qstackedlayout.cpp

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5 ** -

6 ** This file is part of the QtWidgets module of the Qt Toolkit. -

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36 ** $QT_END_LICENSE$ -

37 ** -

38 ****************************************************************************/ -

39 -

40 #include "qstackedlayout.h" -

41 #include "qlayout_p.h" -

42 -

43 #include <qlist.h> -

44 #include "private/qwidget_p.h" -

45 #include "private/qlayoutengine_p.h" -

46 -

47 QT_BEGIN_NAMESPACE -

48 -

49 class QStackedLayoutPrivate : public QLayoutPrivate -

50 { -

51 Q_DECLARE_PUBLIC(QStackedLayout) -

52 public: -

53 QStackedLayoutPrivate() : index(-1), stackingMode(QStackedLayout::StackOne) {} -

54 QLayoutItem* replaceAt(int index, QLayoutItem *newitem) Q_DECL_OVERRIDE; -

55 QList<QLayoutItem *> list; -

56 int index; -

57 QStackedLayout::StackingMode stackingMode; -

58 }; -

59 -

60 QLayoutItem* QStackedLayoutPrivate::replaceAt(int idx, QLayoutItem *newitem) -

61 { -

62 Q_Q(QStackedLayout); -

if (idx < 0 || idx >= list.size() || !newitem)

idx < 0	Description
TRUE	never evaluated
FALSE	never evaluated

idx >= list.size()	Description
TRUE	never evaluated
FALSE	never evaluated

!newitem	Description
TRUE	never evaluated
FALSE	never evaluated

return 0;

never executed: return 0;

65 QWidget *wdg = newitem->widget(); -

if (Q_UNLIKELY(!wdg))) {

__builtin_expe...(!wdg), false)	Description
TRUE	never evaluated
FALSE	never evaluated

67 qWarning("QStackedLayout::replaceAt: Only widgets can be added"); -

return 0;

never executed: return 0;

69 } -

70 QLayoutItem *orgitem = list.at(idx); -

71 list.replace(idx, newitem); -

if (idx == index)

idx == index	Description
TRUE	never evaluated
FALSE	never evaluated

q->setCurrentIndex(index);

never executed: q->setCurrentIndex(index);

return orgitem;

never executed: return orgitem;

