Graphics Reference
In-Depth Information
Working with symbol layers
In the previous chapters, we created symbols to display vector features by instantiating one
of the three basic subclasses of QgsSymbolV2 :
QgsMarkerSymbolV2 for point geometries
QgsLineSymbolV2 for line geometries
QgsFillSymbolV2 for polygon geometries
We did this either by calling one of the preceding class's static createSimple() meth-
ods, or by asking the QgsSymbolV2 class to provide us with the default symbol for a giv-
en type of geometry. Irrespective of how we did it, the result was a ready-to-use symbol ob-
ject that displays a given type of vector geometry.
Internally, symbols consist of one or more symbol layers that are displayed one on top of
the other, to draw the vector feature:
Note
The symbol layers are drawn in the order in which they are added to the symbol. So, in this
example, Symbol Layer 1 will be drawn before Symbol Layer 2 . This has the effect of
drawing the second symbol layer on top of the first. Make sure you get the order of your
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