Today we shall lead you to step by step through the process of simple gradient overlaying by means of the Flutter technology. However, before getting down to the procedures let’s start from the very beginning, so first things first…
What a gradient actually means
A gradient represents a particular instrument for adding depth, volume, and three-dimensionality to a certain design. When applying flat colors, an image doesn’t look as good as it could, and a gradient is the one to provide designers with limitless opportunities.
All colors bring out specific feelings. If designed wisely, people are experiencing positive emotions. An ideal gradient engages, builds powerful impressions, and even motivate people to act. Nowadays, we’re all seeking this kind of experience, thus, it’s pretty understandable why the given phenomenon is holding a strong position as one of web design technologies.
We hope that it’s pretty much clear on a gradient, so we shall proceed.
What Gradient Overlay refers to
The process slightly resembles the color overlay procedures when items on a specific layer can change their colors. Applying gradient overlay one could color items by means of a gradient. Actually, such a phenom represents a Layer Style which could be found in PhotoShop.
By adding a gradient overlay, designers can add a gradient-based effect to their content on both brand-new and already-made layers. By taking advantage of gradient overlay you can customize multiple parameters, say, colors, directions, the opacity of certain objects, the scale of the overlay, etc.
And now we shall figure out what the following phenomenon means.
The Flutter technology is a great solution for iOS/Android developers.
Keep it in mind that React Native and Xamarin approaches differ from those applied by Flutter. The technique in question doesn’t transform the source code making it native used by a specific platform. Flutter is the one to draw every element of the screen separately.
All the widgets, including pieces that render widgets, form the part of the app itself, and not of the platform.
It’s a good thing since this state of affairs makes it possible to build externally analogous interfaces. Still, such widgets location could be a disadvantage as well, cos it poses more difficulties – interface rebuilding will need a particular memory capacity together with processing timing.
On the other hand, speaking of the native app side, one separate screen is made where the Dart system that carries out Flutter has to be uploaded. Therefore, there exist Flutter docs together with virtual machinery, that could be appended subject to a certain OS used – Android or iOS.
We’re not getting too much into the details. That was only a general description of the process and for now it’s enough.
And we shall move to the most exciting part.
How to exercise a Gradient Overlay
We have carried out a particular study to figure out in what way one could use a gradient for a png-picture by means of the alpha channel. We’re to present you what we’ve found out.
Take a look over here:
|What we have originally||What we’re seeking to|
In the overall, it’s not rocket science to overlay a specific color on a png-picture. You only have to perform the following operation:
Didn’t we expect a slightly different outcome? Yes, we did, however, now you know how to change colors in the background when working with png formats.
You might get an idea to study the source-code of the picture class. Though, there’s a great description of BlendMode, but nothing on gradient implementation.
In case you take a look at specific BlendMode records you’ll see what you’re looking for:
Let’s get back to our BoxDirection case. We’re adding BlendMode.dstAtTop, and when it’s about the picture, you’ll be able to add the only colorBlendMode.
Following such instructions, you’ll surely get the following:
So, the picture is actually our destination, thus, we shall try BlendMode.dstOver:
And again we receive the same result.
Still, is it possible to employ Blend Mode for applying a gradient? Are there any Flutter classes to include gradient parameters, pictures and BlendMode?
After a long time spent searching, we have finally found a class with the required characteristics – the ShaderMask class.
Such an option builds a widget that is applying a certain mask created by a Shader. You’ll be happy to know that the class in question possesses all necessary BlendMode and ShaderCallback features. Such properties are exactly what you’ll need to implement a gradient. By the way, there’s a child characteristic, thus, you could apply it to set up the picture.
We do hope that the material described turned to be practical and useful for you to fix troubles you might have.
Enjoy your coding!