QAbstractScrollArea Class Reference

#include <qabstractscrollarea.h>

Inheritance diagram for QAbstractScrollArea:

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Collaboration diagram for QAbstractScrollArea:

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List of all members.

Detailed Description

The QAbstractScrollArea widget provides a scrolling area with on-demand scroll bars.

QAbstractScrollArea is a low-level abstraction of a scrolling area. It gives you full control of the scroll bars, at the cost of simplicity. In most cases, using a QScrollArea is preferable.

QAbstractScrollArea's central child widget is the scrolling area itself, called viewport(). The viewport widget uses all available space. Next to the viewport is a vertical scroll bar (accessible with verticalScrollBar()), and below a horizontal scroll bar (accessible with horizontalScrollBar()). Each scroll bar can be either visible or hidden, depending on the scroll bar's policy (see verticalScrollBarPolicy and horizontalScrollBarPolicy). When a scroll bar is hidden, the viewport expands in order to cover all available space. When a scroll bar becomes visible again, the viewport shrinks in order to make room for the scroll bar.

With a scroll bar policy of Qt::ScrollBarAsNeeded (the default), QAbstractScrollArea shows scroll bars when those provide a non-zero scrolling range, and hides them otherwise. You control the range of each scroll bar with QAbstractSlider::setRange().

In order to track scroll bar movements, reimplement the virtual function scrollContentsBy(). In order to fine-tune scrolling behavior, connect to a scroll bar's QAbstractSlider::actionTriggered() signal and adjust the QAbstractSlider::sliderPosition as you wish.

It is possible to reserve a margin area around the viewport, see setViewportMargins(). The feature is mostly used to place a QHeaderView widget above or beside the scrolling area.

For convenience, QAbstractScrollArea makes all viewport events available in the virtual viewportEvent() handler. QWidget's specialized handlers are remapped to viewport events in the cases where this makes sense. The remapped specialized handlers are: paintEvent(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), wheelEvent(), dragEnterEvent(), dragMoveEvent(), dragLeaveEvent(), dropEvent(), contextMenuEvent(). and resizeEvent().

See also:
QScrollArea

Definition at line 38 of file qabstractscrollarea.h.

Public Member Functions

 QAbstractScrollArea (QWidget *parent=0)
 ~QAbstractScrollArea ()
Qt::ScrollBarPolicy verticalScrollBarPolicy () const
void setVerticalScrollBarPolicy (Qt::ScrollBarPolicy)
QScrollBar * verticalScrollBar () const
void setVerticalScrollBar (QScrollBar *scrollbar)
Qt::ScrollBarPolicy horizontalScrollBarPolicy () const
void setHorizontalScrollBarPolicy (Qt::ScrollBarPolicy)
QScrollBar * horizontalScrollBar () const
void setHorizontalScrollBar (QScrollBar *scrollbar)
QWidget * cornerWidget () const
void setCornerWidget (QWidget *widget)
void addScrollBarWidget (QWidget *widget, Qt::Alignment alignment)
QWidgetList scrollBarWidgets (Qt::Alignment alignment)
QWidget * viewport () const
void setViewport (QWidget *widget)
QSize maximumViewportSize () const
QSize minimumSizeHint () const
QSize sizeHint () const

Protected Slots

void setupViewport (QWidget *viewport)

Protected Member Functions

 QAbstractScrollArea (QAbstractScrollAreaPrivate &dd, QWidget *parent=0)
void setViewportMargins (int left, int top, int right, int bottom)
bool event (QEvent *)
virtual bool viewportEvent (QEvent *)
void resizeEvent (QResizeEvent *)
void paintEvent (QPaintEvent *)
void mousePressEvent (QMouseEvent *)
void mouseReleaseEvent (QMouseEvent *)
void mouseDoubleClickEvent (QMouseEvent *)
void mouseMoveEvent (QMouseEvent *)
void wheelEvent (QWheelEvent *)
void contextMenuEvent (QContextMenuEvent *)
void dragEnterEvent (QDragEnterEvent *)
void dragMoveEvent (QDragMoveEvent *)
void dragLeaveEvent (QDragLeaveEvent *)
void dropEvent (QDropEvent *)
void keyPressEvent (QKeyEvent *)
virtual void scrollContentsBy (int dx, int dy)

Private Member Functions

 Q_PRIVATE_SLOT (d_func(), void _q_hslide(int)) Q_PRIVATE_SLOT(d_func()
void _q_vslide (int)) Q_PRIVATE_SLOT(d_func()

Constructor & Destructor Documentation

QAbstractScrollArea::QAbstractScrollArea ( QWidget *  parent = 0  )  [explicit]

Constructs a viewport.

The parent arguments is sent to the QWidget constructor.

Definition at line 395 of file qabstractscrollarea.cpp.

References d.

00396     :QFrame(*new QAbstractScrollAreaPrivate, parent)
00397 {
00398     Q_D(QAbstractScrollArea);
00399     d->init();
00400 }

QAbstractScrollArea::~QAbstractScrollArea (  ) 

Destroys the viewport.

Definition at line 406 of file qabstractscrollarea.cpp.

References d.

00407 {
00408     Q_D(QAbstractScrollArea);
00409     delete d->viewportFilter;
00410 }

QAbstractScrollArea::QAbstractScrollArea ( QAbstractScrollAreaPrivate &  dd,
QWidget *  parent = 0 
) [protected]

Definition at line 383 of file qabstractscrollarea.cpp.

