chatroom.cpp

一个用QT写的局域网聊天程序.不需要服务器

#include "chatroom.h"

ChatRoom::ChatRoom(QWidget *parent)
    : QDialog(parent)
{
	Layout();

    connect(&lineEdit, SIGNAL(returnPressed()), this, SLOT(returnPressed()));
    connect(&client, SIGNAL(newMessage(const QString &, const QString &)),
            this, SLOT(appendMessage(const QString &, const QString &)));
    connect(&client, SIGNAL(newParticipant(const QString &)),
            this, SLOT(newParticipant(const QString &)));
    connect(&client, SIGNAL(participantLeft(const QString &)),
            this, SLOT(participantLeft(const QString &)));

    myNickName = client.nickName();
    newParticipant(myNickName);
    tableFormat.setBorder(0);
    QTimer::singleShot(10 * 1000, this, SLOT(showInformation()));
}

ChatRoom::~ChatRoom()
{

}

void ChatRoom::Layout()
{
	vboxLayout = new QVBoxLayout;
    hboxLayout = new QHBoxLayout;
    hboxLayout1 = new QHBoxLayout;

    listWidget.setMaximumSize(QSize(180, 16777215));

    hboxLayout->addWidget(&textEdit);
    hboxLayout->addWidget(&listWidget);

    vboxLayout->addLayout(hboxLayout);

    label.setText(tr("Message:"));
    hboxLayout1->addWidget(&label);
    hboxLayout1->addWidget(&lineEdit);

    vboxLayout->addLayout(hboxLayout1);

    lineEdit.setFocusPolicy(Qt::StrongFocus);
    textEdit.setFocusPolicy(Qt::NoFocus);
    textEdit.setReadOnly(true);
    listWidget.setFocusPolicy(Qt::NoFocus);

    setLayout(vboxLayout);
}

void ChatRoom::createActions()
{

}

void ChatRoom::appendMessage(const QString &from, const QString &message)
{
    if (from.isEmpty() || message.isEmpty())
        return;

    QTextCursor cursor(textEdit.textCursor());
    cursor.movePosition(QTextCursor::End);
    QTextTable *table = cursor.insertTable(1, 2, tableFormat);
    table->cellAt(0, 0).firstCursorPosition().insertText("<" + from + "> ");
    table->cellAt(0, 1).firstCursorPosition().insertText(message);
    QScrollBar *bar = textEdit.verticalScrollBar();
    bar->setValue(bar->maximum());
}

void ChatRoom::returnPressed()
{
    QString text = lineEdit.text();
    if (text.isEmpty())
        return;

    if (text.startsWith(QChar('/'))) {
        QColor color = textEdit.textColor();
        textEdit.setTextColor(Qt::red);
        textEdit.append(tr("! Unknown command: %1")
                         .arg(text.left(text.indexOf(' '))));
        textEdit.setTextColor(color);
    } else {
        client.sendMessage(text);
        appendMessage(myNickName, text);
    }

    lineEdit.clear();
}

void ChatRoom::newParticipant(const QString &nick)
{
    if (nick.isEmpty())
        return;

    QColor color = textEdit.textColor();
    textEdit.setTextColor(Qt::gray);
    textEdit.append(tr("* %1 has joined").arg(nick));
    textEdit.setTextColor(color);
    listWidget.addItem(nick);
}

void ChatRoom::participantLeft(const QString &nick)
{
    if (nick.isEmpty())
        return;

    QList<QListWidgetItem *> items = listWidget.findItems(nick, Qt::MatchExactly);
    if (items.isEmpty())
        return;

    delete items.at(0);
    QColor color = textEdit.textColor();
    textEdit.setTextColor(Qt::gray);
    textEdit.append(tr("* %1 has left").arg(nick));
    textEdit.setTextColor(color);
}

void ChatRoom::showInformation()
{
    if (listWidget.count() == 1) {
        QMessageBox::information(this, tr("Chat"),
                                 tr("Launch several instances of this "
                                    "program on your local network and "
                                    "start chatting!"));
    }
}