layer.h

/*
*
* This file is part of QMapControl,
* an open-source cross-platform map widget
*
* Copyright (C) 2007 - 2008 Kai Winter
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with QMapControl. If not, see <http://www.gnu.org/licenses/>.
*
* Contact e-mail: kaiwinter@gmx.de
* Program URL   : http://qmapcontrol.sourceforge.net/
*
*/

#ifndef LAYER_H
#define LAYER_H

#include <QObject>
#include <QDebug>
#include <QPainter>
#include <QMouseEvent>

#include "mapadapter.h"
#include "layermanager.h"
#include "geometry.h"
#include "point.h"

#include "wmsmapadapter.h"
#include "tilemapadapter.h"

namespace qmapcontrol
{
    //! Layer class
    /*!
     * There are two different layer types:
     *  - MapLayer: Displays Maps, but also Geometries. The configuration for displaying maps have to be done in the MapAdapter
     *  - GeometryLayer: Only displays Geometry objects.
     *
     * MapLayers also can display Geometry objects. The difference to the GeometryLayer is the repainting. Objects that are
     * added to a MapLayer are "baken" on the map. This means, when you change it´s position for example the changes are
     * not visible until a new offscreen image has been drawn. If you have "static" Geometries which won´t change their
     * position this is fine. But if you want to change the objects position or pen you should use a GeometryLayer. Those
     * are repainted immediately on changes.
     * You can either use this class and give a layertype on creation or you can use the classes MapLayer and GeometryLayer.
     *
     *	@author Kai Winter <kaiwinter@gmx.de>
     */
    class Layer : public QObject
    {
        Q_OBJECT

    public:
        friend class LayerManager;


        //! sets the type of a layer, see Layer class doc for further information
        enum LayerType
        {
            MapLayer, /*!< uses the MapAdapter to display maps, only gets refreshed when a new offscreen image is needed */
            GeometryLayer /*!< gets refreshed everytime when a geometry changes */
        };

        //! Layer constructor
        /*!
         * This is used to construct a layer.
         *
         * @param layername The name of the Layer
         * @param mapadapter The MapAdapter which does coordinate translation and Query-String-Forming
         * @param layertype The above explained LayerType
         * @param takeevents Should the Layer receive MouseEvents? This is set to true by default. Setting it to false could
         * be something like a "speed up hint"
         */
        Layer(QString layername, MapAdapter* mapadapter, enum LayerType layertype, bool takeevents=true);
        virtual ~Layer();

        //! returns the layer's name
        /*!
         * @return the name of this layer
         */
        QString	layername() const;

        //! returns the layer´s MapAdapter
        /*!
         * This method returns the MapAdapter of this Layer, which can be useful
         * to do coordinate transformations.
         * @return the MapAdapter which us used by this Layer
         */
        const MapAdapter* mapadapter() const;

        //! adds a Geometry object to this Layer
        /*!
         * Please notice the different LayerTypes (MapLayer and GeometryLayer) and the differences
         * @param  geometry the new Geometry
         */
        void addGeometry(Geometry* geometry);

        //! removes the Geometry object from this Layer
        /*!
         * This method removes a Geometry object from this Layer.
         */
        void removeGeometry(Geometry* geometry);

        //! removes all Geometry objects from this Layer
        /*!
         * This method removes all Geometry objects from this Layer.
         */
        void clearGeometries();

        //! return true if the layer is visible
        /*!
         * @return if the layer is visible
         */
        bool isVisible() const;

        //! returns the LayerType of the Layer
        /*!
         * There are two LayerTypes: MapLayer and GeometryLayer
         * @return the LayerType of this Layer
         */
        Layer::LayerType layertype() const;

        void setMapAdapter(MapAdapter* mapadapter);

        Layer& operator=(const Layer& rhs);
        Layer(const Layer& old);

    private:
        void moveWidgets(const QPoint mapmiddle_px) const;
        void drawYourImage(QPainter* painter, const QPoint mapmiddle_px) const;
        void drawYourGeometries(QPainter* painter, const QPoint mapmiddle_px, QRect viewport) const;
        void setSize(QSize size);
        QRect offscreenViewport() const;
        bool takesMouseEvents() const;
        void mouseEvent(const QMouseEvent*, const QPoint mapmiddle_px);
        void zoomIn() const;
        void zoomOut() const;
        void _draw(QPainter* painter, const QPoint mapmiddle_px) const;

        bool visible;
        QString mylayername;
        LayerType mylayertype;
        QSize size;
        QPoint screenmiddle;

        QList<Geometry*> geometries;
        MapAdapter* mapAdapter;
        bool takeevents;
        mutable QRect myoffscreenViewport;

        Geometry* geometrySelected;
        bool draggingGeometry;

    signals:
        //! This signal is emitted when a Geometry is clicked
        /*!
         * A Geometry is clickable, if the containing layer is clickable.
         * The layer emits a signal for every clicked geometry
         * @param  geometry The clicked Geometry
         * @param  point The coordinate (in widget coordinates) of the click
         */
        void geometryClicked(Geometry* geometry, QPoint point);

        //! This signal is emitted while a Geometry is being dragged
        /*!
         * A Geometry is clickable, if the containing layer is clickable.
         * The layer emits a signal as it is dragged
         * @param  geometry The selected Geometry
         * @param  coordinate The new coordinate (in world coordinates)
         */
        void geometryDragged(Geometry* geometrySelected, QPointF coordinate);


        //! This signal is emitted when a User releases the button after selecting a Geometry
        /*!
         * A Geometry is clickable, if the containing layer is clickable.
         * The layer emits a signal when it is released
         * @param  geometry The selected Geometry
         * @param  coordinate The new coordinate (in world coordinates)
         */
        void geometryEndDrag(Geometry* geometrySelected, QPointF coordinate);

        void updateRequest(QRectF rect);
        void updateRequest();

    public slots:
        //! if visible is true, the layer is made visible
        /*!
         * @param  visible if the layer should be visible
         */
        void setVisible(bool visible);

    };
}
#endif