view src/textabbrev.cpp @ 571:012ba1b83328

Show cancel button with progress bar only when running an operation that it makes sense to cancel (we don't really want people cancelling e.g. initial folder scan because it would leave things in an inconsistent state)

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

/*
    EasyMercurial

    Based on HgExplorer by Jari Korhonen
    Copyright (c) 2010 Jari Korhonen
    Copyright (c) 2012 Chris Cannam
    Copyright (c) 2012 Queen Mary, University of London
    
    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.
*/

#include "textabbrev.h"
#include "debug.h"

#include <QFontMetrics>
#include <QApplication>

#include <iostream>

QString
TextAbbrev::getDefaultEllipsis()
{
    return "...";
}

int
TextAbbrev::getFuzzLength(QString ellipsis)
{
    int len = ellipsis.length();
    if (len < 3) return len + 3;
    else if (len > 5) return len + 5;
    else return len * 2;
}

int
TextAbbrev::getFuzzWidth(const QFontMetrics &metrics, QString ellipsis)
{
    int width = metrics.width(ellipsis);
    return width * 2;
}

QString
TextAbbrev::abbreviateTo(QString text, int characters, Policy policy,
                         QString ellipsis)
{
    switch (policy) {

    case ElideEnd:
    case ElideEndAndCommonPrefixes:
        text = text.left(characters) + ellipsis;
        break;
        
    case ElideStart:
        text = ellipsis + text.right(characters);
        break;

    case ElideMiddle:
        if (characters > 2) {
            text = text.left(characters/2 + 1) + ellipsis
                + text.right(characters - (characters/2 + 1));
        } else {
            text = text.left(characters) + ellipsis;
        }
        break;
    }

    return text;
}

QString
TextAbbrev::abbreviate(QString text, int maxLength, Policy policy, bool fuzzy,
                       QString ellipsis)
{
    if (ellipsis == "") ellipsis = getDefaultEllipsis();
    int fl = (fuzzy ? getFuzzLength(ellipsis) : 0);
    if (maxLength <= ellipsis.length()) maxLength = ellipsis.length() + 1;
    if (text.length() <= maxLength + fl) return text;

    int truncated = maxLength - ellipsis.length();
    return abbreviateTo(text, truncated, policy, ellipsis);
}

QString
TextAbbrev::abbreviate(QString text,
                       const QFontMetrics &metrics, int &maxWidth,
                       Policy policy, QString ellipsis, int wrapLines)
{
    if (ellipsis == "") ellipsis = getDefaultEllipsis();

//    std::cerr << "TextAbbrev::abbreviate: text = " << text << std::endl;

    int tw = metrics.width(text);
    int tl = text.length();

//    std::cerr << "\n*** TextAbbrev::abbreviate: tw = " << tw << "\n***\n" << std::endl;

    if (tw <= maxWidth) {
        maxWidth = tw;
        return text;
    }

    QString original = text;

    int acw = metrics.averageCharWidth();

    if (wrapLines < 2) {

//        std::cerr << "only " << wrapLines << " line(s) remaining, going by character..." << std::endl;

        int truncateTo = tl;

        while (tw > maxWidth && truncateTo > 1) {

            if (tw > maxWidth + acw * (ellipsis.length() + 5)) {
                float ratio = float(maxWidth) / float(tw);
                truncateTo = int(truncateTo * ratio * 1.2) + 10;
                if (truncateTo >= tl) truncateTo = tl - 1;
            } else {
                truncateTo--;
            }
            
//            std::cerr << "truncating from " << tl << " to " << truncateTo << std::endl;

            if (truncateTo > ellipsis.length()) {
                text = abbreviateTo(original, truncateTo, policy, ellipsis);
            } else {
                break;
            }
            
            tw = metrics.width(text);
            tl = text.length() - ellipsis.length();
        }

//        std::cerr << "done, final tw = " << tw << std::endl;
        
        maxWidth = std::max(maxWidth, tw);
        return text;

    } else {
        
        QStringList words = text.split(' ', QString::SkipEmptyParts);
        text = "";

        tw = 0;
        int i = 0;
        QString good = "";
        int lastUsed = 0;

//        std::cerr << "have " << wrapLines << " lines remaining, going by word..." << std::endl;

        while (tw < maxWidth && i < words.size()) {
            if (text != "") text += " ";
            text += words[i++];
            tw = metrics.width(text);
            if (tw < maxWidth) {
                good = text;
                lastUsed = i;
            }
        }

//        std::cerr << "done" << std::endl;
            
        if (tw < maxWidth) {
            maxWidth = tw;
            return text;
        }

        text = good;

        QString remainder;
        while (lastUsed < words.size()) {
            if (remainder != "") remainder += " ";
            remainder += words[lastUsed++];
        }
        remainder = abbreviate(remainder, metrics, maxWidth,
                               policy, ellipsis, wrapLines - 1);

        maxWidth = std::max(maxWidth, tw);
        text = text + '\n' + remainder;
        return text;
    }
}

