document.cpp Example File

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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();
  }