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
QScrollView ( QWidget * parent = 0, const char * name = 0, WFlags f = 0 )
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)
Public Slots
void
center ( int x, int y, float xmargin, float ymargin )
Signals
Properties
int
contentsX - the X coordinate of the contents that are at the left edge of the viewport
int
contentsY - the Y coordinate of the contents that are at the top edge of the viewport
bool
dragAutoScroll - whether autoscrolling in drag move events is enabled
int
visibleHeight - the vertical amount of the content that is visible
int
visibleWidth - the horizontal amount of the content that is visible
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
setMargins ( int left, int top, int right, int bottom )
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 )
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 such 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 subwidgets 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()/moveChild() to position widgets
on the view.
To use QScrollView effectively it is important to understand its
widget structure in the three styles of usage: a single large child widget,
a large panning area with some widgets and a large panning area with many widgets.
- 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 may 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.
- Very Big View, 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.
- Very Big View, 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.
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 what 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 handers provide translated events in the
coordinate system of the scrollview. aIf 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 WResizeNoErase, WStaticContents,
WRepaintNoErase and WPaintClever. See Qt::WidgetFlags for
documentation about these flags. Here are some examples:
- An image-manipulation widget would use WResizeNoErase|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 word processing widget might use WResizeNoErase 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.
- A scrolling game widget in which the background scrolls as the
characters move might use WRepaintNoErase (in addition to WStaticContents and WResizeNoErase) so that the window system
background does not flash in and out during scrolling.
Warning: WResizeNoErase is currently set by default, i.e., you always
have to clear the background manually in scrollview subclasses. This
will change in a future version of Qt and we recommend specifying the
flag explicitly.
Member Type Documentation
QScrollView::ResizePolicy
This enum type is used to control QScrollView's reaction to resize
events. There are four possible settings:
- QScrollView::Default - 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 view stays the size set by resizeContents().
- QScrollView::AutoOne - if there is only one child widget the view stays
the size of that widget. Otherwise the behaviour is undefined.
- QScrollView::AutoOneFit - if there is only one child widget the view stays
the size of that widget's sizeHint(). If the scrollview is resized bigger
than the child's sizeHint(), the child will be resized to fit.
If there is more than one child, the behaviour is undefined.
QScrollView::ScrollBarMode
This enum type describes the various modes of QScrollView's scroll
bars. The defined modes are:
- QScrollView::Auto - QScrollView shows a scroll bar when the content is
too tall 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 Documentation
QScrollView::QScrollView ( QWidget * parent = 0, const char * name = 0, WFlags f = 0 )
Constructs a QScrollView with a parent, a name and widget flags f.
The widget flags WStaticContents, WRepaintNoErase 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 destructed.
void QScrollView::addChild ( QWidget * child, int x = 0, int y = 0 ) [virtual]
Inserts 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 current 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
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.
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.
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 access this.
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.
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.
Example: dirview/dirview.cpp.
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.
Example: dirview/dirview.cpp.
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.
Example: dirview/dirview.cpp.
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.
Example: dirview/dirview.cpp.
Reimplemented in QTable.
int QScrollView::contentsHeight () const
Returns the height of the contents area.
See the "contentsHeight" property for details.
void QScrollView::contentsMouseDoubleClickEvent ( QMouseEvent * ) [virtual protected]
This event handler is called whenever the QScrollView receives a
mouseDoubleClickEvent() - the click position is translated to be a
point on the contents.
Reimplemented in QListView.
void QScrollView::contentsMouseMoveEvent ( QMouseEvent * ) [virtual protected]
This event handler is called whenever the QScrollView receives a
mouseMoveEvent() - the mouse position is translated to be a
point on the contents.
Reimplemented in QListView.
void QScrollView::contentsMousePressEvent ( QMouseEvent * ) [virtual protected]
This event handler is called whenever the QScrollView receives a
mousePressEvent() - the press position is translated to be a
point on the contents.
Reimplemented in QListView.
void QScrollView::contentsMouseReleaseEvent ( QMouseEvent * ) [virtual protected]
This event handler is called whenever the QScrollView receives a
mouseReleaseEvent() - the release position 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 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 wether QScrollView uses a static background.
See also setStaticBackground().
QScrollBar * QScrollView::horizontalScrollBar () const
Returns the component horizontal scroll bar. It is made available to allow
accelerators, autoscrolling, etc. and to allow changing
of arrow scroll rates: bar->setSteps( rate, bar->pageStep() ).
It should not be otherwise manipulated.
This function never returns 0.
int QScrollView::leftMargin () const [protected]
Returns the current left margin.
See also setMargins().
void QScrollView::moveChild ( QWidget * child, int x, int y ) [virtual]
Repositions child to (x, y).
This functions the same as addChild().
void QScrollView::removeChild ( QWidget * child )
Removes the child 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 in 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]
Set 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 currently set ResizePolicy.
See the "resizePolicy" property for details.
int QScrollView::rightMargin () const [protected]
Returns the current 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
drawContents() or put widgets in the unused area.
By default all margins are zero.
See also frameChanged().
void QScrollView::setResizePolicy ( ResizePolicy ) [virtual]
Sets the currently set ResizePolicy.
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 otherwise. By default, the background is
scrolling.
Beware 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 current 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 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. and to allow changing
of arrow scroll rates: bar->setSteps( rate, bar->pageStep() ).
It should not be otherwise manipulated.
This function never returns 0.
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.
Example: 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().
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 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.
Set this property's value with setDragAutoScroll() and get this property's value with dragAutoScroll().
This property holds the mode for the horizontal scroll bar.
Set this property's value with setHScrollBarMode() and get this property's value with hScrollBarMode().
See also vScrollBarMode.
This property holds the currently set ResizePolicy.
Set this property's value with setResizePolicy() and get this property's value with resizePolicy().
See also ResizePolicy.
This property holds the mode for the vertical scroll bar.
Set this property's value with setVScrollBarMode() and get this property's value with vScrollBarMode().
See also hScrollBarMode.
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().
Search the documentation, FAQ, qt-interest archive and more (uses
www.trolltech.com):
This file is part of the Qt toolkit,
copyright © 1995-2001
Trolltech, all rights reserved.
Copyright © 2001 Trolltech | Trademarks
| Qt version 3.0.0-beta2
|