References d.

00384     :QFrame(dd, parent)
00385 {
00386     Q_D(QAbstractScrollArea);
00387     d->init();
00388 }

Member Function Documentation

Qt::ScrollBarPolicy QAbstractScrollArea::verticalScrollBarPolicy (  )  const

Definition at line 486 of file qabstractscrollarea.cpp.

References d.

Referenced by QListView::updateGeometries().

00487 {
00488     Q_D(const QAbstractScrollArea);
00489     return d->vbarpolicy;
00490 }

void QAbstractScrollArea::setVerticalScrollBarPolicy ( Qt::ScrollBarPolicy   ) 

Definition at line 492 of file qabstractscrollarea.cpp.

References d, and QWidget::isVisible().

Referenced by EditorPage::addPluralForm(), EditorPage::EditorPage(), QHeaderView::initialize(), KAsteroidsView::KAsteroidsView(), qdesigner_internal::ObjectInspector::ObjectInspector(), OublietteView::OublietteView(), QCalendarView::QCalendarView(), qdesigner_internal::QtGradientStopsWidget::QtGradientStopsWidget(), QComboBox::setEditable(), and QComboBoxPrivateContainer::setItemView().

00493 {
00494     Q_D(QAbstractScrollArea);
00495     d->vbarpolicy = policy;
00496     if (isVisible())
00497         d->layoutChildren();
00498 }

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QScrollBar * QAbstractScrollArea::verticalScrollBar (  )  const

Returns the vertical scroll bar.

See also:
verticalScrollBarPolicy, horizontalScrollBar()

Definition at line 506 of file qabstractscrollarea.cpp.

References d.

Referenced by QGraphicsView::centerOn(), QAbstractItemView::doAutoScroll(), QGraphicsView::ensureVisible(), PieView::indexAt(), TextEdit::keyPressEvent(), SvgWindow::mouseMoveEvent(), PreviewView::mouseMoveEvent(), QGraphicsView::mouseMoveEvent(), PreviewView::mousePressEvent(), SvgWindow::mousePressEvent(), PreviewView::paintEvent(), PieView::paintEvent(), PieView::PieView(), PreviewView::PreviewView(), QAccessibleTextEdit::rect(), PreviewView::resizeEvent(), QTableView::rowCountChanged(), ImageViewer::scaleImage(), QListView::scrollContentsBy(), QTableView::scrollContentsBy(), QTreeView::scrollContentsBy(), QComboBoxPrivateContainer::scrollItemView(), QListView::scrollTo(), QTableView::scrollTo(), PieView::scrollTo(), QTreeView::scrollTo(), QAbstractItemView::scrollToBottom(), OublietteView::scrollToCharacter(), QAbstractItemView::scrollToTop(), qdesigner_internal::ObjectInspector::setFormWindow(), QComboBoxPrivateContainer::setItemView(), PieView::setSelection(), QListView::updateGeometries(), PieView::updateGeometries(), QTableView::updateGeometries(), QComboBoxPrivateContainer::updateScrollers(), QTreeView::verticalOffset(), PieView::verticalOffset(), QListView::verticalOffset(), QAbstractItemView::verticalScrollbarValueChanged(), View::View(), and PieView::visualRect().

00507 {
00508     Q_D(const QAbstractScrollArea);
00509     return d->vbar;
00510 }

void QAbstractScrollArea::setVerticalScrollBar ( QScrollBar *  scrollBar  ) 

Since:
4.2 Replaces the existing vertical scroll bar with scrollBar, and sets all the former scroll bar's slider properties on the new scroll bar. The former scroll bar is then deleted.
QAbstractScrollArea already provides vertical and horizontal scroll bars by default. You can call this function to replace the default vertical scroll bar with your own custom scroll bar.

See also:
verticalScrollBar(), setHorizontalScrollBar()

Definition at line 524 of file qabstractscrollarea.cpp.

References d, qWarning(), and Qt::Vertical.

00525 {
00526     Q_D(QAbstractScrollArea);
00527     if (!scrollBar) {
00528         qWarning("QAbstractScrollArea::setVerticalScrollBar: Cannot set a null scroll bar");
00529         return;
00530     }
00531 
00532     d->replaceScrollBar(scrollBar, Qt::Vertical);
00533 }

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Qt::ScrollBarPolicy QAbstractScrollArea::horizontalScrollBarPolicy (  )  const

Definition at line 544 of file qabstractscrollarea.cpp.

References d.

Referenced by QComboBox::showPopup(), and QListView::updateGeometries().

00545 {
00546     Q_D(const QAbstractScrollArea);
00547     return d->hbarpolicy;
00548 }

void QAbstractScrollArea::setHorizontalScrollBarPolicy ( Qt::ScrollBarPolicy   ) 

Definition at line 550 of file qabstractscrollarea.cpp.

References d, and QWidget::isVisible().

Referenced by EditorPage::addPluralForm(), EditorPage::EditorPage(), QCompleterPrivate::init(), QHeaderView::initialize(), KAsteroidsView::KAsteroidsView(), MessageEditor::MessageEditor(), OublietteView::OublietteView(), QCalendarView::QCalendarView(), qdesigner_internal::QtGradientStopsWidget::QtGradientStopsWidget(), and QComboBoxPrivateContainer::setItemView().

