Andrew Overton 07c46757cc Replace material.io API doc links with links to the relevant header f…
This PR replaces API links containing "/api-docs/" with links to suitable header files in GitHub because the site previously linked to is being taken down and replaced with something that won't handle API docs.

Closes https://github.com/material-components/material-components-ios/pull/10045

COPYBARA_INTEGRATE_REVIEW=https://github.com/material-components/material-components-ios/pull/10045 from andrewoverton:replace-mio-api-docs-with-github-links 0d6e56cc11d0c147366a4f6cde829d8b51567ecc
PiperOrigin-RevId: 323424362
2020-07-27 13:09:23 -07:00

90 lines
2.7 KiB
Markdown

# Collection Layout Attributes
**Notice**: This component will be deprecated over the next few months in favor of the
[Cards](../Cards) and [List](../List) components. See our
[public tracker](https://www.pivotaltracker.com/epic/show/3938766) for more details on timing and
the deprecation plan.
---
Allows passing layout attributes to the cells and supplementary views.
## Design & API Documentation
<ul class="icon-list">
<li class="icon-list-item icon-list-item--link"><a href="https://github.com/material-components/material-components-ios/blob/develop/components/CollectionLayoutAttributes/src/MDCCollectionViewLayoutAttributes.h">API: MDCCollectionViewLayoutAttributes</a></li>
</ul>
- - -
## Installation
### Installation with CocoaPods
To add this component to your Xcode project using CocoaPods, add the following to your `Podfile`:
```
pod 'MaterialComponents/CollectionLayoutAttributes'
```
<!--{: .code-renderer.code-renderer--install }-->
Then, run the following command:
```bash
pod install
```
- - -
## Usage
### Importing
Before using Collection Layout Attributes, you'll need to import it:
<!--<div class="material-code-render" markdown="1">-->
#### Swift
```swift
import MaterialComponents.MaterialCollectionLayoutAttributes
```
#### Objective-C
```objc
#import "MaterialCollectionLayoutAttributes.h"
```
<!--</div>-->
The `MDCCollectionViewLayoutAttributes` class allows passing properties to a cell from a collection
view layout. Override the `-applyLayoutAttributes` method of any `UICollectionReusableView` or
`UICollectionViewCell` subclasses, then apply any of the properties of the attributes class.
<!--<div class="material-code-render" markdown="1">-->
#### Swift
```swift
override func apply(_ layoutAttributes: UICollectionViewLayoutAttributes) {
super.apply(layoutAttributes)
if let attr = layoutAttributes as? MDCCollectionViewLayoutAttributes {
if (attr.representedElementCategory == .cell) {
// Example to set a background image to the cell background view.
self.backgroundView = UIImageView(image: attr.backgroundImage)
}
}
}
```
#### Objective-C
```objc
- (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes {
[super applyLayoutAttributes:layoutAttributes];
if ([layoutAttributes isKindOfClass:[MDCCollectionViewLayoutAttributes class]]) {
MDCCollectionViewLayoutAttributes *attr = (MDCCollectionViewLayoutAttributes *)layoutAttributes;
if (attr.representedElementCategory == UICollectionElementCategoryCell) {
// Example to set a background image to the cell background view.
self.backgroundView = [[UIImageView alloc] initWithImage:attr.backgroundImage];
}
}
}
```
<!--</div>-->