From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/qscrollview.html | 930 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 930 insertions(+) create mode 100644 doc/html/qscrollview.html (limited to 'doc/html/qscrollview.html') diff --git a/doc/html/qscrollview.html b/doc/html/qscrollview.html new file mode 100644 index 0000000..be8d219 --- /dev/null +++ b/doc/html/qscrollview.html @@ -0,0 +1,930 @@ + + + + + +QScrollView Class + + + + + + + +
+ +Home + | +All Classes + | +Main Classes + | +Annotated + | +Grouped Classes + | +Functions +

QScrollView Class Reference

+ +

The QScrollView widget provides a scrolling area with on-demand scroll bars. +More... +

#include <qscrollview.h> +

Inherits QFrame. +

Inherited by QCanvasView, QTable, QGridView, QIconView, QListBox, QListView, and QTextEdit. +

List of all member functions. +

Public Members

+ +

Public Slots

+ +

Signals

+ +

Properties

+ +

Protected Members

+ +

Detailed Description

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

+ +

The QScrollView is a large canvas - potentially larger than the +coordinate system normally supported by the underlying window +system. This is important because it is quite easy to go beyond +these limitations (e.g. many web pages are more than 32000 pixels +high). Additionally, the QScrollView can have QWidgets positioned +on it that scroll around with the drawn content. These sub-widgets +can also have positions outside the normal coordinate range (but +they are still limited in size). +

To provide content for the widget, inherit from QScrollView, +reimplement drawContents() and use resizeContents() to set the +size of the viewed area. Use addChild() and moveChild() to +position widgets on the view. +

To use QScrollView effectively it is important to understand its +widget structure in the three styles of use: a single large child +widget, a large panning area with some widgets and a large panning +area with many widgets. +

Using One Big Widget +

+

+

The first, simplest usage of QScrollView (depicted above), is +appropriate for scrolling areas that are never more than about +4000 pixels in either dimension (this is about the maximum +reliable size on X11 servers). In this usage, you just make one +large child in the QScrollView. The child should be a child of the +viewport() of the scrollview and be added with addChild(): +

+        QScrollView* sv = new QScrollView(...);
+        QVBox* big_box = new QVBox(sv->viewport());
+        sv->addChild(big_box);
+
+ +You can go on to add arbitrary child widgets to the single child +in the scrollview as you would with any widget: +
+        QLabel* child1 = new QLabel("CHILD", big_box);
+        QLabel* child2 = new QLabel("CHILD", big_box);
+        QLabel* child3 = new QLabel("CHILD", big_box);
+        ...
+
+ +

Here the QScrollView has four children: the viewport(), the +verticalScrollBar(), the horizontalScrollBar() and a small +cornerWidget(). The viewport() has one child: the big QVBox. The +QVBox has the three QLabel objects as child widgets. When the view +is scrolled, the QVBox is moved; its children move with it as +child widgets normally do. +

Using a Very Big View with Some Widgets +

+

+

The second usage of QScrollView (depicted above) is appropriate +when few, if any, widgets are on a very large scrolling area that +is potentially larger than 4000 pixels in either dimension. In +this usage you call resizeContents() to set the size of the area +and reimplement drawContents() to paint the contents. You may also +add some widgets by making them children of the viewport() and +adding them with addChild() (this is the same as the process for +the single large widget in the previous example): +

+        QScrollView* sv = new QScrollView(...);
+        QLabel* child1 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child1);
+        QLabel* child2 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child2);
+        QLabel* child3 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child3);
+
+ +Here, the QScrollView has the same four children: the viewport(), +the verticalScrollBar(), the horizontalScrollBar() and a small +cornerWidget(). The viewport() has the three QLabel objects as +child widgets. When the view is scrolled, the scrollview moves the +child widgets individually. +

