 {logger} = require "../../common/logging"
 
 class TileRendererView extends PlotWidget
-  
+
   get_extent: () ->
     return [@x_range.get('start'), @y_range.get('start'), @x_range.get('end'), @y_range.get('end')]
 

            for c in children
              [cx, cy, cz, cbounds] = c
              child_key = @mget('tile_source').tile_xyz_to_key(cx, cy, cz)
              if child_key of @mget('tile_source').tiles
                children.push(child_key)

          need_load.push(t)

    # draw stand-in parents ----------

    tile_data = e.target.tile_data
    tile_data.img = e.target
    tile_data.current = true
    tile_data.loaded = true
    @request_render()

  _on_tile_cache_load: (e) =>
    tile_data = e.target.tile_data
    tile_data.img = e.target
    tile_data.loaded = true

  _on_tile_error: (e) =>
    return ''
