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 "GuiCompleter.h"
  14
  15 #include "Buffer.h"
  16 #include "BufferView.h"
  17 #include "CompletionList.h"
  18 #include "Cursor.h"
  19 #include "Dimension.h"
  20 #include "FuncRequest.h"
  21 #include "GuiWorkArea.h"
  22 #include "GuiView.h"
  23 #include "LyX.h"
  24 #include "LyXRC.h"
  25 #include "Paragraph.h"
  26 #include "version.h"
  27
  28 #include "support/lassert.h"
  29 #include "support/debug.h"
  30
  31 #include <QApplication>
  32 #include <QHeaderView>
  33 #include <QPainter>
  34 #include <QPixmapCache>
  35 #include <QScrollBar>
  36 #include <QItemDelegate>
  37 #include <QTreeView>
  38 #include <QTimer>
  39
  40 using namespace std;
  41 using namespace lyx::support;
  42
  43 namespace lyx {
  44 namespace frontend {
  45
  46 class CompleterItemDelegate : public QItemDelegate
  47 {
  48 public:
  49         explicit CompleterItemDelegate(QObject * parent)
  50                 : QItemDelegate(parent)
  51         {}
  52
  53         ~CompleterItemDelegate()
  54         {}
  55
  56 protected:
  57         void paint(QPainter *painter, const QStyleOptionViewItem &option,
  58                    const QModelIndex &index) const
  59         {
  60                 if (index.column() == 0) {
  61                         QItemDelegate::paint(painter, option, index);
  62                         return;
  63                 }
  64                 QStyleOptionViewItem opt = setOptions(index, option);
  65                 QVariant value = index.data(Qt::DisplayRole);
  66                 QPixmap pixmap = qvariant_cast<QPixmap>(value);
  67
  68                 // draw
  69                 painter->save();
  70                 drawBackground(painter, opt, index);
  71                 if (!pixmap.isNull()) {
  72                         const QSize size = pixmap.size();
  73                         painter->drawPixmap(option.rect.left() + (16 - size.width()) / 2,
  74                                 option.rect.top() + (option.rect.height() - size.height()) / 2,
  75                                 pixmap);
  76                 }
  77                 drawFocus(painter, opt, option.rect);
  78                 painter->restore();
  79         }
  80 };
  81
  82 class GuiCompletionModel : public QAbstractListModel
  83 {
  84 public:
  85         ///
  86         GuiCompletionModel(QObject * parent, CompletionList const * l)
  87                 : QAbstractListModel(parent), list_(l)
  88         {}
  89         ///
  90         ~GuiCompletionModel() { delete list_; }
  91         ///
  92         void setList(CompletionList const * l) {
  93                 delete list_;
  94                 list_ = l;
  95                 reset();
  96         }
  97         ///
  98         bool sorted() const
  99         {
 100                 if (list_)
 101                         return list_->sorted();
 102                 return false;
 103         }
 104         ///
 105         int columnCount(const QModelIndex & /*parent*/ = QModelIndex()) const
 106         {
 107                 return 2;
 108         }
 109         ///
 110         int rowCount(const QModelIndex & /*parent*/ = QModelIndex()) const
 111         {
 112                 if (list_ == 0)
 113                         return 0;
 114                 return list_->size();
 115         }
 116
 117         ///
 118         QVariant data(const QModelIndex & index, int role) const
 119         {
 120                 if (list_ == 0)
 121                         return QVariant();
 122
 123                 if (index.row() < 0 || index.row() >= rowCount())
 124                         return QVariant();
 125
 126                 if (role != Qt::DisplayRole && role != Qt::EditRole)
 127                     return QVariant();
 128
 129                 if (index.column() == 0)
 130                         return toqstr(list_->data(index.row()));
 131
 132                 if (index.column() != 1)
 133                         return QVariant();
 134
 135                 // get icon from cache
 136                 QPixmap scaled;
 137                 QString const name = ":" + toqstr(list_->icon(index.row()));
 138                 if (!QPixmapCache::find("completion" + name, scaled)) {
 139                         // load icon from disk
 140                         QPixmap p = QPixmap(name);
 141                         if (!p.isNull()) {
 142                                 // scale it to 16x16 or smaller
 143                                 scaled = p.scaled(min(16, p.width()), min(16, p.height()),
 144                                         Qt::KeepAspectRatio, Qt::SmoothTransformation);
 145                         }
 146                         QPixmapCache::insert("completion" + name, scaled);
