You can detect by seeing if the IGeoResource resolves to MapGraphic.
You should almost never do instanceof checks in uDig.
But I think I understand the issue. Project does not depend on
MapGraphic so how can you do the detection right? Honestly not sure.
What options do we have?
1. Make a marker interface ?
2. Add something to the render metrics ?
3. Have a extension point where one can declare ways to handle
renderers?
Any other options?
Jesse
On 5-Nov-08, at 8:53 PM, Emily Gouge wrote:
Hmm I think I get what you are trying to say here.
I would need a single list of mapgraphics layers that are rendered to
a "screen tile". Then when I go to compose my tiles I can extract
the section of the mapgraphic image that corresponds to the section
of the tile I am composing. Hmm sounds like fun to implement!
One question - If I want to start treating MapGraphics as "special"
renderers (so I can do different things based on the type of
renderer) I need a way to distinguish between regular renderers and
mapgraphic renderers. All the mapgraphic classes are in a different
package so I can't simply to an "instanceof MapGraphic" test and I
know it's not the correct thing to add the MapGraphic package as a
dependency; so how do I go about determining if a renderer is a
"special" renderer (in this case a mapgraphic renderer).
Thanks
Emily
Jody Garnett wrote:
Jesse the "tiling" system would still need to suck out a small tile
worth of the main mapgraphic image when composing a "tile" for
display ... unless the one specific case where the mapgraphic is
"ontop" of the data layers that are all being tiled up.
Emily I would suggest having the mapgraphic write into an image the
size of the screen; and giving the "tiled renderer" the ability to
select out a rectangle from this large image for use when
"composing" the BufferedImage for an individual Tile...
Not sure if I explained that very well...
Jody
Jesse Eichar wrote:
IMHO I think that MapGraphics should not be part of the tiling.
The reasoning is that they are supposed to be light-weight and
fast. They should normally be fast enough without tiling. And
often are independent of zoom so how would you know when to cache
and when not to.
Jesse
On 4-Nov-08, at 11:49 PM, Emily Gouge wrote:
All,
I'm trying to clean up the the tiled rendering system I worked.
One of the things I'm currently looking at is trying to get
mapgraphics to work nicely with it.
My understanding is that currently mapgraphics pay attention to
the bounds of the screen. So in my tiled rendering system they
are paying attention to the bounds of the screen and using that
information to draw onto the tiles. These tiles don't match up
with the screen so as a result you get some fun results:
* legends, north arrows, etc on every tile.
* grids only partially filled in (if then render tiles are bigger
than the screen only what would fit on the screen is filled in on
the render tile).
So how to fix this?
