QScrollArea¶
The
QScrollArea
class provides a scrolling view onto another widget. More…
Synopsis¶
Functions¶
def
alignment
()def
ensureVisible
(x, y[, xmargin=50[, ymargin=50]])def
ensureWidgetVisible
(childWidget[, xmargin=50[, ymargin=50]])def
setAlignment
(arg__1)def
setWidget
(widget)def
setWidgetResizable
(resizable)def
takeWidget
()def
widget
()def
widgetResizable
()
Detailed Description¶
A scroll area is used to display the contents of a child widget within a frame. If the widget exceeds the size of the frame, the view can provide scroll bars so that the entire area of the child widget can be viewed. The child widget must be specified with
setWidget()
. For example:imageLabel = QLabel() image = QImage("happyguy.png") imageLabel.setPixmap(QPixmap.fromImage(image)) scrollArea = QScrollArea() scrollArea.setBackgroundRole(QPalette.Dark) scrollArea.setWidget(imageLabel)The code above creates a scroll area (shown in the images below) containing an image label. When scaling the image, the scroll area can provide the necessary scroll bars:
The scroll bars appearance depends on the currently set
scroll bar policies
. You can control the appearance of the scroll bars using the inherited functionality fromQAbstractScrollArea
.For example, you can set the
horizontalScrollBarPolicy
andverticalScrollBarPolicy
properties. Or if you want the scroll bars to adjust dynamically when the contents of the scroll area changes, you can use thehorizontalScrollBar()
andverticalScrollBar()
functions (which enable you to access the scroll bars) and set the scroll bars’ values whenever the scroll area’s contents change, using thesetValue()
function.You can retrieve the child widget using the
widget()
function. The view can be made to be resizable with thesetWidgetResizable()
function. The alignment of the widget can be specified withsetAlignment()
.Two convenience functions
ensureVisible()
andensureWidgetVisible()
ensure a certain region of the contents is visible inside the viewport, by scrolling the contents if necessary.
Size Hints and Layouts¶
When using a scroll area to display the contents of a custom widget, it is important to ensure that the
size hint
of the child widget is set to a suitable value. If a standardQWidget
is used for the child widget, it may be necessary to callsetMinimumSize()
to ensure that the contents of the widget are shown correctly within the scroll area.If a scroll area is used to display the contents of a widget that contains child widgets arranged in a layout, it is important to realize that the size policy of the layout will also determine the size of the widget. This is especially useful to know if you intend to dynamically change the contents of the layout. In such cases, setting the layout’s
size constraint
property to one which provides constraints on the minimum and/or maximum size of the layout (e.g.,SetMinAndMaxSize
) will cause the size of the scroll area to be updated whenever the contents of the layout changes.For a complete example using the
QScrollArea
class, see the Image Viewer example. The example shows how to combineQLabel
andQScrollArea
to display an image.
-
class
QScrollArea
([parent=None])¶ - param parent
Constructs an empty scroll area with the given
parent
.See also
-
PySide2.QtWidgets.QScrollArea.
alignment
()¶ - Return type
Alignment
See also
-
PySide2.QtWidgets.QScrollArea.
ensureVisible
(x, y[, xmargin=50[, ymargin=50]])¶ - Parameters
x –
int
y –
int
xmargin –
int
ymargin –
int
Scrolls the contents of the scroll area so that the point (
x
,y
) is visible inside the region of the viewport with margins specified in pixels byxmargin
andymargin
. If the specified point cannot be reached, the contents are scrolled to the nearest valid position. The default value for both margins is 50 pixels.
-
PySide2.QtWidgets.QScrollArea.
ensureWidgetVisible
(childWidget[, xmargin=50[, ymargin=50]])¶ - Parameters
childWidget –
QWidget
xmargin –
int
ymargin –
int
Scrolls the contents of the scroll area so that the
childWidget
ofwidget()
is visible inside the viewport with margins specified in pixels byxmargin
andymargin
. If the specified point cannot be reached, the contents are scrolled to the nearest valid position. The default value for both margins is 50 pixels.
-
PySide2.QtWidgets.QScrollArea.
setAlignment
(arg__1)¶ - Parameters
arg__1 –
Alignment
See also
-
PySide2.QtWidgets.QScrollArea.
setWidget
(widget)¶ - Parameters
widget –
QWidget
Sets the scroll area’s
widget
.The
widget
becomes a child of the scroll area, and will be destroyed when the scroll area is deleted or when a new widget is set.The widget’s
autoFillBackground
property will be set totrue
.If the scroll area is visible when the
widget
is added, you mustshow()
it explicitly.Note that You must add the layout of
widget
before you call this function; if you add it later, thewidget
will not be visible - regardless of when youshow()
the scroll area. In this case, you can also notshow()
thewidget
later.See also
-
PySide2.QtWidgets.QScrollArea.
setWidgetResizable
(resizable)¶ - Parameters
resizable –
bool
See also
-
PySide2.QtWidgets.QScrollArea.
takeWidget
()¶ - Return type
Removes the scroll area’s widget, and passes ownership of the widget to the caller.
See also
-
PySide2.QtWidgets.QScrollArea.
widget
()¶ - Return type
Returns the scroll area’s widget, or 0 if there is none.
See also
-
PySide2.QtWidgets.QScrollArea.
widgetResizable
()¶ - Return type
bool
See also
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