SequenceState Class Reference

#include <SequenceState.h>

Inheritance diagram for SequenceState:

Collaboration diagram for SequenceState:

Classes
struct	Step

Public Types
using	StepAction = std::function< bool()>
	Step action - returns true to continue, false to stop with error.
Public Types inherited from QGCAbstractState
using	EntryCallback = std::function< void()>
using	ExitCallback = std::function< void()>
using	EventHandler = std::function< bool(QEvent *)>

Signals
void	stepCompleted (const QString &stepName, int index)
	Emitted after each step completes successfully.
Signals inherited from QGCAbstractState
void	advance ()
void	error ()

Public Member Functions
	SequenceState (const QString &stateName, QState *parent)
void	addStep (const QString &name, StepAction action)
void	addSteps (const QList< Step > &steps)
	Add multiple steps at once.
int	currentStepIndex () const
	Get the current step index.
QString	currentStepName () const
	Get the current step name.
int	stepCount () const
	Get the total number of steps.
QString	failedStepName () const
	Get the name of the step that failed (valid after error())
Public Member Functions inherited from QGCState
	QGCState (const QString &stateName, QState *parentState)
template<typename PointerToMemberFunction >
QSignalTransition *	addThisTransition (PointerToMemberFunction signal, QAbstractState *target)
	Simpler version of QState::addTransition which assumes the sender is this.
void	setLocalErrorState (QAbstractState *errorState)
QAbstractState *	localErrorState () const
	Get the per-state error state (nullptr if using global)
void	setProperty (QObject *object, const char *name, const QVariant &value)
void	setEnabled (QObject *object, bool enabled)
	Convenience overload for setting enabled state on widgets/controls.
void	setVisible (QObject *object, bool visible)
	Convenience overload for setting visible state on widgets/controls.
Public Member Functions inherited from QGCAbstractState
	QGCAbstractState (const QString &stateName, QState *parent)
QGCStateMachine *	machine () const
Vehicle *	vehicle () const
QString	stateName () const
class StateContext *	context () const
void	setOnEntry (EntryCallback callback)
	Set a callback to be invoked when the state is entered.
void	setOnExit (ExitCallback callback)
	Set a callback to be invoked when the state is exited.
void	setCallbacks (EntryCallback onEntry, ExitCallback onExit=nullptr)
	Set both entry and exit callbacks.
void	setEventHandler (EventHandler handler)
	Set a custom event handler for this state.

Protected Member Functions
void	onEnter () override
	Override to perform actions on state entry.
Protected Member Functions inherited from QGCAbstractState
virtual void	onLeave ()
	Override to perform actions on state exit.
void	onEntry (QEvent *event) override
void	onExit (QEvent *event) override
bool	event (QEvent *event) override

Detailed Description

A composite state that executes a sequence of actions in order.

Each action is executed in turn. If any action fails (returns false), the sequence stops and error() is emitted. When all actions complete successfully, advance() is emitted.

Example usage:

auto* seqState = new SequenceState("LoadSequence", &machine);
seqState->addStep("Validate", []() {
    // Validation logic
    return isValid;  // Return false to stop sequence
});
seqState->addStep("Load", []() {
    // Load logic
    return true;
});
seqState->addStep("Initialize", []() {
    // Init logic
    return true;
});
 
seqState->addTransition(seqState, &SequenceState::advance, successState);
seqState->addTransition(seqState, &SequenceState::error, errorState);

Definition at line 32 of file SequenceState.h.

Member Typedef Documentation

StepAction

using SequenceState::StepAction = std::function<bool()>

Step action - returns true to continue, false to stop with error.

Definition at line 39 of file SequenceState.h.

Constructor & Destructor Documentation

SequenceState()

SequenceState::SequenceState	(	const QString &	stateName,
		QState *	parent
	)

Definition at line 4 of file SequenceState.cc.

Member Function Documentation

addStep()

void SequenceState::addStep	(	const QString &	name,
		StepAction	action
	)

Add a step to the sequence

Parameters

name	Step name for logging
action	Action to execute (returns true to continue, false to error)

Definition at line 9 of file SequenceState.cc.

addSteps()

void SequenceState::addSteps

(

const QList< Step > &

steps

)

Add multiple steps at once.

Definition at line 14 of file SequenceState.cc.

currentStepIndex()

int SequenceState::currentStepIndex ( ) const

inline

Get the current step index.

Definition at line 57 of file SequenceState.h.

currentStepName()

QString SequenceState::currentStepName

(

)

const

Get the current step name.

Definition at line 19 of file SequenceState.cc.

failedStepName()

QString SequenceState::failedStepName ( ) const

inline

Get the name of the step that failed (valid after error())

Definition at line 66 of file SequenceState.h.

onEnter()

void SequenceState::onEnter ( )

overrideprotectedvirtual

Override to perform actions on state entry.

Reimplemented from QGCAbstractState.

Definition at line 27 of file SequenceState.cc.

stepCompleted

void SequenceState::stepCompleted ( const QString &  stepName, int  index  )

signal

Emitted after each step completes successfully.

stepCount()

int SequenceState::stepCount ( ) const

inline

Get the total number of steps.

Definition at line 63 of file SequenceState.h.

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The documentation for this class was generated from the following files:

• src/Utilities/StateMachine/States/SequenceState.h
• src/Utilities/StateMachine/States/SequenceState.cc