- Dec 2015
Roassal maps objects and connections to graphical elements and edges. In additions, values and metrics are represented in visual dimentions (e.g., width, height, intensity of graphical elements). Such mapping is an expressive way to build flexible and rich visualization. This chapter gives an overview of Roassal and its main API. It covers the essential concepts of Roassal, such as the view, elements, shapes, and interactions.
I would try a less technical introduction to combine with this one. How about:
When we're building a visualization, we want the properties of the objects in our domain to be expressed graphically, by shapes, connections and visual dimensions like width, height, intensity of graphical elements. Roassal builds such mappings as an expressive way to build flexible and rich visualizations.
Once a Roassal element has been created, modifying its shape should not result in an update of the element.
This part should be clarified. Could a further example be referenced?
c := TRCanvas new. shape := TRBoxShape new size: 40. c addShape: shape. shape when: TRMouseClick do: [ :event | event shape remove. c signalUpdate ]. c
I get this error
MessageNotUnderstood: TRMouseLeftClick>>myCirclefor this similar code:
| canvas myCircle data | canvas := TRCanvas new. myCircle := TREllipseShape new size: 100; color: Color white. data := #('lion-o' 'panthro' 'tigro' 'chitara' 'munra' 'ozimandias' 'Dr Manhatan'). canvas addShape: myCircle. myCircle when: TRMouseClick do: [:event | event myCircle remove. canvas signalUpdate ]. canvas
If I change
shapeit works fine, but I wouldn't imagine that variable names could be so picky. Generic names should work (
circledoesn't work neither).