Creating Gradient Colors Using CAGradientLayer

Every developer always uses color combinations along with images to produce a good-looking result when creating an app, trying always to achieve the best user experience possible. Sometimes, however, something more might be needed; simple colors might not be good enough for the best outcome in certain cases, but gradient colors could become the perfect fit. I had personally a few times only the opportunity to create gradient colors, and the last time I did so I considered to be a good idea to have a post discussing about gradients, so here it is. The technique to create gradients is simple and it’s a pity not to be used by developers.

So, how can a gradient effect be created quickly and painlessly? There are actually three ways to achieve that. The first and least recommended way is to use images that contain the gradient effect. However the big disadvantage here is that you cannot change the gradient on the fly, unless you design and use a bunch of images representing various states of the gradient. That’s totally unproductive. The second way involves the use of Core Graphics techniques, but you need to have some knowledge about all that (for example the graphics context, color spaces, and more). Also, Core Graphics framework is addressed to more advanced users, so new developers might won’t like the idea of using it just to create a gradient effect. And that brings us to the third, super-fast and simplest approach: The use of a CAGradientLayer object.

The CAGradientLayer, a subclass of the CALayer class that every view object contains, exists just for that purpose; to make gradient effects. Generating a simple gradient takes four lines of code and less than a minute only, while the extremely few properties provided can be used for fine-tuning the final result. Almost all of them can be animated, so at the end you have beautiful results with a little effort. All the details will be discussed in the following parts of this post, but it’s important to understand that when using the CAGradientLayer class to create gradient effects, you’re actually working on the layer of the view that the gradient should apply to. One disadvantage of the CAGradientLayer is the fact that radial gradient is not supported, but that’s something you can live with if you mostly need to make linear gradients.

In the following parts I’m going into the details of each property that can be used to configure the gradient effect. I’m using mostly fancy colors just to make my point, and two colors only so as to keep things simple. However, that’s totally fine for our demo, as whatever you see works for more than two colors as well.

Continue reading my tutorial on Appcoda