view widgets/TextAbbrev.h @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 2006-2007 Chris Cannam and 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 _TEXT_ABBREV_H_
#define _TEXT_ABBREV_H_

#include <QString>
#include <QStringList>

class QFontMetrics;

class TextAbbrev 
{
public:
    enum Policy {
        ElideEnd,
        ElideEndAndCommonPrefixes,
        ElideStart,
        ElideMiddle
    };

    /**
     * Abbreviate the given text to the given maximum length
     * (including ellipsis), using the given abbreviation policy.  If
     * fuzzy is true, the text will be left alone if it is "not much
     * more than" the maximum length.
     * 
     * If ellipsis is non-empty, it will be used to show elisions in
     * preference to the default (which is "...").
     */
    static QString abbreviate(QString text, int maxLength,
                              Policy policy = ElideEnd,
                              bool fuzzy = true,
                              QString ellipsis = "");

    /**
     * Abbreviate the given text to the given maximum painted width,
     * using the given abbreviation policy.  maxWidth is also modified
     * so as to return the painted width of the abbreviated text.
     *
     * If ellipsis is non-empty, it will be used to show elisions in
     * preference to the default (which is tr("...")).
     */
    static QString abbreviate(QString text,
                              const QFontMetrics &metrics,
                              int &maxWidth,
                              Policy policy = ElideEnd,
                              QString ellipsis = "");
    
    /**
     * Abbreviate all of the given texts to the given maximum length,
     * using the given abbreviation policy.  If fuzzy is true, texts
     * that are "not much more than" the maximum length will be left
     * alone.
     *
     * If ellipsis is non-empty, it will be used to show elisions in
     * preference to the default (which is tr("...")).
     */
    static QStringList abbreviate(const QStringList &texts, int maxLength,
                                  Policy policy = ElideEndAndCommonPrefixes,
                                  bool fuzzy = true,
                                  QString ellipsis = "");

    /**
     * Abbreviate all of the given texts to the given maximum painted
     * width, using the given abbreviation policy.  maxWidth is also
     * modified so as to return the maximum painted width of the
     * abbreviated texts.
     *
     * If ellipsis is non-empty, it will be used to show elisions in
     * preference to the default (which is tr("...")).
     */
    static QStringList abbreviate(const QStringList &texts,
                                  const QFontMetrics &metrics,
                                  int &maxWidth,
                                  Policy policy = ElideEndAndCommonPrefixes,
                                  QString ellipsis = "");

protected:
    static QString getDefaultEllipsis();
    static int getFuzzLength(QString ellipsis);
    static int getFuzzWidth(const QFontMetrics &metrics, QString ellipsis);
    static QString abbreviateTo(QString text, int characters,
                                Policy policy, QString ellipsis);
    static QStringList elidePrefixes(const QStringList &texts,
                                     int targetReduction,
                                     QString ellipsis);
    static QStringList elidePrefixes(const QStringList &texts,
                                     const QFontMetrics &metrics,
                                     int targetWidthReduction,
                                     QString ellipsis);
    static int getPrefixLength(const QStringList &texts);
};

#endif