",active=" + active + ",parent="
+ ((parentStateInfo == null) ? "null" : parentStateInfo.state.getName());
}
}
/** The map of all of the states in the state machine */
private HashMap<State, StateInfo> mStateInfo = new HashMap<State, StateInfo>();
/** The initial state that will process the first message */
private State mInitialState;
/** The destination state when transitionTo has been invoked */
private State mDestState;
/**
* Indicates if a transition is in progress
*
* This will be true for all calls of State.exit and all calls of State.enter except for the
* last enter call for the current destination state.
*/
private boolean mTransitionInProgress = false;
/** The list of deferred messages */
private ArrayList<Message> mDeferredMessages = new ArrayList<Message>();
/**
* State entered when transitionToHaltingState is called.
*/
private class HaltingState extends State {
@Override
public boolean processMessage(Message msg) {
mSm.haltedProcessMessage(msg);
return true;
}
}
/**
* State entered when a valid quit message is handled.
*/
private class QuittingState extends State {
@Override
public boolean processMessage(Message msg) {
return NOT_HANDLED;
}
}
/**
* Handle messages sent to the state machine by calling
* the current state's processMessage. It also handles
* the enter/exit calls and placing any deferred messages
* back onto the queue when transitioning to a new state.
*/
@Override
public final void handleMessage(Message msg) {
if (!mHasQuit) {
if (mSm != null && msg.what != SM_INIT_CMD && msg.what != SM_QUIT_CMD) {
mSm.onPreHandleMessage(msg);
}
if (mDbg) mSm.log("handleMessage: E msg.what=" + msg.what);
/** Save the current message */
mMsg = msg;
/** State that processed the message */
State msgProcessedState = null;
if (mIsConstructionCompleted || (mMsg.what == SM_QUIT_CMD)) {
/** Normal path */
msgProcessedState = processMsg(msg);
} else if (!mIsConstructionCompleted && (mMsg.what == SM_INIT_CMD)
&& (mMsg.obj == mSmHandlerObj)) {
/** Initial one time path. */
mIsConstructionCompleted = true;
invokeEnterMethods(0);
} else {
throw new RuntimeException("StateMachine.handleMessage: "
+ "The start method not called, received msg: " + msg);
}
performTransitions(msgProcessedState, msg);
// We need to check if mSm == null here as we could be quitting.
if (mDbg && mSm != null) mSm.log("handleMessage: X");
if (mSm != null && msg.what != SM_INIT_CMD && msg.what != SM_QUIT_CMD) {
mSm.onPostHandleMessage(msg);
}
}
}
/**
* Do any transitions
* @param msgProcessedState is the state that processed the message
*/
private void performTransitions(State msgProcessedState, Message msg) {
/**
* If transitionTo has been called, exit and then enter
* the appropriate states. We loop on this to allow
* enter and exit methods to use transitionTo.
*/
State orgState = mStateStack[mStateStackTopIndex].state;
/**
* Record whether message needs to be logged before we transition and
* and we won't log special messages SM_INIT_CMD or SM_QUIT_CMD which
* always set msg.obj to the handler.
*/
boolean recordLogMsg = mSm.recordLogRec(mMsg) && (msg.obj != mSmHandlerObj);
if (mLogRecords.logOnlyTransitions()) {
/** Record only if there is a transition */
if (mDestState != null) {
mLogRecords.add(mSm, mMsg, mSm.getLogRecString(mMsg), msgProcessedState,
orgState, mDestState);
}
} else if (recordLogMsg) {
/** Record message */
mLogRecords.add(mSm, mMsg, mSm.getLogRecString(mMsg), msgProcessedState, orgState,
mDestState);
}
State destState = mDestState;
if (destState != null) {
/**
* Process the transitions including transitions in the enter/exit methods
*/
while (true) {
if (mDbg) mSm.log("handleMessage: new destination call exit/enter");
/**
* Determine the states to exit and enter and return the
* common ancestor state of the enter/exit states. Then
* invoke the exit methods then the enter methods.
