Cards contain content and actions about a single subject.
Contents
In order to use Material cards, first add the Cards subspec to your Podfile:
pod MaterialComponents/Cards
Then, run the installer:
pod install
After that, import the relevant target or file.
import MaterialComponents.MaterialCards
#import "MaterialCards.h"
On iOS, the Cards component offers two implementations to choose from, MDCCard and MDCCardCollectionCell.
MDCCardMDCCard subclasses UIControl. Subclassing MDCCard allows you to create cards that match the Material spec.
MDCCard uses UIControlState to represent state. Its styling changes depending on whether its state is .normal or .highlighted.
MDCCard allows the following properties to be customized:
MDCCardCollectionCellMDCCardCollectionCell subclasses UICollectionViewCell. Subclassing MDCCardCollectionCell allows you to have Material cards as cells in your UICollectionView.
MDCCardCollectionCell has its own notion of state, MDCCardCellState, which is tied to the UICollectionViewCell highlighted and selected properties.
In addition to those offered by MDCCard, MDCCardCollectionCell offers the following customization options:
Accessibility best practices depend on whether you are using an MDCCard or an MDCCardCollectionCell.
MDCCardaccessibilityThe nested elements in an MDCCard are available to assistive technologies without additional customization. However, additional setup may be needed to accommodate the following scenarios:
Images may have additional context beyond text that is already presented on the card. For example, news article images can benefit from an accessibilityLabel describing their content.
articleImageView.isAccessibilityElement = true articleImageView.accessibilityLabel = "Event or scene description"
articleImageView.isAccessibilityElement = YES; articleImageView.accessibilityLabel = @"Event or scene description";
Star or rating images should have accessibilityLabel property values describing their purpose and accessibilityValue property values describing their rating value.
ratingView.isAccessibilityElement = true ratingView.accessibilityLabel = "Average customer rating, out of " + "\(MDCProductRating.maximumValue) stars" ratingView.accessibilityValue = (String)product.averageRating
ratingView.isAccessibilityElement = YES; ratingView.accessibilityLabel = [NSString stringWithFormat:@"Average customer" + " rating, out of %d stars", MDCProductRating.maximumValue]; ratingView.accessibilityValue = @(product.averageRating).stringValue;
Primary content or actions that appear lower on the screen will be read last by assistive technologies, sometimes after longer or non-primary content. To change the order, or group elements together, you can make the card an accessibility container by adopting the UIAccessibilityContainer protocol. Grouping and order is controlled by creating as many UIAccessibilityElement elements as needed, and returning them in the desired order.
MDCCardCollectionCell accessibilitySince assistive technologies visit all cards in a collection in a sequential order, it is often easier to distinguish between elements that belong to different cards by aggregating all the card‘s information so the card is read as a single sentence. This can be done by setting an appropriate accessibilityLabel for the card. Additionally, set the card’s isAccessibilityElement to true. Cards are a container element and setting isAccessibiltyElement for a container turns off individually selecting its subelements.
card.isAccessibilityElement = true card.accessibilityLabel = "Location \(userLocation.name) is popular with users " + "who enjoy \(userLocation.popularActivityMatchingUserProfile(userProfile))"
card.isAccessibilityElement = YES; card.accessibilityLabel = [NSString stringWithFormat:@"Location %@ is popular with users who enjoy %@", userLocation.name, userLocation.popularActivityMatchingUserProfile(userProfile)];
While iOS has two different implementations for Cards, there is really only one type of card from the design perspective. The example above could be built using either an MDCCard or an MDCCardCollectionCell. Here is an example class that does it with MDCCard.
