fix a warning for the non-webkit guys
[quassel.git] / src / qtui / chatitem.cpp
index a677e10..679dc87 100644 (file)
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  ***************************************************************************/
 
+#include <QApplication>
+#include <QClipboard>
+#include <QDesktopServices>
 #include <QFontMetrics>
 #include <QGraphicsSceneMouseEvent>
-#include <QTextCursor>
-#include <QTextDocument>
+#include <QPainter>
+#include <QPalette>
+#include <QTextLayout>
+#include <QMenu>
 
-#include <QtGui>
 
 #include "chatitem.h"
+#include "chatlinemodel.h"
+#include "qtui.h"
+#include "qtuistyle.h"
 
-ChatItem::ChatItem(const QPersistentModelIndex &index_, QGraphicsItem *parent) : QGraphicsItem(parent), _index(index_) {
-  //if(_wrapMode == WordWrap) {
-  //  setFlags(QGraphicsItem::ItemClipsToShape, true);
-  //}
+ChatItem::ChatItem(const qreal &width, const qreal &height, const QPointF &pos, QGraphicsItem *parent)
+  : QGraphicsItem(parent),
+    _data(0),
+    _boundingRect(0, 0, width, height),
+    _selectionMode(NoSelection),
+    _selectionStart(-1)
+{
+  setAcceptHoverEvents(true);
+  setZValue(20);
+  setPos(pos);
 }
 
 ChatItem::~ChatItem() {
-
+  delete _data;
 }
 
 QVariant ChatItem::data(int role) const {
-  if(!_index.isValid()) {
-    qWarning() << "ChatItem::data(): Model index is invalid!";
+  QModelIndex index = model()->index(row(), column());
+  if(!index.isValid()) {
+    qWarning() << "ChatItem::data(): model index is invalid!" << index;
     return QVariant();
   }
-  return _index.data(role);
+  return model()->data(index, role);
+}
+
+QTextLayout *ChatItem::createLayout(QTextOption::WrapMode wrapMode, Qt::Alignment alignment) const {
+  QTextLayout *layout = new QTextLayout(data(MessageModel::DisplayRole).toString());
+
+  QTextOption option;
+  option.setWrapMode(wrapMode);
+  option.setAlignment(alignment);
+  layout->setTextOption(option);
+
+  QList<QTextLayout::FormatRange> formatRanges
+         = QtUi::style()->toTextLayoutList(data(MessageModel::FormatRole).value<UiStyle::FormatList>(), layout->text().length());
+  layout->setAdditionalFormats(formatRanges);
+  return layout;
+}
+
+void ChatItem::doLayout() {
+  QTextLayout *layout_ = layout();
+  layout_->beginLayout();
+  QTextLine line = layout_->createLine();
+  if(line.isValid()) {
+    line.setLineWidth(width());
+    line.setPosition(QPointF(0,0));
+  }
+  layout_->endLayout();
 }
 
-QRectF ChatItem::boundingRect() const {
-  return QRectF(0, 0, 500,20);
+void ChatItem::clearLayout() {
+  delete _data;
+  _data = 0;
 }
 
+ChatItemPrivate *ChatItem::privateData() const {
+  if(!_data) {
+    ChatItem *that = const_cast<ChatItem *>(this);
+    that->_data = that->newPrivateData();
+    that->doLayout();
+  }
+  return _data;
+}
+
+// NOTE: This is not the most time-efficient implementation, but it saves space by not caching unnecessary data
+//       This is a deliberate trade-off. (-> selectFmt creation, data() call)
 void ChatItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
   Q_UNUSED(option); Q_UNUSED(widget);
+  painter->setClipRect(boundingRect()); // no idea why QGraphicsItem clipping won't work
+  QVector<QTextLayout::FormatRange> formats = additionalFormats();
+  QTextLayout::FormatRange selectFmt = selectionFormat();
+  if(selectFmt.format.isValid()) formats.append(selectFmt);
+  layout()->draw(painter, QPointF(0,0), formats, boundingRect());
 
