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    41 

    42 #include "q3textbrowser.h"

    43 #ifndef QT_NO_TEXTBROWSER

    44 #include <private/q3richtext_p.h>

    45 

    46 #include "qevent.h"

    47 #include "qdesktopwidget.h"

    48 #include "qapplication.h"

    49 #include "qlayout.h"

    50 #include "qpainter.h"

    51 #include "qstack.h"

    52 #include "stdio.h"

    53 #include "qfile.h"

    54 #include "qtextstream.h"

    55 #include "qbitmap.h"

    56 #include "qtimer.h"

    57 #include "qimage.h"

    58 #include "q3simplerichtext.h"

    59 #include "q3dragobject.h"

    60 #include "qurl.h"

    61 #include "qcursor.h"

    62 

    63 QT_BEGIN_NAMESPACE

    64 

    65 /*!

    66     \class Q3TextBrowser

    67     \brief The Q3TextBrowser class provides a rich text browser with hypertext navigation.

    68 

    69     \compat

    70 

    71     This class extends Q3TextEdit (in read-only mode), adding some

    72     navigation functionality so that users can follow links in

    73     hypertext documents. The contents of Q3TextEdit is set with

    74     setText(), but Q3TextBrowser has an additional function,

    75     setSource(), which makes it possible to set the text to a named

    76     document. The name is looked up in the text view's mime source

    77     factory. If a document name ends with an anchor (for example, "\c

    78     #anchor"), the text browser automatically scrolls to that position

    79     (using scrollToAnchor()). When the user clicks on a hyperlink, the

    80     browser will call setSource() itself, with the link's \c href

    81     value as argument. You can track the current source by connetion

    82     to the sourceChanged() signal.

    83 

    84     Q3TextBrowser provides backward() and forward() slots which you can

    85     use to implement Back and Forward buttons. The home() slot sets

    86     the text to the very first document displayed. The linkClicked()

    87     signal is emitted when the user clicks a link.

    88 

    89     By using Q3TextEdit::setMimeSourceFactory() you can provide your

    90     own subclass of Q3MimeSourceFactory. This makes it possible to

    91     access data from anywhere, for example from a network or from a

    92     database. See Q3MimeSourceFactory::data() for details.

    93 

    94     If you intend using the mime factory to read the data directly

    95     from the file system, you may have to specify the encoding for the

    96     file extension you are using. For example:

    97     \snippet doc/src/snippets/code/src_qt3support_text_q3textbrowser.cpp 0

    98     This is to ensure that the factory is able to resolve the document

    99     names.

   100 

   101     Q3TextBrowser interprets the tags it processes in accordance with

   102     the default style sheet. Change the style sheet with

   103     \l{setStyleSheet()}; see QStyleSheet for details.

   104 

   105     If you want to provide your users with editable rich text use

   106     Q3TextEdit. If you want a text browser without hypertext navigation

   107     use Q3TextEdit, and use Q3TextEdit::setReadOnly() to disable

   108     editing. If you just need to display a small piece of rich text

   109     use QSimpleRichText or QLabel.

   110 */

   111 

   112 class Q3TextBrowserData

   113 {

   114 public:

   115     Q3TextBrowserData():textOrSourceChanged(false) {}

   116 

   117     QStack<QString> stack;

   118     QStack<QString> forwardStack;

   119     QString home;

   120     QString curmain;

   121     QString curmark;

   122 

   123     /*flag necessary to give the linkClicked() signal some meaningful

   124       semantics when somebody connected to it calls setText() or

   125       setSource() */

   126     bool textOrSourceChanged;

   127 };

   128 

   129 

   130 /*!

   131     Constructs an empty Q3TextBrowser called \a name, with parent \a

   132     parent.

   133 */

   134 Q3TextBrowser::Q3TextBrowser(QWidget *parent, const char *name)

   135     : Q3TextEdit(parent, name)

   136 {

   137     setReadOnly(true);

   138     d = new Q3TextBrowserData;

   139 

   140     viewport()->setMouseTracking(true);

   141 }

   142 

   143 /*!

   144     \internal

   145 */

   146 Q3TextBrowser::~Q3TextBrowser()

   147 {

   148     delete d;

   149 }

   150 

   151 

   152 /*!

   153     \property Q3TextBrowser::source

   154     \brief the name of the displayed document.

