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Diffstat (limited to 'src/pdf/qpdfsearchmodel.cpp')
| -rw-r--r-- | src/pdf/qpdfsearchmodel.cpp | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/src/pdf/qpdfsearchmodel.cpp b/src/pdf/qpdfsearchmodel.cpp new file mode 100644 index 000000000..a81ae77dc --- /dev/null +++ b/src/pdf/qpdfsearchmodel.cpp @@ -0,0 +1,373 @@ +// Copyright (C) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only + +#include "qpdfdocument_p.h" +#include "qpdflink.h" +#include "qpdfsearchmodel.h" +#include "qpdfsearchmodel_p.h" + +#include "third_party/pdfium/public/fpdf_text.h" +#include "third_party/pdfium/public/fpdfview.h" + +#include <QtCore/qelapsedtimer.h> +#include <QtCore/qloggingcategory.h> +#include <QtCore/QMetaEnum> + +QT_BEGIN_NAMESPACE + +Q_LOGGING_CATEGORY(qLcS, "qt.pdf.search") + +static const int UpdateTimerInterval = 100; +static const int ContextChars = 64; + +/*! + \class QPdfSearchModel + \since 5.15 + \inmodule QtPdf + \inherits QAbstractListModel + + \brief The QPdfSearchModel class searches for a string in a PDF document + and holds the results. + + This is used in the \l {Model/View Programming} paradigm to display + a list of search results, to highlight them on the rendered PDF pages, + and to iterate through them using the "search forward" / "search backward" + buttons and shortcuts that would be found in a typical document-viewing UI: + + \image search-results.png +*/ + +/*! + \enum QPdfSearchModel::Role + + \value Page The page number where the search result is found (int). + \value IndexOnPage The index of the search result on the page (int). + \value Location The position of the search result on the page (QPointF). + \value ContextBefore The adjacent text on the page, before the search string (QString). + \value ContextAfter The adjacent text on the page, after the search string (QString). + \omitvalue NRoles + + \sa QPdfLink +*/ + +/*! + Constructs a new search model with parent object \a parent. +*/ +QPdfSearchModel::QPdfSearchModel(QObject *parent) + : QAbstractListModel(*(new QPdfSearchModelPrivate()), parent) +{ + QMetaEnum rolesMetaEnum = metaObject()->enumerator(metaObject()->indexOfEnumerator("Role")); + for (int r = Qt::UserRole; r < int(Role::NRoles); ++r) { + QByteArray roleName = QByteArray(rolesMetaEnum.valueToKey(r)); + if (roleName.isEmpty()) + continue; + roleName[0] = QChar::toLower(roleName[0]); + m_roleNames.insert(r, roleName); + } + connect(this, &QAbstractListModel::dataChanged, this, &QPdfSearchModel::countChanged); + connect(this, &QAbstractListModel::modelReset, this, &QPdfSearchModel::countChanged); + connect(this, &QAbstractListModel::rowsRemoved, this, &QPdfSearchModel::countChanged); + connect(this, &QAbstractListModel::rowsInserted, this, &QPdfSearchModel::countChanged); +} + +/*! + Destroys the model. +*/ +QPdfSearchModel::~QPdfSearchModel() {} + +/*! + \reimp +*/ +QHash<int, QByteArray> QPdfSearchModel::roleNames() const +{ + return m_roleNames; +} + +/*! + \reimp + + The number of rows in the model is equal to the number of search results found. +*/ +int QPdfSearchModel::rowCount(const QModelIndex &parent) const +{ + Q_D(const QPdfSearchModel); + Q_UNUSED(parent); + return d->rowCountSoFar; +} + +/*! + \reimp +*/ +QVariant QPdfSearchModel::data(const QModelIndex &index, int role) const +{ + Q_D(const QPdfSearchModel); + const auto pi = const_cast<QPdfSearchModelPrivate*>(d)->pageAndIndexForResult(index.row()); + if (pi.page < 0) + return QVariant(); + switch (Role(role)) { + case Role::Page: + return pi.page; + case Role::IndexOnPage: + return pi.index; + case Role::Location: + return d->searchResults[pi.page][pi.index].location(); + case Role::ContextBefore: + return d->searchResults[pi.page][pi.index].contextBefore(); + case Role::ContextAfter: + return