-  painter->drawRect(boundingRect());
-  painter->drawText(boundingRect(), data(MessageModel::DisplayRole).toString());
+  // Debuging Stuff
+  // uncomment partially or all of the following stuff:
+  //
+  // 0) alternativ painter color for debug stuff
+//   if(row() % 2)
+//     painter->setPen(Qt::red);
+//   else
+//     painter->setPen(Qt::blue);
+  // 1) draw wordwrap points in the first line
+//   if(column() == 2) {
+//     ChatLineModel::WrapList wrapList = data(ChatLineModel::WrapListRole).value<ChatLineModel::WrapList>();
+//     foreach(ChatLineModel::Word word, wrapList) {
+//       if(word.endX > width())
+//     break;
+//       painter->drawLine(word.endX, 0, word.endX, height());
+//     }
+//   }
+  // 2) draw MsgId over the time column
+//   if(column() == 0) {
+//     QString msgIdString = QString::number(data(MessageModel::MsgIdRole).value<MsgId>().toInt());
+//     QPointF bottomPoint = boundingRect().bottomLeft();
+//     bottomPoint.ry() -= 2;
+//     painter->drawText(bottomPoint, msgIdString);
+//   }
+  // 3) draw bounding rect
+//   painter->drawRect(_boundingRect.adjusted(0, 0, -1, -1));
 }
 
+qint16 ChatItem::posToCursor(const QPointF &pos) {
+  if(pos.y() > height()) return data(MessageModel::DisplayRole).toString().length();
+  if(pos.y() < 0) return 0;
+  for(int l = layout()->lineCount() - 1; l >= 0; l--) {
+    QTextLine line = layout()->lineAt(l);
+    if(pos.y() >= line.y()) {
+      return line.xToCursor(pos.x(), QTextLine::CursorOnCharacter);
+    }
+  }
+  return 0;
+}
 
-/*
-void ChatItem::setWidth(int w) {
-  _width = w;
-  layout();
+void ChatItem::setFullSelection() {
+  if(_selectionMode != FullSelection) {
+    _selectionMode = FullSelection;
+    update();
+  }
 }
 
-void ChatItem::setTextOption(const QTextOption &option) {
-  _textOption = option;
-  layout();
+void ChatItem::clearSelection() {
+  _selectionMode = NoSelection;
+  update();
 }
 
-QTextOption ChatItem::textOption() const {
-  return _textOption;
+void ChatItem::continueSelecting(const QPointF &pos) {
+  _selectionMode = PartialSelection;
+  _selectionEnd = posToCursor(pos);
+  update();
 }
 
-QString ChatItem::text() const {
-  return _layout.text();
+QTextLayout::FormatRange ChatItem::selectionFormat() const {
+  QTextLayout::FormatRange selectFmt;
+  if(_selectionMode != NoSelection) {
+    selectFmt.format.setForeground(QApplication::palette().brush(QPalette::HighlightedText));
+    selectFmt.format.setBackground(QApplication::palette().brush(QPalette::Highlight));
+    if(_selectionMode == PartialSelection) {
+      selectFmt.start = qMin(_selectionStart, _selectionEnd);
+      selectFmt.length = qAbs(_selectionStart - _selectionEnd);
+    } else { // FullSelection
+      selectFmt.start = 0;
+      selectFmt.length = data(MessageModel::DisplayRole).toString().length();
+    }
+  } else {
+    selectFmt.start = -1;
+    selectFmt.length = 0;
+  }
+  return selectFmt;
 }
 
-void ChatItem::setText(const UiStyle::StyledText &text) {
-  _layout.setText(text.text);
-  _layout.setAdditionalFormats(text.formatList);
-  layout();
+QList<QRectF> ChatItem::findWords(const QString &searchWord, Qt::CaseSensitivity caseSensitive) {
+  QList<QRectF> resultList;
+  const QAbstractItemModel *model_ = model();
+  if(!model_)
+    return resultList;
+
+  QString plainText = model_->data(model_->index(row(), column()), MessageModel::DisplayRole).toString();
+  QList<int> indexList;
+  int searchIdx = plainText.indexOf(searchWord, 0, caseSensitive);
+  while(searchIdx != -1) {
+    indexList << searchIdx;
+    searchIdx = plainText.indexOf(searchWord, searchIdx + 1, caseSensitive);
+  }
+
+  bool hadPrivateData = hasPrivateData();
+
+  foreach(int idx, indexList) {
+    QTextLine line = layout()->lineForTextPosition(idx);
+    qreal x = line.cursorToX(idx);
+    qreal width = line.cursorToX(idx + searchWord.count()) - x;
+    qreal height = line.height();
+    qreal y = height * line.lineNumber();
+    resultList << QRectF(x, y, width, height);
+  }
+
+  if(!hadPrivateData)
+    clearLayout();
+  return resultList;
 }
 