00551 {
00552     Q_D(QAbstractScrollArea);
00553     d->hbarpolicy = policy;
00554     if (isVisible())
00555         d->layoutChildren();
00556 }

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QScrollBar * QAbstractScrollArea::horizontalScrollBar (  )  const

Returns the horizontal scroll bar.

See also:
horizontalScrollBarPolicy, verticalScrollBar()

Definition at line 563 of file qabstractscrollarea.cpp.

References d.

Referenced by QGraphicsView::centerOn(), QTableView::columnCountChanged(), QAbstractItemView::doAutoScroll(), QGraphicsView::ensureVisible(), qdesigner_internal::QtGradientStopsWidgetPrivate::ensureVisible(), qdesigner_internal::QtGradientStopsWidgetPrivate::fromViewport(), QListView::horizontalOffset(), PieView::horizontalOffset(), QAbstractItemView::horizontalScrollbarValueChanged(), PieView::indexAt(), qdesigner_internal::QtGradientStopsWidget::minimumSizeHint(), SvgWindow::mouseMoveEvent(), PreviewView::mouseMoveEvent(), QGraphicsView::mouseMoveEvent(), PreviewView::mousePressEvent(), SvgWindow::mousePressEvent(), QTreeView::moveCursor(), PreviewView::paintEvent(), PieView::paintEvent(), qdesigner_internal::QtGradientStopsWidget::paintEvent(), PieView::PieView(), PreviewView::PreviewView(), qdesigner_internal::QtGradientStopsWidget::QtGradientStopsWidget(), QAccessibleTextEdit::rect(), PreviewView::resizeEvent(), ImageViewer::scaleImage(), QListView::scrollContentsBy(), QTableView::scrollContentsBy(), QTreeView::scrollContentsBy(), QListView::scrollTo(), QTableView::scrollTo(), PieView::scrollTo(), QTreeView::scrollTo(), OublietteView::scrollToCharacter(), qdesigner_internal::ObjectInspector::setFormWindow(), PieView::setSelection(), qdesigner_internal::QtGradientStopsWidget::setZoom(), QCompleterPrivate::showPopup(), QComboBox::showPopup(), qdesigner_internal::QtGradientStopsWidget::sizeHint(), qdesigner_internal::QtGradientStopsWidgetPrivate::toViewport(), QListView::updateGeometries(), PieView::updateGeometries(), QTreeView::updateGeometries(), QTableView::updateGeometries(), View::View(), and PieView::visualRect().

00564 {
00565     Q_D(const QAbstractScrollArea);
00566     return d->hbar;
00567 }

void QAbstractScrollArea::setHorizontalScrollBar ( QScrollBar *  scrollBar  ) 

Since:
4.2
Replaces the existing horizontal scroll bar with scrollBar, and sets all the former scroll bar's slider properties on the new scroll bar. The former scroll bar is then deleted.

QAbstractScrollArea already provides horizontal and vertical scroll bars by default. You can call this function to replace the default horizontal scroll bar with your own custom scroll bar.

See also:
horizontalScrollBar(), setVerticalScrollBar()

Definition at line 582 of file qabstractscrollarea.cpp.

References d, Qt::Horizontal, and qWarning().

00583 {
00584     Q_D(QAbstractScrollArea);
00585     if (!scrollBar) {
00586         qWarning("QAbstractScrollArea::setHorizontalScrollBar: Cannot set a null scroll bar");
00587         return;
00588     }
00589 
00590     d->replaceScrollBar(scrollBar, Qt::Horizontal);
00591 }

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QWidget * QAbstractScrollArea::cornerWidget (  )  const

Since:
4.2
Returns the widget in the corner between the two scroll bars.

By default, no corner widget is present.

Definition at line 600 of file qabstractscrollarea.cpp.

References d.

00601 {
00602     Q_D(const QAbstractScrollArea);
00603     return d->cornerWidget;
00604 }

void QAbstractScrollArea::setCornerWidget ( QWidget *  widget  ) 

Since:
4.2
Sets the widget in the corner between the two scroll bars to be widget.

You will probably also want to set at least one of the scroll bar modes to AlwaysOn.

Passing 0 shows no widget in the corner.

Any previous corner widget is hidden.

You may call setCornerWidget() with the same widget at different times.

All widgets set here will be deleted by the scroll area when it is destroyed unless you separately reparent the widget after setting some other corner widget (or 0).

Any newly set widget should have no current parent.

By default, no corner widget is present.

See also:
horizontalScrollBarPolicy, horizontalScrollBarPolicy

Definition at line 632 of file qabstractscrollarea.cpp.

References d, QWidget::parentWidget(), QWidget::setParent(), and QWidget::show().