*/
StateInfo commonStateInfo = setupTempStateStackWithStatesToEnter(destState);
// flag is cleared in invokeEnterMethods before entering the target state
mTransitionInProgress = true;
invokeExitMethods(commonStateInfo);
int stateStackEnteringIndex = moveTempStateStackToStateStack();
invokeEnterMethods(stateStackEnteringIndex);
/**
* Since we have transitioned to a new state we need to have
* any deferred messages moved to the front of the message queue
* so they will be processed before any other messages in the
* message queue.
*/
moveDeferredMessageAtFrontOfQueue();
if (destState != mDestState) {
// A new mDestState so continue looping
destState = mDestState;
} else {
// No change in mDestState so we're done
break;
}
}
mDestState = null;
}
/**
* After processing all transitions check and
* see if the last transition was to quit or halt.
*/
if (destState != null) {
if (destState == mQuittingState) {
/**
* Call onQuitting to let subclasses cleanup.
*/
mSm.onQuitting();
cleanupAfterQuitting();
} else if (destState == mHaltingState) {
/**
* Call onHalting() if we've transitioned to the halting
* state. All subsequent messages will be processed in
* in the halting state which invokes haltedProcessMessage(msg);
*/
mSm.onHalting();
}
}
}
/**
* Cleanup all the static variables and the looper after the SM has been quit.
*/
private final void cleanupAfterQuitting() {
if (mSm.mSmThread != null) {
// If we made the thread then quit looper which stops the thread.
getLooper().quit();
mSm.mSmThread = null;
}
mSm.mSmHandler = null;
mSm = null;
mMsg = null;
mLogRecords.cleanup();
mStateStack = null;
mTempStateStack = null;
mStateInfo.clear();
mInitialState = null;
mDestState = null;
mDeferredMessages.clear();
mHasQuit = true;
}
/**
* Complete the construction of the state machine.
*/
private final void completeConstruction() {
if (mDbg) mSm.log("completeConstruction: E");
/**
* Determine the maximum depth of the state hierarchy
* so we can allocate the state stacks.
*/
int maxDepth = 0;
for (StateInfo si : mStateInfo.values()) {
int depth = 0;
for (StateInfo i = si; i != null; depth++) {
i = i.parentStateInfo;
}
if (maxDepth < depth) {
maxDepth = depth;
}
}
if (mDbg) mSm.log("completeConstruction: maxDepth=" + maxDepth);
mStateStack = new StateInfo[maxDepth];
mTempStateStack = new StateInfo[maxDepth];
setupInitialStateStack();
/** Sending SM_INIT_CMD message to invoke enter methods asynchronously */
sendMessageAtFrontOfQueue(obtainMessage(SM_INIT_CMD, mSmHandlerObj));
if (mDbg) mSm.log("completeConstruction: X");
}
/**
* Process the message. If the current state doesn't handle
* it, call the states parent and so on. If it is never handled then
* call the state machines unhandledMessage method.
* @return the state that processed the message
*/
private final State processMsg(Message msg) {
StateInfo curStateInfo = mStateStack[mStateStackTopIndex];
if (mDbg) {
mSm.log("processMsg: " + curStateInfo.state.getName());
}
if (isQuit(msg)) {
transitionTo(mQuittingState);
} else {
while (!curStateInfo.state.processMessage(msg)) {
/**
* Not processed
*/
curStateInfo = curStateInfo.parentStateInfo;
if (curStateInfo == null) {
/**
* No parents left so it's not handled
*/
mSm.unhandledMessage(msg);
break;
}
if (mDbg) {
mSm.log("processMsg: " + curStateInfo.state.getName());
}
}
}
return (curStateInfo != null) ? curStateInfo.state : null;
}
/**
* Call the exit method for each state from the top of stack
* up to the common ancestor state.