-void ChatItem::layout() {
-  if(!_layout.additionalFormats().count()) return; // no text set
-  if(_width <= 0) return;
-  prepareGeometryChange();
-  QFontMetrics metrics(_layout.additionalFormats()[0].format.font());
-  int leading = metrics.leading();
-  int height = 0;
-  _layout.setTextOption(textOption());
-  _layout.beginLayout();
-  while(1) {
-    QTextLine line = _layout.createLine();
-    if(!line.isValid()) break;
-    line.setLineWidth(_width);
-    if(textOption().wrapMode() != QTextOption::NoWrap && line.naturalTextWidth() > _width) {
-      // word did not fit, we need to wrap it in the middle
-      // this is a workaround for Qt failing to handle WrapAtWordBoundaryOrAnywhere correctly
-      QTextOption::WrapMode mode = textOption().wrapMode();
-      textOption().setWrapMode(QTextOption::WrapAnywhere);
-      _layout.setTextOption(textOption());
-      line.setLineWidth(_width);
-      textOption().setWrapMode(mode);
-      _layout.setTextOption(textOption());
-    }
-    height += leading;
-    line.setPosition(QPoint(0, height));
-    height += line.height();
+void ChatItem::mousePressEvent(QGraphicsSceneMouseEvent *event) {
+  if(event->buttons() == Qt::LeftButton) {
+    chatScene()->setSelectingItem(this);
+    _selectionStart = _selectionEnd = posToCursor(event->pos());
+    _selectionMode = NoSelection; // will be set to PartialSelection by mouseMoveEvent
+    update();
+    event->accept();
+  } else {
+    event->ignore();
   }
-  _layout.endLayout();
-  update();
-}    QDateTime _timestamp;
-    MsgId _msgId;
+}
 
+void ChatItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event) {
+  if(event->buttons() == Qt::LeftButton) {
+    if(contains(event->pos())) {
+      qint16 end = posToCursor(event->pos());
+      if(end != _selectionEnd) {
+        _selectionEnd = end;
+        _selectionMode = (_selectionStart != _selectionEnd ? PartialSelection : NoSelection);
+        update();
+      }
+    } else {
+      setFullSelection();
+      chatScene()->startGlobalSelection(this, event->pos());
+    }
+    event->accept();
+  } else {
+    event->ignore();
+  }
+}
 
-QRectF ChatItem::boundingRect() const {
-  return _layout.boundingRect();
+void ChatItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) {
+  if(_selectionMode != NoSelection && !event->buttons() & Qt::LeftButton) {
+    _selectionEnd = posToCursor(event->pos());
+    QString selection
+        = data(MessageModel::DisplayRole).toString().mid(qMin(_selectionStart, _selectionEnd), qAbs(_selectionStart - _selectionEnd));
+    chatScene()->putToClipboard(selection);
+    event->accept();
+  } else {
+    event->ignore();
+  }
 }
 
-void ChatItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
+// ************************************************************
+// SenderChatItem
+// ************************************************************
+
+void SenderChatItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
   Q_UNUSED(option); Q_UNUSED(widget);
-  _layout.draw(painter, QPointF(0, 0));
 
+  //painter->setClipRect(boundingRect()); // no idea why QGraphicsItem clipping won't work
+  qreal layoutWidth = layout()->minimumWidth();
+  qreal offset = 0;
+  if(chatScene()->senderCutoffMode() == ChatScene::CutoffLeft)
+    offset = qMin(width() - layoutWidth, (qreal)0);
+  else
+    offset = qMax(layoutWidth - width(), (qreal)0);
+
+  QTextLayout::FormatRange selectFmt = selectionFormat();
+
+  if(layoutWidth > width()) {
+    // Draw a nice gradient for longer items
+    // Qt's text drawing with a gradient brush sucks, so we use an alpha-channeled pixmap instead
+    QPixmap pixmap(QSize(layout()->boundingRect().width(), layout()->boundingRect().height()));
+    pixmap.fill(Qt::transparent);
+    QPainter pixPainter(&pixmap);
+    layout()->draw(&pixPainter, QPointF(qMax(offset, (qreal)0), 0), QVector<QTextLayout::FormatRange>() << selectFmt);
+    pixPainter.end();
+
+    // Create alpha channel mask
+    QPixmap mask(pixmap.size());
+    QPainter maskPainter(&mask);
+    QLinearGradient gradient;
+    if(offset < 0) {
+      gradient.setStart(0, 0);
+      gradient.setFinalStop(12, 0);
+      gradient.setColorAt(0, Qt::black);
+      gradient.setColorAt(1, Qt::white);
+    } else {
+      gradient.setStart(width()-10, 0);
+      gradient.setFinalStop(width(), 0);
+      gradient.setColorAt(0, Qt::white);
+      gradient.setColorAt(1, Qt::black);
+    }
+    maskPainter.fillRect(boundingRect(), gradient);
+    pixmap.setAlphaChannel(mask);
+    painter->drawPixmap(0, 0, pixmap);
+  } else {
+    layout()->draw(painter, QPointF(0,0), QVector<QTextLayout::FormatRange>() << selectFmt, boundingRect());
+  }
 }
-*/
 