 147                 }
 148                 return scaled;
 149         }
 150
 151 private:
 152         /// owned by us
 153         CompletionList const * list_;
 154 };
 155
 156
 157 GuiCompleter::GuiCompleter(GuiWorkArea * gui, QObject * parent)
 158         : QCompleter(parent), gui_(gui), old_cursor_(0), updateLock_(0),
 159           inlineVisible_(false), popupVisible_(false),
 160           modelActive_(false)
 161 {
 162         // Setup the completion popup
 163         model_ = new GuiCompletionModel(this, 0);
 164         setModel(model_);
 165         setCompletionMode(QCompleter::PopupCompletion);
 166         setCaseSensitivity(Qt::CaseInsensitive);
 167         setWidget(gui_);
 168
 169         // create the popup
 170         QTreeView *listView = new QTreeView;
 171         listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
 172         listView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 173         listView->setSelectionBehavior(QAbstractItemView::SelectRows);
 174         listView->setSelectionMode(QAbstractItemView::SingleSelection);
 175         listView->header()->hide();
 176         listView->setIndentation(0);
 177         listView->setUniformRowHeights(true);
 178         setPopup(listView);
 179
 180         itemDelegate_ = new CompleterItemDelegate(this);
 181         popup()->setItemDelegate(itemDelegate_);
 182
 183         // create timeout timers
 184         popup_timer_.setSingleShot(true);
 185         inline_timer_.setSingleShot(true);
 186         connect(this, SIGNAL(highlighted(const QString &)),
 187                 this, SLOT(popupHighlighted(const QString &)));
 188         connect(this, SIGNAL(activated(const QString &)),
 189                 this, SLOT(popupActivated(const QString &)));
 190         connect(&popup_timer_, SIGNAL(timeout()),
 191                 this, SLOT(showPopup()));
 192         connect(&inline_timer_, SIGNAL(timeout()),
 193                 this, SLOT(showInline()));
 194 }
 195
 196
 197 GuiCompleter::~GuiCompleter()
 198 {
 199         popup()->hide();
 200 }
 201
 202
 203 bool GuiCompleter::eventFilter(QObject * watched, QEvent * e)
 204 {
 205         // hijack back the tab key from the popup
 206         // (which stole it from the workspace before)
 207         if (e->type() == QEvent::KeyPress && popupVisible()) {
 208                 QKeyEvent *ke = static_cast<QKeyEvent *>(e);
 209                 switch (ke->key()) {
 210                 case Qt::Key_Tab:
 211                         tab();
 212                         ke->accept();
 213                         return true;
 214                 default: break;
 215                 }
 216         }
 217
 218         return QCompleter::eventFilter(watched, e);
 219 }
 220
 221
 222 bool GuiCompleter::popupPossible(Cursor const & cur) const
 223 {
 224         return QApplication::activeWindow()
 225                 && gui_->hasFocus()
 226                 && cur.inset().completionSupported(cur);
 227 }
 228
 229
 230 bool GuiCompleter::inlinePossible(Cursor const & cur) const
 231 {
 232         return cur.inset().inlineCompletionSupported(cur);
 233 }
 234
 235
 236 bool GuiCompleter::uniqueCompletionAvailable() const
 237 {
 238         if (!modelActive_)
 239                 return false;
 240
 241         size_t n = popup()->model()->rowCount();
 242         if (n > 1 || n == 0)
 243                 return false;
 244
 245         // if there is exactly one, we have to check whether it is a
 246         // real completion, i.e. longer than the current prefix.
 247         if (completionPrefix() == currentCompletion())
 248                 return false;
 249
 250         return true;
 251 }
 252
 253
 254 bool GuiCompleter::completionAvailable() const
 255 {
 256         if (!modelActive_)
 257                 return false;
 258
 259         size_t n = popup()->model()->rowCount();
 260
 261         // if there is exactly one, we have to check whether it is a
 262         // real completion, i.e. longer than the current prefix.
 263         if (n == 1 && completionPrefix() == currentCompletion())
 264             return false;
 265
 266         return n > 0;
 267 }
 268
 269
 270 bool GuiCompleter::popupVisible() const
 271 {
 272         return popupVisible_;
 273 }
 274
 275
 276 bool GuiCompleter::inlineVisible() const
 277 {
 278         // In fact using BufferView::inlineCompletionPos.empty() should be
 279         // here. But unfortunately this information is not good enough
 280         // because destructive operations like backspace might invalidate
 281         // inlineCompletionPos. But then the completion should stay visible
 282         // (i.e. reshown on the next update). Hence be keep this information
 283         // in the inlineVisible_ variable.
