src/frontends/qt4/GuiWorkArea.cpp

   1 /**
   2  * \file GuiWorkArea.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author John Levon
   7  * \author Abdelrazak Younes
   8  *
   9  * Full author contact details are available in file CREDITS.
  10  */
  11
  12 #include <config.h>
  13
  14 #include "GuiWorkArea.h"
  15
  16 #include "GuiApplication.h"
  17 #include "QLPainter.h"
  18 #include "QKeySymbol.h"
  19 #include "qt_helpers.h"
  20
  21 #include "LyXView.h"
  22
  23 #include "BufferView.h"
  24 #include "rowpainter.h"
  25 #include "debug.h"
  26 #include "FuncRequest.h"
  27 #include "Color.h"
  28 #include "version.h"
  29 #include "LyXRC.h"
  30
  31 #include "support/filetools.h" // LibFileSearch
  32 #include "support/os.h"
  33 #include "support/convert.h"
  34
  35 #include "graphics/GraphicsImage.h"
  36 #include "graphics/GraphicsLoader.h"
  37
  38 #include <QLayout>
  39 #include <QMainWindow>
  40 #include <QMimeData>
  41 #include <QUrl>
  42 #include <QDragEnterEvent>
  43 #include <QPainter>
  44 #include <QScrollBar>
  45 #include <QTimer>
  46 #include <QInputContext>
  47
  48 #include <boost/bind.hpp>
  49 #include <boost/current_function.hpp>
  50
  51 #ifdef Q_WS_X11
  52 #include <QX11Info>
  53 extern "C" int XEventsQueued(Display *display, int mode);
  54 #endif
  55
  56 #ifdef Q_WS_WIN
  57 int const CursorWidth = 2;
  58 #else
  59 int const CursorWidth = 1;
  60 #endif
  61
  62
  63 using std::endl;
  64 using std::string;
  65
  66 namespace os = lyx::support::os;
  67
  68
  69 namespace lyx {
  70
  71 using support::FileName;
  72
  73 /// return the LyX key state from Qt's
  74 static key_modifier::state q_key_state(Qt::KeyboardModifiers state)
  75 {
  76         key_modifier::state k = key_modifier::none;
  77         if (state & Qt::ControlModifier)
  78                 k |= key_modifier::ctrl;
  79         if (state & Qt::ShiftModifier)
  80                 k |= key_modifier::shift;
  81         if (state & Qt::AltModifier || state & Qt::MetaModifier)
  82                 k |= key_modifier::alt;
  83         return k;
  84 }
  85
  86
  87 /// return the LyX mouse button state from Qt's
  88 static mouse_button::state q_button_state(Qt::MouseButton button)
  89 {
  90         mouse_button::state b = mouse_button::none;
  91         switch (button) {
  92                 case Qt::LeftButton:
  93                         b = mouse_button::button1;
  94                         break;
  95                 case Qt::MidButton:
  96                         b = mouse_button::button2;
  97                         break;
  98                 case Qt::RightButton:
  99                         b = mouse_button::button3;
 100                         break;
 101                 default:
 102                         break;
 103         }
 104         return b;
 105 }
 106
 107
 108 /// return the LyX mouse button state from Qt's
 109 mouse_button::state q_motion_state(Qt::MouseButtons state)
 110 {
 111         mouse_button::state b = mouse_button::none;
 112         if (state & Qt::LeftButton)
 113                 b |= mouse_button::button1;
 114         if (state & Qt::MidButton)
 115                 b |= mouse_button::button2;
 116         if (state & Qt::RightButton)
 117                 b |= mouse_button::button3;
 118         return b;
 119 }
 120
 121
 122 namespace frontend {
 123
 124 class CursorWidget {
 125 public:
 126         CursorWidget() {}
 127
 128         void draw(QPainter & painter)
 129         {
 130                 if (show_ && rect_.isValid()) {
 131                         switch (shape_) {
 132                         case L_SHAPE:
 133                                 painter.fillRect(rect_.x(), rect_.y(), CursorWidth, rect_.height(), color_);
 134                                 painter.setPen(color_);
 135                                 painter.drawLine(rect_.bottomLeft().x() + CursorWidth, rect_.bottomLeft().y(),
 136                                                                                                  rect_.bottomRight().x(), rect_.bottomLeft().y());
 137                                 break;
 138
 139                         case REVERSED_L_SHAPE:
