Ramotion / elongation-preview翻译 / 编辑






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This project is maintained by Ramotion, Inc.
We specialize in the designing and coding of custom UI for Mobile Apps and Websites..

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This project is maintained by Ramotion, Inc. We specialize in the designing and coding of custom UI for Mobile Apps and Websites.

The iPhone mockup available here.


  • iOS 9.0+
  • Xcode 8
  • Swift 3 (<= 1.0.5)
  • Swift 4 (>= 1.1)


You can install ElongationPreview in several ways:

  • Add source files to your project.

pod 'ElongationPreview'

github "Ramotion/elongation-preview"

How to use

First of all, import module to your source file.

import ElongationPreview


Then subclass ElongationViewController and configure it as you wish.

class RootViewController: ElongationViewController { }

Now you must register reusable cell in tableView. If you prefer to use Storyboards, you can drag UITableViewCell from bottom-right menu, lay it out and change it's class to ElongationCell. Of course, there are some specific requirements on how you can configure cell's subviews.


  • Easier way: copy DemoElongationCell from demo project and change it as you wish. Add your own views to top, bottom and scalable containers.

  • If you want to create cell from scratch, this is how your cell hierarchy should look like:


    Required properties:

    bottomView — the view which comes from behind the cell when you tap on the cell.

    scalableView — the view which will be scaled when you tap on the cell.

    topView — static top view, add here all the views which won't be scaled and must stay on their position.

    Also you must connect this constraints: topViewHeightConstraint, topViewTopConstraint, bottomViewHeightConstraint, bottomViewTopConstraint.

📌 If you need to override

func scrollViewDidScroll(_ scrollView: UIScrollView)


func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)

you must call super because some important configuration was made in these methods in superclass (ElongationViewController).


class DetailViewController: ElongationDetailViewController { }

If you want to display some details for objects from the root view, it's better to subclass ElongationDetailViewController and configure it for displaying your data.

This class holds headerView property which actually represents ElongationCell in expanded state and it'll be used as a header for tableView by default.

📌 Override openDetailView(for: IndexPath) method, create your ElongationDetailViewController instance and call expand(viewController: ElongationDetailViewController, animated: Bool) method with this instance.

This is the place where you need to configure your ElongationDetailViewController subclass.

Appearance & Behaviour

You can customize both appearance & behaviour of ElongationPreview control by tuning some params of ElongationConfig and overriding shared instance.

// Create new config.
var config = ElongationConfig()

// Change desired properties.
config.scaleViewScaleFactor = 0.9
config.topViewHeight = 190
config.bottomViewHeight = 170
config.bottomViewOffset = 20
config.parallaxFactor = 100
config.separatorHeight = 0.5
config.separatorColor = .white

// Save created config as `shared` instance.
ElongationConfig.shared = config

🗒 All parameters with their descriptions listed in ElongationConfig file.

This library is a part of a selection of our best UI open-source projects.


ElongationPreview is released under the MIT license. See LICENSE for details.

Get the Showroom App for iOS to give it a try

Try this UI component and more like this in our iOS app. Contact us if interested.

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