src/frontends/qt4/GuiCompleter.cpp

   1 /**
   2  * \file GuiCompleter.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Stefan Schimanski
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #include <config.h>
  12
  13 #include "GuiWorkArea.h"
  14
  15 #include "Buffer.h"
  16 #include "BufferView.h"
  17 #include "Cursor.h"
  18 #include "Dimension.h"
  19 #include "FuncRequest.h"
  20 #include "GuiView.h"
  21 #include "LyXFunc.h"
  22 #include "LyXRC.h"
  23 #include "Paragraph.h"
  24 #include "version.h"
  25
  26 #include "support/debug.h"
  27
  28 #include <QApplication>
  29 #include <QAbstractListModel>
  30 #include <QHeaderView>
  31 #include <QPainter>
  32 #include <QPixmapCache>
  33 #include <QScrollBar>
  34 #include <QItemDelegate>
  35 #include <QTreeView>
  36 #include <QTimer>
  37
  38 using namespace std;
  39 using namespace lyx::support;
  40
  41 namespace lyx {
  42 namespace frontend {
  43
  44 class RtlItemDelegate : public QItemDelegate {
  45 public:
  46         explicit RtlItemDelegate(QObject * parent = 0)
  47                 : QItemDelegate(parent) {}
  48
  49 protected:
  50         virtual void drawDisplay(QPainter * painter,
  51                 QStyleOptionViewItem const & option,
  52                 QRect const & rect, QString const & text) const
  53         {
  54                 // FIXME: do this more elegantly
  55                 docstring stltext = qstring_to_ucs4(text);
  56                 reverse(stltext.begin(), stltext.end());
  57                 QItemDelegate::drawDisplay(painter, option, rect, toqstr(stltext));
  58         }
  59 };
  60
  61
  62 class PixmapItemDelegate : public QItemDelegate {
  63 public:
  64         explicit PixmapItemDelegate(QObject *parent = 0)
  65         : QItemDelegate(parent) {}
  66
  67 protected:
  68         void paint(QPainter *painter, const QStyleOptionViewItem &option,
  69                    const QModelIndex &index) const
  70         {
  71                 QStyleOptionViewItem opt = setOptions(index, option);
  72                 QVariant value = index.data(Qt::DisplayRole);
  73                 QPixmap pixmap = qvariant_cast<QPixmap>(value);
  74
  75                 // draw
  76                 painter->save();
  77                 drawBackground(painter, opt, index);
  78                 if (!pixmap.isNull()) {
  79                         const QSize size = pixmap.size();
  80                         painter->drawPixmap(option.rect.left() + (16 - size.width()) / 2,
  81                                 option.rect.top() + (option.rect.height() - size.height()) / 2,
  82                                 pixmap);
  83                 }
  84                 drawFocus(painter, opt, option.rect);
  85                 painter->restore();
  86         }
  87 };
  88
  89
  90 class GuiCompletionModel : public QAbstractListModel {
  91 public:
  92         ///
  93         GuiCompletionModel(QObject * parent,
  94                 Inset::CompletionList const * l)
  95                 : QAbstractListModel(parent), list_(l) {}
  96         ///
  97         ~GuiCompletionModel()
  98                 { delete list_; }
  99         ///
 100         bool sorted() const
 101         {
 102                 if (list_)
 103                         return list_->sorted();
 104                 else
 105                         return false;
 106         }
 107         ///
 108         int columnCount(const QModelIndex & /*parent*/ = QModelIndex()) const
 109         {
 110                 return 2;
 111         }
 112         ///
 113         int rowCount(const QModelIndex & /*parent*/ = QModelIndex()) const
 114         {
 115                 if (list_ == 0)
 116                         return 0;
 117                 else
 118                         return list_->size();
 119         }
 120
 121         ///
 122         QVariant data(const QModelIndex & index, int role) const
 123         {
 124                 if (list_ == 0)
 125                         return QVariant();
 126
 127                 if (index.row() < 0 || index.row() >= rowCount())
 128                         return QVariant();
 129
 130                 if (role != Qt::DisplayRole && role != Qt::EditRole)
 131                     return QVariant();
 132
 133                 if (index.column() == 0) {