*/
private final void invokeExitMethods(StateInfo commonStateInfo) {
while ((mStateStackTopIndex >= 0)
&& (mStateStack[mStateStackTopIndex] != commonStateInfo)) {
State curState = mStateStack[mStateStackTopIndex].state;
if (mDbg) mSm.log("invokeExitMethods: " + curState.getName());
curState.exit();
mStateStack[mStateStackTopIndex].active = false;
mStateStackTopIndex -= 1;
}
}
/**
* Invoke the enter method starting at the entering index to top of state stack
*/
private final void invokeEnterMethods(int stateStackEnteringIndex) {
for (int i = stateStackEnteringIndex; i <= mStateStackTopIndex; i++) {
if (stateStackEnteringIndex == mStateStackTopIndex) {
// Last enter state for transition
mTransitionInProgress = false;
}
if (mDbg) mSm.log("invokeEnterMethods: " + mStateStack[i].state.getName());
mStateStack[i].state.enter();
mStateStack[i].active = true;
}
mTransitionInProgress = false; // ensure flag set to false if no methods called
}
/**
* Move the deferred message to the front of the message queue.
*/
private final void moveDeferredMessageAtFrontOfQueue() {
/**
* The oldest messages on the deferred list must be at
* the front of the queue so start at the back, which
* as the most resent message and end with the oldest
* messages at the front of the queue.
*/
for (int i = mDeferredMessages.size() - 1; i >= 0; i--) {
Message curMsg = mDeferredMessages.get(i);
if (mDbg) mSm.log("moveDeferredMessageAtFrontOfQueue; what=" + curMsg.what);
sendMessageAtFrontOfQueue(curMsg);
}
mDeferredMessages.clear();
}
/**
* Move the contents of the temporary stack to the state stack
* reversing the order of the items on the temporary stack as
* they are moved.
*
* @return index into mStateStack where entering needs to start
*/
private final int moveTempStateStackToStateStack() {
int startingIndex = mStateStackTopIndex + 1;
int i = mTempStateStackCount - 1;
int j = startingIndex;
while (i >= 0) {
if (mDbg) mSm.log("moveTempStackToStateStack: i=" + i + ",j=" + j);
mStateStack[j] = mTempStateStack[i];
j += 1;
i -= 1;
}
mStateStackTopIndex = j - 1;
if (mDbg) {
mSm.log("moveTempStackToStateStack: X mStateStackTop=" + mStateStackTopIndex
+ ",startingIndex=" + startingIndex + ",Top="
+ mStateStack[mStateStackTopIndex].state.getName());
}
return startingIndex;
}
/**
* Setup the mTempStateStack with the states we are going to enter.
*
* This is found by searching up the destState's ancestors for a
* state that is already active i.e. StateInfo.active == true.
* The destStae and all of its inactive parents will be on the
* TempStateStack as the list of states to enter.
*
* @return StateInfo of the common ancestor for the destState and
* current state or null if there is no common parent.
*/
private final StateInfo setupTempStateStackWithStatesToEnter(State destState) {
/**
* Search up the parent list of the destination state for an active
* state. Use a do while() loop as the destState must always be entered
* even if it is active. This can happen if we are exiting/entering
* the current state.
*/
mTempStateStackCount = 0;
StateInfo curStateInfo = mStateInfo.get(destState);
do {
mTempStateStack[mTempStateStackCount++] = curStateInfo;
curStateInfo = curStateInfo.parentStateInfo;
} while ((curStateInfo != null) && !curStateInfo.active);
if (mDbg) {
mSm.log("setupTempStateStackWithStatesToEnter: X mTempStateStackCount="
+ mTempStateStackCount + ",curStateInfo: " + curStateInfo);
}
return curStateInfo;
}
/**
* Initialize StateStack to mInitialState.
