`LayerManagerDarwin` can add layer types that are enabled only for JSON style.
It allows to exclude the SDK wrappers for these layers from the project and decrease binary size.
`LayerManagerAndroid` can add layer types that are enabled only for JSON style.
It allows to save binary size - JNI glue code for these layer types won't be
added to the binaries.
At the moment, the annotations implementation in the `mapbox-gl-native`
core is creating concrete layer instances apart from `LayerManager/LayerFactory`
code path.
So, annotations must be disabled if the `LayerManager` implementation does
not provide line, fill or symbol layers (those, used by the annotations).
Note: in future, annotations implementation will be moved from the core to the
platform SDK level(see https://github.com/mapbox/mapbox-plugins-android/tree/master/plugin-annotation)
and `LayerManager` won't need to disable it.
`LayerManager` is now responsible for `RenderLayer` instances creation,
so that there is a single entry point for creating of objects, which
correspond to a certain layer type.
The `LayerType type` field is dropped from `Layer::Impl`.
The `LayerTypeInfo` contains static meta data about certain layer type.
Each layer module should have a single immutable `LayerTypeInfo` instance
for the represented layer type. Both `LayerImpl` and `LayerFactory` from the
module always refer to the same `LayerTypeInfo` instance, so address of this
instance can be used as a layer module Id during the process life time.
The `style::Layer` class now exposes all the properties contained at `style::LayerImpl`.
This allowed to drop `style::Layer::accept()` method usage, avoid the repeated generated code
and thus save some binary size.
This patch is a part of the layers modularization effort.
- No dedicated support for creating format expressions
- Java accessors for 'text-field' flatten back to String
- 'text-field' setter implicitly creates a 'format' expression. For tests, use JsonArray to build an equivalent format expression by hand.