-/*
-void ChatItem::mouseMoveEvent ( QGraphicsSceneMouseEvent * event ) {
-  qDebug() << (void*)this << "moving" << event->pos();
-  if(event->pos().y() < 0) {
-    QTextCursor cursor(document());
-    //cursor.insertText("foo");
-    //cursor.select(QTextCursor::Document);
-    event->ignore();
-  } else QGraphicsTextItem::mouseMoveEvent(event);
+// ************************************************************
+// ContentsChatItem
+// ************************************************************
+ContentsChatItem::ContentsChatItem(const qreal &width, const QPointF &pos, QGraphicsItem *parent)
+  : ChatItem(0, 0, pos, parent)
+{
+  const QAbstractItemModel *model_ = model();
+  QModelIndex index = model_->index(row(), column());
+  _fontMetrics = QtUi::style()->fontMetrics(model_->data(index, ChatLineModel::FormatRole).value<UiStyle::FormatList>().at(0).second);
+
+  setGeometryByWidth(width);
 }
-*/
 
+qreal ContentsChatItem::setGeometryByWidth(qreal w) {
+  if(w != width()) {
+    prepareGeometryChange();
+    setWidth(w);
+    // compute height
+    int lines = 1;
+    WrapColumnFinder finder(this);
+    while(finder.nextWrapColumn() > 0)
+      lines++;
+    setHeight(lines * fontMetrics()->lineSpacing());
+  }
+  return height();
+}
+
+void ContentsChatItem::doLayout() {
+  ChatLineModel::WrapList wrapList = data(ChatLineModel::WrapListRole).value<ChatLineModel::WrapList>();
+  if(!wrapList.count()) return; // empty chatitem
+
+  qreal h = 0;
+  WrapColumnFinder finder(this);
+  layout()->beginLayout();
+  forever {
+    QTextLine line = layout()->createLine();
+    if(!line.isValid())
+      break;
+
+    int col = finder.nextWrapColumn();
+    line.setNumColumns(col >= 0 ? col - line.textStart() : layout()->text().length());
+    line.setPosition(QPointF(0, h));
+    h += fontMetrics()->lineSpacing();
+  }
+  layout()->endLayout();
+}
+
+// NOTE: This method is not threadsafe and not reentrant!
+//       (RegExps are not constant while matching, and they are static here for efficiency)
+QList<ContentsChatItem::Clickable> ContentsChatItem::findClickables() const {
+  // For matching URLs
+  static QString urlEnd("(?:>|[,.;:\"]*\\s|\\b|$)");
+  static QString urlChars("(?:[,.;:]*[\\w\\-~@/?&=+$()!%#])");
+
+  static QRegExp regExp[] = {
+    // URL
+    // QRegExp(QString("((?:https?://|s?ftp://|irc://|mailto:|www\\.)%1+|%1+\\.[a-z]{2,4}(?:?=/%1+|\\b))%2").arg(urlChars, urlEnd)),
+    QRegExp(QString("((?:(?:https?://|s?ftp://|irc://|mailto:)|www)%1+)%2").arg(urlChars, urlEnd), Qt::CaseInsensitive),
+
+    // Channel name
+    // We don't match for channel names starting with + or &, because that gives us a lot of false positives.
+    QRegExp("((?:#|![A-Z0-9]{5})[^,:\\s]+(?::[^,:\\s]+)?)\\b", Qt::CaseInsensitive)
+
+    // TODO: Nicks, we'll need a filtering for only matching known nicknames further down if we do this
+  };
+
+  static const int regExpCount = 2;  // number of regexps in the array above
+
+  qint16 matches[] = { 0, 0, 0 };
+  qint16 matchEnd[] = { 0, 0, 0 };
+
+  QString str = data(ChatLineModel::DisplayRole).toString();
 