*/
private final void setupInitialStateStack() {
if (mDbg) {
mSm.log("setupInitialStateStack: E mInitialState=" + mInitialState.getName());
}
StateInfo curStateInfo = mStateInfo.get(mInitialState);
for (mTempStateStackCount = 0; curStateInfo != null; mTempStateStackCount++) {
mTempStateStack[mTempStateStackCount] = curStateInfo;
curStateInfo = curStateInfo.parentStateInfo;
}
// Empty the StateStack
mStateStackTopIndex = -1;
moveTempStateStackToStateStack();
}
/**
* @return current message
*/
private final Message getCurrentMessage() {
return mMsg;
}
/**
* @return current state
*/
private final IState getCurrentState() {
return mStateStack[mStateStackTopIndex].state;
}
/**
* Add a new state to the state machine. Bottom up addition
* of states is allowed but the same state may only exist
* in one hierarchy.
*
* @param state the state to add
* @param parent the parent of state
* @return stateInfo for this state
*/
private final StateInfo addState(State state, State parent) {
if (mDbg) {
mSm.log("addStateInternal: E state=" + state.getName() + ",parent="
+ ((parent == null) ? "" : parent.getName()));
}
StateInfo parentStateInfo = null;
if (parent != null) {
parentStateInfo = mStateInfo.get(parent);
if (parentStateInfo == null) {
// Recursively add our parent as it's not been added yet.
parentStateInfo = addState(parent, null);
}
}
StateInfo stateInfo = mStateInfo.get(state);
if (stateInfo == null) {
stateInfo = new StateInfo();
mStateInfo.put(state, stateInfo);
}
// Validate that we aren't adding the same state in two different hierarchies.
if ((stateInfo.parentStateInfo != null)
&& (stateInfo.parentStateInfo != parentStateInfo)) {
throw new RuntimeException("state already added");
}
stateInfo.state = state;
stateInfo.parentStateInfo = parentStateInfo;
stateInfo.active = false;
if (mDbg) mSm.log("addStateInternal: X stateInfo: " + stateInfo);
return stateInfo;
}
/**
* Remove a state from the state machine. Will not remove the state if it is currently
* active or if it has any children in the hierarchy.
* @param state the state to remove
*/
private void removeState(State state) {
StateInfo stateInfo = mStateInfo.get(state);
if (stateInfo == null || stateInfo.active) {
return;
}
boolean isParent = mStateInfo.values().stream()
.filter(si -> si.parentStateInfo == stateInfo)
.findAny()
.isPresent();
if (isParent) {
return;
}
mStateInfo.remove(state);
}
/**
* Constructor
*
* @param looper for dispatching messages
* @param sm the hierarchical state machine
*/
private SmHandler(Looper looper, StateMachine sm) {
super(looper);
mSm = sm;
addState(mHaltingState, null);
addState(mQuittingState, null);
}
/** @see StateMachine#setInitialState(State) */
private final void setInitialState(State initialState) {
if (mDbg) mSm.log("setInitialState: initialState=" + initialState.getName());
mInitialState = initialState;
}
/** @see StateMachine#transitionTo(IState) */
private final void transitionTo(IState destState) {
if (mTransitionInProgress) {
Log.wtf(mSm.mName, "transitionTo called while transition already in progress to " +
mDestState + ", new target state=" + destState);
}
mDestState = (State) destState;
if (mDbg) mSm.log("transitionTo: destState=" + mDestState.getName());
}
/** @see StateMachine#deferMessage(Message) */
private final void deferMessage(Message msg) {
if (mDbg) mSm.log("deferMessage: msg=" + msg.what);
/* Copy the "msg" to "newMsg" as "msg" will be recycled */
Message newMsg = obtainMessage();
newMsg.copyFrom(msg);
mDeferredMessages.add(newMsg);
}
/** @see StateMachine#quit() */
private final void quit() {
if (mDbg) mSm.log("quit:");
sendMessage(obtainMessage(SM_QUIT_CMD, mSmHandlerObj));
}
/** @see StateMachine#quitNow() */
private final void quitNow() {
if (mDbg) mSm.log("quitNow:");
sendMessageAtFrontOfQueue(obtainMessage(SM_QUIT_CMD, mSmHandlerObj));
}
/** Validate that the message was sent by quit or quitNow. */
private final boolean isQuit(Message msg) {
return (msg.what == SM_QUIT_CMD) && (msg.obj == mSmHandlerObj);
}
/** @see StateMachine#isDbg() */
private final boolean isDbg() {
return mDbg;
}
/** @see StateMachine#setDbg(boolean) */
private final void setDbg(boolean dbg) {
mDbg = dbg;
}
}
private SmHandler mSmHandler;
private HandlerThread mSmThread;
/**
* Initialize.