00633 {
00634     Q_D(QAbstractScrollArea);
00635     QWidget* oldWidget = d->cornerWidget;
00636     if (oldWidget != widget) {
00637         if (oldWidget)
00638             oldWidget->hide();
00639         d->cornerWidget = widget;
00640 
00641         if (widget && widget->parentWidget() != this)
00642             widget->setParent(this);
00643 
00644         d->layoutChildren();
00645         if (widget)
00646             widget->show();
00647     } else {
00648         d->cornerWidget = widget;
00649         d->layoutChildren();
00650     }
00651 }

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void QAbstractScrollArea::addScrollBarWidget ( QWidget *  widget,
Qt::Alignment  alignment 
)

Since:
4.2 Adds widget as a scroll bar widget in the location specified by alignment.
Scroll bar widgets are shown next to the horizontal or vertical scroll bar, and can be placed on either side of it. If you want the scroll bar widgets to be always visible, set the scrollBarPolicy for the corresponding scroll bar to AlwaysOn.

alignment must be one of Qt::Alignleft and Qt::AlignRight, which maps to the horizontal scroll bar, or Qt::AlignTop and Qt::AlignBottom, which maps to the vertical scroll bar.

A scroll bar widget can be removed by either re-parenting the widget or deleting it. It's also possible to hide a widget with QWidget::hide()

The scroll bar widget will be resized to fit the scroll bar geometry for the current style. The following describes the case for scroll bar widgets on the horizontal scroll bar:

The height of the widget will be set to match the height of the scroll bar. To control the width of the widget, use QWidget::setMinimumWidth and QWidget::setMaximumWidth, or implement QWidget::sizeHint() and set a horizontal size policy. If you want a square widget, call QStyle::pixelMetric(QStyle::PM_ScrollBarExtent) and set the width to this value.

See also:
scrollBarWidgets()

Definition at line 685 of file qabstractscrollarea.cpp.

References Qt::AlignBottom, Qt::AlignLeft, Qt::AlignRight, d, Qt::Horizontal, QWidget::isHidden(), QAbstractScrollAreaScrollBarContainer::LogicalLeft, QAbstractScrollAreaScrollBarContainer::LogicalRight, QWidget::show(), and Qt::Vertical.

00686 {
00687     Q_D(QAbstractScrollArea);
00688 
00689     if (widget == 0)
00690         return;
00691 
00692     const Qt::Orientation scrollBarOrientation
00693         = ((alignment & Qt::AlignLeft) || (alignment & Qt::AlignRight)) ? Qt::Horizontal : Qt::Vertical;
00694     const QAbstractScrollAreaScrollBarContainer::LogicalPosition position
00695         = ((alignment & Qt::AlignRight) || (alignment & Qt::AlignBottom))
00696           ? QAbstractScrollAreaScrollBarContainer::LogicalRight : QAbstractScrollAreaScrollBarContainer::LogicalLeft;
00697     d->scrollBarContainers[scrollBarOrientation]->addWidget(widget, position);
00698     d->layoutChildren();
00699     if (isHidden() == false)
00700         widget->show();
00701 }

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QWidgetList QAbstractScrollArea::scrollBarWidgets ( Qt::Alignment  alignment  ) 

Since:
4.2 Returns a list of the currently set scroll bar widgets. alignment can be any combination of the four location flags.
See also:
addScrollBarWidget()

Definition at line 710 of file qabstractscrollarea.cpp.

References Qt::AlignBottom, Qt::AlignLeft, Qt::AlignRight, Qt::AlignTop, d, Qt::Horizontal, QAbstractScrollAreaScrollBarContainer::LogicalLeft, QAbstractScrollAreaScrollBarContainer::LogicalRight, and Qt::Vertical.

00711 {
00712     Q_D(QAbstractScrollArea);
00713 
00714     QWidgetList list;
00715 
00716     if (alignment & Qt::AlignLeft)
00717         list += d->scrollBarContainers[Qt::Horizontal]->widgets(QAbstractScrollAreaScrollBarContainer::LogicalLeft);
00718     if (alignment & Qt::AlignRight)
00719         list += d->scrollBarContainers[Qt::Horizontal]->widgets(QAbstractScrollAreaScrollBarContainer::LogicalRight);
00720     if (alignment & Qt::AlignTop)
00721         list += d->scrollBarContainers[Qt::Vertical]->widgets(QAbstractScrollAreaScrollBarContainer::LogicalLeft);
00722     if (alignment & Qt::AlignBottom)
00723         list += d->scrollBarContainers[Qt::Vertical]->widgets(QAbstractScrollAreaScrollBarContainer::LogicalRight);
00724 
00725     return list;
00726 }

QWidget * QAbstractScrollArea::viewport (  )  const

Returns the viewport widget.

Use the QScrollArea::widget() function to retrieve the contents of the viewport widget.

See also:
QScrollArea::widget()

Definition at line 450 of file qabstractscrollarea.cpp.

References d.