 140                                 painter.fillRect(rect_.x() + rect_.height() / 3, rect_.y(), CursorWidth, rect_.height(), color_);
 141                                 painter.setPen(color_);
 142                                 painter.drawLine(rect_.bottomRight().x() - CursorWidth, rect_.bottomLeft().y(),
 143                                                                                                          rect_.bottomLeft().x(), rect_.bottomLeft().y());
 144                                 break;
 145
 146                         default:
 147                                 painter.fillRect(rect_, color_);
 148                                 break;
 149                         }
 150                 }
 151         }
 152
 153         void update(int x, int y, int h, CursorShape shape)
 154         {
 155                 color_ = guiApp->colorCache().get(Color::cursor);
 156                 shape_ = shape;
 157                 switch (shape) {
 158                 case L_SHAPE:
 159                         rect_ = QRect(x, y, CursorWidth + h / 3, h);
 160                         break;
 161                 case REVERSED_L_SHAPE:
 162                         rect_ = QRect(x - h / 3, y, CursorWidth + h / 3, h);
 163                         break;
 164                 default:
 165                         rect_ = QRect(x, y, CursorWidth, h);
 166                         break;
 167                 }
 168         }
 169
 170         void show(bool set_show = true) { show_ = set_show; }
 171         void hide() { show_ = false; }
 172
 173         QRect const & rect() { return rect_; }
 174
 175 private:
 176         ///
 177         CursorShape shape_;
 178         ///
 179         bool show_;
 180         ///
 181         QColor color_;
 182         ///
 183         QRect rect_;
 184 };
 185
 186
 187 // This is a 'heartbeat' generating synthetic mouse move events when the
 188 // cursor is at the top or bottom edge of the viewport. One scroll per 0.2 s
 189 SyntheticMouseEvent::SyntheticMouseEvent()
 190         : timeout(200), restart_timeout(true),
 191           x_old(-1), y_old(-1), scrollbar_value_old(-1.0)
 192 {}
 193
 194
 195 GuiWorkArea::GuiWorkArea(int w, int h, int id, LyXView & lyx_view)
 196         : WorkArea(id, lyx_view), need_resize_(false), schedule_redraw_(false),
 197           preedit_lines_(1)
 198 {
 199         screen_ = QPixmap(viewport()->width(), viewport()->height());
 200         cursor_ = new frontend::CursorWidget();
 201         cursor_->hide();
 202
 203         setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
 204         setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
 205         setAcceptDrops(true);
 206         setMouseTracking(true);
 207         setMinimumSize(100, 70);
 208
 209         viewport()->setAutoFillBackground(false);
 210         // We don't need double-buffering nor SystemBackground on
 211         // the viewport because we have our own backing pixmap.
 212         viewport()->setAttribute(Qt::WA_NoSystemBackground);
 213
 214         setFocusPolicy(Qt::WheelFocus);
 215
 216         viewport()->setCursor(Qt::IBeamCursor);
 217
 218         resize(w, h);
 219
 220         synthetic_mouse_event_.timeout.timeout.connect(
 221                 boost::bind(&GuiWorkArea::generateSyntheticMouseEvent,
 222                             this));
 223
 224         // Initialize the vertical Scroll Bar
 225         QObject::connect(verticalScrollBar(), SIGNAL(actionTriggered(int)),
 226                 this, SLOT(adjustViewWithScrollBar(int)));
 227
 228         // disable context menu for the scrollbar
 229         verticalScrollBar()->setContextMenuPolicy(Qt::NoContextMenu);
 230
 231         // PageStep only depends on the viewport height.
 232         verticalScrollBar()->setPageStep(viewport()->height());
 233
 234         LYXERR(Debug::GUI) << BOOST_CURRENT_FUNCTION
 235                 << "\n Area width\t" << width()
 236                 << "\n Area height\t" << height()
 237                 << "\n viewport width\t" << viewport()->width()
 238                 << "\n viewport height\t" << viewport()->height()
 239                 << endl;
 240
 241         // Enables input methods for asian languages.
 242         // Must be set when creating custom text editing widgets.