 134                         docstring const word = list_->data(index.row());
 135                         return toqstr(word);
 136                 } else if (index.column() == 1) {
 137                         // get icon from cache
 138                         QPixmap scaled;
 139                         QString const name = ":" + toqstr(list_->icon(index.row()));
 140                         if (!QPixmapCache::find("completion" + name, scaled)) {
 141                                 // load icon from disk
 142                                 QPixmap p = QPixmap(name);
 143                                 if (!p.isNull()) {
 144                                         // scale it to 16x16 or smaller
 145                                         scaled = p.scaled(min(16, p.width()), min(16, p.height()),
 146                                                 Qt::KeepAspectRatio, Qt::SmoothTransformation);
 147                                 }
 148
 149                                 QPixmapCache::insert("completion" + name, scaled);
 150                         }
 151                         return scaled;
 152                 }
 153                 return QVariant();
 154         }
 155
 156 private:
 157         ///
 158         Inset::CompletionList const * list_;
 159 };
 160
 161
 162 GuiCompleter::GuiCompleter(GuiWorkArea * gui, QObject * parent)
 163         : QCompleter(parent), gui_(gui), updateLock_(0),
 164           inlineVisible_(false)
 165 {
 166         // Setup the completion popup
 167         setModel(new GuiCompletionModel(this, 0));
 168         setCompletionMode(QCompleter::PopupCompletion);
 169         setWidget(gui_);
 170
 171         // create the popup
 172         QTreeView *listView = new QTreeView;
 173         listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
 174         listView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 175         listView->setSelectionBehavior(QAbstractItemView::SelectRows);
 176         listView->setSelectionMode(QAbstractItemView::SingleSelection);
 177         listView->header()->hide();
 178         listView->setIndentation(0);
 179         listView->setUniformRowHeights(true);
 180         setPopup(listView);
 181         popup()->setItemDelegateForColumn(1, new PixmapItemDelegate(this));
 182         rtlItemDelegate_ = new RtlItemDelegate(this);
 183
 184         // create timeout timers
 185         popup_timer_.setSingleShot(true);
 186         inline_timer_.setSingleShot(true);
 187         connect(this, SIGNAL(highlighted(const QString &)),
 188                 this, SLOT(popupHighlighted(const QString &)));
 189         connect(this, SIGNAL(activated(const QString &)),
 190                 this, SLOT(popupActivated(const QString &)));
 191         connect(&popup_timer_, SIGNAL(timeout()),
 192                 this, SLOT(showPopup()));
 193         connect(&inline_timer_, SIGNAL(timeout()),
 194                 this, SLOT(showInline()));
 195 }
 196
 197
 198 GuiCompleter::~GuiCompleter()
 199 {
 200         popup()->hide();
 201 }
 202
 203
 204 bool GuiCompleter::eventFilter(QObject * watched, QEvent * e)
 205 {
 206         // hijack back the tab key from the popup
 207         // (which stole it from the workspace before)
 208         if (e->type() == QEvent::KeyPress && popupVisible()) {
 209                 QKeyEvent *ke = static_cast<QKeyEvent *>(e);
 210                 switch (ke->key()) {
 211                 case Qt::Key_Tab:
 212                         tab();
 213                         ke->accept();
 214                         return true;
 215                 default: break;
 216                 }
 217         }
 218
 219         return QCompleter::eventFilter(watched, e);
 220 }
 221
 222
 223 bool GuiCompleter::popupPossible(Cursor const & cur) const
 224 {
 225         return QApplication::activeWindow()
 226                 && gui_->hasFocus()
 227                 && cur.inset().completionSupported(cur);
 228 }
 229
 230
 231 bool GuiCompleter::inlinePossible(Cursor const & cur) const
 232 {
 233         return cur.inset().inlineCompletionSupported(cur);
 234 }
 235
 236
 237 bool GuiCompleter::completionAvailable() const
 238 {
 239         size_t n = popup()->model()->rowCount();
 240
 241         // if there is exactly one, we have to check whether it is a
 242         // real completion, i.e. longer than the current prefix.
