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Property wrappers allow property declaration to state what kind of property wrapper is used for implementing the property. We can use it for implementing transformations on properties like validating if string is email or not. This is what we will do: creating a property wrapper for email properties and validating emails using NSDataDetector. If value …
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iOS 13 added a new class named UIContextMenuInteraction what is used for attaching menus to views. When adding menu interaction to a view and user uses 3D Touch or long press gesture on devices not supporting it, a menu is presented alongside with the highlighted content view. Therefore depending on the available space, not all …
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Apple's Vision framework contains computer vision related functionality and with iOS 13 it can detect text on images as well. Moreover, Apple added a new framework VisionKit what makes it easy to integrate document scanning functionality. For demonstrating the usage of it, let's build a simple UI what can present the scanner and display scanned …
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It is this time of the year when to look back. In total I published 22 blog posts and had 2765 views by 1632 people. Together with 3 posts from the 2017 I now have 25 blog posts. In the end of the July I posted Sharing UI code with protocol extension what marked the …
Almost every app needs a way of inserting information using keyboard. When keyboard shows up, we do not want to keep content behind the keyboard hidden and instead, allow user to see it. UIResponder contains several notifications we can use to adjust the layout. Keyboard change notifications UIResponder contains a list of notifications and user …
Every app consists of different flows for achieving a specific goal. For example, there is a sequence of views for sign up. When sign up flow ends, we need to move to so called main view what represents the main functionality of the app. There are definitely a lot of different ways how to handle …
Continue reading "Navigating using flow controllers and responder chain on iOS"
This time we are going to take a look on how to create a form with text input using UITableView. Displaying static text in UITableView is easy but for enabling text input in UITableView and propagating the change back to a model object requires a couple of steps. Introduction In this example project we are …
Storing data persistently on iOS is something what is needed quite often. In this post, we are going to look into how to build a persistent data store and how to store image data. Initialising the persistent data store Persistent data store is an object managing a folder on disk. It allows writing and reading …
In the beginning of this year I blogged about how to generate random float and integers. Meanwhile, SE-0202 "Random Unification" got implemented in Swift 4.2 making my additions unnecessary. Let's take a look how to use new API for getting random numbers. Random integers, floats and booleans In my own implementation I was extending range …
This time we will take a look on how to take photos and browse them on iOS. Using UIImagePickerController Creating user interface for taking photos consists of presenting an instance of UIImagePickerController. Controller needs a delegate and source type what defines if we are going to take a photo or pick a photo from the …
In iOS view transitions can be interactive and non-interactive. In this post we are going to take a look on how to implement a custom non-interactive transition. Setting up a custom transition For setting up a custom non-interactive transition it is needed to create an animator object defining the transition and feeding it into UIKit. …
Having a glow behind a sprite can give game a move lively environment. In this blog post I am going to present a way of adding a glow to SKSpriteNode using an instance of SKEffectNode. Node Tree First of all let's take a look on the node tree needed for achieving the end result. SKSpriteNode …
I was working on an upcoming game in SpriteKit only to discover that adding a simple gradient is not so straight-forward as one would expect. Therefore I created an extension to SKTexture. https://gist.github.com/laevandus/c38a8b9e958ef68c6730025f6b4cc7f4 This extension adds support for creating linear and radial gradients. Linear gradient can be drawn with an angle (in radians) although in …
Metal framework on Apple devices provides a way of using GPU for running complex computing tasks much faster than on CPU. In this blog post I am giving a quick overview how to set up a Metal compute pipeline and processing data on the GPU. Metal compute kernel As a first step we need to …