 243         setAttribute(Qt::WA_InputMethodEnabled, true);
 244 }
 245
 246
 247 void GuiWorkArea::setScrollbarParams(int h, int scroll_pos, int scroll_line_step)
 248 {
 249         if (verticalScrollBarPolicy() != Qt::ScrollBarAlwaysOn)
 250                 setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
 251
 252         verticalScrollBar()->setTracking(false);
 253
 254         // do what cursor movement does (some grey)
 255         h += height() / 4;
 256         int scroll_max_ = std::max(0, h - height());
 257
 258         verticalScrollBar()->setRange(0, scroll_max_);
 259         verticalScrollBar()->setSliderPosition(scroll_pos);
 260         verticalScrollBar()->setSingleStep(scroll_line_step);
 261         verticalScrollBar()->setValue(scroll_pos);
 262
 263         verticalScrollBar()->setTracking(true);
 264 }
 265
 266
 267 void GuiWorkArea::adjustViewWithScrollBar(int)
 268 {
 269         scrollBufferView(verticalScrollBar()->sliderPosition());
 270         QApplication::syncX();
 271 }
 272
 273
 274 void GuiWorkArea::dragEnterEvent(QDragEnterEvent * event)
 275 {
 276         if (event->mimeData()->hasUrls())
 277                 event->accept();
 278         /// \todo Ask lyx-devel is this is enough:
 279         /// if (event->mimeData()->hasFormat("text/plain"))
 280         ///     event->acceptProposedAction();
 281 }
 282
 283
 284 void GuiWorkArea::dropEvent(QDropEvent* event)
 285 {
 286         QList<QUrl> files = event->mimeData()->urls();
 287         if (files.isEmpty())
 288                 return;
 289
 290         LYXERR(Debug::GUI) << "GuiWorkArea::dropEvent: got URIs!" << endl;
 291         for (int i = 0; i!=files.size(); ++i) {
 292                 string const file = os::internal_path(fromqstr(files.at(i).toLocalFile()));
 293                 if (!file.empty())
 294                         dispatch(FuncRequest(LFUN_FILE_OPEN, file));
 295         }
 296 }
 297
 298
 299 void GuiWorkArea::focusInEvent(QFocusEvent * /*event*/)
 300 {
 301         // No need to do anything if we didn't change views...
 302 //      if (theApp() == 0 || &lyx_view_ == theApp()->currentView())
 303 //              return;
 304
 305         theApp()->setCurrentView(lyx_view_);
 306
 307         // Repaint the whole screen.
 308         // Note: this is different from redraw() as only the backing pixmap
 309         // will be redrawn, which is cheap.
 310         viewport()->repaint();
 311
 312         // FIXME: it would be better to send a signal "newBuffer()"
 313         // in BufferList that could be connected to the different tabbars.
 314         lyx_view_.updateTab();
 315
 316         startBlinkingCursor();
 317 }
 318
 319
 320 void GuiWorkArea::focusOutEvent(QFocusEvent * /*event*/)
 321 {
 322         stopBlinkingCursor();
 323 }
 324
 325
 326 void GuiWorkArea::mousePressEvent(QMouseEvent * e)
 327 {
 328         if (dc_event_.active && dc_event_ == *e) {
 329                 dc_event_.active = false;
 330                 FuncRequest cmd(LFUN_MOUSE_TRIPLE,
 331                         e->x(), e->y(),
 332                         q_button_state(e->button()));
 333                 dispatch(cmd);
 334                 return;
 335         }
 336
 337         inputContext()->reset();
 338
 339         FuncRequest const cmd(LFUN_MOUSE_PRESS, e->x(), e->y(),
 340                 q_button_state(e->button()));
 341         dispatch(cmd, q_key_state(e->modifiers()));
 342 }
 343
 344
 345 void GuiWorkArea::mouseReleaseEvent(QMouseEvent * e)
 346 {
 347         if (synthetic_mouse_event_.timeout.running())
 348                 synthetic_mouse_event_.timeout.stop();
 349
 350         FuncRequest const cmd(LFUN_MOUSE_RELEASE, e->x(), e->y(),
 351                               q_button_state(e->button()));
 352         dispatch(cmd);
 353 }
 354
 355
 356 void GuiWorkArea::mouseMoveEvent(QMouseEvent * e)
 357 {
 358         // we kill the triple click if we move
 359         doubleClickTimeout();
 360         FuncRequest cmd(LFUN_MOUSE_MOTION, e->x(), e->y(),
 361                               q_motion_state(e->buttons()));
 362
 363         // If we're above or below the work area...