+  QList<Clickable> result;
+  qint16 idx = 0;
+  qint16 minidx;
+  int type = -1;
+
+  do {
+    type = -1;
+    minidx = str.length();
+    for(int i = 0; i < regExpCount; i++) {
+      if(matches[i] < 0 || matchEnd[i] > str.length()) continue;
+      if(idx >= matchEnd[i]) {
+        matches[i] = str.indexOf(regExp[i], qMax(matchEnd[i], idx));
+        if(matches[i] >= 0) matchEnd[i] = matches[i] + regExp[i].cap(1).length();
+      }
+      if(matches[i] >= 0 && matches[i] < minidx) {
+        minidx = matches[i];
+        type = i;
+      }
+    }
+    if(type >= 0) {
+      idx = matchEnd[type];
+      if(type == Clickable::Url && str.at(idx-1) == ')') {  // special case: closing paren only matches if we had an open one
+        if(!str.mid(matches[type], matchEnd[type]-matches[type]).contains('(')) matchEnd[type]--;
+      }
+      result.append(Clickable((Clickable::Type)type, matches[type], matchEnd[type] - matches[type]));
+    }
+  } while(type >= 0);
+
+  /* testing
+  if(!result.isEmpty()) qDebug() << str;
+  foreach(Clickable click, result) {
+    qDebug() << str.mid(click.start, click.length);
+  }
+  */
+  return result;
+}
+
+QVector<QTextLayout::FormatRange> ContentsChatItem::additionalFormats() const {
+  // mark a clickable if hovered upon
+  QVector<QTextLayout::FormatRange> fmt;
+  if(privateData()->currentClickable.isValid()) {
+    Clickable click = privateData()->currentClickable;
+    QTextLayout::FormatRange f;
+    f.start = click.start;
+    f.length = click.length;
+    f.format.setFontUnderline(true);
+    fmt.append(f);
+  }
+  return fmt;
+}
+
+void ContentsChatItem::endHoverMode() {
+  if(hasPrivateData()) {
+    if(privateData()->currentClickable.isValid()) {
+      setCursor(Qt::ArrowCursor);
+      privateData()->currentClickable = Clickable();
+    }
+    clearWebPreview();
+    update();
+  }
+}
+
+void ContentsChatItem::mousePressEvent(QGraphicsSceneMouseEvent *event) {
+  privateData()->hasDragged = false;
+  ChatItem::mousePressEvent(event);
+}
+
+void ContentsChatItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) {
+  if(!event->buttons() && !privateData()->hasDragged) {
+    // got a click
+    Clickable click = privateData()->currentClickable;
+    if(click.isValid()) {
+      QString str = data(ChatLineModel::DisplayRole).toString().mid(click.start, click.length);
+      switch(click.type) {
+        case Clickable::Url:
+         if(!str.contains("://"))
+           str = "http://" + str;
+          QDesktopServices::openUrl(QUrl::fromEncoded(str.toAscii()));
+          break;
+        case Clickable::Channel:
+          // TODO join or whatever...
+          break;
+        default:
+          break;
+      }
+    }
+  }
+  ChatItem::mouseReleaseEvent(event);
+}
+
+void ContentsChatItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event) {
+  // mouse move events always mean we're not hovering anymore...
+  endHoverMode();
+  // also, check if we have dragged the mouse
+  if(hasPrivateData() && !privateData()->hasDragged && event->buttons() & Qt::LeftButton
+    && (event->buttonDownScreenPos(Qt::LeftButton) - event->screenPos()).manhattanLength() >= QApplication::startDragDistance())
+    privateData()->hasDragged = true;
+  ChatItem::mouseMoveEvent(event);
+}
+
+void ContentsChatItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *event) {
+  endHoverMode();
+  event->accept();
+}
+
+void ContentsChatItem::hoverMoveEvent(QGraphicsSceneHoverEvent *event) {
+  bool onClickable = false;
+  qint16 idx = posToCursor(event->pos());
+  for(int i = 0; i < privateData()->clickables.count(); i++) {
+    Clickable click = privateData()->clickables.at(i);
+    if(idx >= click.start && idx < click.start + click.length) {
+      if(click.type == Clickable::Url) {
+        onClickable = true;
+       showWebPreview(click);
+      } else if(click.type == Clickable::Channel) {
+        // TODO: don't make clickable if it's our own name
