/* This file is part of the KDE libraries
    Copyright (C) 2004 Antonio Larrosa <larrosa@kde.org

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#ifndef KPIXMAPREGIONSELECTORWIDGET_H
#define KPIXMAPREGIONSELECTORWIDGET_H

#include <kwidgetsaddons_export.h>

#include <QPixmap>
#include <QWidget>

class QMenu;

/**
 * KPixmapRegionSelectorWidget is a widget that shows a picture and provides the
 * user with a friendly way to select a rectangular subregion of the pixmap.
 *
 * NOTE: There are two copies of this .h and the .cpp file, with subtle differences.
 * One copy is in kdelibs/kdeui, and the other copy is in kdepim/libkdepim
 * This is because kdepim has to remain backwards compatible.  Any changes
 * to either file should be made to the other.
 *
 * \image html kpixmapregionselectorwidget.png "KDE Pixmap Region Selector"
 *
 * @author Antonio Larrosa <larrosa@kde.org>
 */
class KWIDGETSADDONS_EXPORT KPixmapRegionSelectorWidget : public QWidget
{
    Q_OBJECT
    Q_PROPERTY(QPixmap pixmap READ pixmap WRITE setPixmap)

public:
    /**
     * This enum provides a rotation direction.
     * @see KPixmapRegionSelectorWidget::rotate()
     */
    enum RotateDirection { Rotate90, //!< Rotate 90 degrees to the right.
                           Rotate180, //!< Rotate 180 degrees.
                           Rotate270  //!< Rotate 90 degrees to the left.
                         };

    /**
     * Constructor for a KPixmapRegionSelectorWidget.
     */
    explicit KPixmapRegionSelectorWidget(QWidget *parent = 0);

    /**
     * Destructor for a KPixmapRegionSelectorWidget
     */
    ~KPixmapRegionSelectorWidget();

    /**
     * Sets the pixmap which will be shown for the user to select a region from.
     * @param pixmap The pixmap.  Must be non-null.
     *
     */
    void setPixmap(const QPixmap &pixmap);

    /**
     * @return the original whole pixmap that we're using in this widget as the
     * pixmap the user is selecting a region from.
     */
    QPixmap pixmap() const;

    /**
     * Sets the selected region to be @p rect (in zoomed pixmap coordinates)
     */
    void setSelectedRegion(const QRect &rect);

    /**
     * Returns the selected region ( in zoomed pixmap coordinates )
     */
    QRect selectedRegion() const;

    /**
     * Returns the selected region ( in unzoomed, original pixmap coordinates )
     */
    QRect unzoomedSelectedRegion() const;

    /**
     * Resets the selection to use the whole image
     */
    void resetSelection();

    /**
     * @returns a QImage object with just the region the user selected from the
     * image
     */
    QImage selectedImage() const;

    /**
     * Sets the aspect ration that the selected subimage should have. The way to
     * select it, is specifying an example valid @p width and @p height.
     * @see setFreeSelectionAspectRatio()
     */
    void setSelectionAspectRatio(int width, int height);

    /**
     * Allows the user to do a selection which has any aspect ratio. This is
     * the default.
     * @see setSelectionAspectRatio()
     */
    void setFreeSelectionAspectRatio();

    /**
     * Sets the maximum size for the widget. If the image is larger than this
     * (either horizontally or vertically), it's scaled to adjust to the maximum
     * size (preserving the aspect ratio)
     */
    void setMaximumWidgetSize(int width, int height);

    /**
     * Rotates the image as specified by the @p direction parameter, also tries
     * to rotate the selected region so that it doesn't change, as long as the
     * forced aspect ratio setting is respected, in other case, the selected region
     * is reset.
     */
    void rotate(RotateDirection direction);

public Q_SLOTS:
    /**
     * Rotates the current image 90º clockwise
     */
    void rotateClockwise();
    /**
     * Rotates the current image 90º counterclockwise
     */
    void rotateCounterclockwise();

Q_SIGNALS:
    void pixmapRotated();

protected:
    /**
     * Creates a QMenu with the menu that appears when clicking with the right button on the label
     */
    virtual QMenu *createPopupMenu();

private:
    bool eventFilter(QObject *obj, QEvent *ev);

    class Private;
    friend class Private;
    Private *const d;

    Q_DISABLE_COPY(KPixmapRegionSelectorWidget)
};

#endif