 364         if (e->y() <= 20 || e->y() >= viewport()->height() - 20) {
 365                 // Make sure only a synthetic event can cause a page scroll,
 366                 // so they come at a steady rate:
 367                 if (e->y() <= 20)
 368                         // _Force_ a scroll up:
 369                         cmd.y = -40;
 370                 else
 371                         cmd.y = viewport()->height();
 372                 // Store the event, to be handled when the timeout expires.
 373                 synthetic_mouse_event_.cmd = cmd;
 374
 375                 if (synthetic_mouse_event_.timeout.running())
 376                         // Discard the event. Note that it _may_ be handled
 377                         // when the timeout expires if
 378                         // synthetic_mouse_event_.cmd has not been overwritten.
 379                         // Ie, when the timeout expires, we handle the
 380                         // most recent event but discard all others that
 381                         // occurred after the one used to start the timeout
 382                         // in the first place.
 383                         return;
 384                 else {
 385                         synthetic_mouse_event_.restart_timeout = true;
 386                         synthetic_mouse_event_.timeout.start();
 387                         // Fall through to handle this event...
 388                 }
 389
 390         } else if (synthetic_mouse_event_.timeout.running()) {
 391                 // Store the event, to be possibly handled when the timeout
 392                 // expires.
 393                 // Once the timeout has expired, normal control is returned
 394                 // to mouseMoveEvent (restart_timeout = false).
 395                 // This results in a much smoother 'feel' when moving the
 396                 // mouse back into the work area.
 397                 synthetic_mouse_event_.cmd = cmd;
 398                 synthetic_mouse_event_.restart_timeout = false;
 399                 return;
 400         }
 401
 402         // Has anything changed on-screen since the last QMouseEvent
 403         // was received?
 404         double const scrollbar_value = verticalScrollBar()->value();
 405         if (e->x() != synthetic_mouse_event_.x_old ||
 406             e->y() != synthetic_mouse_event_.y_old ||
 407             scrollbar_value != synthetic_mouse_event_.scrollbar_value_old) {
 408                 // Yes it has. Store the params used to check this.
 409                 synthetic_mouse_event_.x_old = e->x();
 410                 synthetic_mouse_event_.y_old = e->y();
 411                 synthetic_mouse_event_.scrollbar_value_old = scrollbar_value;
 412
 413                 // ... and dispatch the event to the LyX core.
 414                 dispatch(cmd);
 415         }
 416 }
 417
 418
 419 void GuiWorkArea::wheelEvent(QWheelEvent * e)
 420 {
 421         // Wheel rotation by one notch results in a delta() of 120 (see
 422         // documentation of QWheelEvent)
 423         int const lines = qApp->wheelScrollLines() * e->delta() / 120;
 424         verticalScrollBar()->setValue(verticalScrollBar()->value() -
 425                         lines *  verticalScrollBar()->singleStep());
 426         adjustViewWithScrollBar();
 427 }
 428
 429
 430 void GuiWorkArea::generateSyntheticMouseEvent()
 431 {
 432 // Set things off to generate the _next_ 'pseudo' event.
 433         if (synthetic_mouse_event_.restart_timeout)
 434                 synthetic_mouse_event_.timeout.start();
 435
 436         // Has anything changed on-screen since the last timeout signal
 437         // was received?
 438         double const scrollbar_value = verticalScrollBar()->value();
 439         if (scrollbar_value != synthetic_mouse_event_.scrollbar_value_old) {
 440                 // Yes it has. Store the params used to check this.
 441                 synthetic_mouse_event_.scrollbar_value_old = scrollbar_value;
 442
 443                 // ... and dispatch the event to the LyX core.
