FlexMonkey: Creating Custom Gesture Recognisers in Swift
The UIGestureRecognizer base class allows us to decouple the logic for recognising and acting When the gesture begins, changes or ends, my function , Most importantly, I want to set the state of the recogniser to Began: .. relationship visualisation1; removeFromSuperview1; selector1; set1; sky cube. Then we attached a UIPanGestureRecognizer instance to it so that we can isReversed = avesisland.info =.ended } circleAnimator. checking for equality, enforcing uniqueness, cascading relationship changes, and a host. UIPanGestureRecognizer only returns state Began and Cancelled ViewController --(present modally segue)--> UINavigationController --( relationship will return all available states: Began, Changed, Cancelled, Ended .
Our final code might look something like this: In the Objective-C world there is Mantle, a great library for handling such things. Before that there was RestKit. RestKit however made some Unfortunately I haven't found a good solution for Swift just yet, and trying to work with Mantle proves to be problematic in it's current form, unless you implement all your models in Obj-C, something I'm not sure we all want to do at this stage. I know this isn't all problems with SwiftyJSON, but they ironically break a lot of Swift conventions in dealing with optional values.
However, the syntax is a little easier on the eyes. Personally, I don't use the library in my projects. Let's take a look. Trying out some sample code I threw together this quick demo UIViewController that adds a blue square to the screen and animates it in, give it a try yourself, it's pretty nifty: Spring sports quite a few animation types, set as a string.
avesisland.info - avesisland.info | Apple Developer Documentation
The library goes beyond this, and in fact allows simple animations to be created in storyboards. So in theory you could put Spring in your Xcode project, and then pass it off to a designer to set up some nifty animations using this library. Very interesting idea, I would like to hear from someone who has tried to do exactly this. It's THE testing framework? Let's take a look at how Quick works as opposed to XCTest, or expecta. In XCTest, you might define an assertion that you're testing against like this: This method is called before the invocation of each test method in the class.
This method is called after the invocation of each test method in the class. Those may sound like the same thing, but take a look at how Quick due to it's usage of the library Nimble expresses the same thing like this: Quick also eases some of the pain of asynchronous testing.
The basic way that works is you can create an expectation object, and then fulfill it when the async operation is complete. Learn how to use UIGestureRecognizers to pinch, zoom, drag, and more! The original tutorial was written by Caroline Begbie. Adding deceleration for movement Setting dependencies between gesture recognizers Creating a custom UIGestureRecognizer so you can tickle the monkey! This tutorial assumes you are familiar with the basic concepts of Storyboards. If you are new to them, you may wish to check out our Storyboard tutorials first.
Designing Animations with UIViewPropertyAnimator in iOS 10 and Swift 3
Open it in Xcode and build and run. You should see the following on your device or simulator: Each programmer wrote slightly different code to detect touches, resulting in subtle bugs and inconsistencies across apps.
These provide a default implementation of detecting common gestures such as taps, pinches, rotations, swipes, pans, and long presses. By using them, not only does it save you a ton of code, but it makes your apps work properly too!
Of course you can still use the old touch notifications, if your app requires them. Using UIGestureRecognizer is extremely simple.
You just perform the following steps: Create a gesture recognizer.IOS 11+, Swift 4+, Beginners, Tutorial : Pan Gesture Tutorial ( UIPanGestureRecognizer )
When you create a gesture recognizer, you specify a callback function so the gesture recognizer can send you updates when the gesture starts, changes, or ends. Add the gesture recognizer to a view. Each gesture recognizer is associated with one and only one view.
- iOS Tutorial: How to make a customizable interactive slide-out menu in Swift
- UIGestureRecognizer Tutorial: Getting Started
This both creates the pan gesture recognizer, and associates it with the monkey Image View: These connections from the starter project are achieved by dragging a gesture recognizer on top of an image view as shown earlier. You may wonder why the UIGestureRecognizer is associated with the image view instead of the view itself. The drawback of this method is sometimes you might want touches to be able to extend beyond the bounds. IBAction func handlePan recognizer: You can retrieve the amount the user has moved their finger by calling the translation in: Here you use that amount to move the center of the monkey the same amount the finger has been dragged.
Note that instead of hard-coding the monkey image view into this function, you get a reference to the monkey image view by calling recognizer. This makes your code more generic, so that you can re-use this same routine for the banana image view later on. A popup will appear — select handlePan recognizer: So select both image views, open up the Attributes Inspector, and check the User Interaction Enabled checkbox.
Compile and run again, and this time you should be able to drag the monkey around the screen! This is because gesture recognizers should be tied to one and only one view.
iOS Tutorial: How to make a customizable interactive slide-out menu in Swift - Thorn Technologies
This is achieved using the same method as attaching a Pan Gesture Recognizer to the monkey Image View as shown earlier. Now connect the handlePan recognizer: Make sure User Interaction Enabled is checked on the banana as well.
Give it a try and you should now be able to drag both image views across the screen. Pretty easy to implement such a cool and fun effect, eh? Think about scrolling a web view, for example. The idea is to detect when the gesture ends, figure out how fast the touch was moving, and animate the object moving to a final destination based on the touch speed.
To detect when the gesture ends: The callback passed to the gesture recognizer is called potentially multiple times — when the gesture recognizer changes its state to began, changed, or ended for example.
You can find out what state the gesture recognizer is in simply by looking at its state property. To detect the touch velocity: Some gesture recognizers return additional information — you can look at the API guide to see what you can get. So add the following to the bottom of the handlePan recognizer: Figure out the length of the velocity vector i.
Calculate a final point based on the velocity and the slideFactor. Compile and run to try it out, you should now have some basic but nice deceleration! Feel free to play around with it and improve it — if you come up with a better implementation, please share in the forum discussion at the end of this article. Pinch and Rotation Gestures Your app is coming along great so far, but it would be even cooler if you could scale and rotate the image views by using pinch and rotation gestures as well!
The starter project has created the handlePinch recognizer: It has also connected the callback functions to the monkey Image View and the banana Image View.