 284         return inlineVisible_;
 285 }
 286
 287
 288 void GuiCompleter::updateVisibility(Cursor & cur, bool start, bool keep, bool cursorInView)
 289 {
 290         // parameters which affect the completion
 291         bool moved = cur != old_cursor_;
 292         if (moved)
 293                 old_cursor_ = cur;
 294
 295         bool possiblePopupState = popupPossible(cur) && cursorInView;
 296         bool possibleInlineState = inlinePossible(cur) && cursorInView;
 297
 298         // we moved or popup state is not ok for popup?
 299         if ((moved && !keep) || !possiblePopupState)
 300                 hidePopup(cur);
 301
 302         // we moved or inline state is not ok for inline completion?
 303         if ((moved && !keep) || !possibleInlineState)
 304                 hideInline(cur);
 305
 306         // we inserted something and are in a possible popup state?
 307         if (!popupVisible() && possiblePopupState && start
 308                 && cur.inset().automaticPopupCompletion())
 309                 popup_timer_.start(int(lyxrc.completion_popup_delay * 1000));
 310
 311         // we inserted something and are in a possible inline completion state?
 312         if (!inlineVisible() && possibleInlineState && start
 313                 && cur.inset().automaticInlineCompletion())
 314                 inline_timer_.start(int(lyxrc.completion_inline_delay * 1000));
 315         else {
 316                 // no inline completion, hence a metrics update is needed
 317                 if (!(cur.result().update() & Update::Force))
 318                         cur.screenUpdateFlags(cur.result().update() | Update::SinglePar);
 319         }
 320
 321         // update prefix if any completion is possible
 322         bool modelActive = modelActive_ && model()->rowCount() > 0;
 323         if (possiblePopupState || possibleInlineState) {
 324                 if (modelActive)
 325                         updatePrefix(cur);
 326                 else
 327                         updateAvailability();
 328         }
 329 }
 330
 331
 332 void GuiCompleter::updateVisibility(bool start, bool keep)
 333 {
 334         Cursor cur = gui_->bufferView().cursor();
 335         cur.screenUpdateFlags(Update::None);
 336
 337         updateVisibility(cur, start, keep);
 338
 339         if (cur.result().update())
 340                 gui_->bufferView().processUpdateFlags(cur.result().update());
 341 }
 342
 343
 344 void GuiCompleter::updatePrefix(Cursor & cur)
 345 {
 346         // get new prefix. Do nothing if unchanged
 347         QString newPrefix = toqstr(cur.inset().completionPrefix(cur));
 348         if (newPrefix == completionPrefix())
 349                 return;
 350
 351         // value which should be kept selected
 352         QString old = currentCompletion();
 353         if (old.length() == 0)
 354                 old = last_selection_;
 355
 356         // update completer to new prefix
 357         setCompletionPrefix(newPrefix);
 358
 359         // update popup because its size might have changed
 360         if (popupVisible())
 361                 updatePopup(cur);
 362
 363         // restore old selection
 364         setCurrentCompletion(old);
 365
 366         // if popup is not empty, the new selection will
 367         // be our last valid one
 368         QString const & s = currentCompletion();
 369         if (popupVisible() || inlineVisible()) {
 370                 if (s.length() > 0)
 371                         last_selection_ = s;
 372                 else
 373                         last_selection_ = old;
 374         }
 375
 376         // update inline completion because the default
 377         // completion string might have changed
 378         if (inlineVisible())
 379                 updateInline(cur, s);
 380 }
 381
 382
 383 void GuiCompleter::updateInline(Cursor & cur, QString const & completion)
 384 {
 385         if (!cur.inset().inlineCompletionSupported(cur))
 386                 return;
 387
 388         // compute postfix
 389         docstring prefix = cur.inset().completionPrefix(cur);
 390         docstring postfix = qstring_to_ucs4(completion.mid(prefix.length()));
 391
 392         // shorten it if necessary
 393         if (lyxrc.completion_inline_dots != -1
 394             && postfix.size() > unsigned(lyxrc.completion_inline_dots))
 395                 postfix = postfix.substr(0, lyxrc.completion_inline_dots - 1) + "...";
 396
 397         // set inline completion at cursor position
 398         size_t uniqueTo = max(longestUniqueCompletion().size(), prefix.size());
 399         gui_->bufferView().setInlineCompletion(cur, cur, postfix, uniqueTo - prefix.size());
 400         inlineVisible_ = true;
 401 }
 402
 403
 404 void GuiCompleter::updatePopup(Cursor & cur)
 405 {
 406         if (!cur.inset().completionSupported(cur))
 407                 return;
 408
 409         popupVisible_ = true;
 410
 411         if (completionCount() == 0) {