 444                 dispatch(synthetic_mouse_event_.cmd);
 445         }
 446 }
 447
 448
 449 void GuiWorkArea::keyPressEvent(QKeyEvent * e)
 450 {
 451         // do nothing if there are other events
 452         // (the auto repeated events come too fast)
 453         // \todo FIXME: remove hard coded Qt keys, process the key binding
 454 #ifdef Q_WS_X11
 455         if (XEventsQueued(QX11Info::display(), 0) > 1 && e->isAutoRepeat()
 456                         && (Qt::Key_PageDown || Qt::Key_PageUp)) {
 457                 LYXERR(Debug::KEY)
 458                         << BOOST_CURRENT_FUNCTION << endl
 459                         << "system is busy: scroll key event ignored" << endl;
 460                 e->ignore();
 461                 return;
 462         }
 463 #endif
 464
 465         LYXERR(Debug::KEY) << BOOST_CURRENT_FUNCTION
 466                 << " count=" << e->count()
 467                 << " text=" << fromqstr(e->text())
 468                 << " isAutoRepeat=" << e->isAutoRepeat()
 469                 << " key=" << e->key()
 470                 << endl;
 471
 472         boost::shared_ptr<QKeySymbol> sym(new QKeySymbol);
 473         sym->set(e);
 474         processKeySym(sym, q_key_state(e->modifiers()));
 475 }
 476
 477 void GuiWorkArea::doubleClickTimeout() {
 478         dc_event_.active = false;
 479 }
 480
 481 void GuiWorkArea::mouseDoubleClickEvent(QMouseEvent * e)
 482 {
 483         dc_event_ = double_click(e);
 484         QTimer::singleShot(QApplication::doubleClickInterval(), this,
 485                            SLOT(doubleClickTimeout()));
 486         FuncRequest cmd(LFUN_MOUSE_DOUBLE,
 487                         e->x(), e->y(),
 488                         q_button_state(e->button()));
 489         dispatch(cmd);
 490 }
 491
 492
 493 void GuiWorkArea::resizeEvent(QResizeEvent * ev)
 494 {
 495         QAbstractScrollArea::resizeEvent(ev);
 496         need_resize_ = true;
 497 }
 498
 499
 500 void GuiWorkArea::update(int x, int y, int w, int h)
 501 {
 502         viewport()->repaint(x, y, w, h);
 503 }
 504
 505
 506 void GuiWorkArea::doGreyOut(QLPainter & pain)
 507 {
 508         pain.fillRectangle(0, 0, width(), height(),
 509                 Color::bottomarea);
 510
 511         //if (!lyxrc.show_banner)
 512         //      return;
 513         LYXERR(Debug::GUI) << "show banner: " << lyxrc.show_banner << endl;
 514         /// The text to be written on top of the pixmap
 515         QString const text = lyx_version ? QString(lyx_version) : qt_("unknown version");
 516         FileName const file = support::libFileSearch("images", "banner", "png");
 517         if (file.empty())
 518                 return;
 519
 520         QPixmap pm(toqstr(file.absFilename()));
 521         if (!pm) {
 522                 lyxerr << "could not load splash screen: '" << file << "'" << endl;
 523                 return;
 524         }
 525
 526         QFont font;
 527         // The font used to display the version info
 528         font.setStyleHint(QFont::SansSerif);
 529         font.setWeight(QFont::Bold);
 530         font.setPointSize(convert<int>(lyxrc.font_sizes[Font::SIZE_LARGE]));
 531
 532         int const w = pm.width();
 533         int const h = pm.height();
 534
 535         int x = (width() - w) / 2;
 536         int y = (height() - h) / 2;
 537
 538         pain.drawPixmap(x, y, pm);
 539
 540         x += 260;
 541         y += 270;
 542
 543         pain.setPen(QColor(255, 255, 0));
 544         pain.setFont(font);
 545         pain.drawText(x, y, text);
 546 }
 547
 548
 549 void GuiWorkArea::paintEvent(QPaintEvent * ev)
 550 {
 551         QRect const rc = ev->rect();
 552         /*
 553         LYXERR(Debug::PAINTING) << "paintEvent begin: x: " << rc.x()
 554                 << " y: " << rc.y()
 555                 << " w: " << rc.width()
 556                 << " h: " << rc.height() << endl;
 557         */
 558
 559         if (need_resize_) {
 560                 verticalScrollBar()->setPageStep(viewport()->height());
 561                 screen_ = QPixmap(viewport()->width(), viewport()->height());
 562                 resizeBufferView();
 563                 updateScreen();
 564                 WorkArea::hideCursor();
 565                 WorkArea::showCursor();
