annotate layer/ColourDatabase.h @ 1534:bfd8b22fd67c

Fix #1904 Scrolling colour 3d plot does not always work when in View normalisation mode. We shouldn't imagine we've just invalidated the cache if the truth is that we've only just created the renderer

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2007 QMUL.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef SV_COLOUR_DATABASE_H
#define SV_COLOUR_DATABASE_H

#include <QObject>
#include <QString>
#include <QColor>
#include <QSize>
#include <QPixmap>
#include <vector>

class ColourDatabase : public QObject
{
    Q_OBJECT

public:
    static ColourDatabase *getInstance();

    /**
     * Return the number of colours in the database.
     */
    int getColourCount() const;

    /**
     * Return the name of the colour at index c.
     */
    QString getColourName(int c) const;

    /**
     * Return the colour at index c.
     */
    QColor getColour(int c) const;

    /**
     * Return the colour with the given name, if found in the
     * database. If not found, return Qt::black.
     */
    QColor getColour(QString name) const;

    /**
     * Return the index of the colour with the given name, if found in
     * the database. If not found, return -1.
     */
    int getColourIndex(QString name) const;

    /**
     * Return the index of the given colour, if found in the
     * database. If not found, return -1. Note that it is possible for
     * a colour to appear more than once in the database: names have
     * to be unique in the database, but colours don't. This always
     * returns the first match.
     */
    int getColourIndex(QColor c) const;

    /**
     * Return true if the given colour exists in the database.
     */
    bool haveColour(QColor c) const;

    /**
     * Return the index of the colour in the database that is closest
     * to the given one, by some simplistic measure (Manhattan
     * distance in RGB space). This always returns some valid index,
     * unless the database is empty, in which case it returns -1.
     */
    int getNearbyColourIndex(QColor c) const;

    /**
     * Add a colour to the database, with the associated name. Return
     * the index of the colour in the database. Names are unique
     * within the database: if another colour exists already with the
     * given name, its colour value is replaced with the given
     * one. Colours may appear more than once under different names.
     */
    int addColour(QColor c, QString name);

    /** 
     * Remove the colour with the given name from the database.
     */
    void removeColour(QString);

    /**
     * Return true if the colour at index c is marked as using a dark
     * background. Such colours are presumably "bright" ones, but all
     * this reports is whether the colour has been marked with
     * setUseDarkBackground, not any intrinsic property of the colour.
     */
    bool useDarkBackground(int c) const;
    
    /**
     * Mark the colour at index c as using a dark
     * background. Generally this should be called for "bright"
     * colours.
     */
    void setUseDarkBackground(int c, bool dark);

    /**
     * Return a colour that contrasts with the one at index c,
     * according to some simplistic algorithm. The returned colour is
     * not necessarily in the database; pass it to
     * getNearbyColourIndex if you need one that is.
     */
    QColor getContrastingColour(int c) const;

    // for use in XML export
    void getStringValues(int index,
                         QString &colourName,
                         QString &colourSpec,
                         QString &darkbg) const;

    // for use in XML import
    int putStringValues(QString colourName,
                        QString colourSpec,
                        QString darkbg);

    // for use by PropertyContainer getPropertyRangeAndValue methods
    void getColourPropertyRange(int *min, int *max) const;

    /**
     * Generate a swatch pixmap illustrating the colour at index c.
     */
    QPixmap getExamplePixmap(int c, QSize size) const;
    
signals:
    void colourDatabaseChanged();

protected:
    ColourDatabase();

    struct ColourRec {
        QColor colour;
        QString name;
        bool darkbg;
    };
    
    typedef std::vector<ColourRec> ColourList;
    ColourList m_colours;

    static ColourDatabase m_instance;
};

#endif