annotate base/TextAbbrev.h @ 335:02d2ad95ea52 spectrogram-cache-rejig

* Get storage advice for each cache in an FFT data server.  Allows us to be
  more confident about the actual memory situation and cut over from memory
  to disc part way through an FFT calculation if necessary.  StorageAdviser
  is now a bit too optimistic though (it's too keen to allocate large numbers
  of small blocks in memory).

/* -*- 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