內容

公共類型
特性
公共函數
重實現保護函數
詳細描述

QHistoryState 類

The QHistoryState class provides a means of returning to a previously active substate. 更多...

頭：	#include <QHistoryState>
Since:	Qt 4.6
繼承：	QAbstractState

所有成員列錶，包括繼承成員

公共類型

enum	HistoryType { ShallowHistory, DeepHistory }

特性

defaultState : QAbstractState *
historyType : HistoryType

1 特性繼承自 QObject

公共函數

	QHistoryState (QState * parent = 0)
	QHistoryState (HistoryType type , QState * parent = 0)
	~QHistoryState ()
QAbstractState *	defaultState () const
HistoryType	historyType () const
void	setDefaultState (QAbstractState * state )
void	setHistoryType (HistoryType type )

2 公共函數繼承自 QAbstractState
29 公共函數繼承自 QObject

重實現保護函數

virtual bool	event (QEvent * e )
virtual void	onEntry (QEvent * event )
virtual void	onExit (QEvent * event )

3 保護函數繼承自 QAbstractState
8 保護函數繼承自 QObject

額外繼承成員

1 公共槽繼承自 QObject
2 信號繼承自 QAbstractState
1 信號繼承自 QObject
7 靜態公共成員繼承自 QObject
3 保護函數繼承自 QAbstractState
8 保護函數繼承自 QObject

詳細描述

The QHistoryState class provides a means of returning to a previously active substate.

A history state is a pseudo-state that represents the child state that the parent state was in the last time the parent state was exited. A transition with a history state as its target is in fact a transition to one of the other child states of the parent state. QHistoryState 屬於狀態機框架 .

使用 setDefaultState () function to set the state that should be entered if the parent state has never been entered. Example:

QStateMachine machine;
QState *s1 = new QState();
QState *s11 = new QState(s1);
QState *s12 = new QState(s1);
QHistoryState *s1h = new QHistoryState(s1);
s1h->setDefaultState(s11);
machine.addState(s1);
QState *s2 = new QState();
machine.addState(s2);
QPushButton *button = new QPushButton();
// Clicking the button will cause the state machine to enter the child state
// that s1 was in the last time s1 was exited, or the history state's default
// state if s1 has never been entered.
s1->addTransition(button, SIGNAL(clicked()), s1h);

By default a history state is shallow, meaning that it won't remember nested states. This can be configured through the historyType 特性。

成員類型文檔編製

enum QHistoryState:: HistoryType

This enum specifies the type of history that a QHistoryState records.

常量	值	描述
`QHistoryState::ShallowHistory`	`0`	Only the immediate child states of the parent state are recorded. In this case a transition with the history state as its target will end up in the immediate child state that the parent was in the last time it was exited. This is the default.
`QHistoryState::DeepHistory`	`1`	Nested states are recorded. In this case a transition with the history state as its target will end up in the most deeply nested descendant state the parent was in the last time it was exited.

特性文檔編製

defaultState : QAbstractState *

This property holds the default state of this history state.

訪問函數：

QAbstractState *	defaultState () const
void	setDefaultState (QAbstractState * state )

historyType : HistoryType

This property holds the type of history that this history state records.

此特性的默認值為 QHistoryState::ShallowHistory .

訪問函數：

HistoryType	historyType () const
void	setHistoryType (HistoryType type )

成員函數文檔編製

QHistoryState:: QHistoryState ( QState * parent = 0)

Constructs a new shallow history state with the given parent 狀態。

QHistoryState:: QHistoryState ( HistoryType type , QState * parent = 0)

Constructs a new history state of the given type ，采用給定 parent 狀態。

QHistoryState:: ~QHistoryState ()

Destroys this history state.

`[virtual protected]` bool QHistoryState:: event ( QEvent * e )

重實現自 QObject::event ().

`[virtual protected]` void QHistoryState:: onEntry ( QEvent * event )

重實現自 QAbstractState::onEntry ().

`[virtual protected]` void QHistoryState:: onExit ( QEvent * event )

重實現自 QAbstractState::onExit ().

內容