Using a Very Big View with Many Widgets +

+

+

+

The final usage of QScrollView (depicted above) is appropriate +when many widgets are on a very large scrolling area that is +potentially larger than 4000 pixels in either dimension. In this +usage you call resizeContents() to set the size of the area and +reimplement drawContents() to paint the contents. You then call +enableClipper(TRUE) and add widgets, again by making them children +of the viewport(), and adding them with addChild(): +

+        QScrollView* sv = new QScrollView(...);
+        sv->enableClipper(TRUE);
+        QLabel* child1 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child1);
+        QLabel* child2 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child2);
+        QLabel* child3 = new QLabel("CHILD", sv->viewport());
+        sv->addChild(child3);
+
+ +

Here, the QScrollView has four children: the clipper() (not the +viewport() this time), the verticalScrollBar(), the +horizontalScrollBar() and a small cornerWidget(). The clipper() +has one child: the viewport(). The viewport() has the same three +labels as child widgets. When the view is scrolled the viewport() +is moved; its children move with it as child widgets normally do. +

+

Details Relevant for All Views +

+

Normally you will use the first or third method if you want any +child widgets in the view. +

Note that the widget you see in the scrolled area is the +viewport() widget, not the QScrollView itself. So to turn mouse +tracking on, for example, use viewport()->setMouseTracking(TRUE). +

To enable drag-and-drop, you would setAcceptDrops(TRUE) on the +QScrollView (because drag-and-drop events propagate to the +parent). But to work out the logical position in the view, you +would need to map the drop co-ordinate from being relative to the +QScrollView to being relative to the contents; use the function +viewportToContents() for this. +

To handle mouse events on the scrolling area, subclass scrollview +as you would subclass other widgets, but rather than +reimplementing mousePressEvent(), reimplement +contentsMousePressEvent() instead. The contents specific event +handlers provide translated events in the coordinate system of the +scrollview. If you reimplement mousePressEvent(), you'll get +called only when part of the QScrollView is clicked: and the only +such part is the "corner" (if you don't set a cornerWidget()) and +the frame; everything else is covered up by the viewport, clipper +or scroll bars. +

When you construct a QScrollView, some of the widget flags apply +to the viewport() instead of being sent to the QWidget constructor +for the QScrollView. This applies to WNoAutoErase, WStaticContents, and WPaintClever. See Qt::WidgetFlags for +documentation about these flags. Here are some examples: +

+

Child widgets may be moved using addChild() or moveChild(). Use +childX() and childY() to get the position of a child widget. +

A widget may be placed in the corner between the vertical and +horizontal scrollbars with setCornerWidget(). You can get access +to the scrollbars using horizontalScrollBar() and +verticalScrollBar(), and to the viewport with viewport(). The +scroll view can be scrolled using scrollBy(), ensureVisible(), +setContentsPos() or center(). +

The visible area is given by visibleWidth() and visibleHeight(), +and the contents area by contentsWidth() and contentsHeight(). The +contents may be repainted using one of the repaintContents() or +updateContents() functions. +

Coordinate conversion is provided by contentsToViewport() and +viewportToContents(). +

The contentsMoving() signal is emitted just before the contents +are moved to a new position. +

Warning: QScrollView currently does not erase the background when +resized, i.e. you must always clear the background manually in +scrollview subclasses. This will change in a future version of Qt +and we recommend specifying the WNoAutoErase flag explicitly. +

+

See also Abstract Widget Classes. + +

Member Type Documentation

+

QScrollView::ResizePolicy

+ +

This enum type is used to control a QScrollView's reaction to +resize events. +

+

QScrollView::ScrollBarMode

+ +

This enum type describes the various modes of QScrollView's scroll +bars. +

(The modes for the horizontal and vertical scroll bars are +independent.) + +

Member Function Documentation

+

QScrollView::QScrollView ( QWidget * parent = 0, const char * name = 0, WFlags f = 0 ) +