75 } -

76 -

77 /*! -

78 \class QStackedLayout -

79 -

80 \brief The QStackedLayout class provides a stack of widgets where -

81 only one widget is visible at a time. -

82 -

83 \ingroup geomanagement -

84 \inmodule QtWidgets -

85 -

86 QStackedLayout can be used to create a user interface similar to -

87 the one provided by QTabWidget. There is also a convenience -

88 QStackedWidget class built on top of QStackedLayout. -

89 -

90 A QStackedLayout can be populated with a number of child widgets -

91 ("pages"). For example: -

92 -

93 \snippet qstackedlayout/main.cpp 0 -

94 \codeline -

95 \snippet qstackedlayout/main.cpp 2 -

96 \snippet qstackedlayout/main.cpp 3 -

97 -

98 QStackedLayout provides no intrinsic means for the user to switch -

99 page. This is typically done through a QComboBox or a QListWidget -

100 that stores the titles of the QStackedLayout's pages. For -

101 example: -

102 -

103 \snippet qstackedlayout/main.cpp 1 -

104 -

105 When populating a layout, the widgets are added to an internal -

106 list. The indexOf() function returns the index of a widget in that -

107 list. The widgets can either be added to the end of the list using -

108 the addWidget() function, or inserted at a given index using the -

109 insertWidget() function. The removeWidget() function removes the -

110 widget at the given index from the layout. The number of widgets -

111 contained in the layout, can be obtained using the count() -

112 function. -

113 -

114 The widget() function returns the widget at a given index -

115 position. The index of the widget that is shown on screen is given -

116 by currentIndex() and can be changed using setCurrentIndex(). In a -

117 similar manner, the currently shown widget can be retrieved using -

118 the currentWidget() function, and altered using the -

119 setCurrentWidget() function. -

120 -

121 Whenever the current widget in the layout changes or a widget is -

122 removed from the layout, the currentChanged() and widgetRemoved() -

123 signals are emitted respectively. -

124 -

125 \sa QStackedWidget, QTabWidget -

126 */ -

127 -

128 /*! -

129 \fn void QStackedLayout::currentChanged(int index) -

130 -

131 This signal is emitted whenever the current widget in the layout -

132 changes. The \a index specifies the index of the new current -

133 widget, or -1 if there isn't a new one (for example, if there -

134 are no widgets in the QStackedLayout) -

135 -

136 \sa currentWidget(), setCurrentWidget() -

137 */ -

138 -

139 /*! -

140 \fn void QStackedLayout::widgetRemoved(int index) -

141 -

142 This signal is emitted whenever a widget is removed from the -

143 layout. The widget's \a index is passed as parameter. -

144 -

145 \sa removeWidget() -

146 */ -

147 -

148 /*! -

149 Constructs a QStackedLayout with no parent. -

150 -

151 This QStackedLayout must be installed on a widget later on to -

152 become effective. -

153 -

154 \sa addWidget(), insertWidget() -

155 */ -

156 QStackedLayout::QStackedLayout() -

157 : QLayout(*new QStackedLayoutPrivate, 0, 0) -

158 { -

159 } -

160 -

161 /*! -

162 Constructs a new QStackedLayout with the given \a parent. -

163 -

164 This layout will install itself on the \a parent widget and -

165 manage the geometry of its children. -

166 */ -

167 QStackedLayout::QStackedLayout(QWidget *parent) -

168 : QLayout(*new QStackedLayoutPrivate, 0, parent) -

169 { -

170 } -

171 -

172 /*! -

173 Constructs a new QStackedLayout and inserts it into -

174 the given \a parentLayout. -

175 */ -

176 QStackedLayout::QStackedLayout(QLayout *parentLayout) -

177 : QLayout(*new QStackedLayoutPrivate, parentLayout, 0) -

178 { -

179 } -

180 -

181 /*! -

182 Destroys this QStackedLayout. Note that the layout's widgets are -

183 \e not destroyed. -

