How to add animated icon to OS X status bar? - cocoa

Question

I want to put an icon in Mac OS status bar as part of my cocoa application. What I do right now is:
NSStatusBar *bar = [NSStatusBar systemStatusBar];
sbItem = [bar statusItemWithLength:NSVariableStatusItemLength];
[sbItem retain];
[sbItem setImage:[NSImage imageNamed:#"Taski_bar_icon.png"]];
[sbItem setHighlightMode:YES];
[sbItem setAction:#selector(stopStart)];
but if I want the icon to be animated (3-4 frames), how do I do it?

Answer 1

You'll need to repeatedly call -setImage: on your NSStatusItem, passing in a different image each time. The easiest way to do this would be with an NSTimer and an instance variable to store the current frame of the animation.
Something like this:
/*
assume these instance variables are defined:
NSInteger currentFrame;
NSTimer* animTimer;
*/
- (void)startAnimating
{
currentFrame = 0;
animTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/30.0 target:self selector:#selector(updateImage:) userInfo:nil repeats:YES];
}
- (void)stopAnimating
{
[animTimer invalidate];
}
- (void)updateImage:(NSTimer*)timer
{
//get the image for the current frame
NSImage* image = [NSImage imageNamed:[NSString stringWithFormat:#"image%d",currentFrame]];
[statusBarItem setImage:image];
currentFrame++;
if (currentFrame % 4 == 0) {
currentFrame = 0;
}
}

Answer 2

I re-wrote Rob's solution so that I can reuse it:
I have number of frames 9 and all the images name has last digit as frame number so that I can reset the image each time to animate the icon.
//IntervalAnimator.h
#import <Foundation/Foundation.h>
#protocol IntervalAnimatorDelegate <NSObject>
- (void)onUpdate;
#end
#interface IntervalAnimator : NSObject
{
NSInteger numberOfFrames;
NSInteger currentFrame;
__unsafe_unretained id <IntervalAnimatorDelegate> delegate;
}
#property(assign) id <IntervalAnimatorDelegate> delegate;
#property (nonatomic) NSInteger numberOfFrames;
#property (nonatomic) NSInteger currentFrame;
- (void)startAnimating;
- (void)stopAnimating;
#end
#import "IntervalAnimator.h"
#interface IntervalAnimator()
{
NSTimer* animTimer;
}
#end
#implementation IntervalAnimator
#synthesize numberOfFrames;
#synthesize delegate;
#synthesize currentFrame;
- (void)startAnimating
{
currentFrame = -1;
animTimer = [NSTimer scheduledTimerWithTimeInterval:0.50 target:delegate selector:#selector(onUpdate) userInfo:nil repeats:YES];
}
- (void)stopAnimating
{
[animTimer invalidate];
}
#end
How to use:
Conform to protocol in your StatusMenu class
//create IntervalAnimator object
animator = [[IntervalAnimator alloc] init];
[animator setDelegate:self];
[animator setNumberOfFrames:9];
[animator startAnimating];
Implement protocol method
-(void)onUpdate {
[animator setCurrentFrame:([animator currentFrame] + 1)%[animator numberOfFrames]];
NSImage* image = [NSImage imageNamed:[NSString stringWithFormat:#"icon%ld", (long)[animator currentFrame]]];
[statusItem setImage:image];
}

Answer 3

Just had to do something similar recently in a simple project, so I'm posting my personal version written in Swift:
class StatusBarIconAnimationUtils: NSObject {
private var currentFrame = 0
private var animTimer : Timer
private var statusBarItem: NSStatusItem!
private var imageNamePattern: String!
private var imageCount : Int!
init(statusBarItem: NSStatusItem!, imageNamePattern: String, imageCount: Int) {
self.animTimer = Timer.init()
self.statusBarItem = statusBarItem
self.imageNamePattern = imageNamePattern
self.imageCount = imageCount
super.init()
}
func startAnimating() {
stopAnimating()
currentFrame = 0
animTimer = Timer.scheduledTimer(timeInterval: 5.0 / 30.0, target: self, selector: #selector(self.updateImage(_:)), userInfo: nil, repeats: true)
}
func stopAnimating() {
animTimer.invalidate()
setImage(frameCount: 0)
}
#objc private func updateImage(_ timer: Timer?) {
setImage(frameCount: currentFrame)
currentFrame += 1
if currentFrame % imageCount == 0 {
currentFrame = 0
}
}
private func setImage(frameCount: Int) {
let imagePath = "\(imageNamePattern!)\(frameCount)"
print("Switching image to: \(imagePath)")
let image = NSImage(named: NSImage.Name(imagePath))
image?.isTemplate = true // best for dark mode
DispatchQueue.main.async {
self.statusBarItem.button?.image = image
}
}
}
Usage:
private let statusItem =
NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
// Assuming we have a set of images with names: statusAnimatedIcon0, ..., statusAnimatedIcon6
private lazy var iconAnimation =
StatusBarIconAnimationUtils.init(statusBarItem: statusItem, imageNamePattern: "statusAnimatedIcon",
imageCount: 7)
private func startAnimation() {
iconAnimation.startAnimating()
}
private func stopAnimating() {
iconAnimation.stopAnimating()
}