*
* @param looper for this state machine
* @param name of the state machine
*/
private void initStateMachine(String name, Looper looper) {
mName = name;
mSmHandler = new SmHandler(looper, this);
}
/**
* Constructor creates a StateMachine with its own thread.
*
* @param name of the state machine
*/
@UnsupportedAppUsage
protected StateMachine(String name) {
mSmThread = new HandlerThread(name);
mSmThread.start();
Looper looper = mSmThread.getLooper();
initStateMachine(name, looper);
}
/**
* Constructor creates a StateMachine using the looper.
*
* @param name of the state machine
*/
@UnsupportedAppUsage
protected StateMachine(String name, Looper looper) {
initStateMachine(name, looper);
}
/**
* Constructor creates a StateMachine using the handler.
*
* @param name of the state machine
*/
@UnsupportedAppUsage
protected StateMachine(String name, Handler handler) {
initStateMachine(name, handler.getLooper());
}
/**
* Notifies subclass that the StateMachine handler is about to process the Message msg
* @param msg The message that is being handled
*/
protected void onPreHandleMessage(Message msg) {
}
/**
* Notifies subclass that the StateMachine handler has finished processing the Message msg and
* has possibly transitioned to a new state.
* @param msg The message that is being handled
*/
protected void onPostHandleMessage(Message msg) {
}
/**
* Add a new state to the state machine
* @param state the state to add
* @param parent the parent of state
*/
public final void addState(State state, State parent) {
mSmHandler.addState(state, parent);
}
/**
* Add a new state to the state machine, parent will be null
* @param state to add
*/
@UnsupportedAppUsage
public final void addState(State state) {
mSmHandler.addState(state, null);
}
/**
* Removes a state from the state machine, unless it is currently active or if it has children.
* @param state state to remove
*/
public final void removeState(State state) {
mSmHandler.removeState(state);
}
/**
* Set the initial state. This must be invoked before
* and messages are sent to the state machine.
*
* @param initialState is the state which will receive the first message.
*/
@UnsupportedAppUsage
public final void setInitialState(State initialState) {
mSmHandler.setInitialState(initialState);
}
/**
* @return current message
*/
public final Message getCurrentMessage() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return null;
return smh.getCurrentMessage();
}
/**
* @return current state
*/
public final IState getCurrentState() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return null;
return smh.getCurrentState();
}
/**
* transition to destination state. Upon returning
* from processMessage the current state's exit will
* be executed and upon the next message arriving
* destState.enter will be invoked.
*
* this function can also be called inside the enter function of the
* previous transition target, but the behavior is undefined when it is
* called mid-way through a previous transition (for example, calling this
* in the enter() routine of a intermediate node when the current transition
* target is one of the nodes descendants).
*
* @param destState will be the state that receives the next message.
*/
@UnsupportedAppUsage
public final void transitionTo(IState destState) {
mSmHandler.transitionTo(destState);
}
/**
* transition to halt state. Upon returning
* from processMessage we will exit all current
* states, execute the onHalting() method and then
* for all subsequent messages haltedProcessMessage
* will be called.
*/
public final void transitionToHaltingState() {
mSmHandler.transitionTo(mSmHandler.mHaltingState);
}
/**
* Defer this message until next state transition.
* Upon transitioning all deferred messages will be
* placed on the queue and reprocessed in the original
* order. (i.e. The next state the oldest messages will
* be processed first)
*
* @param msg is deferred until the next transition.
*/
public final void deferMessage(Message msg) {
mSmHandler.deferMessage(msg);
}
/**
* Called when message wasn't handled
*
* @param msg that couldn't be handled.