 566                 need_resize_ = false;
 567         }
 568
 569         QPainter pain(viewport());
 570         pain.drawPixmap(rc, screen_, rc);
 571         cursor_->draw(pain);
 572 }
 573
 574
 575 void GuiWorkArea::expose(int x, int y, int w, int h)
 576 {
 577         updateScreen();
 578         update(x, y, w, h);
 579 }
 580
 581
 582 void GuiWorkArea::updateScreen()
 583 {
 584         QLPainter pain(&screen_);
 585
 586         if (greyed_out_) {
 587                 LYXERR(Debug::GUI) << "splash screen requested" << endl;
 588                 verticalScrollBar()->hide();
 589                 doGreyOut(pain);
 590                 return;
 591         }
 592
 593         verticalScrollBar()->show();
 594         paintText(*buffer_view_, pain);
 595 }
 596
 597
 598 void GuiWorkArea::showCursor(int x, int y, int h, CursorShape shape)
 599 {
 600         if (schedule_redraw_) {
 601                 if (buffer_view_ && buffer_view_->buffer()) {
 602                         buffer_view_->update(Update::Force);
 603                         updateScreen();
 604                         viewport()->update(QRect(0, 0, viewport()->width(), viewport()->height()));
 605                 }
 606                 schedule_redraw_ = false;
 607                 // Show the cursor immediately after the update.
 608                 hideCursor();
 609                 toggleCursor();
 610                 return;
 611         }
 612
 613         cursor_->update(x, y, h, shape);
 614         cursor_->show();
 615         viewport()->update(cursor_->rect());
 616 }
 617
 618
 619 void GuiWorkArea::removeCursor()
 620 {
 621         cursor_->hide();
 622         //if (!qApp->focusWidget())
 623                 viewport()->update(cursor_->rect());
 624 }
 625
 626
 627 void GuiWorkArea::inputMethodEvent(QInputMethodEvent * e)
 628 {
 629         QString const & commit_string = e->commitString();
 630         docstring const & preedit_string
 631                 = qstring_to_ucs4(e->preeditString());
 632
 633         if(greyed_out_) {
 634                 e->ignore();
 635                 return;
 636         }
 637
 638         if (!commit_string.isEmpty()) {
 639
 640                 LYXERR(Debug::KEY) << BOOST_CURRENT_FUNCTION
 641                         << " preeditString =" << fromqstr(e->preeditString())
 642                         << " commitString  =" << fromqstr(e->commitString())
 643                         << endl;
 644
 645                 int key = 0;
 646
 647                 // FIXME Iwami 04/01/07: we should take care also of UTF16 surrogates here.
 648                 for (int i = 0; i < commit_string.size(); ++i) {
 649                         QKeyEvent ev(QEvent::KeyPress, key, Qt::NoModifier, commit_string[i]);
 650                         keyPressEvent(&ev);
 651                 }
 652         }
 653
 654         // Hide the cursor during the kana-kanji transformation.
 655         if (preedit_string.empty())
 656                 startBlinkingCursor();
 657         else
 658                 stopBlinkingCursor();
 659
 660         // last_width : for checking if last preedit string was/wasn't empty.
 661         static bool last_width = false;
 662         if (!last_width && preedit_string.empty()) {
 663                 // if last_width is last length of preedit string.
 664                 e->accept();
 665                 return;
 666         }
 667
 668         QLPainter pain(&screen_);
 669         buffer_view_->updateMetrics(false);
 670         paintText(*buffer_view_, pain);
 671         Font font = buffer_view_->cursor().getFont();
 672         FontMetrics const & fm = theFontMetrics(font);
 673         int height = fm.maxHeight();
 674         int cur_x = cursor_->rect().left();
 675         int cur_y = cursor_->rect().bottom();
 676
 677         // redraw area of preedit string.
 678         update(0, cur_y - height, GuiWorkArea::width(),
 679                 (height + 1) * preedit_lines_);
 680
 681         if (preedit_string.empty()) {
 682                 last_width = false;
 683                 preedit_lines_ = 1;
 684                 e->accept();
 685                 return;
 686         }
 687         last_width = true;
 688
 689         // att : stores an IM attribute.
