This library provides a basic mechanism for globally managing z-indexes. It works by providing a global (to the map) registry of z-index names to z-indexes. Every non-trivial attached dom element will use this registry to find the proper z-index, given its class name. Classes are similar to CSS classes in that they define a "class" of entities such as "poi", "poi-hover", "traffic-flow", etc.
By convention, the zIndex registry, which is just an object of key -> number mappings.
The ZIndex_Registry is an object containing symbolic name to zindex level constants. The ZIndex utility functions will look up constants in here for non-numeric zindex levels. All constants are absolute.
When multiple poi collections are on the map, set top most to active_poi
Controls will have this zindex unless if overridden
Drawing shape overlay bounding box
Drawing shape overlay point/vertex
Drawing shape overlay
Logos in IE < 10, where the regular logo z-index results in logos displaying above controls.
All map logos and copyrights
info bubble used in search layer
Pois that have not had their zindex set will default to this.
Elevated zindex of the poi while dragging
Poi leader lines will have this zindex
Poi shadows will have this zindex
Drag dot and related
Route pois for stars and via points
The drag ribbons zindex is elevated.
General shapes and overlays that have not had their zindex property set
Traffic flow overlay
POIs specific to traffic
Transit lines overlay
Windows will have this zindex unless if overridden
Absolutizes the zindex for a given tgtElt. This will return a zIndex value appropriate for setting on the style.zIndex property. Inputs can be a string, representing a symbolic zindex level in the registry, a non-zero number or blank/null/undefined. Setting to blank/null/undefined will clear the zindex on the element. Setting a number will result in the dom tree being walked (towards the root) in order to arrive at a zindex relative to the root zindex (found on the first parent element which had ZIndex_setupRoot called on it.