*/
protected void unhandledMessage(Message msg) {
if (mSmHandler.mDbg) loge(" - unhandledMessage: msg.what=" + msg.what);
}
/**
* Called for any message that is received after
* transitionToHalting is called.
*/
protected void haltedProcessMessage(Message msg) {
}
/**
* This will be called once after handling a message that called
* transitionToHalting. All subsequent messages will invoke
* {@link StateMachine#haltedProcessMessage(Message)}
*/
protected void onHalting() {
}
/**
* This will be called once after a quit message that was NOT handled by
* the derived StateMachine. The StateMachine will stop and any subsequent messages will be
* ignored. In addition, if this StateMachine created the thread, the thread will
* be stopped after this method returns.
*/
protected void onQuitting() {
}
/**
* @return the name
*/
public final String getName() {
return mName;
}
/**
* Set number of log records to maintain and clears all current records.
*
* @param maxSize number of messages to maintain at anyone time.
*/
public final void setLogRecSize(int maxSize) {
mSmHandler.mLogRecords.setSize(maxSize);
}
/**
* Set to log only messages that cause a state transition
*
* @param enable {@code true} to enable, {@code false} to disable
*/
public final void setLogOnlyTransitions(boolean enable) {
mSmHandler.mLogRecords.setLogOnlyTransitions(enable);
}
/**
* @return the number of log records currently readable
*/
public final int getLogRecSize() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return 0;
return smh.mLogRecords.size();
}
/**
* @return the number of log records we can store
*/
@VisibleForTesting
public final int getLogRecMaxSize() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return 0;
return smh.mLogRecords.mMaxSize;
}
/**
* @return the total number of records processed
*/
public final int getLogRecCount() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return 0;
return smh.mLogRecords.count();
}
/**
* @return a log record, or null if index is out of range
*/
public final LogRec getLogRec(int index) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return null;
return smh.mLogRecords.get(index);
}
/**
* @return a copy of LogRecs as a collection
*/
public final Collection<LogRec> copyLogRecs() {
Vector<LogRec> vlr = new Vector<LogRec>();
SmHandler smh = mSmHandler;
if (smh != null) {
for (LogRec lr : smh.mLogRecords.mLogRecVector) {
vlr.add(lr);
}
}
return vlr;
}
/**
* Add the string to LogRecords.
*
* @param string
*/
public void addLogRec(String string) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.mLogRecords.add(this, smh.getCurrentMessage(), string, smh.getCurrentState(),
smh.mStateStack[smh.mStateStackTopIndex].state, smh.mDestState);
}
/**
* @return true if msg should be saved in the log, default is true.
*/
protected boolean recordLogRec(Message msg) {
return true;
}
/**
* Return a string to be logged by LogRec, default
* is an empty string. Override if additional information is desired.
*
* @param msg that was processed
* @return information to be logged as a String
*/
protected String getLogRecString(Message msg) {
return "";
}
/**
* @return the string for msg.what
*/
protected String getWhatToString(int what) {
return null;
}
/**
* @return Handler, maybe null if state machine has quit.
*/
public final Handler getHandler() {
return mSmHandler;
}
/**
* Get a message and set Message.target state machine handler.
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @return A Message object from the global pool
*/
public final Message obtainMessage() {
return Message.obtain(mSmHandler);
}
/**
* Get a message and set Message.target state machine handler, what.
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @param what is the assigned to Message.what.
* @return A Message object from the global pool
*/
public final Message obtainMessage(int what) {
return Message.obtain(mSmHandler, what);
}
/**
* Get a message and set Message.target state machine handler,
* what and obj.
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @param what is the assigned to Message.what.
* @param obj is assigned to Message.obj.
