* [ios, macos] Made MGLMapView.style property nullable
MGLMapView’s style property is now nullable (optional in Swift). The property is set to nil while the style loads and in the event that the style has failed to load.
* [ios, macos] Switch to delegate method
* [macos] Create MGLMapView programmatically for layer tests
When MGLMapView is created via a nib, -initWithCoder: is called, causing styleURL to be set to nil, in turn causing the default Streets style to be loaded, fooling MGLStyleLayerTests into thinking one-line has been loaded. Instead, create MGLMapView programmatically, passing the intended style URL into the initializer, preventing Streets from being loaded.
It should be safe to invoke GeometryTileWorker::setData multiple times without invoking GeometryTileWorker::setLayers. Therefore GeometryTileWorker::redoLayout() must not consume the layers.
The screen origin is at the lower-left, so offsets and translations increase rightwards and upwards, in contrast to iOS and Web contexts, where the coordinate system increases rightwards and downwards. Duplicated style layer property declarations to reflect this difference.
Ignore empty feature collections or non–feature collections for the purposes of clustering or tiling. A source’s clustering option can only be set when the source is constructed, but setGeoJSON() enables the developer to swap a clusterable feature for an unclusterable geometry and back.
* [ios, macos] Document requirement about adding sources and layers
Sources and layers added outside of mapView:didFinishLoadingStyle:
and mapViewDidFinishLoadingMap: are not guaranteed to appear
since the map may not be fully loaded and ready to accept new
sources and layers.
This also fixes a compiler warning in iosapp.
Views that are added outside of the viewport do not always have an
instantiated presentationLayer. Attempting to use a nil
presentationLayer to move a view offscreen resulted in the view
being pinned to the left side of the view port (at x == 0).
Reduced the likelihood that the developer might attempt to set textField to an NSTextField or UITextField, or textFont to an NSFont or UIFont, or textSize to a CGSize or NSSize, or circlePitchScale to a number (given iconScale).
Eliminated the separate NSValue+MGLStyleLayerAddition files, moving the categories into their respective style layer headers to be closer to the enumeration declarations.
Update only when, and just prior to, rendering, giving no opportunity to interleave unexpected state changes. This means that every time anything about the state is changed, we'll have to attempt a render to reflect that change. In the case of continuous rendering this has happened before this change as well, but it leaves no room for time to pass between an update and a render. In the case of still image rendering, a render call will only actually paint something to the view when all resources have been loaded.
