qtextbrowser.cpp

奇趣公司比较新的qt/emd版本

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#include "qtextbrowser.h"
#include "qtextedit_p.h"

#ifndef QT_NO_TEXTBROWSER

#include <qstack.h>
#include <qapplication.h>
#include <qevent.h>
#include <qdesktopwidget.h>
#include <qdebug.h>
#include <qabstracttextdocumentlayout.h>
#include "private/qtextdocumentlayout_p.h"
#include <qtextcodec.h>
#include <qpainter.h>
#include <qdir.h>
#include <qwhatsthis.h>
#include <qtextobject.h>
#include <qdesktopservices.h>

class QTextBrowserPrivate : public QTextEditPrivate
{
    Q_DECLARE_PUBLIC(QTextBrowser)
public:
    inline QTextBrowserPrivate()
        : textOrSourceChanged(false), forceLoadOnSourceChange(false), openExternalLinks(false),
          openLinks(true)
#ifdef QT_KEYPAD_NAVIGATION
        , lastKeypadScrollValue(-1)
#endif
    {}

    void init();

    struct HistoryEntry {
        inline HistoryEntry()
            : hpos(0), vpos(0), focusIndicatorPosition(-1),
              focusIndicatorAnchor(-1) {}
        QUrl url;
        int hpos;
        int vpos;
        int focusIndicatorPosition, focusIndicatorAnchor;
    };

    HistoryEntry createHistoryEntry() const;
    void restoreHistoryEntry(const HistoryEntry entry);

    QStack<HistoryEntry> stack;
    QStack<HistoryEntry> forwardStack;
    QUrl home;
    QUrl currentURL;

    QStringList searchPaths;

    /*flag necessary to give the linkClicked() signal some meaningful
      semantics when somebody connected to it calls setText() or
      setSource() */
    bool textOrSourceChanged;
    bool forceLoadOnSourceChange;

    bool openExternalLinks;
    bool openLinks;

#ifndef QT_NO_CURSOR
    QCursor oldCursor;
#endif

    QString findFile(const QUrl &name) const;

    inline void _q_documentModified()
    {
        textOrSourceChanged = true;
        forceLoadOnSourceChange = !currentURL.path().isEmpty();
    }

    void _q_activateAnchor(const QString &href);
    void _q_highlightLink(const QString &href);

    void setSource(const QUrl &url);

    QUrl resolveUrl(const QUrl &url) const;

#ifdef QT_KEYPAD_NAVIGATION
    void keypadMove(bool next);
    QTextCursor prevFocus;
    int lastKeypadScrollValue;
#endif
};

static bool isAbsoluteFileName(const QString &name)
{
    return !name.isEmpty()
           && (name[0] == QLatin1Char('/')
#if defined(Q_WS_WIN)
               || (name[0].isLetter() && name[1] == QLatin1Char(':')) || name.startsWith(QLatin1String("\\\\"))
#endif
               || (name[0]  == QLatin1Char(':') && name[1] == QLatin1Char('/'))
              );

}

QString QTextBrowserPrivate::findFile(const QUrl &name) const
{
    QString fileName;
    if (name.scheme() == QLatin1String("qrc"))
        fileName = QLatin1String(":/") + name.path();
    else
        fileName = name.toLocalFile();

    if (isAbsoluteFileName(fileName))
        return fileName;

    foreach (QString path, searchPaths) {
        if (!path.endsWith(QLatin1Char('/')))
            path.append(QLatin1Char('/'));
        path.append(fileName);
        if (QFileInfo(path).isReadable())
            return path;
    }

    return fileName;
}

QUrl QTextBrowserPrivate::resolveUrl(const QUrl &url) const
{
    if (!url.isRelative())
        return url;

    // For the second case QUrl can merge "#someanchor" with "foo.html"
    // correctly to "foo.html#someanchor"
    if (!(currentURL.isRelative()
          || (currentURL.scheme() == QLatin1String("file")
              && !isAbsoluteFileName(currentURL.toLocalFile())))
          || (url.hasFragment() && url.path().isEmpty())) {
        return currentURL.resolved(url);
    }

    // this is our last resort when current url and new url are both relative
    // we try to resolve against the current working directory in the local
    // file system.
    QFileInfo fi(currentURL.toLocalFile());
    if (fi.exists()) {
        return QUrl::fromLocalFile(fi.absolutePath() + QDir::separator()).resolved(url);
    }

    return url;
}

void QTextBrowserPrivate::_q_activateAnchor(const QString &href)
{
    if (href.isEmpty())
        return;
    Q_Q(QTextBrowser);

#ifndef QT_NO_CURSOR
    viewport->setCursor(oldCursor);
#endif

    const QUrl url = resolveUrl(href);

    if (!openLinks) {
        emit q->anchorClicked(url);
        return;
    }

    textOrSourceChanged = false;

#ifndef QT_NO_DESKTOPSERVICES
    if (openExternalLinks
        && url.scheme() != QLatin1String("file")
        && url.scheme() != QLatin1String("qrc")) {
        QDesktopServices::openUrl(url);
        return;
    }
#endif

    emit q->anchorClicked(url);

    if (textOrSourceChanged)
        return;

    q->setSource(url);
}

void QTextBrowserPrivate::_q_highlightLink(const QString &anchor)
{
    Q_Q(QTextBrowser);
    if (anchor.isEmpty()) {
#ifndef QT_NO_CURSOR
        if (viewport->cursor().shape() != Qt::PointingHandCursor)
            oldCursor = viewport->cursor();
        viewport->setCursor(oldCursor);
#endif
        emit q->highlighted(QUrl());
        emit q->highlighted(QString());
    } else {
#ifndef QT_NO_CURSOR
        viewport->setCursor(Qt::PointingHandCursor);
#endif

        const QUrl url = resolveUrl(anchor);
        emit q->highlighted(url);
        // convenience to ease connecting to QStatusBar::showMessage(const QString &)
        emit q->highlighted(url.toString());
    }
}

void QTextBrowserPrivate::setSource(const QUrl &url)
{
    Q_Q(QTextBrowser);
#ifndef QT_NO_CURSOR
    if (q->isVisible())
        qApp->setOverrideCursor(Qt::WaitCursor);
#endif
    textOrSourceChanged = true;