* @return A Message object from the global pool
*/
public final Message obtainMessage(int what, Object obj) {
return Message.obtain(mSmHandler, what, obj);
}
/**
* Get a message and set Message.target state machine handler,
* what, arg1 and arg2
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @param what is assigned to Message.what
* @param arg1 is assigned to Message.arg1
* @return A Message object from the global pool
*/
public final Message obtainMessage(int what, int arg1) {
// use this obtain so we don't match the obtain(h, what, Object) method
return Message.obtain(mSmHandler, what, arg1, 0);
}
/**
* Get a message and set Message.target state machine handler,
* what, arg1 and arg2
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @param what is assigned to Message.what
* @param arg1 is assigned to Message.arg1
* @param arg2 is assigned to Message.arg2
* @return A Message object from the global pool
*/
@UnsupportedAppUsage
public final Message obtainMessage(int what, int arg1, int arg2) {
return Message.obtain(mSmHandler, what, arg1, arg2);
}
/**
* Get a message and set Message.target state machine handler,
* what, arg1, arg2 and obj
*
* Note: The handler can be null if the state machine has quit,
* which means target will be null and may cause a AndroidRuntimeException
* in MessageQueue#enqueMessage if sent directly or if sent using
* StateMachine#sendMessage the message will just be ignored.
*
* @param what is assigned to Message.what
* @param arg1 is assigned to Message.arg1
* @param arg2 is assigned to Message.arg2
* @param obj is assigned to Message.obj
* @return A Message object from the global pool
*/
@UnsupportedAppUsage
public final Message obtainMessage(int what, int arg1, int arg2, Object obj) {
return Message.obtain(mSmHandler, what, arg1, arg2, obj);
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
@UnsupportedAppUsage
public void sendMessage(int what) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(obtainMessage(what));
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
@UnsupportedAppUsage
public void sendMessage(int what, Object obj) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(obtainMessage(what, obj));
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
@UnsupportedAppUsage
public void sendMessage(int what, int arg1) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(obtainMessage(what, arg1));
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
public void sendMessage(int what, int arg1, int arg2) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(obtainMessage(what, arg1, arg2));
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
@UnsupportedAppUsage
public void sendMessage(int what, int arg1, int arg2, Object obj) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(obtainMessage(what, arg1, arg2, obj));
}
/**
* Enqueue a message to this state machine.
*
* Message is ignored if state machine has quit.
*/
@UnsupportedAppUsage
public void sendMessage(Message msg) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessage(msg);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(int what, long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(obtainMessage(what), delayMillis);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(int what, Object obj, long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(obtainMessage(what, obj), delayMillis);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(int what, int arg1, long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(obtainMessage(what, arg1), delayMillis);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(int what, int arg1, int arg2, long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(obtainMessage(what, arg1, arg2), delayMillis);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(int what, int arg1, int arg2, Object obj,
long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(obtainMessage(what, arg1, arg2, obj), delayMillis);
}
/**
* Enqueue a message to this state machine after a delay.
*
* Message is ignored if state machine has quit.
*/
public void sendMessageDelayed(Message msg, long delayMillis) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageDelayed(msg, delayMillis);
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(int what) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(obtainMessage(what));
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(int what, Object obj) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(obtainMessage(what, obj));
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(int what, int arg1) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1));
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(int what, int arg1, int arg2) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1, arg2));
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(int what, int arg1, int arg2, Object obj) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(obtainMessage(what, arg1, arg2, obj));
}
/**
* Enqueue a message to the front of the queue for this state machine.
* Protected, may only be called by instances of StateMachine.
*
* Message is ignored if state machine has quit.
*/
protected final void sendMessageAtFrontOfQueue(Message msg) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.sendMessageAtFrontOfQueue(msg);
}
/**
* Removes a message from the message queue.
* Protected, may only be called by instances of StateMachine.
*/
protected final void removeMessages(int what) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.removeMessages(what);
}
/**
* Removes a message from the deferred messages queue.
*/
protected final void removeDeferredMessages(int what) {
SmHandler smh = mSmHandler;
if (smh == null) return;
Iterator<Message> iterator = smh.mDeferredMessages.iterator();
while (iterator.hasNext()) {
Message msg = iterator.next();
if (msg.what == what) iterator.remove();
}
}
/**
* Check if there are any pending messages with code 'what' in deferred messages queue.