 243         if (n == 1 && completionPrefix() == currentCompletion())
 244             return false;
 245
 246         return n > 0;
 247 }
 248
 249
 250 bool GuiCompleter::popupVisible() const
 251 {
 252         return popup()->isVisible();
 253 }
 254
 255
 256 bool GuiCompleter::inlineVisible() const
 257 {
 258         // In fact using BufferView::inlineCompletionPos.empty() should be
 259         // here. But unfortunately this information is not good enough
 260         // because destructive operations like backspace might invalidate
 261         // inlineCompletionPos. But then the completion should stay visible
 262         // (i.e. reshown on the next update). Hence be keep this information
 263         // in the inlineVisible_ variable.
 264         return inlineVisible_;
 265 }
 266
 267
 268 void GuiCompleter::updateVisibility(Cursor & cur, bool start, bool keep, bool cursorInView)
 269 {
 270         // parameters which affect the completion
 271         bool moved = cur != old_cursor_;
 272         if (moved)
 273                 old_cursor_ = cur;
 274
 275         bool possiblePopupState = popupPossible(cur) && cursorInView;
 276         bool possibleInlineState = inlinePossible(cur) && cursorInView;
 277
 278         // we moved or popup state is not ok for popup?
 279         if ((moved && !keep) || !possiblePopupState)
 280                 hidePopup(cur);
 281
 282         // we moved or inline state is not ok for inline completion?
 283         if ((moved && !keep) || !possibleInlineState)
 284                 hideInline(cur);
 285
 286         // we inserted something and are in a possible popup state?
 287         if (!popupVisible() && possiblePopupState && start
 288                 && cur.inset().automaticPopupCompletion())
 289                 popup_timer_.start(int(lyxrc.completion_popup_delay * 1000));
 290
 291         // we inserted something and are in a possible inline completion state?
 292         if (!inlineVisible() && possibleInlineState && start
 293                 && cur.inset().automaticInlineCompletion())
 294                 inline_timer_.start(int(lyxrc.completion_inline_delay * 1000));
 295
 296         // update prefix if any completion is possible
 297         bool modelActive = model()->rowCount() > 0;
 298         if (possiblePopupState || possibleInlineState) {
 299                 if (modelActive)
 300                         updatePrefix(cur);
 301                 else
 302                         updateAvailability();
 303         }
 304 }
 305
 306
 307 void GuiCompleter::updateVisibility(bool start, bool keep)
 308 {
 309         Cursor cur = gui_->bufferView().cursor();
 310         cur.updateFlags(Update::None);
 311
 312         updateVisibility(cur, start, keep);
 313
 314         if (cur.disp_.update())
 315                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 316 }
 317
 318
 319 void GuiCompleter::updatePrefix(Cursor & cur)
 320 {
 321         // get new prefix. Do nothing if unchanged
 322         QString newPrefix = toqstr(cur.inset().completionPrefix(cur));
 323         if (newPrefix == completionPrefix())
 324                 return;
 325
 326         // value which should be kept selected
 327         QString old = currentCompletion();
 328         if (old.length() == 0)
 329                 old = last_selection_;
 330
 331         // update completer to new prefix
 332         setCompletionPrefix(newPrefix);
 333
 334         // update popup because its size might have changed
 335         if (popupVisible())
 336                 updatePopup(cur);
 337
 338         // restore old selection
 339         setCurrentCompletion(old);
 340
 341         // if popup is not empty, the new selection will