    QString txt;

    bool doSetText = false;

    QUrl currentUrlWithoutFragment = currentURL;
    currentUrlWithoutFragment.setFragment(QString());
    QUrl newUrlWithoutFragment = currentURL.resolved(url);
    newUrlWithoutFragment.setFragment(QString());

    if (url.isValid()
        && (newUrlWithoutFragment != currentUrlWithoutFragment || forceLoadOnSourceChange)) {
        QVariant data = q->loadResource(QTextDocument::HtmlResource, resolveUrl(url));
        if (data.type() == QVariant::String) {
            txt = data.toString();
        } else if (data.type() == QVariant::ByteArray) {
#ifndef QT_NO_TEXTCODEC
            QByteArray ba = data.toByteArray();
            QTextCodec *codec = Qt::codecForHtml(ba);
            txt = codec->toUnicode(ba);
#else
	    txt = data.toString();
#endif
        }
        if (txt.isEmpty())
            qWarning("QTextBrowser: No document for %s", url.toString().toLatin1().constData());

        if (q->isVisible()) {
            QString firstTag = txt.left(txt.indexOf(QLatin1Char('>')) + 1);
            if (firstTag.left(3) == QLatin1String("<qt") && firstTag.contains(QLatin1String("type")) && firstTag.contains(QLatin1String("detail"))) {
#ifndef QT_NO_CURSOR
                qApp->restoreOverrideCursor();
#endif
#ifndef QT_NO_WHATSTHIS
                QWhatsThis::showText(QCursor::pos(), txt, q);
#endif
                return;
            }
        }

        currentURL = resolveUrl(url);
        doSetText = true;
    }

    if (!home.isValid())
        home = url;

    if (doSetText) {
        q->QTextEdit::setHtml(txt);
#ifdef QT_KEYPAD_NAVIGATION
        prevFocus.movePosition(QTextCursor::Start);
#endif
    }

    forceLoadOnSourceChange = false;

    if (!url.fragment().isEmpty()) {
        q->scrollToAnchor(url.fragment());
    } else {
        hbar->setValue(0);
        vbar->setValue(0);
    }
#ifdef QT_KEYPAD_NAVIGATION 
    lastKeypadScrollValue = vbar->value(); 
#endif 

#ifndef QT_NO_CURSOR
    if (q->isVisible())
        qApp->restoreOverrideCursor();
#endif
    emit q->sourceChanged(url);
}

#ifdef QT_KEYPAD_NAVIGATION
void QTextBrowserPrivate::keypadMove(bool next)
{
    Q_Q(QTextBrowser);

    const int height = viewport->height();
    const int overlap = qBound(20, height / 5, 40); // XXX arbitrary, but a good balance
    const int visibleLinkAmount = overlap; // consistent, but maybe not the best choice (?)
    int yOffset = vbar->value();
    int scrollYOffset = qBound(0, next ? yOffset + height - overlap : yOffset - height + overlap, vbar->maximum());

    bool foundNextAnchor = false;
    bool focusIt = false;
    int focusedPos = -1;

    QTextCursor anchorToFocus;

    QRectF viewRect = QRectF(0, yOffset, control->size().width(), height);
    QRectF newViewRect = QRectF(0, scrollYOffset, control->size().width(), height);
    QRectF bothViewRects = viewRect.united(newViewRect);

    // If we don't have a previous anchor, pretend that we had the first/last character
    // on the screen selected.
    if (prevFocus.isNull()) {
        if (next)
            prevFocus = control->cursorForPosition(QPointF(0, yOffset));
        else
            prevFocus = control->cursorForPosition(QPointF(control->size().width(), yOffset + height));
    }

    // First, check to see if someone has moved the scroll bars independently
    if (lastKeypadScrollValue != yOffset) {
        // Someone (user or programmatically) has moved us, so we might
        // need to start looking from the current position instead of prevFocus

        bool findOnScreen = true;

        // If prevFocus is on screen at all, we just use it.
        if (prevFocus.hasSelection()) {
            QRectF prevRect = control->selectionRect(prevFocus);
            if (viewRect.intersects(prevRect))
                findOnScreen = false;
        }

        // Otherwise, we find a new anchor that's on screen.
        // Basically, create a cursor with the last/first character
        // on screen
        if (findOnScreen) {
            if (next)
                prevFocus = control->cursorForPosition(QPointF(0, yOffset));
            else
                prevFocus = control->cursorForPosition(QPointF(control->size().width(), yOffset + height));
        }
        foundNextAnchor = control->findNextPrevAnchor(prevFocus, next, anchorToFocus);
    } else if (prevFocus.hasSelection()) {
        // Check the pathological case that the current anchor is higher
        // than the screen, and just scroll through it in that case
        QRectF prevRect = control->selectionRect(prevFocus);
        if ((next && prevRect.bottom() > (yOffset + height)) ||
                (!next && prevRect.top() < yOffset)) {
            anchorToFocus = prevFocus;