184 */ -

185 QStackedLayout::~QStackedLayout() -

186 { -

187 Q_D(QStackedLayout); -

188 qDeleteAll(d->list); -

189 } -

190 -

191 /*! -

192 Adds the given \a widget to the end of this layout and returns the -

193 index position of the \a widget. -

194 -

195 If the QStackedLayout is empty before this function is called, -

196 the given \a widget becomes the current widget. -

197 -

198 \sa insertWidget(), removeWidget(), setCurrentWidget() -

199 */ -

200 int QStackedLayout::addWidget(QWidget *widget) -

201 { -

202 Q_D(QStackedLayout); -

203 return insertWidget(d->list.count(), widget); -

204 } -

205 -

206 /*! -

207 Inserts the given \a widget at the given \a index in this -

208 QStackedLayout. If \a index is out of range, the widget is -

209 appended (in which case it is the actual index of the \a widget -

210 that is returned). -

211 -

212 If the QStackedLayout is empty before this function is called, the -

213 given \a widget becomes the current widget. -

214 -

215 Inserting a new widget at an index less than or equal to the current index -

216 will increment the current index, but keep the current widget. -

217 -

218 \sa addWidget(), removeWidget(), setCurrentWidget() -

219 */ -

220 int QStackedLayout::insertWidget(int index, QWidget *widget) -

221 { -

222 Q_D(QStackedLayout); -

223 addChildWidget(widget); -

224 index = qMin(index, d->list.count()); -

225 if (index < 0) -

226 index = d->list.count(); -

227 QWidgetItem *wi = QLayoutPrivate::createWidgetItem(this, widget); -

228 d->list.insert(index, wi); -

229 invalidate(); -

230 if (d->index < 0) { -

231 setCurrentIndex(index); -

232 } else { -

233 if (index <= d->index) -

234 ++d->index; -

235 if (d->stackingMode == StackOne) -

236 widget->hide(); -

237 widget->lower(); -

238 } -

239 return index; -

240 } -

241 -

242 /*! -

243 \reimp -

244 */ -

245 QLayoutItem *QStackedLayout::itemAt(int index) const -

246 { -

247 Q_D(const QStackedLayout); -

248 return d->list.value(index); -

249 } -

250 -

251 // Code that enables proper handling of the case that takeAt() is -

252 // called somewhere inside QObject destructor (can't call hide() -

253 // on the object then) -

254 static bool qt_wasDeleted(const QWidget *w) -

255 { -

256 return QWidgetPrivate::get(w)->wasDeleted; -

257 } -

258 -

259 -

260 /*! -

261 \reimp -

262 */ -

263 QLayoutItem *QStackedLayout::takeAt(int index) -

264 { -

265 Q_D(QStackedLayout); -

266 if (index <0 || index >= d->list.size()) -

267 return 0; -

268 QLayoutItem *item = d->list.takeAt(index); -

269 if (index == d->index) { -

270 d->index = -1; -

271 if ( d->list.count() > 0 ) { -

272 int newIndex = (index == d->list.count()) ? index-1 : index; -

273 setCurrentIndex(newIndex); -

274 } else { -

275 emit currentChanged(-1); -

276 } -

277 } else if (index < d->index) { -

278 --d->index; -

279 } -

280 emit widgetRemoved(index); -

281 if (item->widget() && !qt_wasDeleted(item->widget())) -

282 item->widget()->hide(); -

283 return item; -

284 } -

285 -

286 /*! -

287 \property QStackedLayout::currentIndex -

288 \brief the index position of the widget that is visible -

289 -

290 The current index is -1 if there is no current widget. -

291 -

292 \sa currentWidget(), indexOf() -

293 */ -

294 void QStackedLayout::setCurrentIndex(int index) -

295 { -

296 Q_D(QStackedLayout); -

297 QWidget *prev = currentWidget(); -

298 QWidget *next = widget(index); -

299 if (!next || next == prev) -

300 return; -

301 -

302 bool reenableUpdates = false; -

303 QWidget *parent = parentWidget(); -

304 -

305 if (parent && parent->updatesEnabled()) { -

306 reenableUpdates = true; -

307 parent->setUpdatesEnabled(false); -

308 } -

309 -

310 QPointer<QWidget> fw = parent ? parent->window()->focusWidget() : 0; -