 342         // be our last valid one
 343         QString const & s = currentCompletion();
 344         if (s.length() > 0)
 345                 last_selection_ = s;
 346         else
 347                 last_selection_ = old;
 348
 349         // update inline completion because the default
 350         // completion string might have changed
 351         if (inlineVisible())
 352                 updateInline(cur, s);
 353 }
 354
 355
 356 void GuiCompleter::updateInline(Cursor & cur, QString const & completion)
 357 {
 358         if (!cur.inset().inlineCompletionSupported(cur))
 359                 return;
 360
 361         // compute postfix
 362         docstring prefix = cur.inset().completionPrefix(cur);
 363         docstring postfix = from_utf8(fromqstr(completion.mid(prefix.length())));
 364
 365         // shorten it if necessary
 366         if (lyxrc.completion_inline_dots != -1
 367             && postfix.size() > unsigned(lyxrc.completion_inline_dots))
 368                 postfix = postfix.substr(0, lyxrc.completion_inline_dots - 1) + "...";
 369
 370         // set inline completion at cursor position
 371         size_t uniqueTo = max(longestUniqueCompletion().size(), prefix.size());
 372         gui_->bufferView().setInlineCompletion(cur, cur, postfix, uniqueTo - prefix.size());
 373         inlineVisible_ = true;
 374 }
 375
 376
 377 void GuiCompleter::updatePopup(Cursor & cur)
 378 {
 379         if (!cur.inset().completionSupported(cur))
 380                 return;
 381
 382         if (completionCount() == 0)
 383                 return;
 384
 385         // get dimensions of completion prefix
 386         Dimension dim;
 387         int x;
 388         int y;
 389         cur.inset().completionPosAndDim(cur, x, y, dim);
 390
 391         // and calculate the rect of the popup
 392         QRect rect;
 393         if (popup()->layoutDirection() == Qt::RightToLeft)
 394                 rect = QRect(x + dim.width() - 200, y - dim.ascent() - 3, 200, dim.height() + 6);
 395         else
 396                 rect = QRect(x, y - dim.ascent() - 3, 200, dim.height() + 6);
 397
 398         // show/update popup
 399         QTreeView * p = static_cast<QTreeView *>(popup());
 400         p->setColumnWidth(0, popup()->width() - 22 - p->verticalScrollBar()->width());
 401
 402         complete(rect);
 403 }
 404
 405
 406 void GuiCompleter::updateAvailability()
 407 {
 408         // this should really only be of interest if no completion is
 409         // visible yet, i.e. especially if automatic completion is disabled.
 410         if (inlineVisible() || popupVisible())
 411                 return;
 412         Cursor & cur = gui_->bufferView().cursor();
 413         if (!popupPossible(cur) && !inlinePossible(cur))
 414                 return;
 415
 416         updateModel(cur, false, false);
 417 }
 418
 419
 420 void GuiCompleter::updateModel(Cursor & cur, bool popupUpdate, bool inlineUpdate)
 421 {
 422         // value which should be kept selected
 423         QString old = currentCompletion();
 424         if (old.length() == 0)
 425                 old = last_selection_;
 426
 427         // set whether rtl
 428         bool rtl = false;
 429         if (cur.inTexted()) {
 430                 Paragraph const & par = cur.paragraph();
 431                 Font const font =
 432                 par.getFontSettings(cur.bv().buffer().params(), cur.pos());
 433                 rtl = font.isVisibleRightToLeft();
 434         }
 435         popup()->setLayoutDirection(rtl ? Qt::RightToLeft : Qt::LeftToRight);
 436
 437         // turn the direction of the strings in the popup.
 438         // Qt does not do that itself.