+        //onClickable = true; //FIXME disabled for now
+      }
+      if(onClickable) {
+        setCursor(Qt::PointingHandCursor);
+        privateData()->currentClickable = click;
+        update();
+        break;
+      }
+    }
+  }
+  if(!onClickable) endHoverMode();
+  event->accept();
+}
+
+void ContentsChatItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) {
+  qint16 idx = posToCursor(event->pos());
+  for(int i = 0; i < privateData()->clickables.count(); i++) {
+    Clickable click = privateData()->clickables.at(i);
+    if(idx >= click.start && idx < click.start + click.length) {
+      if(click.type == Clickable::Url) {
+        QMenu menu;
+        QAction *copyToClipboard = menu.addAction(QObject::tr("Copy to Clipboard"));
+        QAction *selected = menu.exec(event->screenPos());
+        if(selected == copyToClipboard) {
+          QString url = data(ChatLineModel::DisplayRole).toString().mid(click.start, click.length);
+#   ifdef Q_WS_X11
+          QApplication::clipboard()->setText(url, QClipboard::Selection);
+#   endif
+//# else
+          QApplication::clipboard()->setText(url);
+//# endif
+        }
+      }
+    }
+  }
+}
+
+void ContentsChatItem::showWebPreview(const Clickable &click) {
+#ifndef HAVE_WEBKIT
+  Q_UNUSED(click);
+#else
+  QTextLine line = layout()->lineForTextPosition(click.start);
+  qreal x = line.cursorToX(click.start);
+  qreal width = line.cursorToX(click.start + click.length) - x;
+  qreal height = line.height();
+  qreal y = height * line.lineNumber();
+
+  QPointF topLeft = scenePos() + QPointF(x, y);
+  QRectF urlRect = QRectF(topLeft.x(), topLeft.y(), width, height);
+
+  QString url = data(ChatLineModel::DisplayRole).toString().mid(click.start, click.length);
+  if(!url.contains("://"))
+    url = "http://" + url;
+  chatScene()->loadWebPreview(this, url, urlRect);
+#endif
+}
+
+void ContentsChatItem::clearWebPreview() {
+#ifdef HAVE_WEBKIT
+  chatScene()->clearWebPreview(this);
+#endif
+}
+
+/*************************************************************************************************/
+
+ContentsChatItem::WrapColumnFinder::WrapColumnFinder(ChatItem *_item)
+  : item(_item),
+    layout(0),
+    wrapList(item->data(ChatLineModel::WrapListRole).value<ChatLineModel::WrapList>()),
+    wordidx(0),
+    lineCount(0),
+    choppedTrailing(0)
+{
+}
+
+ContentsChatItem::WrapColumnFinder::~WrapColumnFinder() {
+  delete layout;
+}
+
+qint16 ContentsChatItem::WrapColumnFinder::nextWrapColumn() {
+  if(wordidx >= wrapList.count())
+    return -1;
+
+  lineCount++;
+  qreal targetWidth = lineCount * item->width() + choppedTrailing;
+
+  qint16 start = wordidx;
+  qint16 end = wrapList.count() - 1;
+
+  // check if the whole line fits
+  if(wrapList.at(end).endX <= targetWidth) //  || start == end)
+    return -1;
+
+  // check if we have a very long word that needs inter word wrap
+  if(wrapList.at(start).endX > targetWidth) {
+    if(!line.isValid()) {
+      layout = item->createLayout(QTextOption::NoWrap);
+      layout->beginLayout();
+      line = layout->createLine();
+      layout->endLayout();
+    }
+    return line.xToCursor(targetWidth, QTextLine::CursorOnCharacter);
+  }
+
+  while(true) {
+    if(start + 1 == end) {
+      wordidx = end;
+      const ChatLineModel::Word &lastWord = wrapList.at(start); // the last word we were able to squeeze in
+
+      // both cases should be cought preliminary
+      Q_ASSERT(lastWord.endX <= targetWidth); // ensure that "start" really fits in
+      Q_ASSERT(end < wrapList.count()); // ensure that start isn't the last word
+
+      choppedTrailing += lastWord.trailing - (targetWidth - lastWord.endX);
+      return wrapList.at(wordidx).start;
+    }
+
+    qint16 pivot = (end + start) / 2;
+    if(wrapList.at(pivot).endX > targetWidth) {
+      end = pivot;
+    } else {
+      start = pivot;
+    }
+  }
+  Q_ASSERT(false);
+  return -1;
+}