[OpenLayers-Trac] [OpenLayers] #1120: users should be able to customize the select style per feature

[OpenLayers]

#1120: users should be able to customize the select style per feature
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  Reporter:  tschaub           |       Owner:             
      Type:  task              |      Status:  new        
  Priority:  minor             |   Milestone:  2.6 Release
 Component:  general           |     Version:  2.5        
Resolution:                    |    Keywords:             
     State:  Needs Discussion  |  
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Changes (by ahocevar):

  * state:  Needs More Work => Needs Discussion

Comment:

 Here are some ideas on a !StyleMap object that would satisfy the
 requirement and others as well.

 This is what tschaub proposed in #1297:
 > At some point, I'd like to see features get a style map with keys that
 mapped to arrays of styles. I'm sure this will get crschmidt's hackles up,
 but I'd rather have simple constructors and complex objects than just
 simple objects (I'm talking here about a more complex style class that has
 a nice simple constructor for people who only want orange lines).

 I agree with this in principle, although I would see the !StyleMap
 object's purpose to manage styles, not arrays of styles. The reason is
 that the array of styles resulting from applying a SLD !UserStyle will
 differ on a per-feature and per-render base, depending on the fules for
 feature properties and map scale. But the result would be the same. A yet-
 to-define method in the !StyleMap object before rendering a feature will
 return an array of styles, which is the symbolizers for which style rules
 applied to:
 {{{
 !StyleMap.getStyle = function(/*Feature.Vector*/ feature,
 /*String*/renderIntent) {
     return /*Array*/ styles
 }
 }}}
 This method would look up the appropriate style for the passed
 renderIntent (e.g. "select"), and call the Style's creatStyle method with
 the {extend: false} option (see the latest patch for #1297), and return
 the resulting styles array.

 The constructor for the !StyleMap object could have a simple signature for
 users who do not care about fancy style processing, with just a style hash
 as parameter. This would then be mapped to the "default" renderIntent key.
 A more sophisticated signature of the constructor would allow to pass a
 hash map of style hashes, keyed by renderIntent. Similar constructor
 signatures could take a single Style object as "default" renderIntent, and
 a hash of Style objects.

 The nice thing about this would be that all methods for translating
 between the different style specifications could be encapsulated in the
 !StyleMap class.

 So all style information a feature or layer needs would then in a single
 object.

 Does this make sense?

-- 
Ticket URL: <http://trac.openlayers.org/ticket/1120#comment:6>
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