MDCCard exampleMDCCard can be used like a regular UIView. This is an example of a regular card:
let card = MDCCard(frame: CGRect(x: 30, y: 100, width: 150, height: 150)) card.applyTheme(withScheme: containerScheme) view.addSubview(card)
MDCCard *card = [[MDCCard alloc] initWithFrame:CGRectMake(30, 100, 150, 150)]; [card applyThemeWithScheme:containerScheme]; [view addSubview:card];
MDCCardCollectionCell exampleMDCCardCollectionCell GitHub source
MDCCardCollectionCell can be used like a regular UICollectionViewCell. This is an example of MDCCardCollectionCells in a collection:
collectionView.register(MDCCardCollectionCell.self, forCellWithReuseIdentifier: "Cell") func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! MDCCardCollectionCell // If you wanted to have the card show the selected state when tapped // then you need to turn isSelectable to true, otherwise the default is false. cell.isSelectable = true cell.cornerRadius = 8 return cell }
[self.collectionView registerClass:[MDCCardCollectionCell class] forCellWithReuseIdentifier:@"Cell"]; - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath { MDCCardCollectionCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath]; // If you wanted to have the card show the selected state when tapped // then you need to turn selectable to true, otherwise the default is false. [cell setSelectable:YES]; [cell setCornerRadius:8]; return cell; }
A card has a container and an optional thumbnail, header text, secondary text, media, supporting text, buttons and icons.
Note: All the optional elements of a card's content are implemented through the use of other views/components.
MDCCard attributes| Attribute | Related method(s) | Default value | |
|---|---|---|---|
| Color | backgroundColor | -setBackgroundColor:backgroundColor: | Surface color |
| Foreground color | N/A | N/A | N/A |
| Stroke color | layer.borderColor | -setBorderColor:forState:-borderColorForState: | On surface color at 37% opacity |
| Stroke width | layer.borderWidth | -setBorderWidth:forState:-borderWidthForState: | 1 |
| Shape | shapeGenerator | -setShapeGenerator:-shapeGenerator | MDCRectangleShapeGenerator |
| Elevation | N/A | -setShadowElevation:forState:-shadowElevationForState: | 1 |
| Ripple color | rippleView.rippleColor | N/A | nil |
MDCCardCollectionCell attributes| Attribute | Related method(s) | Default value | |
|---|---|---|---|
| Color | backgroundColor | -setBackgroundColor:backgroundColor: | Surface color |
| Foreground color | N/A | N/A | N/A |
| Stroke color | layer.borderColor | -setBorderColor:forState:-borderColorForState: | On surface color at 37% opacity |
| Stroke width | layer.borderWidth | -setBorderWidth:forState:-borderWidthForState: | 1 |
| Shape | shapeGenerator | -setShapeGenerator:-shapeGenerator | MDCRectangleShapeGenerator |
| Elevation | N/A | -setShadowElevation:forState:-shadowElevationForState: | 1 |
| Ripple color | rippleView.rippleColor | N/A | nil |
Cards supports Material Theming using a Container Scheme. MDCCard and MDCCardCollectionCell have both default and outlined theming methods. Learn more about theming extensions here. Below is a screenshot of an MDCCard with the Material Design Shrine theme:
To make use of Cards theming install the Cards theming extensions with Cocoapods. First, add the following line to your Podfile:
pod MaterialComponents/Cards+Theming
Then run the installer:
pod install
Next, import the Cards theming target, and call the correct theming method.
import MaterialComponents.MaterialCards import MaterialComponents.MaterialCards_Theming ... // Create a card let card = MDCCard() // Create or use your app's Container Scheme let containerScheme = MDCContainerScheme() // Theme the card with either default theme card.applyTheme(withScheme: containerScheme) // Or outlined theme card.applyOutlinedTheme(withScheme: containerScheme)
#import "MaterialCards.h" #import "MaterialCards+Theming.h" ... // Create a card MDCCard *card = [[MDCCard alloc] init]; // Create or use your app's Container Scheme MDCContainerScheme *containerScheme = [[MDCContainerScheme alloc] init]; // Theme the card with either default theme [self.card applyThemeWithScheme:containerScheme]; // Or outlined theme [self.card applyOutlinedThemeWithScheme:containerScheme];