 412                 QTimer::singleShot(0, popup(), SLOT(hide()));
 413                 return;
 414         }
 415
 416         QTimer::singleShot(0, this, SLOT(asyncUpdatePopup()));
 417 }
 418
 419
 420 void GuiCompleter::asyncUpdatePopup()
 421 {
 422         Cursor cur = gui_->bufferView().cursor();
 423         if (!cur.inset().completionSupported(cur)
 424                   || !cur.bv().paragraphVisible(cur)) {
 425                 popupVisible_ = false;
 426                 return;
 427         }
 428
 429         // get dimensions of completion prefix
 430         Dimension dim;
 431         int x;
 432         int y;
 433         cur.inset().completionPosAndDim(cur, x, y, dim);
 434
 435         // and calculate the rect of the popup
 436         QRect rect;
 437         if (popup()->layoutDirection() == Qt::RightToLeft)
 438                 rect = QRect(x + dim.width() - 200, y - dim.ascent() - 3, 200, dim.height() + 6);
 439         else
 440                 rect = QRect(x, y - dim.ascent() - 3, 200, dim.height() + 6);
 441
 442         // Resize the columns in the popup.
 443         // This should really be in the constructor. But somehow the treeview
 444         // has a bad memory about it and we have to tell him again and again.
 445         QTreeView * listView = static_cast<QTreeView *>(popup());
 446         listView->header()->setStretchLastSection(false);
 447         listView->header()->setResizeMode(0, QHeaderView::Stretch);
 448         listView->header()->setResizeMode(1, QHeaderView::Fixed);
 449         listView->header()->resizeSection(1, 22);
 450
 451         // show/update popup
 452         complete(rect);
 453 }
 454
 455
 456 void GuiCompleter::updateAvailability()
 457 {
 458         // this should really only be of interest if no completion is
 459         // visible yet, i.e. especially if automatic completion is disabled.
 460         if (inlineVisible() || popupVisible())
 461                 return;
 462         Cursor & cur = gui_->bufferView().cursor();
 463         if (!popupPossible(cur) && !inlinePossible(cur))
 464                 return;
 465
 466         updateModel(cur, false, false);
 467 }
 468
 469
 470 void GuiCompleter::updateModel(Cursor & cur, bool popupUpdate, bool inlineUpdate)
 471 {
 472         // value which should be kept selected
 473         QString old = currentCompletion();
 474         if (old.length() == 0)
 475                 old = last_selection_;
 476
 477         // set whether rtl
 478         bool rtl = false;
 479         if (cur.inTexted()) {
 480                 Paragraph const & par = cur.paragraph();
 481                 Font const & font =
 482                         par.getFontSettings(cur.bv().buffer().params(), cur.pos());
 483                 rtl = font.isVisibleRightToLeft();
 484         }
 485         popup()->setLayoutDirection(rtl ? Qt::RightToLeft : Qt::LeftToRight);
 486
 487         // set new model
 488         CompletionList const * list = cur.inset().createCompletionList(cur);
 489         model_->setList(list);
 490         modelActive_ = true;
 491         if (list->sorted())
 492                 setModelSorting(QCompleter::CaseSensitivelySortedModel);
 493         else
 494                 setModelSorting(QCompleter::UnsortedModel);
 495
 496         // set prefix
 497         QString newPrefix = toqstr(cur.inset().completionPrefix(cur));
 498         if (newPrefix != completionPrefix())
 499                 setCompletionPrefix(newPrefix);
 500
 501         // show popup
 502         if (popupUpdate)
 503                 updatePopup(cur);
 504
 505         // restore old selection
 506         setCurrentCompletion(old);
 507
 508         // if popup is not empty, the new selection will
 509         // be our last valid one
 510         if (popupVisible() || inlineVisible()) {
 511                 QString const & s = currentCompletion();
 512                 if (s.length() > 0)
 513                         last_selection_ = s;
 514                 else
 515                         last_selection_ = old;
 516         }
 517
 518         // show inline completion
 519         if (inlineUpdate)
 520                 updateInline(cur, currentCompletion());
 521 }
 522
 523
 524 void GuiCompleter::showPopup(Cursor & cur)
 525 {
 526         if (!popupPossible(cur))
 527                 return;
 528
 529         updateModel(cur, true, inlineVisible());
 530 }
 531
 532
 533 void GuiCompleter::hidePopup(Cursor &)
 534 {
 535         popupVisible_ = false;
 536
 537         if (popup_timer_.isActive())
 538                 popup_timer_.stop();
 539
 540         // hide popup asynchronously because we might be here inside of
 541         // LFUN dispatchers. Hiding a popup can trigger a focus event on the
 542         // workarea which then redisplays the cursor. But the metrics are not
 543         // yet up to date such that the coord cache has not all insets yet. The
 544         // cursorPos methods would triggers asserts in the coord cache then.
