Connecting signals and slots help pls

[bod]

Hello,
I have a object on the left and a treewidget on the right.When I selected an item from the right, I want object to change its color.
Here is my code:

glWidget = new GLWidget;
tree = new QTreeWidget;
tree->setHeaderLabel("Items");
qtItem = new QTreeWidgetItem(tree);
qtItem->setText(0, tr("QtLogo"));
connect(qtItem , SIGNAL(isSelected()), glWidget, SLOT(setHighlighted()));

glWidget = new GLWidget;
tree = new QTreeWidget;
tree->setHeaderLabel("Items");
qtItem = new QTreeWidgetItem(tree);
qtItem->setText(0, tr("QtLogo"));
connect(qtItem , SIGNAL(isSelected()), glWidget, SLOT(setHighlighted()));

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However it gives me an error:

"\Window.cpp(50) : error C2664: 'bool QObject::connect(const QObject *,const char *,const QObject *,const char *,Qt::ConnectionType)' : cannot convert parameter 1 from 'QTreeWidgetItem' to 'const QObject *'
1> No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called"

I did not understand the mistake, help me pls.

[mcosta]

QTreeWidgetItem isn't QObject child, then you cannot use as SIGNAL sender.

You can connect your slot to QTreeWidget::itemActivated signal

[bod]

I did it but it does not work.
Where is the mistake, I dont get it. I wonder if it calls the required method, so i put a text browser in the window. But It does not see it from the class that I wrote the function in.
here is my code:
window.cpp:

#include <QtGui>
 
#include "glwidget.h"
#include "window.h"
 
Window::Window()
{
    glWidget = new GLWidget;
	tree = new QTreeWidget;
	tree->setHeaderLabel("Items");
	qtItem = new QTreeWidgetItem(tree);
	qtItem->setText(0, tr("QtLogo"));
 
	//tree->addTopLevelItem(tmp);
 
	connect(tree , SIGNAL(itemClicked(qtItem,0)), glWidget, SLOT(setHighlighted())); 
 
	QTextBrowser *tb = new QTextBrowser;
    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addWidget(glWidget);
	mainLayout->addWidget(tree);
	mainLayout->addWidget(tb);
	tb->append("asdasda\n");
    setLayout(mainLayout);

#include <QtGui>

#include "glwidget.h"
#include "window.h"

Window::Window()
{
    glWidget = new GLWidget;
	tree = new QTreeWidget;
	tree->setHeaderLabel("Items");
	qtItem = new QTreeWidgetItem(tree);
	qtItem->setText(0, tr("QtLogo"));
	
	//tree->addTopLevelItem(tmp);

	connect(tree , SIGNAL(itemClicked(qtItem,0)), glWidget, SLOT(setHighlighted())); 
	
	QTextBrowser *tb = new QTextBrowser;
    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addWidget(glWidget);
	mainLayout->addWidget(tree);
	mainLayout->addWidget(tb);
	tb->append("asdasda\n");
    setLayout(mainLayout);

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and here is from my glwidget.cpp file.
My slot function:

void GLWidget::setHighlighted(){
 
	Purple = QColor::fromCmykF(0.25, 0.25, 0.0, 0.0);
	qglColor(Purple);
	updateGL();
	paintGL();
}

void GLWidget::setHighlighted(){

	Purple = QColor::fromCmykF(0.25, 0.25, 0.0, 0.0);
	qglColor(Purple);
	updateGL();
	paintGL();
}

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[mcosta]

The correct syntax is

connect(tree , SIGNAL(itemClicked(QTreeWidgetItem*, int)), glWidget, SLOT(setHighlighted()));

connect(tree , SIGNAL(itemClicked(QTreeWidgetItem*, int)), glWidget, SLOT(setHighlighted()));

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In the setHighlighted remove calling to paintGL(): it's automatically called from updateGL()

[bod]

Nothing changed??
When i clicked it does not change the Qt logos color.
I am not even sure of, when i click it calls the setHighlighted method.

[jpn]

Does the class declaration of GLWidget contain required Q_OBJECT macro? Did you declare GLWidget::setHighlighted() as a slot?

[bod]

Yes, here is my header file:

#ifndef GLWIDGET_H
#define GLWIDGET_H
 
#include <QGLWidget>
#include "window.h"
 
class GLWidget : public QGLWidget
{
    Q_OBJECT
 
public:
    GLWidget(QWidget *parent = 0);
    ~GLWidget();
 
    QSize minimumSizeHint() const;
    QSize sizeHint() const;
 
public slots:
    void setXRotation(int angle);
    void setYRotation(int angle);
    void setZRotation(int angle);
	void setHighlighted();
 
signals:
    void xRotationChanged(int angle);
    void yRotationChanged(int angle);
    void zRotationChanged(int angle);
 
protected:
    void initializeGL();
    void paintGL();
    void resizeGL(int width, int height);
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
 
private:
    GLuint makeObject();
    void quad(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2,
              GLdouble x3, GLdouble y3, GLdouble x4, GLdouble y4);
    void extrude(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2);
    void normalizeAngle(int *angle);
 
    GLuint object;
    int xRot;
    int yRot;
    int zRot;
    QPoint lastPos;
    QColor trolltechGreen;
    QColor trolltechPurple;
	QColor Purple;
};
 
#endif

#ifndef GLWIDGET_H
#define GLWIDGET_H

#include <QGLWidget>
#include "window.h"

class GLWidget : public QGLWidget
{
    Q_OBJECT

public:
    GLWidget(QWidget *parent = 0);
    ~GLWidget();

    QSize minimumSizeHint() const;
    QSize sizeHint() const;

public slots:
    void setXRotation(int angle);
    void setYRotation(int angle);
    void setZRotation(int angle);
	void setHighlighted();

signals:
    void xRotationChanged(int angle);
    void yRotationChanged(int angle);
    void zRotationChanged(int angle);

protected:
    void initializeGL();
    void paintGL();
    void resizeGL(int width, int height);
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);

private:
    GLuint makeObject();
    void quad(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2,
              GLdouble x3, GLdouble y3, GLdouble x4, GLdouble y4);
    void extrude(GLdouble x1, GLdouble y1, GLdouble x2, GLdouble y2);
    void normalizeAngle(int *angle);

    GLuint object;
    int xRot;
    int yRot;
    int zRot;
    QPoint lastPos;
    QColor trolltechGreen;
    QColor trolltechPurple;
	QColor Purple;
};

#endif

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How can i just print just a string, to see whether it calls the setHighlighted function or not. So we would understand that there is a problem in connection or there is a problem in updating the glwidget.

[jpn]

How can i just print just a string, to see whether it calls the setHighlighted function or not. So we would understand that there is a problem in connection or there is a problem in updating the glwidget.

See Debugging Techniques. Notice that QObject::connect() does output a warning in case establishing the connection fails.

[bod]

So, the mistake is in updating glwidget ??

[bod]

Okey, I run it debug mode in visual studio.and it enters the function. Thnx for everyone.