QSignalMapper problems

[ChiBriTri]

Hi,

I am having problems with slots getting called multiple times. Each time I add another mapping, the slot gets called n+1 times - where n is the previous number of times called. Made a very simple demo program - can someone tell me what I'm doing wrong here?

Project is a qtreewidget that starts with one button to add a top level item. Each top level item adds a button to add a child. Adding a top level always just adds one (not part of the mapping), but adding a child has exponential growth. Assuming I'm somehow inserting it into the mapping in a looping manner, but just can't seem to figure out where.

testwidget.h

#pragma once
#include "qwidget.h"
#include "qsignalmapper.h"
 
class QTreeWidget;
class QTreeWidgetItem;
class FilterGroup;
class FilterGroupWidget;
 
class TestWidget: public QWidget
{
	Q_OBJECT
 
public:
	TestWidget(QWidget* pParent);
 
	private Q_SLOTS:
	void addNewFilter();
	void addChildFilter(QWidget *pItem);
 
private:
	void updateRow(QTreeWidgetItem *pRow);
 
	QTreeWidget *m_pTree;
	QSignalMapper m_Mapper;
};

#pragma once
#include "qwidget.h"
#include "qsignalmapper.h"

class QTreeWidget;
class QTreeWidgetItem;
class FilterGroup;
class FilterGroupWidget;

class TestWidget: public QWidget
{
	Q_OBJECT

public:
	TestWidget(QWidget* pParent);

	private Q_SLOTS:
	void addNewFilter();
	void addChildFilter(QWidget *pItem);

private:
	void updateRow(QTreeWidgetItem *pRow);

	QTreeWidget *m_pTree;
	QSignalMapper m_Mapper;
};

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testwidget.cpp

#include "stdafx.h"
#include "TestWidget.h"
#include "QtWidgets\qboxlayout.h"
#include "FilterColumns.h"
#include "qtreewidget.h"
#include "qheaderview.h"
#include "FilterTypeWidgets.h"
#include "FilterWidget.h"
 
TestWidget::TestWidget(QWidget* pParent):QWidget(pParent)
{
	auto pMainLayout=new QVBoxLayout();
	m_pTree=new QTreeWidget();
	m_pTree->setColumnCount(1);
 
	auto pRow=new QTreeWidgetItem();
	m_pTree->insertTopLevelItem(0, pRow);
 
	auto pAdd=new QPushButton();
	pAdd->setText("Add top level");
	m_pTree->setItemWidget(pRow, 0, pAdd);
 
	connect(pAdd, &QPushButton::clicked, this, &TestWidget::addNewFilter);
 
	setLayout(pMainLayout);
	pMainLayout->setMargin(0);
	pMainLayout->addWidget(m_pTree);
}
 
 
void TestWidget::addNewFilter()
{
	auto pRow=new QTreeWidgetItem();
	m_pTree->insertTopLevelItem(m_pTree->topLevelItemCount() - 1, pRow);
 
	updateRow(pRow);
}
 
void TestWidget::addChildFilter(QWidget *pItem)
{
	auto pParent=(QTreeWidgetItem *)pItem;
	auto pRow=new QTreeWidgetItem();
 
	pParent->addChild(pRow);
	pParent->setExpanded(true);
 
	updateRow(pRow);
}
 
void TestWidget::updateRow(QTreeWidgetItem *pRow)
{
	auto pWidget=new QPushButton("add child");
	auto test=connect(pWidget, SIGNAL(clicked()), &m_Mapper, SLOT(map()));
	m_Mapper.setMapping(pWidget, (QWidget *)pRow);
 
	connect(&m_Mapper, SIGNAL(mapped(QWidget *)), this, SLOT(addChildFilter(QWidget *)));
 
	m_pTree->setItemWidget(pRow, 0, pWidget);
}

#include "stdafx.h"
#include "TestWidget.h"
#include "QtWidgets\qboxlayout.h"
#include "FilterColumns.h"
#include "qtreewidget.h"
#include "qheaderview.h"
#include "FilterTypeWidgets.h"
#include "FilterWidget.h"

TestWidget::TestWidget(QWidget* pParent):QWidget(pParent)
{
	auto pMainLayout=new QVBoxLayout();
	m_pTree=new QTreeWidget();
	m_pTree->setColumnCount(1);

	auto pRow=new QTreeWidgetItem();
	m_pTree->insertTopLevelItem(0, pRow);

	auto pAdd=new QPushButton();
	pAdd->setText("Add top level");
	m_pTree->setItemWidget(pRow, 0, pAdd);

	connect(pAdd, &QPushButton::clicked, this, &TestWidget::addNewFilter);

	setLayout(pMainLayout);
	pMainLayout->setMargin(0);
	pMainLayout->addWidget(m_pTree);
}


void TestWidget::addNewFilter()
{
	auto pRow=new QTreeWidgetItem();
	m_pTree->insertTopLevelItem(m_pTree->topLevelItemCount() - 1, pRow);

	updateRow(pRow);
}

void TestWidget::addChildFilter(QWidget *pItem)
{
	auto pParent=(QTreeWidgetItem *)pItem;
	auto pRow=new QTreeWidgetItem();

	pParent->addChild(pRow);
	pParent->setExpanded(true);

	updateRow(pRow);
}

void TestWidget::updateRow(QTreeWidgetItem *pRow)
{
	auto pWidget=new QPushButton("add child");
	auto test=connect(pWidget, SIGNAL(clicked()), &m_Mapper, SLOT(map()));
	m_Mapper.setMapping(pWidget, (QWidget *)pRow);

	connect(&m_Mapper, SIGNAL(mapped(QWidget *)), this, SLOT(addChildFilter(QWidget *)));

	m_pTree->setItemWidget(pRow, 0, pWidget);
}

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[anda_skoa]

In line 56 you call connect from the mapper to a slot.
Every time updateRow() is called.
So obviously you get as many connections as updateRow() calls.

You probably want to connect only once, e.g. in the constructor.

Cheers,
_