 545         QTimer::singleShot(0, this, SLOT(asyncHidePopup()));
 546
 547         // mark that the asynchronous part will reset the model
 548         if (!inlineVisible())
 549                 modelActive_ = false;
 550 }
 551
 552
 553 void GuiCompleter::asyncHidePopup()
 554 {
 555         popup()->hide();
 556         if (!inlineVisible())
 557                 model_->setList(0);
 558 }
 559
 560
 561 void GuiCompleter::showInline(Cursor & cur)
 562 {
 563         if (!inlinePossible(cur))
 564                 return;
 565
 566         updateModel(cur, popupVisible(), true);
 567 }
 568
 569
 570 void GuiCompleter::hideInline(Cursor & cur)
 571 {
 572         gui_->bufferView().setInlineCompletion(cur, DocIterator(cur.buffer()), docstring());
 573         inlineVisible_ = false;
 574
 575         if (inline_timer_.isActive())
 576                 inline_timer_.stop();
 577
 578         // Trigger asynchronous part of hideInline. We might be
 579         // in a dispatcher here and the setModel call might
 580         // trigger focus events which is are not healthy here.
 581         QTimer::singleShot(0, this, SLOT(asyncHideInline()));
 582
 583         // mark that the asynchronous part will reset the model
 584         if (!popupVisible())
 585                 modelActive_ = false;
 586 }
 587
 588
 589 void GuiCompleter::asyncHideInline()
 590 {
 591         if (!popupVisible())
 592                 model_->setList(0);
 593 }
 594
 595
 596 void GuiCompleter::showPopup()
 597 {
 598         Cursor cur = gui_->bufferView().cursor();
 599         cur.screenUpdateFlags(Update::None);
 600
 601         showPopup(cur);
 602
 603         // redraw if needed
 604         if (cur.result().update())
 605                 gui_->bufferView().processUpdateFlags(cur.result().update());
 606 }
 607
 608
 609 void GuiCompleter::showInline()
 610 {
 611         Cursor cur = gui_->bufferView().cursor();
 612         cur.screenUpdateFlags(Update::None);
 613
 614         showInline(cur);
 615
 616         // redraw if needed
 617         if (cur.result().update())
 618                 gui_->bufferView().processUpdateFlags(cur.result().update());
 619 }
 620
 621
 622 void GuiCompleter::hidePopup()
 623 {
 624         Cursor cur = gui_->bufferView().cursor();
 625         cur.screenUpdateFlags(Update::None);
 626
 627         hidePopup(cur);
 628
 629         // redraw if needed
 630         if (cur.result().update())
 631                 gui_->bufferView().processUpdateFlags(cur.result().update());
 632 }
 633
 634
 635 void GuiCompleter::hideInline()
 636 {
 637         Cursor cur = gui_->bufferView().cursor();
 638         cur.screenUpdateFlags(Update::None);
 639
 640         hideInline(cur);
 641
 642         // redraw if needed
 643         if (cur.result().update())
 644                 gui_->bufferView().processUpdateFlags(cur.result().update());
 645 }
 646
 647
 648 void GuiCompleter::activate()
 649 {
 650         if (!popupVisible() && !inlineVisible())
 651                 tab();
 652         else
 653                 popupActivated(currentCompletion());
 654 }
 655
 656
 657 void GuiCompleter::tab()
 658 {
 659         BufferView * bv = &gui_->bufferView();
 660         Cursor cur = bv->cursor();
 661         cur.screenUpdateFlags(Update::None);
 662
 663         // check that inline completion is active
 664         if (!inlineVisible() && !uniqueCompletionAvailable()) {
 665                 // try to activate the inline completion
 666                 if (cur.inset().inlineCompletionSupported(cur)) {
 667                         showInline();
 668
 669                         // show popup without delay because the completion was not unique
 670                         if (lyxrc.completion_popup_after_complete
 671                             && !popupVisible()
 672                             && popup()->model()->rowCount() > 1)
 673                                 popup_timer_.start(0);
 674
 675                         return;
 676                 }
 677                 // or try popup
