Update README.md

README.md

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 # PinterestLayout
-Custom collection view layout inspired by Pinterest layout.
+
+Custom collection view layout with different image and text sizes.
+
+|             PinterestVC         |         Custom Cell          |
+|---------------------------------|------------------------------|
+|![Demo](https://github.com/MagicLab-team/PinterestLayout/blob/master/PinterestLayoutExample/DemoAssets/Demo_1.gif)|![Demo](https://github.com/MagicLab-team/PinterestLayout/blob/master/PinterestLayoutExample/DemoAssets/Demo_2.gif)|
+
+## Contents
+- [Requirements](#requirements)
+- [Installation](#installation)
+- [Usage](#usage)
+- [License](#license)
+
+
+## Requirements
+
+- iOS 8.0+
+- Swift 3.0+
+
+## Installation
+
+### CocoaPods
+
+[CocoaPods](http://cocoapods.org) is a dependency manager for Cocoa projects. You can install it with the following command:
+
+```bash
+$ gem install cocoapods
+```
+
+> CocoaPods 1.1.0+ is required to build Reusable 1.0.0+.
+
+To integrate Reusable into your Xcode project using CocoaPods, specify it in your `Podfile`:
+
+```ruby
+source 'https://github.com/CocoaPods/Specs.git'
+platform :ios, '8.0'
+use_frameworks!
+
+target '<Your Target Name>' do
+    pod 'PinterestLayout'
+end
+```
+
+Then, run the following command:
+
+```bash
+$ pod install
+```
+
+# Usage
+
+## PinterestVC subclass
+
+- All you need to do is to sublcass from PinterestVC and provide items to be shown.
+- PinterestVC will calculate image and text sizes.
+
+```swift
+import UIKit
+import PinterestLayout
+
+class MyPinterestVC: PinterestVC {
+
+    override public func viewDidLoad() {
+        super.viewDidLoad()
+
+        let text = "Some text. Some text. Some text. Some text."
+
+        items = [
+            PinterestItem(image: UIImage(named: "new_york"), text: text),
+            PinterestItem(image: UIImage(named: "bigben_river"), text: text),
+            PinterestItem(image: UIImage(named: "dubai"), text: text),
+            PinterestItem(image: UIImage(named: "4"), text: text),
+            PinterestItem(image: UIImage(named: "tiger"), text: text)
+        ]
+    }
+}
+```
+
+## Using custom cell
+
+0 - Import PinterestLayout
+```swift
+import PinterestLayout
+```
+
+1 - Set PinterestLayout to your collection view.
+```swift
+let layout = PinterestLayout()
+collectionView.collectionViewLayout = layout
+```
+
+2 - Setup layout 
+```swift
+layout.delegate = self
+layout.cellPadding = 5
+layout.numberOfColumns = 2
+```
+
+3 - Implement methods of [PinterestLayoutDelegate](https://github.com/MagicLab-team/PinterestLayout/blob/master/PinterestLayout/PinterestLayoutDelegate.swift)
+```swift 
+/**
+Height for image view in cell.
+     
+@param collectionView - collectionView
+@param indexPath - index path for cell
+     
+Returns height of image view.
+*/
+func collectionView(collectionView: UICollectionView,
+                    heightForImageAtIndexPath indexPath: IndexPath,
+                    withWidth: CGFloat) -> CGFloat
+
+/**
+Height for annotation view (label) in cell.
+     
+@param collectionView - collectionView
+@param indexPath - index path for cell
+     
+Returns height of annotation view.
+*/
+func collectionView(collectionView: UICollectionView,
+                    heightForAnnotationAtIndexPath indexPath: IndexPath,
+                    withWidth: CGFloat) -> CGFloat
+```
+
+- PinterestLayout provides public API to easily calculate the best imageview and text heigths based on available width. 
+
+```swift
+public extension UIImage {
+    /**
+     Calculates the best height of the image for available width.
+     */
+    public func height(forWidth width: CGFloat) -> CGFloat
+//...
+public extension String {
+    /**
+     Calculates the best height of the text for available width and font used.
+     */
+    public func heightForWidth(width: CGFloat, font: UIFont) -> CGFloat 
+```
+- So implementation of PinterestLayoutDelegate might be:
+```swift
+extension CustomCollectionVC: PinterestLayoutDelegate {
+
+    func collectionView(collectionView: UICollectionView,
+                        heightForImageAtIndexPath indexPath: IndexPath,
+                        withWidth: CGFloat) -> CGFloat {
+        let image = images[indexPath.item]
+
+        return image.height(forWidth: withWidth)
+    }
+
+    func collectionView(collectionView: UICollectionView,
+                        heightForAnnotationAtIndexPath indexPath: IndexPath,
+                        withWidth: CGFloat) -> CGFloat {
+        let textFont = UIFont(name: "Arial-ItalicMT", size: 11)!                
+        return "Some text".heightForWidth(width: withWidth, font: textFont)
+    }
+}
+```
+
+4 - Create custom cell and apply [PinterestLayoutAttributes](https://github.com/MagicLab-team/PinterestLayout/blob/master/PinterestLayout/PinterestLayoutAttributes.swift)
+- Example is [here](https://github.com/MagicLab-team/PinterestLayout/blob/master/PinterestLayoutExample/CollectionViewCell.swift)
+```swift
+class CollectionViewCell: UICollectionViewCell {
+//...
+override func apply(_ layoutAttributes: UICollectionViewLayoutAttributes) {
+        super.apply(layoutAttributes)
+        if let attributes = layoutAttributes as? PinterestLayoutAttributes {
+            //change image view height by changing its constraint
+            imageViewHeightLayoutConstraint.constant = attributes.imageHeight
+        }
+    }
+}
+```
+
+## License
+
+Reusable is released under the MIT license. See [LICENSE](https://github.com/KhrystynaShevchuk/CustomCollectionViewWithLayouts/blob/master/LICENSE) for details.
+