简化实现qt中的信号阻塞blockSignals

http://www.oschina.net/code/snippet_54100_1304
QT中经常会用到blockSignals, 且是成对出现，实现时常在函数的开始阻塞信号，在函数的结尾释放信号。
若里面有大量需要阻塞的变量对象，这样写是件很麻烦的事，代码也比较多。
如果能实现象下面的方式实现，这样能简化很多，且不关心释放问题.
下面的例子是关于slider与spinbox联动问题,若改slider影响spinbox,反之如此。

标签： 信号阻塞 blockSignals Qt

代码片段(2)[全屏查看所有代码]

1. [代码]cpp代码    跳至 [1] [2] [全屏预览]

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01void ImEffectWidget::slotSlider(int pos)

02{

03 staticint oldPos = 0;

04 if(oldPos != pos)

05 {

06  QRect r;

07  QObject *o = sender();

08//

09  ImSignalBlock block;

10  block << m_ui.spinBoxTransparent << m_ui.spinBoxVerticalPos

11     << m_ui.spinBoxHerizontalPos << m_ui.spinBoxSTTransparent

12     << m_ui.spinBoxSTVPos;

13  inttabType = m_treeItem->mdata("effect_catalog").toInt();

14  if(tabType == TAB_CATALOG_WATERMARK ){

15   r = m_treeItem->getEffectItem("effect_item_rect").toRect();

16  }

17  

18  /* 3. for watermark  ***************************/

19  elseif (o->objectName() =="sliderTransparent"){

20   m_ui.spinBoxTransparent->setValue(pos); //与spinbox关联

21   m_treeItem->setEffectItem("effect_item_transparent", pos);

22  }elseif (o->objectName() =="sliderVerticalPos"){

23   r.moveLeft(pos);

24   m_ui.spinBoxVerticalPos->setValue(pos);

25  }elseif (o->objectName() =="sliderHorizontalPos"){

26   r.moveTop(pos);

27   m_ui.spinBoxHerizontalPos->setValue(pos);

28  }

29  /* 5. for subtitle  ***************************/

30  elseif (o->objectName() =="sliderSTTransparent"){

31   m_ui.spinBoxSTTransparent->setValue(pos);

32   m_treeItem->setMediaData("effect_subtitle_transparent", pos);

33  }elseif (o->objectName() =="sliderSTVPos"){

34   m_ui.spinBoxSTVPos->setValue(pos);

35   m_treeItem->setMediaData("effect_subtitle_pos", pos);

36  }

37  

38  if(tabType == TAB_CATALOG_WATERMARK ){

39   m_treeItem->setEffectItem("effect_item_rect", r);

40  }

41  sendEffectEvent();  //向sdl发信号

42  oldPos = pos;

43 }

44}

2. [代码]ImSignalBlock.h    跳至 [1] [2] [全屏预览]

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01#ifndef IMSIGNALBLOCK_H_

02#define IMSIGNALBLOCK_H_

03#include <QObject>

04class ImSignalBlock

05{

06public:

07 ImSignalBlock();

08 ~ImSignalBlock();

09  ImSignalBlock &operator<< (QObject *o);

10private:

11 QList<QObject*> m_objs;

12};

13#endif

14ImSignalBlock.cpp:

15#include <QDebug>

16#include "ImSignalBlock.h"

17ImSignalBlock::ImSignalBlock()

18{

19}

20ImSignalBlock::~ImSignalBlock()

21{

22 foreach (QObject* o, m_objs)

23 {

24  if(o) o->blockSignals(false);

25 }

26}

27ImSignalBlock &ImSignalBlock::operator<< (QObject *o)

28{

29 if(o)

30 {

31  m_objs.append(o);

32  qDebug() << o->objectName();

33  o->blockSignals(true);

34 }

35 return*this;

36}


http://blog.csdn.net/koilin/article/details/7599223

我有两个QComboBox combo1, combo2：

[cpp] view plaincopyprint?

1. QComboBox *combo1 = new QComboBox;  
2. QComboBox *combo2 = new QComboBox;  
3. combo1->addItem("1-1");  
4. combo1->addItem("1-2");  
5. combo2->addItem("2-1");  
6. combo2->addItem("2-2");  
7. connect(combo1, SIGNAL(currentIndexChanged(int)), combo2, SLOT(process(int)));  
8. connect(combo2, SIGNAL(currentIndexChanged(int)), combo1, SLOT(process(int)));  

QComboBox *combo1 = new QComboBox;QComboBox *combo2 = new QComboBox;combo1->addItem("1-1");combo1->addItem("1-2");combo2->addItem("2-1");combo2->addItem("2-2");connect(combo1, SIGNAL(currentIndexChanged(int)), combo2, SLOT(process(int)));connect(combo2, SIGNAL(currentIndexChanged(int)), combo1, SLOT(process(int)));

然后是信号处理函数：

[cpp] view plaincopyprint?

1. void process(int index)  
2. {  
3.     QComboBox *combo1 = new QComboBox;  
4.     QComboBox *combo2 = new QComboBox;  
5.     if (sender() == combo1)  
6.     {  
7.         combo2->setCurrentIndex(index);  
8.     }  
9.     else if (sender() == combo2)  
10.     {  
11.         combo1->setCurrentIndex(index);  
12.     }  
13. }  

void process(int index){QComboBox *combo1 = new QComboBox;QComboBox *combo2 = new QComboBox;if (sender() == combo1){combo2->setCurrentIndex(index);}else if (sender() == combo2){combo1->setCurrentIndex(index);}}

这样两个combobox之间就产生了死循环。因为不管是手动改变combobox的当前index还是使用函数来设置当前的index都会发出index改变的消息，此时就需要使用关闭信号：

[cpp] view plaincopyprint?

1. void process(int index)  
2. {  
3.     QComboBox *combo1 = new QComboBox;  
4.     QComboBox *combo2 = new QComboBox;  
5.     if (sender() == combo1)  
6.     {  
7.         combo2->blockSignals(true);  
8.         combo2->setCurrentIndex(index);  
9.         combo2->blockSignals(false);  
10.     }  
11.     else if (sender() == combo2)  
12.     {  
13.         combo1->blockSignals(true);  
14.         combo1->setCurrentIndex(index);  
15.         combo1->blockSignals(false);  
16.     }  
17. }