d->searchResults[pi.page][pi.index].contextAfter(); + case Role::NRoles: + break; + } + if (role == Qt::DisplayRole) { + const QString ret = d->searchResults[pi.page][pi.index].contextBefore() + + QLatin1String("<b>") + d->searchString + QLatin1String("</b>") + + d->searchResults[pi.page][pi.index].contextAfter(); + return ret; + } + return QVariant(); +} + +/*! + \since 6.8 + \property QPdfSearchModel::count + \brief the number of search results found +*/ +int QPdfSearchModel::count() const +{ + return rowCount(QModelIndex()); +} + +void QPdfSearchModel::updatePage(int page) +{ + Q_D(QPdfSearchModel); + d->doSearch(page); +} + +/*! + \property QPdfSearchModel::searchString + \brief the string to search for +*/ +QString QPdfSearchModel::searchString() const +{ + Q_D(const QPdfSearchModel); + return d->searchString; +} + +void QPdfSearchModel::setSearchString(const QString &searchString) +{ + Q_D(QPdfSearchModel); + if (d->searchString == searchString) + return; + + d->searchString = searchString; + beginResetModel(); + d->clearResults(); + emit searchStringChanged(); + endResetModel(); +} + +/*! + Returns the list of all results found on the given \a page. +*/ +QList<QPdfLink> QPdfSearchModel::resultsOnPage(int page) const +{ + Q_D(const QPdfSearchModel); + const_cast<QPdfSearchModelPrivate *>(d)->doSearch(page); + if (d->searchResults.size() <= page) + return {}; + return d->searchResults[page]; +} + +/*! + Returns a result found by \a index in the \l document, regardless of the + page on which it was found. \a index must be less than \l rowCount. +*/ +QPdfLink QPdfSearchModel::resultAtIndex(int index) const +{ + Q_D(const QPdfSearchModel); + const auto pi = const_cast<QPdfSearchModelPrivate*>(d)->pageAndIndexForResult(index); + if (pi.page < 0 || index < 0) + return {}; + return d->searchResults[pi.page][pi.index]; +} + +/*! + \property QPdfSearchModel::document + \brief the document to search +*/ +QPdfDocument *QPdfSearchModel::document() const +{ + Q_D(const QPdfSearchModel); + return d->document; +} + +void QPdfSearchModel::setDocument(QPdfDocument *document) +{ + Q_D(QPdfSearchModel); + if (d->document == document) + return; + + disconnect(d->documentConnection); + d->documentConnection = connect(document, &QPdfDocument::pageCountChanged, this, + [this]() { d_func()->clearResults(); }); + + d->document = document; + d->clearResults(); + emit documentChanged(); +} + +void QPdfSearchModel::timerEvent(QTimerEvent *event) +{ + Q_D(QPdfSearchModel); + if (event->timerId() != d->updateTimerId) + return; + if (!d->document || d->nextPageToUpdate >= d->document->pageCount()) { + if (d->document) + qCDebug(qLcS) << "done updating search results on" << d->searchResults.size() << "pages"; + killTimer(d->updateTimerId); + d->updateTimerId = -1; + } + d->doSearch(d->nextPageToUpdate++); +} + +QPdfSearchModelPrivate::QPdfSearchModelPrivate() : QAbstractItemModelPrivate() +{ +} + +void QPdfSearchModelPrivate::clearResults() +{ + Q_Q(QPdfSearchModel); + rowCountSoFar = 0; + searchResults.clear(); + pagesSearched.clear(); + if (document) { + searchResults.resize(document->pageCount()); + pagesSearched.resize(document->pageCount()); + } + nextPageToUpdate = 0; + updateTimerId = q->startTimer(UpdateTimerInterval); +} + +bool QPdfSearchModelPrivate::doSearch(int page) +{ + if (page < 0 || page >= pagesSearched.size() || searchString.isEmpty()) + return false; + if (pagesSearched[page]) + return true; + Q_Q(QPdfSearchModel); + + const QPdfMutexLocker lock; + QElapsedTimer timer; + timer.start(); + FPDF_PAGE pdfPage = FPDF_LoadPage(document->d->doc, page); + if (!pdfPage) { + qWarning() << "failed to load page" << page; + return false; + } + FPDF_TEXTPAGE textPage = FPDFText_LoadPage(pdfPage); + if (!textPage) { + qWarning() << "failed to load text of page" << page; + FPDF_ClosePage(pdfPage); + return