Referenced by QGraphicsView::centerOn(), QAccessibleTextEdit::childAt(), QTreeView::collapse(), QTreeView::columnCountChanged(), QGraphicsView::contextMenuEvent(), TabbedBrowser::createHelpWindow(), PieView::dataChanged(), QGraphicsView::drawItems(), QGraphicsView::ensureVisible(), qdesigner_internal::QtGradientStopsWidgetPrivate::ensureVisible(), QGraphicsView::fitInView(), qdesigner_internal::QtGradientStopsWidget::focusInEvent(), qdesigner_internal::QPropertyEditor::focusInEvent(), qdesigner_internal::QtGradientStopsWidget::focusOutEvent(), qdesigner_internal::QtGradientStopsWidgetPrivate::fromViewport(), QTreeView::indexRowSizeHint(), PieView::itemRect(), KAsteroidsView::KAsteroidsView(), QTreeView::mouseDoubleClickEvent(), QGraphicsView::mouseDoubleClickEvent(), qdesigner_internal::QtGradientStopsWidget::mouseDoubleClickEvent(), qdesigner_internal::QtGradientStopsWidget::mouseMoveEvent(), QGraphicsView::mouseMoveEvent(), QGraphicsView::mousePressEvent(), QTreeView::mousePressEvent(), qdesigner_internal::QtGradientStopsWidget::mousePressEvent(), PieView::mouseReleaseEvent(), QGraphicsView::mouseReleaseEvent(), QTreeView::moveCursor(), PieView::moveCursor(), QTreeView::paintEvent(), PreviewView::paintEvent(), PieView::paintEvent(), qdesigner_internal::QtGradientStopsWidget::paintEvent(), QGraphicsView::paintEvent(), PreviewView::PreviewView(), PrintPreview::PrintPreview(), qdesigner_internal::QtGradientStopsWidget::QtGradientStopsWidget(), QAccessibleTextEdit::rect(), QGraphicsView::render(), QGraphicsView::resetCachedContent(), QComboBoxListView::resizeEvent(), MessageEditor::resizeEvent(), PreviewView::resizeEvent(), PieView::scrollContentsBy(), scrollContentsBy(), QGraphicsView::scrollContentsBy(), PieView::scrollTo(), QGraphicsView::setBackgroundBrush(), QGraphicsItem::setCursor(), SpreadSheetItem::setData(), QGraphicsView::setDragMode(), QGraphicsView::setForegroundBrush(), QAbstractItemView::setIndexWidget(), QComboBoxPrivateContainer::setItemView(), QGraphicsView::setMatrix(), QGraphicsView::setRenderHint(), QGraphicsView::setRenderHints(), QTableView::setRootIndex(), QFileDialogPrivate::setupTreeView(), setupViewport(), qdesigner_internal::QtGradientStopsWidget::setZoom(), QDBusViewer::showContextMenu(), HelpDialog::showIndexItemMenu(), HelpDialog::showListItemMenu(), MainWindow::showSearchLink(), HelpDialog::showTreeItemMenu(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotCurrentStopChanged(), qdesigner_internal::ObjectInspector::slotPopupContextMenu(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotStopAdded(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotStopChanged(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotStopMoved(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotStopRemoved(), qdesigner_internal::QtGradientStopsWidgetPrivate::slotStopSelected(), qdesigner_internal::QtGradientStopsWidgetPrivate::toViewport(), QListView::updateGeometries(), PieView::updateGeometries(), PreviewView::updateLayout(), QGraphicsView::updateScene(), QGraphicsView::wheelEvent(), PreviewView::zoomIn(), and PreviewView::zoomOut().

00451 {
00452     Q_D(const QAbstractScrollArea);
00453     return d->viewport;
00454 }

void QAbstractScrollArea::setViewport ( QWidget *  widget  ) 

Since:
4.2 Sets the viewport to be the given widget. The QAbstractScrollArea will take ownership of the given widget.
If widget is 0, QAbstractScrollArea will assign a new QWidget instance for the viewport.

See also:
viewport()

Definition at line 423 of file qabstractscrollarea.cpp.

References d, QMetaObject::invokeMethod(), QWidget::isVisible(), and Q_ARG.

Referenced by QGraphicsView::QGraphicsView(), and View::toggleOpenGL().

00424 {
00425     Q_D(QAbstractScrollArea);
00426     if (widget != d->viewport) {
00427         QWidget *oldViewport = d->viewport;
00428         if (!widget)
00429             widget = new QWidget;
00430         d->viewport = widget;
00431         d->viewport->setParent(this);
00432         d->viewport->setFocusProxy(this);
00433         d->viewport->installEventFilter(d->viewportFilter);
00434         d->layoutChildren();
00435         if (isVisible())
00436             d->viewport->show();
00437         QMetaObject::invokeMethod(this, "setupViewport", Q_ARG(QWidget *, widget));
00438         delete oldViewport;
00439     }
00440 }

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QSize QAbstractScrollArea::maximumViewportSize (  )  const

Returns the size of the viewport as if the scroll bars had no valid scrolling range.

Definition at line 462 of file qabstractscrollarea.cpp.

References d, QSize::rheight(), QSize::rwidth(), Qt::ScrollBarAlwaysOn, and QWidget::size().

Referenced by MainWindow::setPixmap(), QListView::updateGeometries(), and QTableView::updateGeometries().

00463 {
00464     Q_D(const QAbstractScrollArea);
00465     int hsbExt = d->hbar->sizeHint().height();
00466     int vsbExt = d->vbar->sizeHint().width();
00467 
00468     int f = 2 * d->frameWidth;
00469     QSize max = size() - QSize(f + d->left + d->right, f + d->top + d->bottom);
00470     if (d->vbarpolicy == Qt::ScrollBarAlwaysOn)
00471         max.rwidth() -= vsbExt;
00472     if (d->hbarpolicy == Qt::ScrollBarAlwaysOn)
00473         max.rheight() -= hsbExt;
00474     return max;
00475 }

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QSize QAbstractScrollArea::minimumSizeHint (  )  const [virtual]

Reimplemented from QWidget.

Definition at line 1126 of file qabstractscrollarea.cpp.

