Coverage for gws-app/gws/base/legend/__init__.py: 100%

1"""Base classes for layer legends. 

2 

3A legend belongs to a layer and renders an image that explains the layer's 

4symbols. The base package provides the generic ``Object`` with the common 

5``Config`` options (``cacheMaxAge``, ``options``) and ``combine_outputs``, which 

6stacks several legend images vertically into one. Concrete legend types are 

7plugins in ``gws.plugin.legend`` (``static``, ``remote``, ``html``, 

8``combined``) and in other plugins such as ``gws.plugin.qgis``. A group layer 

9without its own legend gets a ``combined`` legend of its children. 

10 

11Layers render their legends with ``Layer.render_legend``, the client fetches 

12them with the ``mapGetLegend`` command. 

13 

14Submodules: 

15 

16- ``core``: the base ``Object``, ``Config``, ``Props`` and ``combine_outputs``. 

17 

18Example:: 

19 

20 map.layers+ { 

21 type "qgis" 

22 provider.path "/data/projects/roads.qgs" 

23 legend { type "static" path "/data/legends/roads.png" } 

24 } 

25 

26A legend type in a plugin:: 

27 

28 @gws.ext.object.legend('mylegend') 

29 class Object(gws.base.legend.Object): 

30 def render(self, args=None): 

31 images = [gws.lib.image.from_path(p) for p in self.cfg('paths')] 

32 lros = [gws.LegendRenderOutput(image=img, size=img.size()) for img in images] 

33 return gws.base.legend.combine_outputs(lros, self.options) 

34""" 

35 

36from .core import ( 

37 Config, 

38 Object, 

39 Props, 

40 combine_outputs, 

41)