+Constructs a QScrollView called name with parent parent and +widget flags f. +

The widget flags WStaticContents, WNoAutoErase and WPaintClever are propagated to the viewport() widget. The other +widget flags are propagated to the parent constructor as usual. + +

QScrollView::~QScrollView () +

+Destroys the QScrollView. Any children added with addChild() will +be deleted. + +

void QScrollView::addChild ( QWidget * child, int x = 0, int y = 0 ) [virtual] +

+Inserts the widget, child, into the scrolled area positioned at +(x, y). The position defaults to (0, 0). If the child is +already in the view, it is just moved. +

You may want to call enableClipper(TRUE) if you add a large number +of widgets. + +

Example: scrollview/scrollview.cpp. +

int QScrollView::bottomMargin () const [protected] +

+Returns the bottom margin. +

See also setMargins(). + +

void QScrollView::center ( int x, int y ) [slot] +

+Scrolls the content so that the point (x, y) is in the center +of visible area. + +

Example: scrollview/scrollview.cpp. +

void QScrollView::center ( int x, int y, float xmargin, float ymargin ) [slot] +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Scrolls the content so that the point (x, y) is visible with +the xmargin and ymargin margins (as fractions of visible +the area). +

For example: +

+ +

bool QScrollView::childIsVisible ( QWidget * child ) +

+This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. +

Returns TRUE if child is visible. This is equivalent +to child->isVisible(). + +

int QScrollView::childX ( QWidget * child ) +

+Returns the X position of the given child widget. Use this +rather than QWidget::x() for widgets added to the view. +

This function returns 0 if child has not been added to the view. + +

int QScrollView::childY ( QWidget * child ) +

+Returns the Y position of the given child widget. Use this +rather than QWidget::y() for widgets added to the view. +

This function returns 0 if child has not been added to the view. + +

QWidget * QScrollView::clipper () const +

+Returns the clipper widget. Contents in the scrollview are +ultimately clipped to be inside the clipper widget. +

You should not need to use this function. +

See also visibleWidth and visibleHeight. + +

void QScrollView::contentsContextMenuEvent ( QContextMenuEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +contextMenuEvent() in e: the mouse position is translated to +be a point on the contents. + +

Example: chart/canvasview.cpp. +

void QScrollView::contentsDragEnterEvent ( QDragEnterEvent * ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +dragEnterEvent(): the drag position is translated to be a point +on the contents. + +

Reimplemented in QTable. +

void QScrollView::contentsDragLeaveEvent ( QDragLeaveEvent * ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +dragLeaveEvent(): the drag position is translated to be a point +on the contents. + +

Reimplemented in QTable. +

void QScrollView::contentsDragMoveEvent ( QDragMoveEvent * ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +dragMoveEvent(): the drag position is translated to be a point on +the contents. + +

Reimplemented in QTable. +

void QScrollView::contentsDropEvent ( QDropEvent * ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +dropEvent(): the drop position is translated to be a point on the +contents. + +

Reimplemented in QTable. +

int QScrollView::contentsHeight () const +

Returns the height of the contents area. +See the "contentsHeight" property for details. +

void QScrollView::contentsMouseDoubleClickEvent ( QMouseEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +mouseDoubleClickEvent(): the click position in e is translated to be a +point on the contents. +

The default implementation generates a normal mouse press event. + +

Reimplemented in QListView. +

void QScrollView::contentsMouseMoveEvent ( QMouseEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +mouseMoveEvent(): the mouse position in e is translated to be a point +on the contents. + +

Examples: canvas/canvas.cpp and chart/canvasview.cpp. +

Reimplemented in QListView. +

void QScrollView::contentsMousePressEvent ( QMouseEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +mousePressEvent(): the press position in e is translated to be a point +on the contents. + +

Examples: canvas/canvas.cpp and chart/canvasview.cpp. +

Reimplemented in QListView. +

void QScrollView::contentsMouseReleaseEvent ( QMouseEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +mouseReleaseEvent(): the release position in e is translated to be a +point on the contents. + +