   155 

   156     This is a an empty string if no document is displayed or if the

   157     source is unknown.

   158 

   159     Setting this property uses the mimeSourceFactory() to lookup the

   160     named document. It also checks for optional anchors and scrolls

   161     the document accordingly.

   162 

   163     If the first tag in the document is \c{<qt type=detail>}, the

   164     document is displayed as a popup rather than as new document in

   165     the browser window itself. Otherwise, the document is displayed

   166     normally in the text browser with the text set to the contents of

   167     the named document with setText().

   168 

   169     If you are using the filesystem access capabilities of the mime

   170     source factory, you must ensure that the factory knows about the

   171     encoding of specified files; otherwise no data will be available.

   172     The default factory handles a couple of common file extensions

   173     such as \c *.html and \c *.txt with reasonable defaults. See

   174     Q3MimeSourceFactory::data() for details.

   175 */

   176 

   177 QString Q3TextBrowser::source() const

   178 {

   179     if (d->stack.isEmpty())

   180         return QString();

   181     else

   182         return d->stack.top();

   183 }

   184 

   185 /*!

   186     Reloads the current set source.

   187 */

   188 

   189 void Q3TextBrowser::reload()

   190 {

   191     QString s = d->curmain;

   192     d->curmain = QLatin1String("");

   193     setSource(s);

   194 }

   195 

   196 

   197 void Q3TextBrowser::setSource(const QString& name)

   198 {

   199 #ifndef QT_NO_CURSOR

   200     if (isVisible())

   201         qApp->setOverrideCursor(Qt::WaitCursor);

   202 #endif

   203     d->textOrSourceChanged = true;

   204     QString source = name;

   205     QString mark;

   206     int hash = name.indexOf(QLatin1Char('#'));

   207     if (hash != -1) {

   208         source = name.left(hash);

   209         mark = name.mid(hash+1);

   210     }

   211 

   212     if (source.left(5) == QLatin1String("file:"))

   213         source = source.mid(6);

   214 

   215     QString url = mimeSourceFactory()->makeAbsolute(source, context());

   216     QString txt;

   217     bool dosettext = false;

   218 

   219     if (!source.isEmpty() && url != d->curmain) {

   220         const QMimeSource* m =

   221                     mimeSourceFactory()->data(source, context());

   222         if (!m){

   223             qWarning("Q3TextBrowser: no mimesource for %s", source.latin1());

   224         }

   225         else {

   226             if (!Q3TextDrag::decode(m, txt)) {

   227                 qWarning("Q3TextBrowser: cannot decode %s", source.latin1());

   228             }

   229         }

   230         if (isVisible()) {

   231             QString firstTag = txt.left(txt.indexOf(QLatin1Char('>')) + 1);

   232             if (firstTag.left(3) == QLatin1String("<qt") && firstTag.contains(QLatin1String("type")) && firstTag.contains(QLatin1String("detail"))) {

   233                 popupDetail(txt, QCursor::pos());

   234 #ifndef QT_NO_CURSOR

   235                 qApp->restoreOverrideCursor();

   236 #endif

   237                 return;

   238             }

   239         }

   240 

   241         d->curmain = url;

   242         dosettext = true;

   243     }

   244 

   245     d->curmark = mark;

   246 

   247     if (!mark.isEmpty()) {

   248         url += QLatin1Char('#');

   249         url += mark;

   250     }

   251     if (d->home.count() == 0)

   252         d->home = url;

   253 

   254     if (d->stack.isEmpty() || d->stack.top() != url)

   255         d->stack.push(url);

   256 

   257     int stackCount = (int)d->stack.count();

   258     if (d->stack.top() == url)

   259         stackCount--;

   260     emit backwardAvailable(stackCount > 0);

   261     stackCount = (int)d->forwardStack.count();

   262     if (d->forwardStack.isEmpty() || d->forwardStack.top() == url)

   263         stackCount--;

   264     emit forwardAvailable(stackCount > 0);

   265 

   266     if (dosettext)

   267         Q3TextEdit::setText(txt, url);

   268 

   269     if (!mark.isEmpty())

   270         scrollToAnchor(mark);

   271     else

   272         setContentsPos(0, 0);

   273 

   274 #ifndef QT_NO_CURSOR

   275     if (isVisible())

   276         qApp->restoreOverrideCursor();

   277 #endif

   278 

   279     emit sourceChanged(url);

   280 }

   281 

   282 /*!

