imagedocument.h

/*
 * SPDX-FileCopyrightText: (C) 2020 Carl Schwan <carl@carlschwan.eu>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
#pragma once
 
#include <QImage>
#include <QObject>
#include <QStack>
#include <QUrl>
#include <qqmlregistration.h>
 
#include "commands/command.h"
 
/**
 * @brief An ImageDocument is the base class of the ImageEditor.
 *
 * This class handles various image manipulation and contains an undo stack to allow
 * reverting the last actions. This class does not display the image, use @c ImageItem
 * for this task.
 *
 * @code{.qml}
 * KQuickImageEditor.ImageDocument {
 *    id: imageDocument
 *    path: myModel.image
 * }
 *
 * Kirigami.Actions {
 *    iconName: "object-rotate-left"
 *    onTriggered: imageDocument.rotate(-90);
 * }
 *
 * KQuickImageEditor.ImageItem {
 *     image: imageDocument.image
 * }
 * @endcode
 */
class ImageDocument : public QObject
{
    Q_OBJECT
    QML_ELEMENT
 
    Q_PROPERTY(QUrl path READ path WRITE setPath NOTIFY pathChanged)
    Q_PROPERTY(QImage image READ image NOTIFY imageChanged)
    Q_PROPERTY(bool edited READ edited NOTIFY editedChanged)
    Q_PROPERTY(bool changesApplied READ changesApplied NOTIFY changesAppliedChanged)
    Q_PROPERTY(int brightness READ brightness NOTIFY brightnessChanged FINAL)
    Q_PROPERTY(int contrast READ contrast NOTIFY contrastChanged FINAL)
    Q_PROPERTY(int saturation READ saturation NOTIFY saturationChanged FINAL)
    Q_PROPERTY(int hue READ hue NOTIFY hueChanged FINAL)
 
    Q_PROPERTY(QRectF area READ area WRITE setArea NOTIFY areaChanged RESET resetArea)
 
public:
    ImageDocument(QObject *parent = nullptr);
    // ~ImageDocument() override = default;
 
    /**
     * The image was is displayed. This propriety is updated when the path change
     * or commands are applied.
     *
     * @see imageChanged
     */
    QImage image() const;
 
    /**
     * This propriety store if the document was changed or not.
     *
     * @see setEdited
     * @see editedChanged
     */
    bool edited() const;
 
    /**
     * Change the edited value.
     * @param value The new value.
     */
    void setEdited(bool value);
 
    QUrl path() const;
    void setPath(const QUrl &path);
 
    /**
     * Rotate the image.
     * @param angle The angle of the rotation in degree.
     */
    Q_INVOKABLE void rotate(int angle);
 
    /**
     * Mirror the image.
     * @param horizontal Mirror the image horizontally.
     * @param vertical Mirror the image vertically.
     */
    Q_INVOKABLE void mirror(bool horizontal, bool vertical);
 
    /**
     * Crop the image.
     * @param x The x coordinate of the new image in the old image.
     * @param y The y coordinate of the new image in the old image.
     * @param width The width of the new image.
     * @param height The height of the new image.
     */
    Q_INVOKABLE void crop
        (int x, int y, int width, int height);
 
    /**
     * Resize the image.
     * @param width The width of the new image.
     * @param height The height of the new image.
     */
    Q_INVOKABLE void resize(int width, int height);
 
    /**
     * Undo the last edit on the images.
     */
    Q_INVOKABLE void undo();
 
    /**
     * Cancel all the edit.
     */
    Q_INVOKABLE void cancel();
 
    /**
     * Save current edited image in place. This is a destructive operation and can't be reverted.
     * @return true iff the file saving operation was successful.
     */
    Q_INVOKABLE bool save();
 
    /**
     * Save current edited image as a new image.
     * @param location The location where to save the new image.
     * @return true iff the file saving operattion was successful.
     */
    Q_INVOKABLE bool saveAs(const QUrl &location);
 
    Q_INVOKABLE void adjustBrightness(int value);// between -255 and 255
    Q_INVOKABLE void adjustContrast(int value); // between -255 and 255
    Q_INVOKABLE void adjustSaturation(int value); //between -255 and 255
    Q_INVOKABLE void adjustHue(int value); //between 0 and 180
 
    Q_INVOKABLE void applyChanges();
 
    int brightness() const;
    int contrast() const;
    int saturation() const;
    int hue() const;
 
    QRectF area() const;
    void setArea(const QRectF &newArea);
    void resetArea();
 
    bool changesApplied() const;
 
Q_SIGNALS:
    void pathChanged(const QUrl &url);
    void imageChanged();
    void editedChanged();
    void brightnessChanged();
    void contrastChanged();
    void saturationChanged();
    void areaChanged();
    void hueChanged();
    void changesAppliedChanged();
 
private:
    QUrl m_path;
    QStack<Command *> m_undos;
    QImage m_image;
    QImage m_originalImage;
    bool m_edited;
    int m_brightness = 0;
    int m_contrast = 0;
    int m_saturation = 0;
    int m_hue = 0;
    QRectF m_area;
 
    void resetValues();
    bool m_changesApplied;
};