[udig-devel] Positioning text with LabelPlacement

[Cory Horner]

tony.roth at GMX.de wrote:
> Hi list,
> two questions about putting text to a feature in the map:
>  
> i) I'm using a Textsymbolizer object, which is positioned by a 
> LabelPlacement. The problem is, that the position is fixed and 
> independet from the position of the object in the map. Sometimes it is 
> near the left or right edge of the map and the text is 
> truncated especially if you have long attribute values. I can calculate 
> the position of the Textsymbolizer depending on text length and relative 
> position to the viewpane but ... no.
> Is it somehow possible in UDIG to generate a "floating" Textsymbolizer 
> object which is positioned by the Rendermanager?

Tony, this doesn't sound right.  What geometry type are your features, 
and what SLD snippet are you using? Usually text is positioned as a 
proportion of the text length, with 0 being right-aligned, 1 being 
left-aligned, and 0.5 being the midpoint (for points at least).  Offsets 
can also be applied.

> ii) In the project I'm involved in, we use the Textsymbolizer to inform 
> the user about certain feature attributes. More convenient for the user 
> would be something like an onmouseover effect which opens a tool tipp if 
> the mouse position is next to a feature (of a certain layer). Is 
> something like this existing in Udig itself or in related projects?

This doesn't exist -- a good idea though! When should the tool tip 
appear? Only when a certain tool is selected (like the info tool), or 
anything? (the latter being more difficult)

Cory.