Reimplemented in QListView. +

void QScrollView::contentsMoving ( int x, int y ) [signal] +

+ +

This signal is emitted just before the contents are moved to +position (x, y). +

See also contentsX and contentsY. + +

void QScrollView::contentsToViewport ( int x, int y, int & vx, int & vy ) const +

+Translates a point (x, y) in the contents to a point (vx, +vy) on the viewport() widget. + +

QPoint QScrollView::contentsToViewport ( const QPoint & p ) const +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Returns the point p translated to a point on the viewport() +widget. + +

void QScrollView::contentsWheelEvent ( QWheelEvent * e ) [virtual protected] +

+This event handler is called whenever the QScrollView receives a +wheelEvent() in e: the mouse position is translated to be a +point on the contents. + +

int QScrollView::contentsWidth () const +

Returns the width of the contents area. +See the "contentsWidth" property for details. +

int QScrollView::contentsX () const +

Returns the X coordinate of the contents that are at the left edge of the viewport. +See the "contentsX" property for details. +

int QScrollView::contentsY () const +

Returns the Y coordinate of the contents that are at the top edge of the viewport. +See the "contentsY" property for details. +

QWidget * QScrollView::cornerWidget () const +

+Returns the widget in the corner between the two scroll bars. +

By default, no corner widget is present. + +

Example: scrollview/scrollview.cpp. +

bool QScrollView::dragAutoScroll () const +

Returns TRUE if autoscrolling in drag move events is enabled; otherwise returns FALSE. +See the "dragAutoScroll" property for details. +

void QScrollView::drawContents ( QPainter * p, int clipx, int clipy, int clipw, int cliph ) [virtual protected] +

+ +

Reimplement this function if you are viewing a drawing area rather +than a widget. +

The function should draw the rectangle (clipx, clipy, clipw, cliph) of the contents using painter p. The clip +rectangle is in the scrollview's coordinates. +

For example: +

+    {
+        // Fill a 40000 by 50000 rectangle at (100000,150000)
+
+        // Calculate the coordinates...
+        int x1 = 100000, y1 = 150000;
+        int x2 = x1+40000-1, y2 = y1+50000-1;
+
+        // Clip the coordinates so X/Windows will not have problems...
+        if (x1 < clipx) x1=clipx;
+        if (y1 < clipy) y1=clipy;
+        if (x2 > clipx+clipw-1) x2=clipx+clipw-1;
+        if (y2 > clipy+cliph-1) y2=clipy+cliph-1;
+
+        // Paint using the small coordinates...
+        if ( x2 >= x1 && y2 >= y1 )
+            p->fillRect(x1, y1, x2-x1+1, y2-y1+1, red);
+    }
+
+ +

The clip rectangle and translation of the painter p is already +set appropriately. + +

Example: qdir/qdir.cpp. +

Reimplemented in QCanvasView and QTable. +

void QScrollView::drawContentsOffset ( QPainter * p, int offsetx, int offsety, int clipx, int clipy, int clipw, int cliph ) [virtual protected] +

+For backward-compatibility only. It is easier to use +drawContents(QPainter*,int,int,int,int). +

The default implementation translates the painter appropriately +and calls drawContents(QPainter*,int,int,int,int). See +drawContents() for an explanation of the parameters p, offsetx, offsety, clipx, clipy, clipw and cliph. + +

Reimplemented in QListView. +

void QScrollView::enableClipper ( bool y ) +

+When a large numbers of child widgets are in a scrollview, +especially if they are close together, the scrolling performance +can suffer greatly. If y is TRUE the scrollview will use an +extra widget to group child widgets. +