References d, Qt::Horizontal, and Qt::Vertical.

01127 {
01128     Q_D(const QAbstractScrollArea);
01129     int hsbExt = d->hbar->sizeHint().height();
01130     int vsbExt = d->vbar->sizeHint().width();
01131     int extra = 2 * d->frameWidth;
01132     return QSize(d->scrollBarContainers[Qt::Horizontal]->sizeHint().width() + vsbExt + extra,
01133                  d->scrollBarContainers[Qt::Vertical]->sizeHint().height() + hsbExt + extra);
01134 }

QSize QAbstractScrollArea::sizeHint (  )  const [virtual]

Reimplemented from QFrame.

Definition at line 1139 of file qabstractscrollarea.cpp.

References d, QWidget::fontMetrics(), h, QWidget::height(), and qMax().

Referenced by QGraphicsView::sizeHint(), QTableView::sizeHintForColumn(), and QTableView::sizeHintForRow().

01140 {
01141     return QSize(256, 192);
01142 #if 0
01143     Q_D(const QAbstractScrollArea);
01144     int h = qMax(10, fontMetrics().height());
01145     int f = 2 * d->frameWidth;
01146     return QSize((6 * h) + f, (4 * h) + f);
01147 #endif
01148 }

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void QAbstractScrollArea::setupViewport ( QWidget *  viewport  )  [protected, slot]

This slot is called by QAbstractScrollArea after setViewport(viewport) has been called. Reimplement this function in a subclass of QAbstractScrollArea to initialize the new viewport before it is used.

See also:
setViewport()

Definition at line 1158 of file qabstractscrollarea.cpp.

References viewport().

01159 {
01160     Q_UNUSED(viewport);
01161 }

void QAbstractScrollArea::setViewportMargins ( int  left,
int  top,
int  right,
int  bottom 
) [protected]

Sets the margins around the scrolling area to left, top, right and bottom. This is useful for applications such as spreadsheets with "locked" rows and columns. The marginal space is is left blank; put widgets in the unused area.

By default all margins are zero.

Definition at line 737 of file qabstractscrollarea.cpp.

References d.

Referenced by QTreeView::updateGeometries(), and QTableView::updateGeometries().

00738 {
00739     Q_D(QAbstractScrollArea);
00740     d->left = left;
00741     d->top = top;
00742     d->right = right;
00743     d->bottom = bottom;
00744     d->layoutChildren();
00745 }

bool QAbstractScrollArea::event ( QEvent *  event  )  [protected, virtual]

This is the main event handler for the QAbstractScrollArea widget (not the scrolling area viewport()). The specified event is a general event object that may need to be cast to the appropriate class depending on its type.

See also:
QEvent::type()

Reimplemented from QFrame.

Definition at line 759 of file qabstractscrollarea.cpp.

References QWidget::acceptDrops(), QEvent::AcceptDropsChange, QEvent::ContextMenu, d, QEvent::DragEnter, QEvent::DragLeave, QEvent::DragMove, QStyle::drawPrimitive(), QEvent::Drop, QFrame::event(), QWidget::hasMouseTracking(), QContextMenuEvent::Keyboard, QEvent::MouseButtonDblClick, QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseMove, QEvent::MouseTrackingChange, p, QEvent::Paint, QFrame::paintEvent(), QStyle::PE_PanelScrollAreaCorner, QEvent::Resize, QWidget::style(), QEvent::StyleChange, QEvent::type(), and QEvent::Wheel.

Referenced by QAbstractItemView::event(), QGraphicsView::event(), QScrollArea::event(), QTextEdit::event(), and viewportEvent().

00760 {
00761     Q_D(QAbstractScrollArea);
00762     switch (e->type()) {
00763     case QEvent::AcceptDropsChange:
00764         d->viewport->setAcceptDrops(acceptDrops());
00765         break;
00766     case QEvent::MouseTrackingChange:
00767         d->viewport->setMouseTracking(hasMouseTracking());
00768         break;
00769     case QEvent::Resize:
00770             d->layoutChildren();
00771             break;
00772     case QEvent::Paint:
00773         if (d->cornerPaintingRect.isValid()) {
00774             QStyleOption option;
00775             option.rect = d->cornerPaintingRect;
00776             QPainter p(this);
00777             style()->drawPrimitive(QStyle::PE_PanelScrollAreaCorner, &option, &p, this);
00778         }
00779 #ifdef Q_WS_MAC
00780         if (d->reverseCornerPaintingRect.isValid()) {
00781             QStyleOption option;
00782             option.rect = d->reverseCornerPaintingRect;
00783             QPainter p(this);
00784             style()->drawPrimitive(QStyle::PE_PanelScrollAreaCorner, &option, &p, this);
00785         }
00786 #endif
00787         QFrame::paintEvent((QPaintEvent*)e);
00788         break;
00789     case QEvent::ContextMenu:
00790         if (static_cast<QContextMenuEvent *>(e)->reason() == QContextMenuEvent::Keyboard)
00791            return QFrame::event(e);
00792         e->ignore();
00793         break;
00794     case QEvent::MouseButtonPress:
00795     case QEvent::MouseButtonRelease:
00796     case QEvent::MouseButtonDblClick:
00797     case QEvent::MouseMove:
00798     case QEvent::Wheel:
00799 #ifndef QT_NO_DRAGANDDROP
00800     case QEvent::Drop:
00801     case QEvent::DragEnter:
00802     case QEvent::DragMove:
00803     case QEvent::DragLeave:
00804 #endif
00805         return false;
00806     case QEvent::StyleChange:
00807         d->layoutChildren();
00808         // fall through
00809     default:
00810         return QFrame::event(e);
00811     }
00812     return true;
00813 }

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bool QAbstractScrollArea::viewportEvent ( QEvent *  event  )  [protected, virtual]

The main event handler for the scrolling area (the viewport() widget). It handles the event specified, and can be called by subclasses to provide reasonable default behavior.

