class QBoxLayout

The QBoxLayout class lines up child widgets horizontally or vertically. More

Inheritance diagram of PySide6.QtWidgets.QBoxLayout

Inherited by: QVBoxLayout, QHBoxLayout

Synopsis

Methods

Note

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Detailed Description

QBoxLayout takes the space it gets (from its parent layout or from the parentWidget() ), divides it up into a row of boxes, and makes each managed widget fill one box.

../../_images/qhboxlayout-with-5-children.png

If the QBoxLayout ‘s orientation is Qt::Horizontal the boxes are placed in a row, with suitable sizes. Each widget (or other box) will get at least its minimum size and at most its maximum size. Any excess space is shared according to the stretch factors (more about that below).

../../_images/qvboxlayout-with-5-children.png

If the QBoxLayout ‘s orientation is Qt::Vertical, the boxes are placed in a column, again with suitable sizes.

The easiest way to create a QBoxLayout is to use one of the convenience classes, e.g. QHBoxLayout (for Qt::Horizontal boxes) or QVBoxLayout (for Qt::Vertical boxes). You can also use the QBoxLayout constructor directly, specifying its direction as LeftToRight , RightToLeft , TopToBottom , or BottomToTop .

If the QBoxLayout is not the top-level layout (i.e. it is not managing all of the widget’s area and children), you must add it to its parent layout before you can do anything with it. The normal way to add a layout is by calling parentLayout-> addLayout() .

Once you have done this, you can add boxes to the QBoxLayout using one of four functions:

  • addWidget() to add a widget to the QBoxLayout and set the widget’s stretch factor. (The stretch factor is along the row of boxes.)

  • addSpacing() to create an empty box; this is one of the functions you use to create nice and spacious dialogs. See below for ways to set margins.

  • addStretch() to create an empty, stretchable box.

  • addLayout() to add a box containing another QLayout to the row and set that layout’s stretch factor.

Use insertWidget() , insertSpacing() , insertStretch() or insertLayout() to insert a box at a specified position in the layout.

QBoxLayout also includes two margin widths:

  • setContentsMargins() sets the width of the outer border on each side of the widget. This is the width of the reserved space along each of the QBoxLayout ‘s four sides.

  • setSpacing() sets the width between neighboring boxes. (You can use addSpacing() to get more space at a particular spot.)

The margin default is provided by the style. The default margin most Qt styles specify is 9 for child widgets and 11 for windows. The spacing defaults to the same as the margin width for a top-level layout, or to the same as the parent layout.

To remove a widget from a layout, call removeWidget() . Calling hide() on a widget also effectively removes the widget from the layout until show() is called.

You will almost always want to use QVBoxLayout and QHBoxLayout rather than QBoxLayout because of their convenient constructors.

class Direction

This type is used to determine the direction of a box layout.

Constant

Description

QBoxLayout.LeftToRight

Horizontal from left to right.

QBoxLayout.RightToLeft

Horizontal from right to left.

QBoxLayout.TopToBottom

Vertical from top to bottom.

QBoxLayout.BottomToTop

Vertical from bottom to top.

__init__(arg__1[, parent=None])
Parameters:

Constructs a new QBoxLayout with direction dir and parent widget parent.

The layout is set directly as the top-level layout for parent. There can be only one top-level layout for a widget. It is returned by layout() .

addLayout(layout[, stretch=0])
Parameters:
  • layoutQLayout

  • stretch – int

Adds layout to the end of the box, with serial stretch factor stretch.

See also

insertLayout() addItem() addWidget()

addSpacerItem(spacerItem)
Parameters:

spacerItemQSpacerItem

Adds spacerItem to the end of this box layout.

addSpacing(size)
Parameters:

size – int

Adds a non-stretchable space (a QSpacerItem ) with size size to the end of this box layout. QBoxLayout provides default margin and spacing. This function adds additional space.

See also

insertSpacing() addItem() QSpacerItem

addStretch([stretch=0])
Parameters:

stretch – int

Adds a stretchable space (a QSpacerItem ) with zero minimum size and stretch factor stretch to the end of this box layout.

See also

insertStretch() addItem() QSpacerItem

addStrut(arg__1)
Parameters:

arg__1 – int

Limits the perpendicular dimension of the box (e.g. height if the box is LeftToRight ) to a minimum of size. Other constraints may increase the limit.

See also

addItem()

addWidget(arg__1[, stretch=0[, alignment=Qt.Alignment()]])
Parameters:

Adds widget to the end of this box layout, with a stretch factor of stretch and alignment alignment.

The stretch factor applies only in the direction of the QBoxLayout , and is relative to the other boxes and widgets in this QBoxLayout . Widgets and boxes with higher stretch factors grow more.

If the stretch factor is 0 and nothing else in the QBoxLayout has a stretch factor greater than zero, the space is distributed according to the QWidget :sizePolicy() of each widget that’s involved.

The alignment is specified by alignment. The default alignment is 0, which means that the widget fills the entire cell.

direction()
Return type:

Direction

Returns the direction of the box. addWidget() and addSpacing() work in this direction; the stretch stretches in this direction.

insertItem(index, arg__2)
Parameters:

Inserts item into this box layout at position index. If index is negative, the item is added at the end.

insertLayout(index, layout[, stretch=0])
Parameters:
  • index – int

  • layoutQLayout

  • stretch – int

Inserts layout at position index, with stretch factor stretch. If index is negative, the layout is added at the end.

layout becomes a child of the box layout.

insertSpacerItem(index, spacerItem)
Parameters:

Inserts spacerItem at position index, with zero minimum size and stretch factor. If index is negative the space is added at the end.

insertSpacing(index, size)
Parameters:
  • index – int

  • size – int

Inserts a non-stretchable space (a QSpacerItem ) at position index, with size size. If index is negative the space is added at the end.

The box layout has default margin and spacing. This function adds additional space.

insertStretch(index[, stretch=0])
Parameters:
  • index – int

  • stretch – int

Inserts a stretchable space (a QSpacerItem ) at position index, with zero minimum size and stretch factor stretch. If index is negative the space is added at the end.

insertWidget(index, widget[, stretch=0[, alignment=Qt.Alignment()]])
Parameters:

Inserts widget at position index, with stretch factor stretch and alignment alignment. If index is negative, the widget is added at the end.

The stretch factor applies only in the direction of the QBoxLayout , and is relative to the other boxes and widgets in this QBoxLayout . Widgets and boxes with higher stretch factors grow more.

If the stretch factor is 0 and nothing else in the QBoxLayout has a stretch factor greater than zero, the space is distributed according to the QWidget :sizePolicy() of each widget that’s involved.

The alignment is specified by alignment. The default alignment is 0, which means that the widget fills the entire cell.

setDirection(arg__1)
Parameters:

arg__1Direction

Sets the direction of this layout to direction.

See also

direction()

setStretch(index, stretch)
Parameters:
  • index – int

  • stretch – int

Sets the stretch factor at position index. to stretch.

See also

stretch()

setStretchFactor(l, stretch)
Parameters:
Return type:

bool

This is an overloaded function.

Sets the stretch factor for the layout layout to stretch and returns true if layout is found in this layout (not including child layouts); otherwise returns false.

setStretchFactor(w, stretch)
Parameters:
Return type:

bool

Sets the stretch factor for widget to stretch and returns true if widget is found in this layout (not including child layouts); otherwise returns false.

See also

setAlignment()

stretch(index)
Parameters:

index – int

Return type:

int

Returns the stretch factor at position index.

See also

setStretch()