Qt 5.11 | Qt Widgets | Undo Framework | commands.cpp Example File

Qt 5.11.3 Reference Documentation

# commands.cpp Example File

tools/undo/commands.cpp

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      #include "commands.h"

      static const int setShapeRectCommandId = 1;
      static const int setShapeColorCommandId = 2;

      /******************************************************************************
      ** AddShapeCommand
      */

      AddShapeCommand::AddShapeCommand(Document *doc, const Shape &shape, QUndoCommand *parent)
          : QUndoCommand(parent)
      {
          m_doc = doc;
          m_shape = shape;
      }

      void AddShapeCommand::undo()
      {
          m_doc->deleteShape(m_shapeName);
      }

      void AddShapeCommand::redo()
      {
          // A shape only gets a name when it is inserted into a document
          m_shapeName = m_doc->addShape(m_shape);
          setText(QObject::tr("Add %1").arg(m_shapeName));
      }

      /******************************************************************************
      ** RemoveShapeCommand
      */

      RemoveShapeCommand::RemoveShapeCommand(Document *doc, const QString &shapeName,
                                              QUndoCommand *parent)
          : QUndoCommand(parent)
      {
          setText(QObject::tr("Remove %1").arg(shapeName));
          m_doc = doc;
          m_shape = doc->shape(shapeName);
          m_shapeName = shapeName;
      }

      void RemoveShapeCommand::undo()
      {
          m_shapeName = m_doc->addShape(m_shape);
      }

      void RemoveShapeCommand::redo()
      {
          m_doc->deleteShape(m_shapeName);
      }

      /******************************************************************************
      ** SetShapeColorCommand
      */

      SetShapeColorCommand::SetShapeColorCommand(Document *doc, const QString &shapeName,
                                                  const QColor &color, QUndoCommand *parent)
          : QUndoCommand(parent)
      {
          setText(QObject::tr("Set %1's color").arg(shapeName));

          m_doc = doc;
          m_shapeName = shapeName;
          m_oldColor = doc->shape(shapeName).color();
          m_newColor = color;
      }

      void SetShapeColorCommand::undo()
      {
          m_doc->setShapeColor(m_shapeName, m_oldColor);
      }

      void SetShapeColorCommand::redo()
      {
          m_doc->setShapeColor(m_shapeName, m_newColor);
      }

      bool SetShapeColorCommand::mergeWith(const QUndoCommand *command)
      {
          if (command->id() != setShapeColorCommandId)
              return false;

          const SetShapeColorCommand *other = static_cast<const SetShapeColorCommand*>(command);
          if (m_shapeName != other->m_shapeName)
              return false;

          m_newColor = other->m_newColor;
          return true;
      }

      int SetShapeColorCommand::id() const
      {
          return setShapeColorCommandId;
      }

      /******************************************************************************
      ** SetShapeRectCommand
      */

      SetShapeRectCommand::SetShapeRectCommand(Document *doc, const QString &shapeName,
                                                  const QRect &rect, QUndoCommand *parent)
          : QUndoCommand(parent)
      {
          setText(QObject::tr("Change %1's geometry").arg(shapeName));

          m_doc = doc;
          m_shapeName = shapeName;
          m_oldRect = doc->shape(shapeName).rect();
          m_newRect = rect;
      }

      void SetShapeRectCommand::undo()
      {
          m_doc->setShapeRect(m_shapeName, m_oldRect);
      }

      void SetShapeRectCommand::redo()
      {
          m_doc->setShapeRect(m_shapeName, m_newRect);
      }

      bool SetShapeRectCommand::mergeWith(const QUndoCommand *command)
      {
          if (command->id() != setShapeRectCommandId)
              return false;

          const SetShapeRectCommand *other = static_cast<const SetShapeRectCommand*>(command);
          if (m_shapeName != other->m_shapeName)
              return false;

          m_newRect = other->m_newRect;
          return true;
      }

      int SetShapeRectCommand::id() const
      {
          return setShapeRectCommandId;
      }