How to extend method expanded in QTreeView
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wrote on 31 Aug 2011, 04:20 last edited by
I want overwrite QTreeView
@class SelfDifineTree : public QTreeView{
public:
SelfDifineTree();
virtual ~SelfDifineTree();
Q_SIGNALS:
void expanded(const QModelIndex &index);
@
but got a error
@D:\bak\mytreewindow\mytreewindow-build-desktop......\QtSDK\Desktop\Qt\4.7.3\mingw\include\QtGui\qtreeview.h:151: candidates are: void QTreeView::expanded(const QModelIndex&)@can anyone help me on this problem?thx a lot
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wrote on 31 Aug 2011, 05:06 last edited by
The signal "expanded is already declared at class QTreeView":http://doc.qt.nokia.com/latest/qtreeview.html#expanded which is inherited by your class SelfDifineTree.
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wrote on 31 Aug 2011, 05:19 last edited by
Thx for your reply, it is true that expanded is already defined, and this is also my purpose, I want do overwrite this method
@
void SelfDifineTree::expanded(const QModelIndex &index){
//to do somthing
this->QTreeView::expanded(&index);
}
@
is this possible?
[quote author="leon.anavi" date="1314767211"]The signal "expanded is already declared at class QTreeView":http://doc.qt.nokia.com/latest/qtreeview.html#expanded which is inherited by your class SelfDifineTree.[/quote] -
wrote on 31 Aug 2011, 05:27 last edited by
[quote author="shen yang" date="1314767996"]Thx for your reply, it is true that expanded is already defined, and this is also my purpose, I want do overwrite this method
[/quote]No, you can't because it is not declared as virtual and it is a signal.
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wrote on 31 Aug 2011, 05:59 last edited by
expanded() is a signal, and is as leon.anavi rightly points out, not virtual. Instead of subclassing and reimplenting the method, why not simply create a new slot in your subclass, and connect to the signal instead?
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wrote on 31 Aug 2011, 06:21 last edited by
Thx anyway, now I'm wondering what make this method expanded can not been overwrite, I can only see
@define Q_SIGNALS protected
@
for this, I write a small test, when I call testp(), it call the testprotected() in childclass, really puzzled.
parentclass.h
@
class ParentClass{
public:
ParentClass();
virtual ~ParentClass();
protected:
void testprotected();
};@
childclass.h
@
#include "parentclass.h"class ChildClass:public ParentClass{
public:
ChildClass();
void testp();
virtual ~ChildClass();protected:
void testprotected();
};@
parentclass.cpp
@
#include "parentclass.h"
#include <QDebug>ParentClass:: ParentClass (){
qDebug()<<"Build Parent"; }ParentClass:: ~ParentClass(){
qDebug()<<"delete parent";
}void ParentClass:: testprotected(){
qDebug()<<"testprotected parent";
}@
childclass.cpp
@
#include "childclass.h"
#include <QDebug>ChildClass::ChildClass(){
}
ChildClass::~ChildClass(){
}void ChildClass:: testprotected(){
qDebug()<<"testprotected child";
}void ChildClass:: testp(){
testprotected();
}
@
And even change to this, this small test can also,run.
@define Q_SIGNALS protected
class ParentClass{
public:
ParentClass();
virtual ~ParentClass();
Q_SIGNALS:
void testprotected();
};
@[quote author="leon.anavi" date="1314768472"]
[quote author="shen yang" date="1314767996"]Thx for your reply, it is true that expanded is already defined, and this is also my purpose, I want do overwrite this method
[/quote]No, you can't because it is not declared as virtual and it is a signal.
[/quote] -
wrote on 31 Aug 2011, 06:30 last edited by
Got it, thx.
[quote author="Andre" date="1314770348"]expanded() is a signal, and is as leon.anavi rightly points out, not virtual. Instead of subclassing and reimplenting the method, why not simply create a new slot in your subclass, and connect to the signal instead?[/quote]
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