311 const bool focusWasOnOldPage = fw && (prev && prev->isAncestorOf(fw)); -

312 -

313 if (prev) { -

314 prev->clearFocus(); -

315 if (d->stackingMode == StackOne) -

316 prev->hide(); -

317 } -

318 -

319 d->index = index; -

320 next->raise(); -

321 next->show(); -

322 -

323 // try to move focus onto the incoming widget if focus -

324 // was somewhere on the outgoing widget. -

325 -

326 if (parent) { -

327 if (focusWasOnOldPage) { -

328 // look for the best focus widget we can find -

329 if (QWidget *nfw = next->focusWidget()) -

330 nfw->setFocus(); -

331 else { -

332 // second best: first child widget in the focus chain -

333 if (QWidget *i = fw) { -

334 while ((i = i->nextInFocusChain()) != fw) { -

335 if (((i->focusPolicy() & Qt::TabFocus) == Qt::TabFocus) -

336 && !i->focusProxy() && i->isVisibleTo(next) && i->isEnabled() -

337 && next->isAncestorOf(i)) { -

338 i->setFocus(); -

339 break; -

340 } -

341 } -

342 // third best: incoming widget -

343 if (i == fw ) -

344 next->setFocus(); -

345 } -

346 } -

347 } -

348 } -

349 if (reenableUpdates) -

350 parent->setUpdatesEnabled(true); -

351 emit currentChanged(index); -

352 } -

353 -

354 int QStackedLayout::currentIndex() const -

355 { -

356 Q_D(const QStackedLayout); -

357 return d->index; -

358 } -

359 -

360 -

361 /*! -

362 \fn void QStackedLayout::setCurrentWidget(QWidget *widget) -

363 -

364 Sets the current widget to be the specified \a widget. The new -

365 current widget must already be contained in this stacked layout. -

366 -

367 \sa setCurrentIndex(), currentWidget() -

368 */ -

369 void QStackedLayout::setCurrentWidget(QWidget *widget) -

370 { -

371 int index = indexOf(widget); -

372

if (Q_UNLIKELY(index == -1))) {

__builtin_expe...== -1), false)	Description
TRUE	never evaluated
FALSE	never evaluated

373 qWarning("QStackedLayout::setCurrentWidget: Widget %p not contained in stack", widget); -

374

return;

never executed: return;

375 } -

376 setCurrentIndex(index); -

377

}

never executed: end of block

378 -

379 -

380 /*! -

381 Returns the current widget, or 0 if there are no widgets in this -

382 layout. -

383 -

384 \sa currentIndex(), setCurrentWidget() -

385 */ -

386 QWidget *QStackedLayout::currentWidget() const -

387 { -

388 Q_D(const QStackedLayout); -

389 return d->index >= 0 ? d->list.at(d->index)->widget() : 0; -

390 } -

391 -

392 /*! -

393 Returns the widget at the given \a index, or 0 if there is no -

394 widget at the given position. -

395 -

396 \sa currentWidget(), indexOf() -

397 */ -

398 QWidget *QStackedLayout::widget(int index) const -

399 { -

400 Q_D(const QStackedLayout); -

401 if (index < 0 || index >= d->list.size()) -

402 return 0; -

403 return d->list.at(index)->widget(); -

404 } -

405 -

406 /*! -

407 \property QStackedLayout::count -

408 \brief the number of widgets contained in the layout -

409 -

410 \sa currentIndex(), widget() -

411 */ -

412 int QStackedLayout::count() const -

413 { -

414 Q_D(const QStackedLayout); -

415 return d->list.size(); -

416 } -

417 -

418 -

419 /*! -

420 \reimp -

421 */ -

422 void QStackedLayout::addItem(QLayoutItem *item) -

423 { -

424 QWidget *widget = item->widget(); -

425

if (widget) {

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

addWidget

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

(Q_UNLIKELY(!widget);

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

delete item;

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

} else

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

)) {

__builtin_expe...idget), false)	Description
TRUE	never evaluated
FALSE	never evaluated

426 qWarning("QStackedLayout::addItem: Only widgets can be added"); -

427

return;

never executed: return;