Note that you may only call enableClipper() prior to adding +widgets. +

For a full discussion, see this class's detailed description. + +

Example: scrollview/scrollview.cpp. +

void QScrollView::ensureVisible ( int x, int y ) [slot] +

+Scrolls the content so that the point (x, y) is visible with at +least 50-pixel margins (if possible, otherwise centered). + +

void QScrollView::ensureVisible ( int x, int y, int xmargin, int ymargin ) [slot] +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Scrolls the content so that the point (x, y) is visible with at +least the xmargin and ymargin margins (if possible, +otherwise centered). + +

bool QScrollView::eventFilter ( QObject * obj, QEvent * e ) [virtual protected] +

+This event filter ensures the scroll bars are updated when a +single contents widget is resized, shown, hidden or destroyed; it +passes mouse events to the QScrollView. The event is in e and +the object is in obj. + +

Reimplemented from QObject. +

Reimplemented in QListView. +

ScrollBarMode QScrollView::hScrollBarMode () const +

Returns the mode for the horizontal scroll bar. +See the "hScrollBarMode" property for details. +

bool QScrollView::hasStaticBackground () const +

+Returns TRUE if QScrollView uses a static background; otherwise +returns FALSE. +

See also setStaticBackground(). + +

QScrollBar * QScrollView::horizontalScrollBar () const +

+Returns the component horizontal scroll bar. It is made available +to allow accelerators, autoscrolling, etc. +

It should not be used for other purposes. +

This function never returns 0. + +

void QScrollView::horizontalSliderPressed () [signal] +

+ +

This signal is emitted whenever the user presses the horizontal slider. + +

void QScrollView::horizontalSliderReleased () [signal] +

+ +

This signal is emitted whenever the user releases the horizontal slider. + +

bool QScrollView::isHorizontalSliderPressed () +

+Returns TRUE if horizontal slider is pressed by user; otherwise returns FALSE. + +

bool QScrollView::isVerticalSliderPressed () +

+Returns TRUE if vertical slider is pressed by user; otherwise returns FALSE. + +

int QScrollView::leftMargin () const [protected] +

+Returns the left margin. +

See also setMargins(). + +

void QScrollView::moveChild ( QWidget * child, int x, int y ) [virtual] +

+Repositions the child widget to (x, y). This function is +the same as addChild(). + +

void QScrollView::removeChild ( QWidget * child ) +

+Removes the child widget from the scrolled area. Note that this +happens automatically if the child is deleted. + +

void QScrollView::repaintContents ( int x, int y, int w, int h, bool erase = TRUE ) +

+Calls repaint() on a rectangle defined by x, y, w, h, +translated appropriately. If the rectangle is not visible, nothing +is repainted. If erase is TRUE the background is cleared using +the background color. +

See also updateContents(). + +

void QScrollView::repaintContents ( const QRect & r, bool erase = TRUE ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Repaints the contents of rectangle r. If erase is TRUE the +background is cleared using the background color. + +

void QScrollView::repaintContents ( bool erase = TRUE ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Repaints the contents. If erase is TRUE the background is +cleared using the background color. + +

void QScrollView::resizeContents ( int w, int h ) [virtual slot] +

+Sets the size of the contents area to w pixels wide and h +pixels high and updates the viewport accordingly. + +

ResizePolicy QScrollView::resizePolicy () const +

Returns the resize policy. +See the "resizePolicy" property for details. +

int QScrollView::rightMargin () const [protected] +

+Returns the right margin. +

See also setMargins(). + +

void QScrollView::scrollBy ( int dx, int dy ) [slot] +

+Scrolls the content by dx to the left and dy upwards. + +

void QScrollView::setContentsPos ( int x, int y ) [virtual slot] +

+Scrolls the content so that the point (x, y) is in the top-left +corner. + +

Example: process/process.cpp. +

void QScrollView::setCornerWidget ( QWidget * corner ) [virtual] +

+Sets the widget in the corner between the two scroll bars. +

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 QScrollView 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 vScrollBarMode and hScrollBarMode. + +