Returns true to indicate to the event system that the event has been handled, and needs no further processing; otherwise returns false to indicate that the event should be propagated further.

You can reimplement this function in a subclass, but we recommend using one of the specialized event handlers instead.

Specialised handlers for viewport events are: paintEvent(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), wheelEvent(), dragEnterEvent(), dragMoveEvent(), dragLeaveEvent(), dropEvent(), contextMenuEvent(), and resizeEvent().

Definition at line 835 of file qabstractscrollarea.cpp.

References QEvent::ContextMenu, QEvent::DragEnter, QEvent::DragLeave, QEvent::DragMove, QEvent::Drop, event(), QFrame::event(), QEvent::LayoutRequest, QEvent::MouseButtonDblClick, QEvent::MouseButtonPress, QEvent::MouseButtonRelease, QEvent::MouseMove, QEvent::Paint, QEvent::Resize, QEvent::type(), and QEvent::Wheel.

Referenced by QAbstractItemView::viewportEvent(), and QGraphicsView::viewportEvent().

00836 {
00837     switch (e->type()) {
00838     case QEvent::Resize:
00839     case QEvent::Paint:
00840     case QEvent::MouseButtonPress:
00841     case QEvent::MouseButtonRelease:
00842     case QEvent::MouseButtonDblClick:
00843     case QEvent::MouseMove:
00844     case QEvent::ContextMenu:
00845 #ifndef QT_NO_WHEELEVENT
00846     case QEvent::Wheel:
00847 #endif
00848 #ifndef QT_NO_DRAGANDDROP
00849     case QEvent::Drop:
00850     case QEvent::DragEnter:
00851     case QEvent::DragMove:
00852     case QEvent::DragLeave:
00853 #endif
00854         return QFrame::event(e);
00855     case QEvent::LayoutRequest:
00856         return event(e);
00857     default:
00858         break;
00859     }
00860     return false; // let the viewport widget handle the event
00861 }

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void QAbstractScrollArea::resizeEvent ( QResizeEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive resize events (passed in event), for the viewport() widget.

When resizeEvent() is called, the viewport already has its new geometry: Its new size is accessible through the QResizeEvent::size() function, and the old size through QResizeEvent::oldSize().

See also:
QWidget::resizeEvent()

Reimplemented from QWidget.

Definition at line 876 of file qabstractscrollarea.cpp.

Referenced by QGraphicsView::resizeEvent(), and QAbstractItemView::resizeEvent().

00877 {
00878 }

void QAbstractScrollArea::paintEvent ( QPaintEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive paint events (passed in event), for the viewport() widget.

Note: If you open a painter, make sure to open it on the viewport().

See also:
QWidget::paintEvent()

Reimplemented from QFrame.

Definition at line 891 of file qabstractscrollarea.cpp.

Referenced by QGraphicsView::paintEvent().

00892 {
00893 }

void QAbstractScrollArea::mousePressEvent ( QMouseEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive mouse press events for the viewport() widget. The event is passed in e.

See also:
QWidget::mousePressEvent()

Reimplemented from QWidget.

Definition at line 902 of file qabstractscrollarea.cpp.

References QEvent::ignore().

00903 {
00904     e->ignore();
00905 }

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void QAbstractScrollArea::mouseReleaseEvent ( QMouseEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive mouse release events for the viewport() widget. The event is passed in e.

See also:
QWidget::mouseReleaseEvent()

Reimplemented from QWidget.

Definition at line 914 of file qabstractscrollarea.cpp.

References QEvent::ignore().

00915 {
00916     e->ignore();
00917 }

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void QAbstractScrollArea::mouseDoubleClickEvent ( QMouseEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive mouse double click events for the viewport() widget. The event is passed in e.

See also:
QWidget::mouseDoubleClickEvent()

Reimplemented from QWidget.

Definition at line 926 of file qabstractscrollarea.cpp.

References QEvent::ignore().

00927 {
00928     e->ignore();
00929 }

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void QAbstractScrollArea::mouseMoveEvent ( QMouseEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive mouse move events for the viewport() widget. The event is passed in e.

See also:
QWidget::mouseMoveEvent()

Reimplemented from QWidget.

Definition at line 938 of file qabstractscrollarea.cpp.

References QEvent::ignore().

00939 {
00940     e->ignore();
00941 }

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void QAbstractScrollArea::wheelEvent ( QWheelEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive wheel events for the viewport() widget. The event is passed in e.

See also:
QWidget::wheelEvent()

Reimplemented from QWidget.

Definition at line 951 of file qabstractscrollarea.cpp.

References d, Qt::Horizontal, and QCoreApplication::sendEvent().

Referenced by QTextEdit::wheelEvent(), and QGraphicsView::wheelEvent().

