https://github.com/kornerr/ios-collapse-expand

Sample iOS application to implement collapse/expand animation
https://github.com/kornerr/ios-collapse-expand

ios ios-application swift

Last synced: 11 days ago
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Sample iOS application to implement collapse/expand animation

• Host: GitHub
• URL: https://github.com/kornerr/ios-collapse-expand
• Owner: kornerr
• Created: 2018-07-18T11:19:16.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2018-07-20T14:51:39.000Z (almost 8 years ago)
• Last Synced: 2025-07-04T13:23:29.259Z (12 months ago)
• Topics: ios, ios-application, swift
• Language: Swift
• Size: 695 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

          

# Overview

This is a sample iOS application to implement collapse / expansion animation.

# Preview

This is what the app looks like:

![Preview][preview]

# Collapse / expansion animation

The are several entities at play:

* `LayoutReportingView`

    * a simple `UIView` derivative to report when `UIView` instance gets `layoutSubviews()` call

* `MainVC.storyboard`

    * provides `DetailsView`, which is `LayoutReportingView`

    * constraints `DetailsView` to the collapsed state with a fixed height constraint

        * height: 100

        * priority: 750

    * expands `DetailsView` to the top of the superview

        * priority: 1000

* `CollapseExpansionController`

    * accepts height range available for expansion

    * installs `UIPanGestureRecognizer` into tracked view

    * reports new `height` values each pan gesture

    * reports final `height` value once pan gesture is finished

* `AppDelegate`

    * creates `CollapseExpansionController`

        * only does so once height range of `DetailsView` becomes available

        * provides `DetailsView` as tracked view

    * sets `DetailsView` height to the `height` while panning (`heightChanged` callback)

    * animates `DetailsView` height to the `height` after panning (`completeHeightChange` callback)

**Note**: [XcodeGen][xcodegen] was used to generate Xcode project

[preview]: preview.gif

[xcodegen]: https://github.com/yonaskolb/XcodeGen