document.cpp Example File

tools/undo/document.cpp
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#include <qevent.h>
#include <QPainter>
#include <QTextStream>
#include <QUndoStack>
#include "document.h"
#include "commands.h"

static const int resizeHandleWidth = 6;

/******************************************************************************
** Shape
*/

const QSize Shape::minSize(80, 50);

Shape::Shape(Type type, const QColor &color, const QRect &rect)
    : m_type(type), m_rect(rect), m_color(color)
{
}

Shape::Type Shape::type() const
{
    return m_type;
}

QRect Shape::rect() const
{
    return m_rect;
}

QColor Shape::color() const
{
    return m_color;
}

QString Shape::name() const
{
    return m_name;
}

QRect Shape::resizeHandle() const
{
    QPoint br = m_rect.bottomRight();
    return QRect(br - QPoint(resizeHandleWidth, resizeHandleWidth), br);
}

QString Shape::typeToString(Type type)
{
    QString result;

    switch (type) {
        case Rectangle:
            result = QLatin1String("Rectangle");
            break;
        case Circle:
            result = QLatin1String("Circle");
            break;
        case Triangle:
            result = QLatin1String("Triangle");
            break;
    }

    return result;
}

Shape::Type Shape::stringToType(const QString &s, bool *ok)
{
    if (ok != 0)
        *ok = true;

    if (s == QLatin1String("Rectangle"))
        return Rectangle;
    if (s == QLatin1String("Circle"))
        return Circle;
    if (s == QLatin1String("Triangle"))
        return Triangle;

    if (ok != 0)
        *ok = false;
    return Rectangle;
}

/******************************************************************************
** Document
*/

Document::Document(QWidget *parent)
    : QWidget(parent), m_currentIndex(-1), m_mousePressIndex(-1), m_resizeHandlePressed(false)
{
    m_undoStack = new QUndoStack(this);

    setAutoFillBackground(true);
    setBackgroundRole(QPalette::Base);

    QPalette pal = palette();
    pal.setBrush(QPalette::Base, QPixmap(":/icons/background.png"));
    pal.setColor(QPalette::HighlightedText, Qt::red);
    setPalette(pal);
}

QString Document::addShape(const Shape &shape)
{
    QString name = Shape::typeToString(shape.type());
    name = uniqueName(name);

    m_shapeList.append(shape);
    m_shapeList[m_shapeList.count() - 1].m_name = name;
    setCurrentShape(m_shapeList.count() - 1);

    return name;
}

void Document::deleteShape(const QString &shapeName)
{
    int index = indexOf(shapeName);
    if (index == -1)
        return;

    update(m_shapeList.at(index).rect());

    m_shapeList.removeAt(index);

    if (index <= m_currentIndex) {
        m_currentIndex = -1;
        if (index == m_shapeList.count())
            --index;
        setCurrentShape(index);
    }
}

Shape Document::shape(const QString &shapeName) const
{
    int index = indexOf(shapeName);
    if (index == -1)
        return Shape();
    return m_shapeList.at(index);
}

void Document::setShapeRect(const QString &shapeName, const QRect &rect)
{
    int index = indexOf(shapeName);
    if (index == -1)
        return;

    Shape &shape = m_shapeList[index];

    update(shape.rect());
    update(rect);

    shape.m_rect = rect;
}

void Document::setShapeColor(const QString &shapeName, const QColor &color)
{

    int index = indexOf(shapeName);
    if (index == -1)
        return;

    Shape &shape = m_shapeList[index];
    shape.m_color = color;

    update(shape.rect());
}

QUndoStack *Document::undoStack() const
{
    return m_undoStack;
}

bool Document::load(QTextStream &stream)
{
    m_shapeList.clear();

    while (!stream.atEnd()) {
        QString shapeType, shapeName, colorName;
        int left, top, width, height;
        stream >> shapeType >> shapeName >> colorName >> left >> top >> width >> height;
        if (stream.status() != QTextStream::Ok)
            return false;
        bool ok;
        Shape::Type type = Shape::stringToType(shapeType, &ok);
        if (!ok)
            return false;
        QColor color(colorName);
        if (!color.isValid())
            return false;

        Shape shape(type);
        shape.m_name = shapeName;
        shape.m_color = color;
        shape.m_rect = QRect(left, top, width, height);

        m_shapeList.append(shape);
    }

    m_currentIndex = m_shapeList.isEmpty() ? -1 : 0;

    return true;
}

void Document::save(QTextStream &stream)
{
    for (int i = 0; i < m_shapeList.count(); ++i) {
        const Shape &shape = m_shapeList.at(i);
        QRect r = shape.rect();
        stream << Shape::typeToString(shape.type()) << QLatin1Char(' ')
                << shape.name() << QLatin1Char(' ')
                << shape.color().name() << QLatin1Char(' ')
                << r.left() << QLatin1Char(' ')
                << r.top() << QLatin1Char(' ')
                << r.width() << QLatin1Char(' ')
                << r.height();
        if (i != m_shapeList.count() - 1)
            stream << QLatin1Char('\n');
    }
    m_undoStack->setClean();
}