Example: scrollview/scrollview.cpp. +

void QScrollView::setDragAutoScroll ( bool b ) [virtual] +

Sets whether autoscrolling in drag move events is enabled to b. +See the "dragAutoScroll" property for details. +

void QScrollView::setHBarGeometry ( QScrollBar & hbar, int x, int y, int w, int h ) [virtual protected] +

+Called when the horizontal scroll bar geometry changes. This is +provided as a protected function so that subclasses can do +interesting things such as providing extra buttons in some of the +space normally used by the scroll bars. +

The default implementation simply gives all the space to hbar. +The new geometry is given by x, y, w and h. +

See also setVBarGeometry(). + +

void QScrollView::setHScrollBarMode ( ScrollBarMode ) [virtual] +

Sets the mode for the horizontal scroll bar. +See the "hScrollBarMode" property for details. +

void QScrollView::setMargins ( int left, int top, int right, int bottom ) [virtual 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 +inside the frameRect() and is left blank; reimplement +drawFrame() or put widgets in the unused area. +

By default all margins are zero. +

See also frameChanged(). + +

void QScrollView::setResizePolicy ( ResizePolicy ) [virtual] +

Sets the resize policy. +See the "resizePolicy" property for details. +

void QScrollView::setStaticBackground ( bool y ) +

+Sets the scrollview to have a static background if y is TRUE, +or a scrolling background if y is FALSE. By default, the +background is scrolling. +

Be aware that this mode is quite slow, as a full repaint of the +visible area has to be triggered on every contents move. +

See also hasStaticBackground(). + +

void QScrollView::setVBarGeometry ( QScrollBar & vbar, int x, int y, int w, int h ) [virtual protected] +

+Called when the vertical scroll bar geometry changes. This is +provided as a protected function so that subclasses can do +interesting things such as providing extra buttons in some of the +space normally used by the scroll bars. +

The default implementation simply gives all the space to vbar. +The new geometry is given by x, y, w and h. +

See also setHBarGeometry(). + +

void QScrollView::setVScrollBarMode ( ScrollBarMode ) [virtual] +

Sets the mode for the vertical scroll bar. +See the "vScrollBarMode" property for details. +

void QScrollView::showChild ( QWidget * child, bool y = TRUE ) +

+This function is obsolete. It is provided to keep old source working. We strongly advise against using it in new code. +

Sets the visibility of child. Equivalent to +QWidget::show() or QWidget::hide(). + +

int QScrollView::topMargin () const [protected] +

+Returns the top margin. +

See also setMargins(). + +

void QScrollView::updateContents ( int x, int y, int w, int h ) +

+Calls update() on a rectangle defined by x, y, w, h, +translated appropriately. If the rectangle is not visible, nothing +is repainted. +

See also repaintContents(). + +

void QScrollView::updateContents ( const QRect & r ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Updates the contents in rectangle r + +

void QScrollView::updateContents () +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

void QScrollView::updateScrollBars () [slot] +

+Updates scroll bars: all possibilities are considered. You should +never need to call this in your code. + +

ScrollBarMode QScrollView::vScrollBarMode () const +

Returns the mode for the vertical scroll bar. +See the "vScrollBarMode" property for details. +

QScrollBar * QScrollView::verticalScrollBar () const +

+Returns the component vertical scroll bar. It is made available to +allow accelerators, autoscrolling, etc. +

It should not be used for other purposes. +

This function never returns 0. + +

void QScrollView::verticalSliderPressed () [signal] +

+ +

This signal is emitted whenever the user presses the vertical slider. + +

void QScrollView::verticalSliderReleased () [signal] +

+ +

This signal is emitted whenever the user releases the vertical slider. + +

QWidget * QScrollView::viewport () const +

+Returns the viewport widget of the scrollview. This is the widget +containing the contents widget or which is the drawing area. + +

