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Thread: slot problem

  1. 9th December 2008, 11:29 #1
    yagabey
    yagabey is offline Intermediate user
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    Default slot problem

    Hello,

    I promoted a widget to a custom widget (scalableWidget)...But when i run the application i get a slot connection problem error like:

    Object::connect: No such slot QWidget::setScaleVal(int)
    Object::connect: (sender name: 'horizontalSlider')
    Object::connect: (receiver name: 'widget')

    I couldn't find anything wrong...What may be the problem...?

    Qt Code: 
    1. #include "mainwindow.h"
    2.  
    3. MainWindow::MainWindow(QWidget *parent, Qt::WFlags flags)
    4.     : QMainWindow(parent, flags)
    5. {
    6.     ui.setupUi(this);
    7.     QObject::connect(ui.horizontalSlider, SIGNAL(valueChanged(int)), ui.widget, SLOT(setScaleVal(int)));
    8.  
    9. }
    10.  
    11. MainWindow::~MainWindow()
    12. {
    13.  
    14. }
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    my custom widget:

    Qt Code: 
    1. #ifndef SCALABLEWIDGET_H
    2. #define SCALABLEWIDGET_H
    3. #include <QWidget>
    4. #include <QPainter>
    5.  
    6. class scalableWidget : public  QWidget
    7. {
    8.  
    9. public:
    10.     scalableWidget(QWidget * parent = 0, Qt::WindowFlags f = 0);
    11.     qreal scaleFactor;
    12.  
    13. protected:
    14.     void paintEvent(QPaintEvent *event);
    15.  
    16. public slots:
    17.     void setScaleVal(int);
    18.  
    19. };
    20.  
    21. #endif // SCALABLEWIDGET_H
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    Qt Code: 
    1. #include "scalablewidget.h"
    2.  
    3. scalableWidget::scalableWidget(QWidget * parent, Qt::WindowFlags f)
    4.         :QWidget( parent, f )
    5. {
    6. }
    7.  
    8. void scalableWidget::paintEvent(QPaintEvent *event)
    9. {
    10.     QPainter painter(this);
    11.     painter.scale(scaleFactor,scaleFactor);
    12.  
    13. }
    14.  
    15. void scalableWidget::setScaleVal(int comingValue)
    16. {
    17.     scaleFactor=(qreal)comingValue;
    18. }
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    generated file :

    Qt Code: 
    1. #ifndef UI_MAINWINDOW_H
    2. #define UI_MAINWINDOW_H
    3.  
    4. #include <QtCore/QVariant>
    5. #include <QtGui/QAction>
    6. #include <QtGui/QApplication>
    7. #include <QtGui/QButtonGroup>
    8. #include <QtGui/QMainWindow>
    9. #include <QtGui/QMenuBar>
    10. #include <QtGui/QPushButton>
    11. #include <QtGui/QSlider>
    12. #include <QtGui/QStatusBar>
    13. #include <QtGui/QToolBar>
    14. #include <QtGui/QWidget>
    15. #include "scalablewidget.h"
    16.  
    17. QT_BEGIN_NAMESPACE
    18.  
    19. class Ui_MainWindowClass
    20. {
    21. public:
    22.     QWidget *centralWidget;
    23.     scalableWidget *widget;
    24.     QPushButton *pushButton;
    25.     QPushButton *pushButton_2;
    26.     QSlider *horizontalSlider;
    27.     QMenuBar *menuBar;
    28.     QToolBar *mainToolBar;
    29.     QStatusBar *statusBar;
    30.  
    31.     void setupUi(QMainWindow *MainWindowClass)
    32.     {
    33.     if (MainWindowClass->objectName().isEmpty())
    34.         MainWindowClass->setObjectName(QString::fromUtf8("MainWindowClass"));
    35.     MainWindowClass->resize(600, 400);
    36.     centralWidget = new QWidget(MainWindowClass);
    37.     centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
    38.     widget = new scalableWidget(centralWidget);
    39.     widget->setObjectName(QString::fromUtf8("widget"));
    40.     widget->setGeometry(QRect(220, 30, 171, 131));
    41.     pushButton = new QPushButton(widget);
    42.     pushButton->setObjectName(QString::fromUtf8("pushButton"));
    43.     pushButton->setGeometry(QRect(40, 30, 80, 25));
    44.     pushButton_2 = new QPushButton(widget);
    45.     pushButton_2->setObjectName(QString::fromUtf8("pushButton_2"));
    46.     pushButton_2->setGeometry(QRect(70, 80, 80, 25));
    47.     horizontalSlider = new QSlider(centralWidget);
    48.     horizontalSlider->setObjectName(QString::fromUtf8("horizontalSlider"));
    49.     horizontalSlider->setGeometry(QRect(70, 210, 160, 16));
    50.     horizontalSlider->setOrientation(Qt::Horizontal);
    51.     MainWindowClass->setCentralWidget(centralWidget);
    52.     menuBar = new QMenuBar(MainWindowClass);
    53.     menuBar->setObjectName(QString::fromUtf8("menuBar"));
    54.     menuBar->setGeometry(QRect(0, 0, 600, 23));
    55.     MainWindowClass->setMenuBar(menuBar);
    56.     mainToolBar = new QToolBar(MainWindowClass);
    57.     mainToolBar->setObjectName(QString::fromUtf8("mainToolBar"));
    58.     MainWindowClass->addToolBar(Qt::TopToolBarArea, mainToolBar);
    59.     statusBar = new QStatusBar(MainWindowClass);
    60.     statusBar->setObjectName(QString::fromUtf8("statusBar"));
    61.     MainWindowClass->setStatusBar(statusBar);
    62.  
    63.     retranslateUi(MainWindowClass);
    64.  
    65.     QMetaObject::connectSlotsByName(MainWindowClass);
    66.     } // setupUi
    67.  
    68.     void retranslateUi(QMainWindow *MainWindowClass)
    69.     {
    70.     MainWindowClass->setWindowTitle(QApplication::translate("MainWindowClass", "MainWindow", 0, QApplication::UnicodeUTF8));
    71.     pushButton->setText(QApplication::translate("MainWindowClass", "PushButton", 0, QApplication::UnicodeUTF8));
    72.     pushButton_2->setText(QApplication::translate("MainWindowClass", "PushButton", 0, QApplication::UnicodeUTF8));
    73.     Q_UNUSED(MainWindowClass);
    74.     } // retranslateUi
    75.  
    76. };
    77.  
    78. namespace Ui {
    79.     class MainWindowClass: public Ui_MainWindowClass {};
    80. } // namespace Ui
    81.  
    82. QT_END_NAMESPACE
    83.  
    84. #endif // UI_MAINWINDOW_H
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  2. 9th December 2008, 12:49 #2
    ^NyAw^'s Avatar
    ^NyAw^
    ^NyAw^ is offline Advanced user
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    Default Re: slot problem

    Hi,

    It seems that you forget the Q_OBJECT macro:

    Qt Code: 
    1. class scalableWidget : public QWidget
    2. {
    3.   Q_OBJECT
    4. ...
    5. }
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    Òscar Llarch i Galán
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