 678                 if (!popupVisible() && cur.inset().completionSupported(cur)) {
 679                         showPopup();
 680                         return;
 681                 }
 682
 683                 return;
 684         }
 685
 686         // Make undo possible
 687         cur.recordUndo();
 688
 689         // If completion is active, at least complete by one character
 690         docstring prefix = cur.inset().completionPrefix(cur);
 691         docstring completion = qstring_to_ucs4(currentCompletion());
 692         if (completion.size() <= prefix.size()) {
 693                 // finalize completion
 694                 cur.inset().insertCompletion(cur, docstring(), true);
 695
 696                 // hide popup and inline completion
 697                 hidePopup(cur);
 698                 hideInline(cur);
 699                 updateVisibility(false, false);
 700                 return;
 701         }
 702         docstring nextchar = completion.substr(prefix.size(), 1);
 703         if (!cur.inset().insertCompletion(cur, nextchar, false))
 704                 return;
 705         updatePrefix(cur);
 706
 707         // try to complete as far as it is unique
 708         docstring longestCompletion = longestUniqueCompletion();
 709         prefix = cur.inset().completionPrefix(cur);
 710         docstring postfix = longestCompletion.substr(min(longestCompletion.size(), prefix.size()));
 711         cur.inset().insertCompletion(cur, postfix, false);
 712         old_cursor_ = bv->cursor();
 713         updatePrefix(cur);
 714
 715         // show popup without delay because the completion was not unique
 716         if (lyxrc.completion_popup_after_complete
 717             && !popupVisible()
 718             && popup()->model()->rowCount() > 1)
 719                 popup_timer_.start(0);
 720
 721         // redraw if needed
 722         if (cur.result().update())
 723                 gui_->bufferView().processUpdateFlags(cur.result().update());
 724 }
 725
 726
 727 QString GuiCompleter::currentCompletion() const
 728 {
 729         if (!popup()->selectionModel()->hasSelection())
 730                 return QString();
 731
 732         // Not sure if this is bug in Qt: currentIndex() always
 733         // return the first element in the list.
 734         QModelIndex idx = popup()->currentIndex();
 735         return popup()->model()->data(idx, Qt::EditRole).toString();
 736 }
 737
 738
 739 void GuiCompleter::setCurrentCompletion(QString const & s)
 740 {
 741         QAbstractItemModel const & model = *popup()->model();
 742         size_t n = model.rowCount();
 743         if (n == 0)
 744                 return;
 745
 746         // select the first if s is empty
 747         if (s.length() == 0) {
 748                 updateLock_++;
 749                 popup()->setCurrentIndex(model.index(0, 0));
 750                 updateLock_--;
 751                 return;
 752         }
 753
 754         // find old selection in model
 755         size_t i;
 756         if (modelSorting() == QCompleter::UnsortedModel) {
 757                 // In unsorted models, iterate through list until the s is found
 758                 for (i = 0; i < n; ++i) {
 759                         QString const & is
 760                         = model.data(model.index(i, 0), Qt::EditRole).toString();
 761                         if (is == s)
 762                                 break;
 763                 }
 764         } else {
 765                 // In sorted models, do binary search for s.
 766                 int l = 0;
 767                 int r = n - 1;
 768                 while (r >= l && l < int(n)) {
 769                         size_t mid = (r + l) / 2;
 770                         QString const & mids
 771                         = model.data(model.index(mid, 0),
 772                                      Qt::EditRole).toString();
 773
 774                         // left or right?
 775                         // FIXME: is this really the same order that the docstring
 776                         // from the CompletionList has?