false; + } + FPDF_SCHHANDLE sh = FPDFText_FindStart(textPage, searchString.utf16(), 0, 0); + QList<QPdfLink> newSearchResults; + constexpr double CharacterHitTolerance = 6.0; + while (FPDFText_FindNext(sh)) { + int idx = FPDFText_GetSchResultIndex(sh); + int count = FPDFText_GetSchCount(sh); + int rectCount = FPDFText_CountRects(textPage, idx, count); + QList<QRectF> rects; + int startIndex = -1; + int endIndex = -1; + for (int r = 0; r < rectCount; ++r) { + // get bounding box of search result in page coordinates + double left, top, right, bottom; + FPDFText_GetRect(textPage, r, &left, &top, &right, &bottom); + // deal with any internal PDF transforms and + // convert to the 1x (pixels = points) 4th-quadrant coordinate system + rects << document->d->mapPageToView(pdfPage, left, top, right, bottom); + if (r == 0) { + startIndex = FPDFText_GetCharIndexAtPos(textPage, left, top, + CharacterHitTolerance, CharacterHitTolerance); + } + if (r == rectCount - 1) { + endIndex = FPDFText_GetCharIndexAtPos(textPage, right, top, + CharacterHitTolerance, CharacterHitTolerance); + } + qCDebug(qLcS) << rects.last() << "char idx" << startIndex << "->" << endIndex + << "from page rect" << left << top << right << bottom; + } + QString contextBefore, contextAfter; + if (startIndex >= 0 || endIndex >= 0) { + startIndex = qMax(0, startIndex - ContextChars); + endIndex += ContextChars; + int count = endIndex - startIndex + 1; + if (count > 0) { + QList<ushort> buf(count + 1); + int len = FPDFText_GetText(textPage, startIndex, count, buf.data()); + Q_ASSERT(len - 1 <= count); // len is number of characters written, including the terminator + QString context = QString::fromUtf16( + reinterpret_cast<const char16_t *>(buf.constData()), len - 1); + context = context.replace(QLatin1Char('\n'), QStringLiteral("\u23CE")); + context = context.remove(QLatin1Char('\r')); + // try to find the search string near the middle of the context if possible + int si = context.indexOf(searchString, ContextChars - 5, Qt::CaseInsensitive); + if (si < 0) + si = context.indexOf(searchString, Qt::CaseInsensitive); + if (si < 0) + qWarning() << "search string" << searchString << "not found in context" << context; + contextBefore = context.mid(0, si); + contextAfter = context.mid(si + searchString.size()); + } + } + if (!rects.isEmpty()) + newSearchResults << QPdfLink(page, rects, contextBefore, contextAfter); + } + FPDFText_FindClose(sh); + FPDFText_ClosePage(textPage); + FPDF_ClosePage(pdfPage); + qCDebug(qLcS) << searchString << "took" << timer.elapsed() << "ms to find" + << newSearchResults.size() << "results on page" << page; + + pagesSearched[page] = true; + searchResults[page] = newSearchResults; + if (newSearchResults.size() > 0) { + int rowsBefore = rowsBeforePage(page); + qCDebug(qLcS) << "from row" << rowsBefore << "rowCount" << rowCountSoFar << "increasing by" << newSearchResults.size(); + rowCountSoFar += newSearchResults.size(); + q->beginInsertRows(QModelIndex(), rowsBefore, rowsBefore + newSearchResults.size() - 1); + q->endInsertRows(); + } + return true; +} + +QPdfSearchModelPrivate::PageAndIndex QPdfSearchModelPrivate::pageAndIndexForResult(int resultIndex) +{ + if (pagesSearched.isEmpty()) + return {-1, -1}; + const int pageCount = document->pageCount(); + int totalSoFar = 0; + int previousTotalSoFar = 0; + for (int page = 0; page < pageCount; ++page) { + if (!pagesSearched[page]) + doSearch(page); + totalSoFar += searchResults[page].size(); + if (totalSoFar > resultIndex) + return {page, resultIndex - previousTotalSoFar}; + previousTotalSoFar = totalSoFar; + } + return {-1, -1}; +} + +int QPdfSearchModelPrivate::rowsBeforePage(int page) +{ + int ret = 0; + for (int i = 0; i < page; ++i) + ret += searchResults[i].size(); + return ret; +} + +QT_END_NAMESPACE + +#include "moc_qpdfsearchmodel.cpp" |