 439         popup()->setItemDelegateForColumn(0, rtl ? rtlItemDelegate_ : 0);
 440
 441         // set new model
 442         Inset::CompletionList const * list = cur.inset().createCompletionList(cur);
 443         setModel(new GuiCompletionModel(this, list));
 444         if (list->sorted())
 445                 setModelSorting(QCompleter::CaseSensitivelySortedModel);
 446         else
 447                 setModelSorting(QCompleter::UnsortedModel);
 448
 449         // set prefix
 450         QString newPrefix = toqstr(cur.inset().completionPrefix(cur));
 451         if (newPrefix != completionPrefix())
 452                 setCompletionPrefix(newPrefix);
 453
 454         // show popup
 455         if (popupUpdate)
 456                 updatePopup(cur);
 457
 458         // restore old selection
 459         setCurrentCompletion(old);
 460
 461         // if popup is not empty, the new selection will
 462         // be our last valid one
 463         QString const & s = currentCompletion();
 464         if (s.length() > 0)
 465                 last_selection_ = s;
 466         else
 467                 last_selection_ = old;
 468
 469         // show inline completion
 470         if (inlineUpdate)
 471                 updateInline(cur, currentCompletion());
 472 }
 473
 474
 475 void GuiCompleter::showPopup(Cursor & cur)
 476 {
 477         if (!popupPossible(cur))
 478                 return;
 479
 480         updateModel(cur, true, inlineVisible());
 481 }
 482
 483
 484 void GuiCompleter::hidePopup(Cursor & cur)
 485 {
 486         popup()->hide();
 487         if (popup_timer_.isActive())
 488                 popup_timer_.stop();
 489
 490         if (!inlineVisible())
 491                 setModel(new GuiCompletionModel(this, 0));
 492 }
 493
 494
 495 void GuiCompleter::showInline(Cursor & cur)
 496 {
 497         if (!inlinePossible(cur))
 498                 return;
 499
 500         updateModel(cur, popupVisible(), true);
 501 }
 502
 503
 504 void GuiCompleter::hideInline(Cursor & cur)
 505 {
 506         gui_->bufferView().setInlineCompletion(cur, DocIterator(), docstring());
 507         inlineVisible_ = false;
 508
 509         if (!popupVisible())
 510                 setModel(new GuiCompletionModel(this, 0));
 511 }
 512
 513
 514 void GuiCompleter::showPopup()
 515 {
 516         Cursor cur = gui_->bufferView().cursor();
 517         cur.updateFlags(Update::None);
 518
 519         showPopup(cur);
 520
 521         // redraw if needed
 522         if (cur.disp_.update())
 523                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 524 }
 525
 526
 527 void GuiCompleter::showInline()
 528 {
 529         Cursor cur = gui_->bufferView().cursor();
 530         cur.updateFlags(Update::None);
 531
 532         showInline(cur);
 533
 534         // redraw if needed
 535         if (cur.disp_.update())
 536                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 537 }
 538
 539
 540 void GuiCompleter::hidePopup()
 541 {
 542         Cursor cur = gui_->bufferView().cursor();
 543         cur.updateFlags(Update::None);
 544
 545         hidePopup(cur);
 546
 547         // redraw if needed
 548         if (cur.disp_.update())
 549                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 550 }
 551
 552
 553 void GuiCompleter::hideInline()
 554 {
 555         Cursor cur = gui_->bufferView().cursor();
 556         cur.updateFlags(Update::None);
 557
 558         hideInline(cur);
 559
 560         // redraw if needed
 561         if (cur.disp_.update())
 562                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 563 }
 564
 565
 566 void GuiCompleter::activate()
 567 {
 568         if (!popupVisible() && !inlineVisible())
 569                 return;
 570
 571         popupActivated(currentCompletion());
 572 }
 573
 574
 575 void GuiCompleter::tab()
 576 {
 577         BufferView * bv = &gui_->bufferView();
 578         Cursor cur = bv->cursor();
 579         cur.updateFlags(Update::None);
 580
 581         // check that inline completion is active
 582         if (!inlineVisible()) {
 583                 // try to activate the inline completion
 584                 if (cur.inset().inlineCompletionSupported(cur)) {
 585                         showInline();
 586
 587                         // show popup without delay because the completion was not unique