QStringList
TextAbbrev::abbreviate(const QStringList &texts, int maxLength,
                       Policy policy, bool fuzzy, QString ellipsis)
{
    if (policy == ElideEndAndCommonPrefixes &&
        texts.size() > 1) {

        if (ellipsis == "") ellipsis = getDefaultEllipsis();
        int fl = (fuzzy ? getFuzzLength(ellipsis) : 0);
        if (maxLength <= ellipsis.length()) maxLength = ellipsis.length() + 1;

        int maxOrigLength = 0;
        for (int i = 0; i < texts.size(); ++i) {
            int len = texts[i].length();
            if (len > maxOrigLength) maxOrigLength = len;
        }
        if (maxOrigLength <= maxLength + fl) return texts;

        return abbreviate(elidePrefixes
                          (texts, maxOrigLength - maxLength, ellipsis),
                          maxLength, ElideEnd, fuzzy, ellipsis);
    }

    QStringList results;
    for (int i = 0; i < texts.size(); ++i) {
        results.push_back
            (abbreviate(texts[i], maxLength, policy, fuzzy, ellipsis));
    }
    return results;
}

QStringList
TextAbbrev::abbreviate(const QStringList &texts, const QFontMetrics &metrics,
                       int &maxWidth, Policy policy, QString ellipsis)
{
    if (policy == ElideEndAndCommonPrefixes &&
        texts.size() > 1) {

        if (ellipsis == "") ellipsis = getDefaultEllipsis();

        int maxOrigWidth = 0;
        for (int i = 0; i < texts.size(); ++i) {
            int w = metrics.width(texts[i]);
            if (w > maxOrigWidth) maxOrigWidth = w;
        }

        return abbreviate(elidePrefixes(texts, metrics,
                                        maxOrigWidth - maxWidth, ellipsis),
                          metrics, maxWidth, ElideEnd, ellipsis);
    }

    QStringList results;
    int maxAbbrWidth = 0;
    for (int i = 0; i < texts.size(); ++i) {
        int width = maxWidth;
        QString abbr = abbreviate(texts[i], metrics, width, policy, ellipsis);
        if (width > maxAbbrWidth) maxAbbrWidth = width;
        results.push_back(abbr);
    }
    maxWidth = maxAbbrWidth;
    return results;
}

QStringList
TextAbbrev::elidePrefixes(const QStringList &texts,
                          int targetReduction,
                          QString ellipsis)
{
    if (texts.empty()) return texts;
    int plen = getPrefixLength(texts);
    int fl = getFuzzLength(ellipsis);
    if (plen < fl) return texts;

    QString prefix = texts[0].left(plen);
    int truncated = plen;
    if (plen >= targetReduction + fl) {
        truncated = plen - targetReduction;
    } else {
        truncated = fl;
    }
    prefix = abbreviate(prefix, truncated, ElideEnd, false, ellipsis);

    QStringList results;
    for (int i = 0; i < texts.size(); ++i) {
        results.push_back
            (prefix + texts[i].right(texts[i].length() - plen));
    }
    return results;
}

QStringList
TextAbbrev::elidePrefixes(const QStringList &texts,
                          const QFontMetrics &metrics,
                          int targetWidthReduction,
                          QString ellipsis)
{
    if (texts.empty()) return texts;
    int plen = getPrefixLength(texts);
    int fl = getFuzzLength(ellipsis);
    if (plen < fl) return texts;

    QString prefix = texts[0].left(plen);
    int pwid = metrics.width(prefix);
    int twid = pwid - targetWidthReduction;
    if (twid < metrics.width(ellipsis) * 2) twid = metrics.width(ellipsis) * 2;
    prefix = abbreviate(prefix, metrics, twid, ElideEnd, ellipsis);

    QStringList results;
    for (int i = 0; i < texts.size(); ++i) {
        results.push_back
            (prefix + texts[i].right(texts[i].length() - plen));
    }
    return results;
}

static bool
havePrefix(QString prefix, const QStringList &texts)
{
    for (int i = 1; i < texts.size(); ++i) {
        if (!texts[i].startsWith(prefix)) return false;
    }
    return true;
}

int
TextAbbrev::getPrefixLength(const QStringList &texts)
{
    QString reference = texts[0];

    if (reference == "" || havePrefix(reference, texts)) {
        return reference.length();
    }

    int candidate = reference.length();
    QString splitChars(";:,./#-!()$_+=[]{}\\");

    while (--candidate > 1) {
        if (splitChars.contains(reference[candidate])) {
            if (havePrefix(reference.left(candidate), texts)) {
                break;
            }
        }
    }

//    std::cerr << "TextAbbrev::getPrefixLength: prefix length is " << candidate << std::endl;
//    for (int i = 0; i < texts.size(); ++i) {
//        std::cerr << texts[i].left(candidate).toStdString() << "|" << texts[i].right(texts[i].length() - candidate).toStdString() << std::endl;
//    }

    return candidate;
}