   283     \fn void Q3TextBrowser::backwardAvailable(bool available)

   284 

   285     This signal is emitted when the availability of backward()

   286     changes. \a available is false when the user is at home();

   287     otherwise it is true.

   288 */

   289 

   290 /*!

   291     \fn void Q3TextBrowser::forwardAvailable(bool available)

   292 

   293     This signal is emitted when the availability of forward() changes.

   294     \a available is true after the user navigates backward() and false

   295     when the user navigates or goes forward().

   296 */

   297 

   298 /*!

   299     \fn void Q3TextBrowser::sourceChanged(const QString& src)

   300 

   301     This signal is emitted when the mime source has changed, \a src

   302     being the new source.

   303 

   304     Source changes happen both programmatically when calling

   305     setSource(), forward(), backword() or home() or when the user

   306     clicks on links or presses the equivalent key sequences.

   307 */

   308 

   309 /*!  \fn void Q3TextBrowser::highlighted (const QString &link)

   310 

   311     This signal is emitted when the user has selected but not

   312     activated a link in the document. \a link is the value of the \c

   313     href i.e. the name of the target document.

   314 */

   315 

   316 /*!

   317     \fn void Q3TextBrowser::linkClicked(const QString& link)

   318 

   319     This signal is emitted when the user clicks a link. The \a link is

   320     the value of the \c href i.e. the name of the target document.

   321 

   322     The \a link will be the absolute location of the document, based

   323     on the value of the anchor's href tag and the current context of

   324     the document.

   325 

   326     \sa anchorClicked()

   327 */

   328 

   329 /*!

   330     \fn void Q3TextBrowser::anchorClicked(const QString& name, const QString &link)

   331 

   332     This signal is emitted when the user clicks an anchor. The \a link is

   333     the value of the \c href i.e. the name of the target document.  The \a name

   334     is the name of the anchor.

   335 

   336     \sa linkClicked()

   337 */

   338 

   339 /*!

   340     Changes the document displayed to the previous document in the

   341     list of documents built by navigating links. Does nothing if there

   342     is no previous document.

   343 

   344     \sa forward(), backwardAvailable()

   345 */

   346 void Q3TextBrowser::backward()

   347 {

   348     if (d->stack.count() <= 1)

   349         return;

   350     d->forwardStack.push(d->stack.pop());

   351     setSource(d->stack.pop());

   352     emit forwardAvailable(true);

   353 }

   354 

   355 /*!

   356     Changes the document displayed to the next document in the list of

   357     documents built by navigating links. Does nothing if there is no

   358     next document.

   359 

   360     \sa backward(), forwardAvailable()

   361 */

   362 void Q3TextBrowser::forward()

   363 {

   364     if (d->forwardStack.isEmpty())

   365         return;

   366     setSource(d->forwardStack.pop());

   367     emit forwardAvailable(!d->forwardStack.isEmpty());

   368 }

   369 

   370 /*!

   371     Changes the document displayed to be the first document the

   372     browser displayed.

   373 */

   374 void Q3TextBrowser::home()

   375 {

   376     if (!d->home.isNull())

   377         setSource(d->home);

   378 }

   379 

   380 /*!

   381     The event \a e is used to provide the following keyboard shortcuts:

   382     \table

   383     \header \i Keypress            \i Action

   384     \row \i Alt+Left Arrow  \i \l backward()

   385     \row \i Alt+Right Arrow \i \l forward()

   386     \row \i Alt+Up Arrow    \i \l home()

   387     \endtable

   388 */

   389 void Q3TextBrowser::keyPressEvent(QKeyEvent * e)

   390 {

   391     if (e->state() & Qt::AltButton) {

   392         switch (e->key()) {

   393         case Qt::Key_Right:

   394             forward();

   395             return;

   396         case Qt::Key_Left:

   397             backward();

   398             return;

   399         case Qt::Key_Up:

   400             home();

   401             return;

   402         }

   403     }

   404     Q3TextEdit::keyPressEvent(e);

   405 }

   406 

   407 class QTextDetailPopup : public QWidget

   408 {

   409 public:

