MarqueeLabel is a UILabel subclass adds a scrolling marquee effect when the text of the label outgrows the available width. The label scrolling direction and speed/rate can be specified as well. All standard UILabel properties (where it makes sense) are available in MarqueeLabel and it behaves just like a UILabel.
- Clone MarqueeLabel from Github, and check out the demo project
- Read the MarqueeLabel CocoaDocs documentation.
- Drop in MarqueeLabel as a replacement to your lengthy UILabels!
- Take a look at the special notes section to be aware of any gotchas.
- Help out with bug fixes and new features
CocoaPods is a dependency manager for Objective-C, which automates and simplifies the process of using 3rd-party libraries in your projects.
If you use CocoaPods, you can install the latest release version of MarqueeLabel by adding the following to your project's Podfile:
pod 'MarqueeLabel', '~> 1.3'- Add MarqueeLabel.h and MarqueeLabel.m to your project.
- Add QuartzCore.framework to your project frameworks.
- Import MarqueeLabel.h and replace your UILabels with MarqueeLabels as needed.
Note: MarqueeLabel uses ARC.
MarqueeLabel supports moving the label at either a defined rate (points per second) or duration (seconds). The animation curve can also be defined, and defaults to UIViewAnimationOptionCurveEaseInOut. It also features a variable-length fade at the left and right side view borders, in order to fade the label text into the background rather than simply being chopped off.
Replace:
UILabel *lengthyLabel = [[UILabel alloc] initWithFrame:labelCGRectFrame];
With:
MarqueeLabel *scrollyLabel = [[MarqueeLabel alloc] initWithFrame:labelCGRectFrame duration:8.0 andFadeLength:10.0f];
This creates a MarqueeLabel that will scroll across its content in 8.0 seconds, and adds 10.0 point long fade at the left and right boundaries.
If you'd rather have a label that scrolls at a specific rate (points per second), instead of completing the scroll in a specific time frame, you can use this:
MarqueeLabel *scrollyLabel = [[MarqueeLabel alloc] initWithFrame:labelCGRectFrame rate:50.0 andFadeLength:10.0f];
Check out the MarqueeLabel documentation more features, with explanations in the comments there:
- Bulk-manipulation class methods to conveniently restart, pause, and unpause all labels in a view controller
- Scrolling direction: left->right, right->left, and continuous looping (both left and right)
- Label edge fades
- Pausing/unpausing mid-animation scrolling of the label
- Tap to scroll once
Labelize
Using the labelize feature will cause a MarqueeLabel to act like a normal UILabel - including the line break mode you've set. This could cause the ellipsis (...) to appear if you leave the lineBreakMode property as the default NSLineBreakByTruncatingTail.
If you simply wish to pause scrolling with the label at the "home" location, set the holdScrolling property to YES instead. The automatic scroll animation won't restart until you set holdScrolling back to NO.
Modal View Controllers
I haven't yet found a clean way to auto-restart MarqueeLabels upon the dismissal of a modal view controller or other view controller that blocks the view of your view controller. It's not always necessary, as sometimes the scroll animations will continue happily in the background. However, see the Important Animation Note section below.
MarqueeLabel is based on UIView animations, which does cause some problems when views appear and disappear and the repeating animation is stopped by iOS and does not automatically restart.
To combat this, MarqueeLabel provides a few class methods that allow easy "restarting" of all MarqueeLabels associated with a UIViewController. Specifically, the class method restartLabelsOfController: should be called by your view controller (which passes in self for the controller parameter`) when it is revealed or about to be revealed. Keep in mind that presenting a modal view controller can pause repeating UIView animations in the controller that is being covered!
controllerLabelsShouldLabelize: and controllerLabelsShouldAnimate: are for convienience, allowing labelizing and re-animating all labels of a UIViewController. Labelizing can be useful for performance, such as labelizing all MarqueeLabels when a UITableView/UIScrollView starts scrolling.
- Implement true Apple-style edge fades, in which the fade animates in before scrolling.
Charles Powell
Give me a shout if you're using this in your project!