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MML Browser Example

This example demonstrates how to use QtMmlWidget. It allows the user to browse MML files, displaying their content. If a directory contains an MML file and a PNG image with the same name, the image is assumed to be a reference of how the MML file should be rendered, and is also displayed. The complete sources may be found in the example directory. The most rellevant files are shown below.

#ifndef MAIN_WINDOW_H
#define MAIN_WINDOW_H

#include <qmainwindow.h>

class QtMmlWidget;
class QLabel;
class FileBrowser;

class MainWindow : public QMainWindow
{
    Q_OBJECT

    public:
        MainWindow(QWidget *parent = 0, const char *name = 0);

    public slots:
        void zoomIn();
        void zoomOut();
        void toggleDrawFrames();
        void openFile(const QString &mml_file_name);

    private:
        QtMmlWidget *m_mml_widget;
        QLabel *m_compare_image;
        FileBrowser *m_file_browser;
};

void showWarning(const QString &msg);

#endif

#include <stdlib.h>
#include <errno.h>

#include <qfile.h>
#include <qtextstream.h>
#include <qlabel.h>
#include <qlayout.h>
#include <qpixmap.h>
#include <qtoolbutton.h>
#include <qtoolbar.h>
#include <qsplitter.h>
#include <qmessagebox.h>

#include <qtmmlwidget.h>

#include "mainwindow.h"
#include "filebrowser.h"

void showWarning(const QString &msg)
{
    QMessageBox::warning(0, "Warning", msg,
                            QMessageBox::Ok,
                            QMessageBox::NoButton,
                            QMessageBox::NoButton);
}

MainWindow::MainWindow(QWidget *parent, const char *name)
    : QMainWindow(parent, name)
{
    setCaption("MathML Browser");

    QSplitter *splitter = new QSplitter(this);
    splitter->setChildrenCollapsible(false);

    m_file_browser = new FileBrowser("*.mml", splitter);

    QWidget *formula_widget = new QWidget(splitter);
    QVBoxLayout *layout = new QVBoxLayout(formula_widget);
    layout->setAutoAdd(true);
    layout->setSpacing(3);
    m_mml_widget = new QtMmlWidget(formula_widget);
    m_mml_widget->setPaletteBackgroundColor(Qt::white);
    m_compare_image = new QLabel(formula_widget);
    m_compare_image->setAlignment(Qt::AlignCenter);
    m_compare_image->setPaletteBackgroundColor(Qt::white);

    setCentralWidget(splitter);

    QToolBar *tool_bar = new QToolBar(this);
    new QToolButton(QPixmap::fromMimeSource("zoom_in.png"), "Zoom in",
                    "Zoom in", this, SLOT(zoomIn()), tool_bar);
    new QToolButton(QPixmap::fromMimeSource("zoom_out.png"), "Zoom out",
                    "Zoom out", this, SLOT(zoomOut()), tool_bar);
    new QToolButton(QPixmap::fromMimeSource("frames.png"), "Toggle frames",
                    "Toggle frames", this, SLOT(toggleDrawFrames()), tool_bar);

    connect(m_file_browser, SIGNAL(fileSelected(const QString &)), this, SLOT(openFile(const QString &)));
}

void MainWindow::zoomIn()
{
    m_mml_widget->setBaseFontPointSize(m_mml_widget->baseFontPointSize() + 2);
}

void MainWindow::zoomOut()
{
    m_mml_widget->setBaseFontPointSize(m_mml_widget->baseFontPointSize() - 2);
}

void MainWindow::toggleDrawFrames()
{
    m_mml_widget->setDrawFrames(!m_mml_widget->drawFrames());
}

void MainWindow::openFile(const QString &mml_file_name)
{
    m_mml_widget->clear();
    m_compare_image->clear();

    QFile file(mml_file_name);
    if (!file.open(IO_ReadOnly)) {
        showWarning("File error: Could not open \""
                        + mml_file_name
                        + "\": " + file.errorString());
        return;
    }

    QTextStream stream(&file);
    stream.setEncoding(QTextStream::UnicodeUTF8);
    QString text = stream.read();
    file.close();

    QString error_msg;
    int error_line, error_column;
    bool result = m_mml_widget->setContent(text, &error_msg, &error_line,
                                                &error_column);

    if (!result) {
        showWarning("Parse error: line " + QString::number(error_line)
                        + ", col " + QString::number(error_column)
                        + ": " + error_msg);
        return;
    }

    QPixmap pm;
    int idx = mml_file_name.findRev('.');
    if (idx != -1) {
        QString image_file_name = mml_file_name.mid(0, idx + 1) + "png";
        if (pm.load(image_file_name))
            m_compare_image->setPixmap(pm);
    }
}