QGraphicsView:: drawBackground is called whenever something of the graphics view needs to be redrawn. This something might be smaller than the whole view for a better performance.. Example: When you have a rectangular item, let’s say 50 x 50 pixels, within a bigger scene / view and you move this rectangle by 20 pixels to the right, only the region covered by the previous.
This function is called automatically for you when the backgroundBrush or QGraphicsScene::backgroundBrush properties change you only need to call this function if you have reimplemented QGraphicsScene::drawBackground() or QGraphicsView::drawBackground() to draw a custom background, and need to trigger a full redraw. See also cacheMode().
Detailed Description. The class serves as a container for QGraphicsItems. It is used together with QGraphicsView for visualizing graphical items, such as lines, rectangles, text, or even custom items, on a 2D surface. QGraphicsScene is part of the Graphics View Framework.. QGraphicsScene also provides functionality that lets you efficiently determine both the location.
[protected] void QItemDelegate:: drawBackground (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const. Renders the item background for the given index, using the given painter and style option. This function was introduced in.
Embedding OSG in QT 4.5.0 with QGLWidget + QGraphicsScene / drawBackground () – need a little help. (too old to reply) Martin Scheffler 2010-06-15 13:05:38 UTC. Permalink … osg with toolkits such as Qt Quick/QML can create very powerful and beautiful user interfaces. The marriage of the two can create great things.
8/8/2011 · Derived QGraphisScene class enables child class to reimplement drawBackground () function of the parent class. By reimplementing drawBackground () function, child class draws the background of the scene using painter. Sample project started as a QT Gui Application and contains main.cpp, CustomQGraphicsScene.h, CustomQGraphicsScene.cpp, Dialog.h and …
This function is called automatically for you when the backgroundBrush or QGraphicsScene::backgroundBrush properties change you only need to call this function if you have reimplemented QGraphicsScene::drawBackground() or QGraphicsView::drawBackground() to draw a custom background, and need to trigger a full redraw.
This property sets the background brush for the scene in this view. It is used to override the scene’s own background, and defines the behavior of drawBackground(). To provide custom background drawing for this view, you can reimplement drawBackground() instead. By default, this property contains a brush with the NoBrush pattern.
Use QGraphicsScene in Qt to rewrite drawBackGround to draw the background. Demand explanation I want to learn the interface design of Qt , hoping to optimize the interface background and then use the Qt interface and graphics to draw.
Detailed Description. The QGraphicsScene class provides a surface for managing a large number of 2D graphical items.. The class serves as a container for QGraphicsItems. It is used together with QGraphicsView for visualizing graphical items, such as lines, rectangles, text, or even custom items, on a 2D surface. QGraphicsScene is part of the Graphics View Framework.
