Drawing with the Canvas

According to Apple documentation, the Canvas is a view type that supports immediate mode drawing. In simpler and more familiar terms, if you have previous experience with UIKit, this is a view that allows you to implement custom bidimensional graphics that you are more accustomed to by using Core Graphics. It allows you to create custom and intricate graphics that you can use in your own user interface.

The programming is basically the same as in Core Graphics. The Canvas requires you to write a closure defining its contents. This closure receives two parameters, GraphicsContext and a size expressed in CGSize that can be used to customize the size of what you want to draw.

You can think about the context as a kind of “handle” of the drawing “pencil” inside the canvas, and you determine what you want to draw by calling the different methods supported by the canvas.

These are graphical primitives that allow you to draw different...