QString Document::fileName() const
{
    return m_fileName;
}

void Document::setFileName(const QString &fileName)
{
    m_fileName = fileName;
}

int Document::indexAt(const QPoint &pos) const
{
    for (int i = m_shapeList.count() - 1; i >= 0; --i) {
        if (m_shapeList.at(i).rect().contains(pos))
            return i;
    }
    return -1;
}

void Document::mousePressEvent(QMouseEvent *event)
{
    event->accept();
    int index = indexAt(event->pos());;
    if (index != -1) {
        setCurrentShape(index);

        const Shape &shape = m_shapeList.at(index);
        m_resizeHandlePressed = shape.resizeHandle().contains(event->pos());

        if (m_resizeHandlePressed)
            m_mousePressOffset = shape.rect().bottomRight() - event->pos();
        else
            m_mousePressOffset = event->pos() - shape.rect().topLeft();
    }
    m_mousePressIndex = index;
}

void Document::mouseReleaseEvent(QMouseEvent *event)
{
    event->accept();
    m_mousePressIndex = -1;
}

void Document::mouseMoveEvent(QMouseEvent *event)
{
    event->accept();

    if (m_mousePressIndex == -1)
        return;

    const Shape &shape = m_shapeList.at(m_mousePressIndex);

    QRect rect;
    if (m_resizeHandlePressed) {
        rect = QRect(shape.rect().topLeft(), event->pos() + m_mousePressOffset);
    } else {
        rect = shape.rect();
        rect.moveTopLeft(event->pos() - m_mousePressOffset);
    }

    QSize size = rect.size().expandedTo(Shape::minSize);
    rect.setSize(size);

    m_undoStack->push(new SetShapeRectCommand(this, shape.name(), rect));
}

static QGradient gradient(const QColor &color, const QRect &rect)
{
    QColor c = color;
    c.setAlpha(160);
    QLinearGradient result(rect.topLeft(), rect.bottomRight());
    result.setColorAt(0, c.dark(150));
    result.setColorAt(0.5, c.light(200));
    result.setColorAt(1, c.dark(150));
    return result;
}

static QPolygon triangle(const QRect &rect)
{
    QPolygon result(3);
    result.setPoint(0, rect.center().x(), rect.top());
    result.setPoint(1, rect.right(), rect.bottom());
    result.setPoint(2, rect.left(), rect.bottom());
    return result;
}

void Document::paintEvent(QPaintEvent *event)
{
    QRegion paintRegion = event->region();
    QPainter painter(this);
    QPalette pal = palette();

    for (int i = 0; i < m_shapeList.count(); ++i) {
        const Shape &shape = m_shapeList.at(i);

        if (!paintRegion.contains(shape.rect()))
            continue;

        QPen pen = pal.text().color();
        pen.setWidth(i == m_currentIndex ? 2 : 1);
        painter.setPen(pen);
        painter.setBrush(gradient(shape.color(), shape.rect()));

        QRect rect = shape.rect();
        rect.adjust(1, 1, -resizeHandleWidth/2, -resizeHandleWidth/2);

        // paint the shape
        switch (shape.type()) {
            case Shape::Rectangle:
                painter.drawRect(rect);
                break;
            case Shape::Circle:
                painter.setRenderHint(QPainter::Antialiasing);
                painter.drawEllipse(rect);
                painter.setRenderHint(QPainter::Antialiasing, false);
                break;
            case Shape::Triangle:
                painter.setRenderHint(QPainter::Antialiasing);
                painter.drawPolygon(triangle(rect));
                painter.setRenderHint(QPainter::Antialiasing, false);
                break;
        }

        // paint the resize handle
        painter.setPen(pal.text().color());
        painter.setBrush(Qt::white);
        painter.drawRect(shape.resizeHandle().adjusted(0, 0, -1, -1));

        // paint the shape name
        painter.setBrush(pal.text());
        if (shape.type() == Shape::Triangle)
            rect.adjust(0, rect.height()/2, 0, 0);
        painter.drawText(rect, Qt::AlignCenter, shape.name());
    }
}

void Document::setCurrentShape(int index)
{
    QString currentName;

    if (m_currentIndex != -1)
        update(m_shapeList.at(m_currentIndex).rect());

    m_currentIndex = index;

    if (m_currentIndex != -1) {
        const Shape &current = m_shapeList.at(m_currentIndex);
        update(current.rect());
        currentName = current.name();
    }

    emit currentShapeChanged(currentName);
}

int Document::indexOf(const QString &shapeName) const
{
    for (int i = 0; i < m_shapeList.count(); ++i) {
        if (m_shapeList.at(i).name() == shapeName)
            return i;
    }
    return -1;
}

QString Document::uniqueName(const QString &name) const
{
    QString unique;

    for (int i = 0; ; ++i) {
        unique = name;
        if (i > 0)
            unique += QString::number(i);
        if (indexOf(unique) == -1)
            break;
    }

    return unique;
}

QString Document::currentShapeName() const
{
    if (m_currentIndex == -1)
        return QString();
    return m_shapeList.at(m_currentIndex).name();
}

© 2016 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.