428 } -

429 addWidget(widget); -

430 delete item; -

431

}

never executed: end of block

432 -

433 /*! -

434 \reimp -

435 */ -

436 QSize QStackedLayout::sizeHint() const -

437 { -

438 Q_D(const QStackedLayout); -

439 QSize s(0, 0); -

440 int n = d->list.count(); -

441 -

442 for (int i = 0; i < n; ++i) -

443 if (QWidget *widget = d->list.at(i)->widget()) { -

444 QSize ws(widget->sizeHint()); -

445 if (widget->sizePolicy().horizontalPolicy() == QSizePolicy::Ignored) -

446 ws.setWidth(0); -

447 if (widget->sizePolicy().verticalPolicy() == QSizePolicy::Ignored) -

448 ws.setHeight(0); -

449 s = s.expandedTo(ws); -

450 } -

451 return s; -

452 } -

453 -

454 /*! -

455 \reimp -

456 */ -

457 QSize QStackedLayout::minimumSize() const -

458 { -

459 Q_D(const QStackedLayout); -

460 QSize s(0, 0); -

461 int n = d->list.count(); -

462 -

463 for (int i = 0; i < n; ++i) -

464 if (QWidget *widget = d->list.at(i)->widget()) -

465 s = s.expandedTo(qSmartMinSize(widget)); -

466 return s; -

467 } -

468 -

469 /*! -

470 \reimp -

471 */ -

472 void QStackedLayout::setGeometry(const QRect &rect) -

473 { -

474 Q_D(QStackedLayout); -

475 switch (d->stackingMode) { -

476 case StackOne: -

477 if (QWidget *widget = currentWidget()) -

478 widget->setGeometry(rect); -

479 break; -

480 case StackAll: -

481 if (const int n = d->list.count()) -

482 for (int i = 0; i < n; ++i) -

483 if (QWidget *widget = d->list.at(i)->widget()) -

484 widget->setGeometry(rect); -

485 break; -

486 } -

487 } -

488 -

489 /*! -

490 \reimp -

491 */ -

492 bool QStackedLayout::hasHeightForWidth() const -

493 { -

494 const int n = count(); -

495 -

496 for (int i = 0; i < n; ++i) { -

497 if (QLayoutItem *item = itemAt(i)) { -

498 if (item->hasHeightForWidth()) -

499 return true; -

500 } -

501 } -

502 return false; -

503 } -

504 -

505 /*! -

506 \reimp -

507 */ -

508 int QStackedLayout::heightForWidth(int width) const -

509 { -

510 const int n = count(); -

511 -

512 int hfw = 0; -

513 for (int i = 0; i < n; ++i) { -

514 if (QLayoutItem *item = itemAt(i)) { -

515 if (QWidget *w = item->widget()) -

516 /* -

517 Note: Does not query the layout item, but bypasses it and asks the widget -

518 directly. This is consistent with how QStackedLayout::sizeHint() is -

519 implemented. This also avoids an issue where QWidgetItem::heightForWidth() -

520 returns -1 if the widget is hidden. -

521 */ -

522 hfw = qMax(hfw, w->heightForWidth(width)); -

523 } -

524 } -

525 hfw = qMax(hfw, minimumSize().height()); -

526 return hfw; -

527 } -

528 -

529 /*! -

530 \enum QStackedLayout::StackingMode -

531 \since 4.4 -

532 -

533 This enum specifies how the layout handles its child widgets -

534 regarding their visibility. -

535 -

536 \value StackOne -

537 Only the current widget is visible. This is the default. -

538 -

539 \value StackAll -

540 All widgets are visible. The current widget is merely raised. -

541 */ -

542 -

543 -

544 /*! -

545 \property QStackedLayout::stackingMode -

546 \brief determines the way visibility of child widgets are handled. -

547 \since 4.4 -

548 -

549 The default value is StackOne. Setting the property to StackAll -

550 allows you to make use of the layout for overlay widgets -

551 that do additional drawing on top of other widgets, for example, -

552 graphical editors. -

553 */ -

554 -

555 QStackedLayout::StackingMode QStackedLayout::stackingMode() const -

556 { -

557 Q_D(const QStackedLayout); -

558 return d->stackingMode; -

559 } -

560 -

561 void QStackedLayout::setStackingMode(StackingMode stackingMode) -

562 { -

563 Q_D(QStackedLayout); -

564 if (d->stackingMode == stackingMode) -

565 return; -

566 d->stackingMode = stackingMode; -

567 -

568 const int n = d->list.count(); -

569 if (n == 0) -

570 return; -

571 -

572 switch (d->stackingMode) { -

573 case StackOne: -

574 if (const int idx = currentIndex()) -

575 for (int i = 0; i < n; ++i) -

576 if (QWidget *widget = d->list.at(i)->widget()) -

577 widget->setVisible(i == idx); -

578 break; -

579 case StackAll: { // Turn overlay on: Make sure all widgets are the same size -

580 QRect geometry; -

581 if (const QWidget *widget = currentWidget()) -

582 geometry = widget->geometry(); -

583 for (int i = 0; i < n; ++i) -

584 if (QWidget *widget = d->list.at(i)->widget()) { -

585 if (!geometry.isNull()) -

586 widget->setGeometry(geometry); -

587 widget->setVisible(true); -

588 } -

589 } -

590 break; -

591 } -

592 } -

593 -

594 QT_END_NAMESPACE -

595 -

596 #include "moc_qstackedlayout.cpp" -

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