 690         QList<QInputMethodEvent::Attribute> const & att = e->attributes();
 691
 692         // get attributes of input method cursor.
 693         // cursor_pos : cursor position in preedit string.
 694         size_t cursor_pos = 0;
 695         bool cursor_is_visible = false;
 696         for (int i = 0; i < att.size(); ++i) {
 697                 if (att.at(i).type == QInputMethodEvent::Cursor) {
 698                         cursor_pos = att.at(i).start;
 699                         cursor_is_visible = att.at(i).length != 0;
 700                         break;
 701                 }
 702         }
 703
 704         size_t preedit_length = preedit_string.length();
 705
 706         // get position of selection in input method.
 707         // FIXME: isn't there a way to do this simplier?
 708         // rStart : cursor position in selected string in IM.
 709         size_t rStart = 0;
 710         // rLength : selected string length in IM.
 711         size_t rLength = 0;
 712         if (cursor_pos < preedit_length) {
 713                 for (int i = 0; i < att.size(); ++i) {
 714                         if (att.at(i).type == QInputMethodEvent::TextFormat) {
 715                                 if (att.at(i).start <= int(cursor_pos)
 716                                         && int(cursor_pos) < att.at(i).start + att.at(i).length) {
 717                                                 rStart = att.at(i).start;
 718                                                 rLength = att.at(i).length;
 719                                                 if (!cursor_is_visible)
 720                                                         cursor_pos += rLength;
 721                                                 break;
 722                                 }
 723                         }
 724                 }
 725         }
 726         else {
 727                 rStart = cursor_pos;
 728                 rLength = 0;
 729         }
 730
 731         int const right_margin = rightMargin();
 732         Painter::preedit_style ps;
 733         // Most often there would be only one line:
 734         preedit_lines_ = 1;
 735         for (size_t pos = 0; pos != preedit_length; ++pos) {
 736                 char_type const typed_char = preedit_string[pos];
 737                 // reset preedit string style
 738                 ps = Painter::preedit_default;
 739
 740                 // if we reached the right extremity of the screen, go to next line.
 741                 if (cur_x + fm.width(typed_char) > GuiWorkArea::width() - right_margin) {
 742                         cur_x = right_margin;
 743                         cur_y += height + 1;
 744                         ++preedit_lines_;
 745                 }
 746                 // preedit strings are displayed with dashed underline
 747                 // and partial strings are displayed white on black indicating
 748                 // that we are in selecting mode in the input method.
 749                 // FIXME: rLength == preedit_length is not a changing condition
 750                 // FIXME: should be put out of the loop.
 751                 if (pos >= rStart
 752                         && pos < rStart + rLength
 753                         && !(cursor_pos < rLength && rLength == preedit_length))
 754                         ps = Painter::preedit_selecting;
 755
 756                 if (pos == cursor_pos
 757                         && (cursor_pos < rLength && rLength == preedit_length))
 758                         ps = Painter::preedit_cursor;
 759
 760                 // draw one character and update cur_x.
 761                 cur_x += pain.preeditText(cur_x, cur_y, typed_char, font, ps);
 762         }
 763
 764         // update the preedit string screen area.
 765         update(0, cur_y - preedit_lines_*height, GuiWorkArea::width(),
 766                 (height + 1) * preedit_lines_);
 767
 768         // Don't forget to accept the event!
 769         e->accept();
 770 }
 771
 772
 773 QVariant GuiWorkArea::inputMethodQuery(Qt::InputMethodQuery query) const
 774 {
 775         QRect cur_r(0,0,0,0);
 776         switch (query) {
 777                 // this is the CJK-specific composition window position.
 778                 case Qt::ImMicroFocus:
 779                         cur_r = cursor_->rect();
 780                         if (preedit_lines_ != 1)
 781                                 cur_r.moveLeft(10);
 782                         cur_r.moveBottom(cur_r.bottom() + cur_r.height() * preedit_lines_);
 783                         // return lower right of cursor in LyX.
 784                         return cur_r;
 785                 default:
 786                         return QWidget::inputMethodQuery(query);
 787         }
 788 }
 789
 790 } // namespace frontend
 791 } // namespace lyx
 792
 793 #include "GuiWorkArea_moc.cpp"