 588                         if (lyxrc.completion_popup_after_complete
 589                             && !popupVisible()
 590                             && popup()->model()->rowCount() > 1)
 591                                 popup_timer_.start(0);
 592
 593                         return;
 594                 }
 595                 // or try popup
 596                 if (!popupVisible() && cur.inset().completionSupported(cur)) {
 597                         showPopup();
 598                         return;
 599                 }
 600
 601                 return;
 602         }
 603
 604         // If completion is active, at least complete by one character
 605         docstring prefix = cur.inset().completionPrefix(cur);
 606         docstring completion = from_utf8(fromqstr(currentCompletion()));
 607         if (completion.size() <= prefix.size()) {
 608                 // finalize completion
 609                 cur.inset().insertCompletion(cur, docstring(), true);
 610
 611                 // hide popup and inline completion
 612                 hidePopup(cur);
 613                 hideInline(cur);
 614                 updateVisibility(false, false);
 615                 return;
 616         }
 617         docstring nextchar = completion.substr(prefix.size(), 1);
 618         if (!cur.inset().insertCompletion(cur, nextchar, false))
 619                 return;
 620         updatePrefix(cur);
 621
 622         // try to complete as far as it is unique
 623         docstring longestCompletion = longestUniqueCompletion();
 624         prefix = cur.inset().completionPrefix(cur);
 625         docstring postfix = longestCompletion.substr(min(longestCompletion.size(), prefix.size()));
 626         cur.inset().insertCompletion(cur, postfix, false);
 627         old_cursor_ = bv->cursor();
 628         updatePrefix(cur);
 629
 630         // show popup without delay because the completion was not unique
 631         if (lyxrc.completion_popup_after_complete
 632             && !popupVisible()
 633             && popup()->model()->rowCount() > 1)
 634                 popup_timer_.start(0);
 635
 636         // redraw if needed
 637         if (cur.disp_.update())
 638                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 639 }
 640
 641
 642 QString GuiCompleter::currentCompletion() const
 643 {
 644         if (!popup()->selectionModel()->hasSelection())
 645                 return QString();
 646
 647         // Not sure if this is bug in Qt: currentIndex() always
 648         // return the first element in the list.
 649         QModelIndex idx = popup()->currentIndex();
 650         return popup()->model()->data(idx, Qt::EditRole).toString();
 651 }
 652
 653
 654 void GuiCompleter::setCurrentCompletion(QString const & s)
 655 {
 656         QAbstractItemModel const & model = *popup()->model();
 657         size_t n = model.rowCount();
 658         if (n == 0)
 659                 return;
 660
 661         // select the first if s is empty
 662         if (s.length() == 0) {
 663                 updateLock_++;
 664                 popup()->setCurrentIndex(model.index(0, 0));
 665                 updateLock_--;
 666                 return;
 667         }
 668
 669         // find old selection in model
 670         size_t i;
 671         if (modelSorting() == QCompleter::UnsortedModel) {
 672                 // In unsorted models, iterate through list until the s is found
 673                 for (i = 0; i < n; ++i) {
 674                         QString const & is
 675                         = model.data(model.index(i, 0), Qt::EditRole).toString();
 676                         if (is == s)
 677                                 break;
 678                 }
 679         } else {
 680                 // In sorted models, do binary search for s.
 681                 int l = 0;
 682                 int r = n - 1;
 683                 while (r >= l && l < int(n)) {
 684                         size_t mid = (r + l) / 2;
 685                         QString const & mids
 686                         = model.data(model.index(mid, 0),
 687                                      Qt::EditRole).toString();
 688
 689                         // left or right?
 690                         // FIXME: is this really the same order that the docstring
 691                         // from the CompletionList has?