   410     QTextDetailPopup()

   411         : QWidget (0, "automatic QText detail widget", Qt::WType_Popup)

   412     {

   413 	setAttribute(Qt::WA_DeleteOnClose, true);

   414     }

   415 

   416 protected:

   417     void mousePressEvent(QMouseEvent *)

   418     {

   419         close();

   420     }

   421 };

   422 

   423 

   424 void Q3TextBrowser::popupDetail(const QString& contents, const QPoint& pos)

   425 {

   426 

   427     const int shadowWidth = 6;   // also used as '5' and '6' and even '8' below

   428     const int vMargin = 8;

   429     const int hMargin = 12;

   430 

   431     QWidget* popup = new QTextDetailPopup;

   432     popup->setAttribute(Qt::WA_NoSystemBackground, true);

   433 

   434     Q3SimpleRichText* doc = new Q3SimpleRichText(contents, popup->font());

   435     doc->adjustSize();

   436     QRect r(0, 0, doc->width(), doc->height());

   437 

   438     int w = r.width() + 2*hMargin;

   439     int h = r.height() + 2*vMargin;

   440 

   441     popup->resize(w + shadowWidth, h + shadowWidth);

   442 

   443     // okay, now to find a suitable location

   444     //###### we need a global fancy popup positioning somewhere

   445     popup->move(pos - popup->rect().center());

   446     if (popup->geometry().right() > QApplication::desktop()->width())

   447         popup->move(QApplication::desktop()->width() - popup->width(),

   448                      popup->y());

   449     if (popup->geometry().bottom() > QApplication::desktop()->height())

   450         popup->move(popup->x(),

   451                      QApplication::desktop()->height() - popup->height());

   452     if (popup->x() < 0)

   453         popup->move(0, popup->y());

   454     if (popup->y() < 0)

   455         popup->move(popup->x(), 0);

   456 

   457 

   458     popup->show();

   459 

   460     // now for super-clever shadow stuff.  super-clever mostly in

   461     // how many window system problems it skirts around.

   462 

   463     QPainter p(popup);

   464     p.setPen(QApplication::palette().color(QPalette::Active, QPalette::WindowText));

   465     p.drawRect(0, 0, w, h);

   466     p.setPen(QApplication::palette().color(QPalette::Active, QPalette::Mid));

   467     p.setBrush(QColor(255, 255, 240));

   468     p.drawRect(1, 1, w-2, h-2);

   469     p.setPen(Qt::black);

   470 

   471     doc->draw(&p, hMargin, vMargin, r, popup->palette(), 0);

   472     delete doc;

   473 

   474     p.drawPoint(w + 5, 6);

   475     p.drawLine(w + 3, 6,

   476                 w + 5, 8);

   477     p.drawLine(w + 1, 6,

   478                 w + 5, 10);

   479     int i;

   480     for(i=7; i < h; i += 2)

   481         p.drawLine(w, i,

   482                     w + 5, i + 5);

   483     for(i = w - i + h; i > 6; i -= 2)

   484         p.drawLine(i, h,

   485                     i + 5, h + 5);

   486     for(; i > 0 ; i -= 2)

   487         p.drawLine(6, h + 6 - i,

   488                     i + 5, h + 5);

   489 }

   490 

   491 /*!

   492     \fn void Q3TextBrowser::setText(const QString &txt)

   493 

   494     \overload

   495 

   496     Sets the text to \a txt.

   497 */

   498 

   499 /*!

   500     \reimp

   501 */

   502 

   503 void Q3TextBrowser::setText(const QString &txt, const QString &context)

   504 {

   505     d->textOrSourceChanged = true;

   506     d->curmark = QLatin1String("");

   507     d->curmain = QLatin1String("");

   508     Q3TextEdit::setText(txt, context);

   509 }

   510 

   511 void Q3TextBrowser::emitHighlighted(const QString &s)

   512 {

   513     emit highlighted(s);

   514 }

   515 

   516 void Q3TextBrowser::emitLinkClicked(const QString &s)

   517 {

   518     d->textOrSourceChanged = false;

   519     emit linkClicked(s);

   520     if (!d->textOrSourceChanged)

   521         setSource(s);

   522 }

   523 

   524 QT_END_NAMESPACE

   525 

   526 #endif  // QT_NO_TEXTBROWSER