- Qt 5.5
- Qt Widgets
- Validators Example
- main.cpp Example File
- Qt 5.5.1 Reference Documentation

# main.cpp Example File

widgets/validators/main.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
    ** met:
    **   * Redistributions of source code must retain the above copyright
    **     notice, this list of conditions and the following disclaimer.
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    **     notice, this list of conditions and the following disclaimer in
    **     the documentation and/or other materials provided with the
    **     distribution.
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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    #include <qdebug.h>
    #include <QApplication>
    #include <QLineEdit>
    #include <QValidator>

    #include "ui_validators.h"

    class ValidatorWidget : public QWidget, public Ui::ValidatorsForm
    {
        Q_OBJECT
    public:
        ValidatorWidget(QWidget *parent = 0);

    private slots:
        void updateValidator();
        void updateDoubleValidator();
        void _setLocale(const QLocale &l) { setLocale(l); updateValidator(); updateDoubleValidator(); }

    private:
        QIntValidator *validator;
        QDoubleValidator *doubleValidator;
    };

    ValidatorWidget::ValidatorWidget(QWidget *parent)
        : QWidget(parent)
    {
        setupUi(this);

        connect(localeSelector, SIGNAL(localeSelected(QLocale)), this, SLOT(_setLocale(QLocale)));

        connect(minVal, SIGNAL(editingFinished()), this, SLOT(updateValidator()));
        connect(maxVal, SIGNAL(editingFinished()), this, SLOT(updateValidator()));
        connect(editor, SIGNAL(editingFinished()), ledWidget, SLOT(flash()));

        connect(doubleMaxVal, SIGNAL(editingFinished()), this, SLOT(updateDoubleValidator()));
        connect(doubleMinVal, SIGNAL(editingFinished()), this, SLOT(updateDoubleValidator()));
        connect(doubleDecimals, SIGNAL(valueChanged(int)), this, SLOT(updateDoubleValidator()));
        connect(doubleFormat, SIGNAL(activated(int)), this, SLOT(updateDoubleValidator()));
        connect(doubleEditor, SIGNAL(editingFinished()), doubleLedWidget, SLOT(flash()));

        validator = 0;
        doubleValidator = 0;
        updateValidator();
        updateDoubleValidator();
    };

    void ValidatorWidget::updateValidator()
    {
        QIntValidator *v = new QIntValidator(minVal->value(), maxVal->value(), this);
        v->setLocale(locale());
        editor->setValidator(v);
        delete validator;
        validator = v;

        QString s = editor->text();
        int i = 0;
        if (validator->validate(s, i) == QValidator::Invalid) {
            editor->clear();
        } else {
            editor->setText(s);
        }
    }

    void ValidatorWidget::updateDoubleValidator()
    {
        QDoubleValidator *v
            = new QDoubleValidator(doubleMinVal->value(), doubleMaxVal->value(),
                                    doubleDecimals->value(), this);
        v->setNotation(static_cast<QDoubleValidator::Notation>(doubleFormat->currentIndex()));
        v->setLocale(locale());
        doubleEditor->setValidator(v);
        delete doubleValidator;
        doubleValidator = v;

        QString s = doubleEditor->text();
        int i = 0;
        if (doubleValidator->validate(s, i) == QValidator::Invalid) {
            doubleEditor->clear();
        } else {
            doubleEditor->setText(s);
        }
    }

    int main(int argc, char **argv)
    {
        Q_INIT_RESOURCE(validators);

        QApplication app(argc, argv);

        ValidatorWidget w;
        w.show();

        return app.exec();
    }

    #include "main.moc"