 692                         int c = s.compare(mids, Qt::CaseSensitive);
 693                         if (c == 0) {
 694                                 l = mid;
 695                                 break;
 696                         } else if (l == r) {
 697                                 l = n;
 698                                 break;
 699                         } else if (c > 0)
 700                                 // middle is not far enough
 701                                 l = mid + 1;
 702                         else
 703                                 // middle is too far
 704                                 r = mid - 1;
 705                 }
 706
 707                 // loop was left without finding anything
 708                 if (r < l)
 709                         i = n;
 710                 else
 711                         i = l;
 712                 BOOST_ASSERT(0 <= i && i <= n);
 713         }
 714
 715         // select the first if none was found
 716         if (i == n)
 717                 i = 0;
 718
 719         updateLock_++;
 720         popup()->setCurrentIndex(model.index(i, 0));
 721         updateLock_--;
 722 }
 723
 724
 725 size_t commonPrefix(QString const & s1, QString const & s2)
 726 {
 727         // find common prefix
 728         size_t j;
 729         size_t n1 = s1.length();
 730         size_t n2 = s2.length();
 731         for (j = 0; j < n1 && j < n2; ++j) {
 732                 if (s1.at(j) != s2.at(j))
 733                         break;
 734         }
 735         return j;
 736 }
 737
 738
 739 docstring GuiCompleter::longestUniqueCompletion() const
 740 {
 741         QAbstractItemModel const & model = *popup()->model();
 742         QString s = currentCompletion();
 743         size_t n = model.rowCount();
 744
 745         if (modelSorting() == QCompleter::UnsortedModel) {
 746                 // For unsorted model we cannot do more than iteration.
 747                 // Iterate through the completions and cut off where s differs
 748                 for (size_t i = 0; i < n && s.length() > 0; ++i) {
 749                         QString const & is
 750                         = model.data(model.index(i, 0), Qt::EditRole).toString();
 751
 752                         s = s.left(commonPrefix(is, s));
 753                 }
 754         } else {
 755                 // For sorted models we can do binary search multiple times,
 756                 // each time to find the first string which has s not as prefix.
 757                 size_t i = 0;
 758                 while (i < n && s.length() > 0) {
 759                         // find first string that does not have s as prefix
 760                         // via binary search in [i,n-1]
 761                         size_t r = n - 1;
 762                         do {
 763                                 // get common prefix with the middle string
 764                                 size_t mid = (r + i) / 2;
 765                                 QString const & mids
 766                                 = model.data(model.index(mid, 0),
 767                                         Qt::EditRole).toString();
 768                                 size_t oldLen = s.length();
 769                                 size_t len = commonPrefix(mids, s);
 770                                 s = s.left(len);
 771
 772                                 // left or right?
 773                                 if (oldLen == len) {
 774                                         // middle is not far enough
 775                                         i = mid + 1;
 776                                 } else {
 777                                         // middle is maybe too far
 778                                         r = mid;
 779                                 }
 780                         } while (r - i > 0 && i < n);
 781                 }
 782         }
 783
 784         return from_utf8(fromqstr(s));
 785 }
 786
 787
 788 void GuiCompleter::popupActivated(const QString & completion)
 789 {
 790         Cursor cur = gui_->bufferView().cursor();
 791         cur.updateFlags(Update::None);
 792
 793         docstring prefix = cur.inset().completionPrefix(cur);
 794         docstring postfix = from_utf8(fromqstr(completion.mid(prefix.length())));
 795         cur.inset().insertCompletion(cur, postfix, true);
 796         hidePopup(cur);
 797         hideInline(cur);
 798
 799         if (cur.disp_.update())
 800                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 801 }
 802
 803
 804 void GuiCompleter::popupHighlighted(const QString & completion)
 805 {
 806         if (updateLock_ > 0)
 807                 return;
 808
 809         Cursor cur = gui_->bufferView().cursor();
 810         cur.updateFlags(Update::None);
 811
 812         if (inlineVisible())
 813                 updateInline(cur, completion);
 814
 815         if (cur.disp_.update())
 816                 gui_->bufferView().processUpdateFlags(cur.disp_.update());
 817 }
 818
 819 } // namespace frontend
 820 } // namespace lyx
 821
 822 #include "GuiCompleter_moc.cpp"