Examples: helpsystem/tooltip.cpp and scrollview/scrollview.cpp. +

void QScrollView::viewportPaintEvent ( QPaintEvent * pe ) [virtual protected] +

+This is a low-level painting routine that draws the viewport +contents. Reimplement this if drawContents() is too high-level +(for example, if you don't want to open a QPainter on the +viewport). The paint event is passed in pe. + +

void QScrollView::viewportResizeEvent ( QResizeEvent * ) [virtual protected] +

+To provide simple processing of events on the contents, this +function receives all resize events sent to the viewport. +

See also QWidget::resizeEvent(). + +

Example: chart/canvasview.cpp. +

QSize QScrollView::viewportSize ( int x, int y ) const +

+Returns the viewport size for size (x, y). +

The viewport size depends on (x, y) (the size of the contents), +the size of this widget and the modes of the horizontal and +vertical scroll bars. +

This function permits widgets that can trade vertical and +horizontal space for each other to control scroll bar appearance +better. For example, a word processor or web browser can control +the width of the right margin accurately, whether or not there +needs to be a vertical scroll bar. + +

void QScrollView::viewportToContents ( int vx, int vy, int & x, int & y ) const +

+Translates a point (vx, vy) on the viewport() widget to a +point (x, y) in the contents. + +

QPoint QScrollView::viewportToContents ( const QPoint & vp ) const +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

Returns the point on the viewport vp translated to a point in +the contents. + +

int QScrollView::visibleHeight () const +

Returns the vertical amount of the content that is visible. +See the "visibleHeight" property for details. +

int QScrollView::visibleWidth () const +

Returns the horizontal amount of the content that is visible. +See the "visibleWidth" property for details. +

Property Documentation

+

int contentsHeight

+

This property holds the height of the contents area. +

+

Get this property's value with contentsHeight(). +

int contentsWidth

+

This property holds the width of the contents area. +

+

Get this property's value with contentsWidth(). +

int contentsX

+

This property holds the X coordinate of the contents that are at the left edge of the viewport. +

+

Get this property's value with contentsX(). +

int contentsY

+

This property holds the Y coordinate of the contents that are at the top edge of the viewport. +

+

Get this property's value with contentsY(). +

bool dragAutoScroll

+

This property holds whether autoscrolling in drag move events is enabled. +

If this property is set to TRUE (the default), the QScrollView +automatically scrolls the contents in drag move events if the user +moves the cursor close to a border of the view. Of course this +works only if the viewport accepts drops. Specifying FALSE +disables this autoscroll feature. +

Warning: Enabling this property might not be enough to +effectively turn on autoscrolling. If you put a custom widget in +the QScrollView, you might need to call QDragEvent::ignore() on +the event in the dragEnterEvent() and dragMoveEvent() +reimplementations. + +

Set this property's value with setDragAutoScroll() and get this property's value with dragAutoScroll(). +

ScrollBarMode hScrollBarMode

+

This property holds the mode for the horizontal scroll bar. +

The default mode is QScrollView::Auto. +

See also vScrollBarMode. + +

Set this property's value with setHScrollBarMode() and get this property's value with hScrollBarMode(). +

ResizePolicy resizePolicy

+

This property holds the resize policy. +

The default is Default. +

See also ResizePolicy. + +

Set this property's value with setResizePolicy() and get this property's value with resizePolicy(). +

ScrollBarMode vScrollBarMode

+

This property holds the mode for the vertical scroll bar. +

The default mode is QScrollView::Auto. +

See also hScrollBarMode. + +

Set this property's value with setVScrollBarMode() and get this property's value with vScrollBarMode(). +

int visibleHeight

+

This property holds the vertical amount of the content that is visible. +

+

Get this property's value with visibleHeight(). +

int visibleWidth

+

This property holds the horizontal amount of the content that is visible. +

+

Get this property's value with visibleWidth(). + +

+This file is part of the Qt toolkit. +Copyright © 1995-2007 +Trolltech. All Rights Reserved.

+ +
Copyright © 2007 +TrolltechTrademarks +
Qt 3.3.8
+
+ -- cgit v1.2.3