*/
protected final boolean hasDeferredMessages(int what) {
SmHandler smh = mSmHandler;
if (smh == null) return false;
Iterator<Message> iterator = smh.mDeferredMessages.iterator();
while (iterator.hasNext()) {
Message msg = iterator.next();
if (msg.what == what) return true;
}
return false;
}
/**
* Check if there are any pending posts of messages with code 'what' in
* the message queue. This does NOT check messages in deferred message queue.
*/
protected final boolean hasMessages(int what) {
SmHandler smh = mSmHandler;
if (smh == null) return false;
return smh.hasMessages(what);
}
/**
* Validate that the message was sent by
* {@link StateMachine#quit} or {@link StateMachine#quitNow}.
* */
protected final boolean isQuit(Message msg) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return msg.what == SM_QUIT_CMD;
return smh.isQuit(msg);
}
/**
* Quit the state machine after all currently queued up messages are processed.
*/
public final void quit() {
// mSmHandler can be null if the state machine is already stopped.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.quit();
}
/**
* Quit the state machine immediately all currently queued messages will be discarded.
*/
public final void quitNow() {
// mSmHandler can be null if the state machine is already stopped.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.quitNow();
}
/**
* @return if debugging is enabled
*/
public boolean isDbg() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return false;
return smh.isDbg();
}
/**
* Set debug enable/disabled.
*
* @param dbg is true to enable debugging.
*/
public void setDbg(boolean dbg) {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
smh.setDbg(dbg);
}
/**
* Start the state machine.
*/
@UnsupportedAppUsage
public void start() {
// mSmHandler can be null if the state machine has quit.
SmHandler smh = mSmHandler;
if (smh == null) return;
/** Send the complete construction message */
smh.completeConstruction();
}
/**
* Dump the current state.
*
* @param fd
* @param pw
* @param args
*/
@UnsupportedAppUsage
public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
pw.println(getName() + ":");
pw.println(" total records=" + getLogRecCount());
for (int i = 0; i < getLogRecSize(); i++) {
pw.println(" rec[" + i + "]: " + getLogRec(i));
pw.flush();
}
final IState curState = getCurrentState();
pw.println("curState=" + (curState == null ? "<QUIT>" : curState.getName()));
}
@Override
public String toString() {
String name = "(null)";
String state = "(null)";
try {
name = mName.toString();
state = mSmHandler.getCurrentState().getName().toString();
} catch (NullPointerException | ArrayIndexOutOfBoundsException e) {
// Will use default(s) initialized above.
}
return "name=" + name + " state=" + state;
}
/**
* Log with debug and add to the LogRecords.
*
* @param s is string log
*/
protected void logAndAddLogRec(String s) {
addLogRec(s);
log(s);
}
/**
* Log with debug
*
* @param s is string log
*/
protected void log(String s) {
Log.d(mName, s);
}
/**
* Log with debug attribute
*
* @param s is string log
*/
protected void logd(String s) {
Log.d(mName, s);
}
/**
* Log with verbose attribute
*
* @param s is string log
*/
protected void logv(String s) {
Log.v(mName, s);
}
/**
* Log with info attribute
*
* @param s is string log
*/
protected void logi(String s) {
Log.i(mName, s);
}
/**
* Log with warning attribute
*
* @param s is string log
*/
protected void logw(String s) {
Log.w(mName, s);
}
/**
* Log with error attribute
*
* @param s is string log
*/
protected void loge(String s) {
Log.e(mName, s);
}
/**
* Log with error attribute
*
* @param s is string log
* @param e is a Throwable which logs additional information.
*/
protected void loge(String s, Throwable e) {
Log.e(mName, s, e);
}
}
如果在自己项目中使用HSM层次状态机,把上面三个文件直接复制到自己项目中去。去掉一些源代码中无关紧要的注解符即可。
