QRubberBand

The QRubberBand class provides a rectangle or line that can indicate a selection or a boundary. More…

Synopsis

Functions

• def initStyleOption (option)

• def shape ()

Detailed Description

A rubber band is often used to show a new bounding area (as in a QSplitter or a QDockWidget that is undocking). Historically this has been implemented using a QPainter and XOR, but this approach doesn’t always work properly since rendering can happen in the window below the rubber band, but before the rubber band has been “erased”.

You can create a QRubberBand whenever you need to render a rubber band around a given area (or to represent a single line), then call setGeometry() , move() or resize() to position and size it. A common pattern is to do this in conjunction with mouse events. For example:

class Widget:
    def mousePressEvent(self, event):
        origin = event.pos()
        if not self.rubberBand:
            self.rubberBand = QRubberBand(QRubberBand.Rectangle, self)
        rubberBand.setGeometry(QRect(origin, QSize()))
        rubberBand.show()

    def mouseMoveEvent(self, event):
        rubberBand.setGeometry(QRect(origin, event.pos()).normalized())

    def mouseReleaseEvent(self, event):
        rubberBand.hide()
        # determine selection, for example using QRect.intersects()
        # and QRect.contains().

If you pass a parent to QRubberBand ‘s constructor, the rubber band will display only inside its parent, but stays on top of other child widgets. If no parent is passed, QRubberBand will act as a top-level widget.

Call show() to make the rubber band visible; also when the rubber band is not a top-level. Hiding or destroying the widget will make the rubber band disappear. The rubber band can be a Rectangle or a Line (vertical or horizontal), depending on the shape() it was given when constructed.

class PySide2.QtWidgets.QRubberBand(arg__1[, parent=None])

param parent:

PySide2.QtWidgets.QWidget

param arg__1:

Shape

Constructs a rubber band of shape s , with parent p .

By default a rectangular rubber band (s is Rectangle ) will use a mask, so that a small border of the rectangle is all that is visible. Some styles (e.g., native macOS) will change this and call setWindowOpacity() to make a semi-transparent filled selection rectangle.

PySide2.QtWidgets.QRubberBand.Shape

This enum specifies what shape a QRubberBand should have. This is a drawing hint that is passed down to the style system, and can be interpreted by each QStyle .

Constant	Description
QRubberBand.Line	A QRubberBand can represent a vertical or horizontal line. Geometry is still given in rect() and the line will fill the given geometry on most styles.
QRubberBand.Rectangle	A QRubberBand can represent a rectangle. Some styles will interpret this as a filled (often semi-transparent) rectangle, or a rectangular outline.

PySide2.QtWidgets.QRubberBand.initStyleOption(option)

Parameters:

option – PySide2.QtWidgets.QStyleOptionRubberBand

Initialize option with the values from this QRubberBand . This method is useful for subclasses when they need a QStyleOptionRubberBand , but don’t want to fill in all the information themselves.

See also

initFrom()

PySide2.QtWidgets.QRubberBand.shape()

Return type:

Shape

Returns the shape of this rubber band. The shape can only be set upon construction.