#include <QtGui/QApplication>

#include "QLoginDialog.h"

#include "Widget.h"

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    Widget w;

    w.show();

    return a.exec();

}

#ifndef WIDEGT_H

#define WIDEGT_H

#include <QWidget>

#include <QPushButton>

class Widget : public QWidget

{

    Q_OBJECT

private:

    QPushButton testBtn;

private slots:

    void TestBtn_Clicked();

public:

    Widget(QWidget* parent = 0);

    ~Widget();

};

#endif // WIDEGT_H

#include <QDebug>

#include "Widget.h"

#include "QLoginDialog.h"

Widget::Widget(QWidget* parent) : QWidget(parent) ,testBtn(this)

{

    testBtn.setText("Test Login Dialog");

    setFixedSize(200, 100);

    connect(&testBtn, SIGNAL(clicked()), this, SLOT(TestBtn_Clicked()));

}

void Widget::TestBtn_Clicked()

{

    QLoginDialog dialog;

    if(dialog.exec() == QDialog::Accepted)

    {

        qDebug() << "User Name: " + dialog.GetUser();

        qDebug() << "Password: " + dialog.GetPwd();

    }

}

Widget::~Widget()

{

}

#ifndef DIALOG_H

#define DIALOG_H

#include <QtGui/QDialog>

#include <QPushButton>

#include <QLabel>

#include <QLineEdit>

#include <QTimer>

class QLoginDialog : public QDialog

{

    Q_OBJECT

private:

    QLabel UserLable;

    QLabel PwdLable;

    QLabel CaptLable;

    QPushButton CancelBtn;

    QPushButton LoginBtn;

    QLineEdit UserLineEdit;

    QLineEdit PwdLineEdit;

    QLineEdit CaptEdit;

    QString m_user;

    QString m_pwd;

    QString m_captcha;

    Qt::GlobalColor* m_color;

    QTimer m_timer;

private slots:

    void CancelBtn_Clicked();

    void LoginBtn_Clicked();

    void Timer_Timeout();

protected:

    void paintEvent(QPaintEvent* evt);

    QString getCaptcha();

    Qt::GlobalColor* getColor();

public:

    QLoginDialog(QWidget *parent = 0);

    QString GetUser();

    QString GetPwd();

    ~QLoginDialog();

};

#endif // DIALOG_H

#include <QDebug>

#include <QPainter>

#include <QTime>

#include <QMessageBox>

#include "QLoginDialog.h"

QLoginDialog::QLoginDialog(QWidget *parent) : QDialog(parent, Qt::WindowCloseButtonHint),

    UserLable(this), PwdLable(this), CaptLable(this), CancelBtn(this), LoginBtn(this),

    UserLineEdit(this), PwdLineEdit(this), CaptEdit(this)

{

    UserLable.setText("User Name");

    UserLable.move(20, 30);

    UserLable.resize(60, 25);

    UserLineEdit.move(85, 30);

    UserLineEdit.resize(180, 25);

    PwdLable.setText("Password");

    PwdLable.move(20, 65);

    PwdLable.resize(60, 25);

    PwdLineEdit.move(85, 65);

    PwdLineEdit.resize(180, 25);

    PwdLineEdit.setEchoMode(QLineEdit::Password);

    CaptLable.setText("Captcha");

    CaptLable.move(20, 100);

    CaptLable.resize(60, 25);

    CaptEdit.move(85, 100);

    CaptEdit.resize(85, 25);

    CancelBtn.setText("Cancel");

    CancelBtn.move(85, 140);

    CancelBtn.resize(85, 30);

    LoginBtn.setText("Login");

    LoginBtn.move(180, 140);

    LoginBtn.resize(85, 30);

    m_timer.setParent(this);

    setWindowTitle("Login");

    setFixedSize(290, 190);

    connect(&CancelBtn, SIGNAL(clicked()), this, SLOT(CancelBtn_Clicked()));

    connect(&LoginBtn, SIGNAL(clicked()), this, SLOT(LoginBtn_Clicked()));

    connect(&m_timer, SIGNAL(timeout()), this, SLOT(Timer_Timeout()));

    qsrand(QTime::currentTime().second() * 1000 + QTime::currentTime().msec());

    m_captcha = getCaptcha();

    m_color = getColor();

    m_timer.start(200);

}

void QLoginDialog::CancelBtn_Clicked()

{

    qDebug("CancelBtn_Clicked start");

    done(Rejected);

    qDebug("CancelBtn_Clicked end");

}

void QLoginDialog::LoginBtn_Clicked()

{

    qDebug("LoginBtn_Clicked start");

    m_user = UserLineEdit.text().trimmed();//trimmed():Delete space

    m_pwd = PwdLineEdit.text();

    QString captcha = CaptEdit.text().replace(" ", "");

    if(captcha.toLower() == m_captcha.toLower())

    {

        if(m_user.isEmpty())

        {

            QMessageBox::information(this, "Info", "User ID can not be empty");

            m_captcha = getCaptcha();

        }

        else if(m_pwd.isEmpty())

        {

             QMessageBox::information(this, "Info", "Password can not be empty");

             m_captcha = getCaptcha();

        }

        else

        {

            done(Accepted);

        }

    }

    else

    {

        QMessageBox::warning(this, "Warning", "Captcha is not macthed");

        m_captcha = getCaptcha();

//        CaptEdit.selectAll();

    }

    qDebug("LoginBtn_Clicked end");

}

void QLoginDialog::Timer_Timeout()

{

    m_color = getColor();

    update();

}

QString QLoginDialog::GetUser()

{

    return m_user;

}

QString QLoginDialog::GetPwd()

{

    return m_pwd;

}

void QLoginDialog::paintEvent(QPaintEvent *evt)

{

    QPainter painter(this);

    painter.fillRect(180, 100, 84, 24, Qt::white);

    painter.setFont(QFont("Comic Sans MS"));

    for(int i = 0; i < 100; i++)

    {

        painter.setPen(m_color[i % 4]);

        painter.drawPoint(180 + (qrand() % 84), 100 + (qrand() % 24));

    }

    for(int i = 0; i < 4; i++)

    {

        painter.setPen(m_color[i]);

        painter.drawText(180 + 20 * i, 100, 20, 24, Qt::AlignCenter, QString(m_captcha[i]));

    }

}

QString QLoginDialog::getCaptcha()

{

    QString ret = "";

    for(int i = 0; i < 4; i++)

    {

        int c = (qrand() % 2) ? 'a' : 'A';

        ret += static_cast<QChar>(c + qrand() % 26);

    }

    return ret;

}

Qt::GlobalColor* QLoginDialog::getColor()

{

    static Qt::GlobalColor colors[4];

    for(int i = 0; i < 4; i++)

    {

        colors[i] = static_cast<Qt::GlobalColor>((qrand() % 16) + 2);

    }

    return colors;

}

QLoginDialog::~QLoginDialog()

{

}