QScrollView(3qt)QScrollView(3qt)NAMEQScrollView - Scrolling area with on-demand scroll bars
SYNOPSIS
#include <qscrollview.h>
Inherits QFrame.
Inherited by QCanvasView, QTable, QGridView, QIconView, QListBox,
QListView, and QTextEdit.
Public Members
QScrollView ( QWidget * parent = 0, const char * name = 0, WFlags f = 0
)
~QScrollView ()
enum ResizePolicy { Default, Manual, AutoOne, AutoOneFit }
virtual void setResizePolicy ( ResizePolicy )
ResizePolicy resizePolicy () const
void removeChild ( QWidget * child )
virtual void addChild ( QWidget * child, int x = 0, int y = 0 )
virtual void moveChild ( QWidget * child, int x, int y )
int childX ( QWidget * child )
int childY ( QWidget * child )
bool childIsVisible ( QWidget * child ) (obsolete)
void showChild ( QWidget * child, bool y = TRUE ) (obsolete)
enum ScrollBarMode { Auto, AlwaysOff, AlwaysOn }
ScrollBarMode vScrollBarMode () const
virtual void setVScrollBarMode ( ScrollBarMode )
ScrollBarMode hScrollBarMode () const
virtual void setHScrollBarMode ( ScrollBarMode )
QWidget * cornerWidget () const
virtual void setCornerWidget ( QWidget * corner )
QScrollBar * horizontalScrollBar () const
QScrollBar * verticalScrollBar () const
QWidget * viewport () const
QWidget * clipper () const
int visibleWidth () const
int visibleHeight () const
int contentsWidth () const
int contentsHeight () const
int contentsX () const
int contentsY () const
void updateContents ( int x, int y, int w, int h )
void updateContents ( const QRect & r )
void updateContents ()
void repaintContents ( int x, int y, int w, int h, bool erase = TRUE )
void repaintContents ( const QRect & r, bool erase = TRUE )
void repaintContents ( bool erase = TRUE )
void contentsToViewport ( int x, int y, int & vx, int & vy ) const
void viewportToContents ( int vx, int vy, int & x, int & y ) const
QPoint contentsToViewport ( const QPoint & p ) const
QPoint viewportToContents ( const QPoint & vp ) const
void enableClipper ( bool y )
void setStaticBackground ( bool y )
bool hasStaticBackground () const
QSize viewportSize ( int x, int y ) const
bool isHorizontalSliderPressed ()
bool isVerticalSliderPressed ()
virtual void setDragAutoScroll ( bool b )
bool dragAutoScroll () const
Public Slots
virtual void resizeContents ( int w, int h )
void scrollBy ( int dx, int dy )
virtual void setContentsPos ( int x, int y )
void ensureVisible ( int x, int y )
void ensureVisible ( int x, int y, int xmargin, int ymargin )
void center ( int x, int y )
void center ( int x, int y, float xmargin, float ymargin )
void updateScrollBars ()
Signals
void contentsMoving ( int x, int y )
void horizontalSliderPressed ()
void horizontalSliderReleased ()
void verticalSliderPressed ()
void verticalSliderReleased ()
Properties
int contentsHeight - the height of the contents area (read only)
int contentsWidth - the width of the contents area (read only)
int contentsX - the X coordinate of the contents that are at the left
edge of the viewport (read only)
int contentsY - the Y coordinate of the contents that are at the top
edge of the viewport (read only)
bool dragAutoScroll - whether autoscrolling in drag move events is
enabled
ScrollBarMode hScrollBarMode - the mode for the horizontal scroll bar
ResizePolicy resizePolicy - the resize policy
ScrollBarMode vScrollBarMode - the mode for the vertical scroll bar
int visibleHeight - the vertical amount of the content that is visible
(read only)
int visibleWidth - the horizontal amount of the content that is visible
(read only)
Protected Members
virtual void drawContents ( QPainter * p, int clipx, int clipy, int
clipw, int cliph )
virtual void drawContentsOffset ( QPainter * p, int offsetx, int
offsety, int clipx, int clipy, int clipw, int cliph )
virtual void contentsMousePressEvent ( QMouseEvent * e )
virtual void contentsMouseReleaseEvent ( QMouseEvent * e )
virtual void contentsMouseDoubleClickEvent ( QMouseEvent * e )
virtual void contentsMouseMoveEvent ( QMouseEvent * e )
virtual void contentsDragEnterEvent ( QDragEnterEvent * )
virtual void contentsDragMoveEvent ( QDragMoveEvent * )
virtual void contentsDragLeaveEvent ( QDragLeaveEvent * )
virtual void contentsDropEvent ( QDropEvent * )
virtual void contentsWheelEvent ( QWheelEvent * e )
virtual void contentsContextMenuEvent ( QContextMenuEvent * e )
virtual void viewportPaintEvent ( QPaintEvent * pe )
virtual void viewportResizeEvent ( QResizeEvent * )
virtual void setMargins ( int left, int top, int right, int bottom )
int leftMargin () const
int topMargin () const
int rightMargin () const
int bottomMargin () const
virtual void setHBarGeometry ( QScrollBar & hbar, int x, int y, int w,
int h )
virtual void setVBarGeometry ( QScrollBar & vbar, int x, int y, int w,
int h )
virtual bool eventFilter ( QObject * obj, QEvent * e )
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
<center>
[Image Omitted]
</center>
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
<center>
[Image Omitted]
</center>
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
<center>
[Image Omitted]
</center>
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:
An image-manipulation widget would use WNoAutoErase|WStaticContents
because the widget draws all pixels itself, and when its size
increases, it only needs a paint event for the new part because the old
part remains unchanged.
A scrolling game widget in which the background scrolls as the
characters move might use WNoAutoErase (in addition to WStaticContents)
so that the window system background does not flash in and out during
scrolling.
A word processing widget might use WNoAutoErase and repaint itself line
by line to get a less-flickery resizing. If the widget is in a mode in
which no text justification can take place, it might use
WStaticContents too, so that it would only get a repaint for the newly
visible parts.
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.
[Image Omitted]
[Image Omitted]
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::Default - the QScrollView selects one of the other
settings automatically when it has to. In this version of Qt,
QScrollView changes to Manual if you resize the contents with
resizeContents() and to AutoOne if a child is added.
QScrollView::Manual - the contents stays the size set by
resizeContents().
QScrollView::AutoOne - if there is only one child widget the contents
stays the size of that widget. Otherwise the behavior is undefined.
QScrollView::AutoOneFit - if there is only one child widget the
contents stays the size of that widget's sizeHint(). If the scrollview
is resized larger than the child's sizeHint(), the child will be
resized to fit. If there is more than one child, the behavior is
undefined.
QScrollView::ScrollBarMode
This enum type describes the various modes of QScrollView's scroll
bars.
QScrollView::Auto - QScrollView shows a scroll bar when the content is
too large to fit and not otherwise. This is the default.
QScrollView::AlwaysOff - QScrollView never shows a scroll bar.
QScrollView::AlwaysOn - QScrollView always shows a scroll bar.
(The modes for the horizontal and vertical scroll bars are
independent.)
MEMBER FUNCTION DOCUMENTATIONQScrollView::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:
Margin 0.0 allows (x, y) to be on the edge of the visible area.
Margin 0.5 ensures that (x, y) is in middle 50% of the visible area.
Margin 1.0 ensures that (x, y) is in the center of the the visible
area.
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:
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:
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:
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().
SEE ALSO
http://doc.trolltech.com/qscrollview.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
web browser. This man page is provided as a convenience for those users
who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qscrollview.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QScrollView(3qt)