 777                         int c = s.compare(mids, Qt::CaseSensitive);
 778                         if (c == 0) {
 779                                 l = mid;
 780                                 break;
 781                         } else if (l == r) {
 782                                 l = n;
 783                                 break;
 784                         } else if (c > 0)
 785                                 // middle is not far enough
 786                                 l = mid + 1;
 787                         else
 788                                 // middle is too far
 789                                 r = mid - 1;
 790                 }
 791
 792                 // loop was left without finding anything
 793                 if (r < l)
 794                         i = n;
 795                 else
 796                         i = l;
 797                 LASSERT(i <= n, /**/);
 798         }
 799
 800         // select the first if none was found
 801         if (i == n)
 802                 i = 0;
 803
 804         updateLock_++;
 805         popup()->setCurrentIndex(model.index(i, 0));
 806         updateLock_--;
 807 }
 808
 809
 810 size_t commonPrefix(QString const & s1, QString const & s2)
 811 {
 812         // find common prefix
 813         size_t j;
 814         size_t n1 = s1.length();
 815         size_t n2 = s2.length();
 816         for (j = 0; j < n1 && j < n2; ++j) {
 817                 if (s1.at(j) != s2.at(j))
 818                         break;
 819         }
 820         return j;
 821 }
 822
 823
 824 docstring GuiCompleter::longestUniqueCompletion() const
 825 {
 826         QAbstractItemModel const & model = *popup()->model();
 827         size_t n = model.rowCount();
 828         if (n == 0)
 829                 return docstring();
 830         QString s = model.data(model.index(0, 0), Qt::EditRole).toString();
 831
 832         if (modelSorting() == QCompleter::UnsortedModel) {
 833                 // For unsorted model we cannot do more than iteration.
 834                 // Iterate through the completions and cut off where s differs
 835                 for (size_t i = 0; i < n && s.length() > 0; ++i) {
 836                         QString const & is
 837                         = model.data(model.index(i, 0), Qt::EditRole).toString();
 838
 839                         s = s.left(commonPrefix(is, s));
 840                 }
 841         } else {
 842                 // For sorted models we can do binary search multiple times,
 843                 // each time to find the first string which has s not as prefix.
 844                 size_t i = 0;
 845                 while (i < n && s.length() > 0) {
 846                         // find first string that does not have s as prefix
 847                         // via binary search in [i,n-1]
 848                         size_t r = n - 1;
 849                         do {
 850                                 // get common prefix with the middle string
 851                                 size_t mid = (r + i) / 2;
 852                                 QString const & mids
 853                                 = model.data(model.index(mid, 0),
 854                                         Qt::EditRole).toString();
 855                                 size_t oldLen = s.length();
 856                                 size_t len = commonPrefix(mids, s);
 857                                 s = s.left(len);
 858
 859                                 // left or right?
 860                                 if (oldLen == len) {
 861                                         // middle is not far enough
 862                                         i = mid + 1;
 863                                 } else {
 864                                         // middle is maybe too far
 865                                         r = mid;
 866                                 }
 867                         } while (r - i > 0 && i < n);
 868                 }
 869         }
 870
 871         return qstring_to_ucs4(s);
 872 }
 873
 874
 875 void GuiCompleter::popupActivated(const QString & completion)
 876 {
 877         Cursor cur = gui_->bufferView().cursor();
 878         cur.screenUpdateFlags(Update::None);
 879
 880         cur.recordUndo();
 881
 882         docstring prefix = cur.inset().completionPrefix(cur);
 883         docstring postfix = qstring_to_ucs4(completion.mid(prefix.length()));
 884         cur.inset().insertCompletion(cur, postfix, true);
 885         hidePopup(cur);
 886         hideInline(cur);
 887
 888         if (cur.result().update())
 889                 gui_->bufferView().processUpdateFlags(cur.result().update());
 890 }
 891
 892
 893 void GuiCompleter::popupHighlighted(const QString & completion)
 894 {
 895         if (updateLock_ > 0)
 896                 return;
 897
 898         Cursor cur = gui_->bufferView().cursor();
 899         cur.screenUpdateFlags(Update::None);
 900
 901         if (inlineVisible())
 902                 updateInline(cur, completion);
 903
 904         if (cur.result().update())
 905                 gui_->bufferView().processUpdateFlags(cur.result().update());
 906 }
 907
 908 } // namespace frontend
 909 } // namespace lyx
 910
 911 #include "moc_GuiCompleter.cpp"