qgsgraphicsviewmousehandles.h

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/***************************************************************************
                             qgsgraphicsviewmousehandles.h
                             -----------------------
    begin                : March 2020
    copyright            : (C) 2020 by Nyall Dawson
    email                : [email protected]
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef QGSGRAPHICSVIEWMOUSEHANDLES_H
#define QGSGRAPHICSVIEWMOUSEHANDLES_H
 
// We don't want to expose this in the public API
#define SIP_NO_FILE
 
#include <QGraphicsRectItem>
#include <QObject>
#include <QPointer>
#include <memory>
 
#include "qgis_gui.h"
 
class QGraphicsView;
class QInputEvent;
 
 
class GUI_EXPORT QgsGraphicsViewMouseHandles: public QObject, public QGraphicsRectItem
{
    Q_OBJECT
  public:
 
    enum MouseAction
    {
      MoveItem,
      ResizeUp,
      ResizeDown,
      ResizeLeft,
      ResizeRight,
      ResizeLeftUp,
      ResizeRightUp,
      ResizeLeftDown,
      ResizeRightDown,
      SelectItem,
      NoAction
    };
 
    enum ItemPositionMode
    {
      UpperLeft,
      UpperMiddle,
      UpperRight,
      MiddleLeft,
      Middle,
      MiddleRight,
      LowerLeft,
      LowerMiddle,
      LowerRight
    };
 
    enum SnapGuideMode
    {
      Item,
      Point
    };
 
    QgsGraphicsViewMouseHandles( QGraphicsView *view );
 
    QgsGraphicsViewMouseHandles::MouseAction mouseActionForScenePos( QPointF sceneCoordPos );
 
    bool isDragging() const { return mIsDragging; }
 
    bool isResizing() const { return mIsResizing; }
 
    bool shouldBlockEvent( QInputEvent *event ) const;
 
  public slots:
 
    void selectedItemSizeChanged();
 
    void selectedItemRotationChanged();
 
  protected:
 
    void paintInternal( QPainter *painter, bool showHandles, bool showStaticBoundingBoxes,
                        bool showTemporaryBoundingBoxes, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr );
 
    virtual void setViewportCursor( Qt::CursorShape cursor ) = 0;
 
    virtual QList<QGraphicsItem *> sceneItemsAtPoint( QPointF scenePoint ) = 0;
    virtual QList<QGraphicsItem *> selectedSceneItems( bool includeLockedItems = true ) const = 0;
    virtual bool itemIsLocked( QGraphicsItem *item ) { Q_UNUSED( item ); return false; }
    virtual bool itemIsGroupMember( QGraphicsItem *item ) { Q_UNUSED( item ); return false; }
    virtual QRectF itemRect( QGraphicsItem *item ) const = 0;
    virtual QRectF storedItemRect( QGraphicsItem *item ) const;
    virtual void moveItem( QGraphicsItem *item, double deltaX, double deltaY ) = 0;
    virtual void previewItemMove( QGraphicsItem *item, double deltaX, double deltaY );
    virtual void setItemRect( QGraphicsItem *item, QRectF rect ) = 0;
 
    virtual QRectF previewSetItemRect( QGraphicsItem *item, QRectF rect );
 
    virtual void startMacroCommand( const QString &text );
    virtual void endMacroCommand();
    virtual void createItemCommand( QGraphicsItem *item );
    virtual void endItemCommand( QGraphicsItem *item );
    virtual void showStatusMessage( const QString &message ) { Q_UNUSED( message ) }
    virtual void hideAlignItems() {}
    virtual QPointF snapPoint( QPointF originalPoint, SnapGuideMode mode, bool snapHorizontal = true, bool snapVertical = true );
 
    virtual void expandItemList( const QList< QGraphicsItem * > &items, QList< QGraphicsItem * > &collected ) const;
 
    void mouseDoubleClickEvent( QGraphicsSceneMouseEvent *event ) override;
    void hoverMoveEvent( QGraphicsSceneHoverEvent *event ) override;
    void hoverLeaveEvent( QGraphicsSceneHoverEvent *event ) override;
    void mousePressEvent( QGraphicsSceneMouseEvent *event ) override;
    void mouseMoveEvent( QGraphicsSceneMouseEvent *event ) override;
    void mouseReleaseEvent( QGraphicsSceneMouseEvent *event ) override;
 
    //resets the layout designer status bar to the default message
    void resetStatusBar();
 
    bool selectionRotation( double &rotation ) const;
 
    void updateHandles();
 
    void dragMouseMove( QPointF currentPosition, bool lockMovement, bool preventSnap );
 
    void resizeMouseMove( QPointF currentPosition, bool lockAspect, bool fromCenter );
 
    void setHandleSize( double size );
 
    MouseAction mouseActionForPosition( QPointF itemCoordPos );
 
    QSizeF calcCursorEdgeOffset( QPointF cursorPos );
 
    QRectF selectionBounds() const;
 
    static void relativeResizeRect( QRectF &rectToResize, const QRectF &boundsBefore, const QRectF &boundsAfter );
 
    static double relativePosition( double position, double beforeMin, double beforeMax, double afterMin, double afterMax );
 
  private:
 
    QGraphicsView *mView = nullptr;
 
    double mHandleSize = 10;
 
    QSizeF mCursorOffset;
    double mResizeMoveX = 0;
    double mResizeMoveY = 0;
 
    double mBeginHandleWidth = 0;
    double mBeginHandleHeight = 0;
 
    QRectF mResizeRect;
 
    QPointF mMouseMoveStartPos;
 
    QPointF mLastMouseEventPos;
 
    MouseAction mCurrentMouseMoveAction = NoAction;
 
    bool mIsDragging = false;
    bool mIsResizing = false;
 
    QPointF mBeginMouseEventPos;
 
    QPointF mBeginHandlePos;
 
    void drawHandles( QPainter *painter, double rectHandlerSize );
 
    void drawSelectedItemBounds( QPainter *painter );
 
    double rectHandlerBorderTolerance();
 
    Qt::CursorShape cursorForPosition( QPointF itemCoordPos );
 
 
 
};
 
 
#endif // QGSLAYOUTMOUSEHANDLES_H