00952 {
00953     Q_D(QAbstractScrollArea);
00954     if (static_cast<QWheelEvent*>(e)->orientation() == Qt::Horizontal)
00955         QApplication::sendEvent(d->hbar, e);
00956     else
00957         QApplication::sendEvent(d->vbar, e);
00958 }

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void QAbstractScrollArea::contextMenuEvent ( QContextMenuEvent *  e  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive context menu events for the viewport() widget. The event is passed in e.

See also:
QWidget::contextMenuEvent()

Reimplemented from QWidget.

Definition at line 968 of file qabstractscrollarea.cpp.

References QEvent::ignore().

00969 {
00970     e->ignore();
00971 }

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void QAbstractScrollArea::dragEnterEvent ( QDragEnterEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive drag enter events (passed in event), for the viewport() widget.

See also:
QWidget::dragEnterEvent()

Reimplemented from QWidget.

Definition at line 1020 of file qabstractscrollarea.cpp.

01021 {
01022 }

void QAbstractScrollArea::dragMoveEvent ( QDragMoveEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive drag move events (passed in event), for the viewport() widget.

See also:
QWidget::dragMoveEvent()

Reimplemented from QWidget.

Definition at line 1032 of file qabstractscrollarea.cpp.

01033 {
01034 }

void QAbstractScrollArea::dragLeaveEvent ( QDragLeaveEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive drag leave events (passed in event), for the viewport() widget.

See also:
QWidget::dragLeaveEvent()

Reimplemented from QWidget.

Definition at line 1044 of file qabstractscrollarea.cpp.

01045 {
01046 }

void QAbstractScrollArea::dropEvent ( QDropEvent *  event  )  [protected, virtual]

This event handler can be reimplemented in a subclass to receive drop events (passed in event), for the viewport() widget.

See also:
QWidget::dropEvent()

Reimplemented from QWidget.

Definition at line 1056 of file qabstractscrollarea.cpp.

01057 {
01058 }

void QAbstractScrollArea::keyPressEvent ( QKeyEvent *  e  )  [protected, virtual]

This function is called with key event e when key presses occur. It handles PageUp, PageDown, Up, Down, Left, and Right, and ignores all other key presses.

Reimplemented from QWidget.

Definition at line 978 of file qabstractscrollarea.cpp.

References QEvent::accept(), d, QEvent::ignore(), QKeyEvent::key(), Qt::Key_Down, Qt::Key_Left, Qt::Key_Right, Qt::Key_Up, QKeySequence::MoveToNextPage, QKeySequence::MoveToPreviousPage, QAbstractSlider::SliderPageStepAdd, QAbstractSlider::SliderPageStepSub, QAbstractSlider::SliderSingleStepAdd, and QAbstractSlider::SliderSingleStepSub.

Referenced by QGraphicsView::keyPressEvent(), and QTextEdit::keyPressEvent().

00979 {
00980     Q_D(QAbstractScrollArea);
00981     if (false){
00982 #ifndef QT_NO_SHORTCUT
00983     } else if (e == QKeySequence::MoveToPreviousPage) {
00984         d->vbar->triggerAction(QScrollBar::SliderPageStepSub);
00985     } else if (e == QKeySequence::MoveToNextPage) {
00986         d->vbar->triggerAction(QScrollBar::SliderPageStepAdd);
00987 #endif
00988     } else {
00989         switch (e->key()) {
00990         case Qt::Key_Up:
00991             d->vbar->triggerAction(QScrollBar::SliderSingleStepSub);
00992             break;
00993         case Qt::Key_Down:
00994             d->vbar->triggerAction(QScrollBar::SliderSingleStepAdd);
00995             break;
00996         case Qt::Key_Left:
00997             d->hbar->triggerAction(QScrollBar::SliderSingleStepSub);
00998             break;
00999         case Qt::Key_Right:
01000             d->hbar->triggerAction(QScrollBar::SliderSingleStepAdd);
01001             break;
01002         default:
01003             e->ignore();
01004             return;
01005         }
01006     }
01007     e->accept();
01008 }

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void QAbstractScrollArea::scrollContentsBy ( int  dx,
int  dy 
) [protected, virtual]

This virtual handler is called when the scroll bars are moved by dx, dy, and consequently the viewport's contents should be scrolled accordingly.

The default implementation simply calls update() on the entire viewport(), subclasses can reimplement this handler for optimization purposes, or - like QScrollArea - to move a contents widget. The parameters dx and dy are there for convenience, so that the class knows how much should be scrolled (useful e.g. when doing pixel-shifts). You may just as well ignore these values and scroll directly to the position the scroll bars indicate.

Calling this function in order to scroll programmatically is an error, use the scroll bars instead (e.g. by calling QScrollBar::setValue() directly).

Definition at line 1081 of file qabstractscrollarea.cpp.

References QWidget::update(), and viewport().

01082 {
01083     viewport()->update();
01084 }

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QAbstractScrollArea::Q_PRIVATE_SLOT ( d_func()  ,
void   _q_hslide(int) 
) [private]

void QAbstractScrollArea::_q_vslide ( int   )  [private]

The documentation for this class was generated from the following files:
Generated on Thu Mar 15 16:42:58 2007 for Qt 4.2 User's Guide by  doxygen 1.5.1