qgssymbolbutton.h

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/***************************************************************************
     qgssymbolbutton.h
     -----------------
    Date                 : July 2017
    Copyright            : (C) 2017 by Nyall Dawson
    Email                : nyall dot dawson at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   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 QGSSYMBOLBUTTON_H
#define QGSSYMBOLBUTTON_H
 
#include <memory>
 
#include "qgis.h"
#include "qgis_gui.h"
#include "qgis_sip.h"
 
#include <QPointer>
#include <QToolButton>
 
class QgsMapCanvas;
class QgsVectorLayer;
class QgsExpressionContextGenerator;
class QgsPanelWidget;
class QgsMessageBar;
class QMimeData;
class QgsSymbol;
class QgsSymbolSelectorWidget;

class GUI_EXPORT QgsSymbolButton : public QToolButton
{
    Q_OBJECT
 
    Q_PROPERTY( QString dialogTitle READ dialogTitle WRITE setDialogTitle )
 
  public:

    QgsSymbolButton( QWidget *parent SIP_TRANSFERTHIS = nullptr, const QString &dialogTitle = QString() );
    ~QgsSymbolButton() override;
 
    QSize minimumSizeHint() const override;
    QSize sizeHint() const override;

    void setSymbolType( Qgis::SymbolType type );

    Qgis::SymbolType symbolType() const { return mType; }

    void setDialogTitle( const QString &title );

    QString dialogTitle() const;

    QgsSymbol *symbol();

    template<class SymbolType> SymbolType *clonedSymbol() SIP_SKIP
    {
      QgsSymbol *tmpSymbol = mSymbol.get();
      SymbolType *symbolCastToType = dynamic_cast<SymbolType *>( tmpSymbol );
 
      if ( symbolCastToType )
      {
        return symbolCastToType->clone();
      }
      else
      {
        //could not cast
        return nullptr;
      }
    }

    QgsMapCanvas *mapCanvas() const;

    void setMapCanvas( QgsMapCanvas *canvas );

    void setMessageBar( QgsMessageBar *bar );

    QgsMessageBar *messageBar() const;

    QgsVectorLayer *layer() const;

    void setLayer( QgsVectorLayer *layer );

    void registerExpressionContextGenerator( QgsExpressionContextGenerator *generator );

    void setDefaultSymbol( QgsSymbol *symbol SIP_TRANSFER );

    const QgsSymbol *defaultSymbol() const;

    bool showNull() const;

    bool isNull() const;

    bool fixedSizeConstraints() const;
 
  public slots:

    void setSymbol( QgsSymbol *symbol SIP_TRANSFER );

    void setColor( const QColor &color );

    void copySymbol();

    void pasteSymbol();

    void copyColor();

    void pasteColor();

    void setShowNull( bool showNull );

    void setToNull();

    void setToDefaultSymbol();

    void setFixedSizeConstraints( bool fixedSizeConstraints );
 
  signals:

    void changed();
 
  protected:
    void changeEvent( QEvent *e ) override;
    void showEvent( QShowEvent *e ) override;
    void resizeEvent( QResizeEvent *event ) override;
 
    // Reimplemented to detect right mouse button clicks on the color button and allow dragging colors
    void mousePressEvent( QMouseEvent *e ) override;
    // Reimplemented to allow dragging colors/symbols from button
    void mouseMoveEvent( QMouseEvent *e ) override;
    void mouseReleaseEvent( QMouseEvent *e ) override;
    void keyPressEvent( QKeyEvent *e ) override;
    // Reimplemented to accept dragged colors
    void dragEnterEvent( QDragEnterEvent *e ) override;
 
    // Reimplemented to reset button appearance after drag leave
    void dragLeaveEvent( QDragLeaveEvent *e ) override;
 
    // Reimplemented to accept dropped colors
    void dropEvent( QDropEvent *e ) override;
 
    void wheelEvent( QWheelEvent *event ) override;
 
  private slots:
 
    void showSettingsDialog();
    void updateSymbolFromWidget( QgsSymbolSelectorWidget *widget );

    void prepareMenu();
 
    void addRecentColor( const QColor &color );

    void activatePicker();
 
  private:
    QSize mSizeHint;
 
    QString mDialogTitle;
 
    Qgis::SymbolType mType = Qgis::SymbolType::Fill;
 
    QgsMapCanvas *mMapCanvas = nullptr;
    QgsMessageBar *mMessageBar = nullptr;
 
    QPoint mDragStartPosition;
 
    QMenu *mMenu = nullptr;
 
    QPointer<QgsVectorLayer> mLayer;
 
    QSize mIconSize;
 
    std::unique_ptr<QgsSymbol> mSymbol;
 
    QgsExpressionContextGenerator *mExpressionContextGenerator = nullptr;
 
    bool mPickingColor = false;
 
    bool mShowNull = false;
 
    bool mFixedSizeConstraints = true;
 
    std::unique_ptr<QgsSymbol> mDefaultSymbol;

    void updatePreview( const QColor &color = QColor(), QgsSymbol *tempSymbol = nullptr );

    bool colorFromMimeData( const QMimeData *mimeData, QColor &resultColor, bool &hasAlpha );

    QPixmap createColorIcon( const QColor &color ) const;

    void stopPicking( QPoint eventPos, bool samplingColor = true );
 
    void showColorDialog();
 
    void updateSizeHint();
};
 
#endif // QGSSYMBOLBUTTON_H