Now that we are familiar with extending OpenLayers 3 classes and vector management, we can go on and create some interactions and controls. These two terms became distinct in the library, unlike its predecessor. In a nutshell, interactions are special controls that involve a pointer and pointer events, while controls are the traditional controls that are static in nature and can be mapped to a GUI button or DOM element. This is not a bad thing, but it requires more architectural considerations when we create an application. We need to create a structure that can handle both of them in a nice, responsive GUI way.
In this chapter, we will cover the following topics:
Creating a toolbar for control management
Building custom controls and interactions
Selecting, drawing, modifying, and removing features
Measuring distances and areas on the map