Is a Right-to-Left progress bar possible on iOS?

Question

I've tried sending [UIProgressView setProgress] negative values, and that doesn't work.

Is there some other way to get a progress bar that fills from the right-hand end?

Sixtyfourmo

You could always create your own progress bar -- it's not hard at all. – Incontrovertible

Can we rotate progressbar as Vertical ? – Calley

Answer 1

You could try setting the transform property of your UIProgressView to a new CGAffineTransform that rotates the view by 180 degrees and flips it vertically (to preserve the "shininess") (see CGAffineTransformMake() and CGAffineTransformRotate()).

Something along the lines of:

UIProgressView *pv = [[UIProgressView alloc] initWithProgressViewStyle:UIProgressViewStyleBar];
pv.frame = CGRectMake(10, 100, 300, 11);
CGAffineTransform transform = CGAffineTransformMake(1, 0, 0, -1, 0, pv.frame.size.height); // Flip view vertically
transform = CGAffineTransformRotate(transform, M_PI); //Rotation angle is in radians
pv.transform = transform;
pv.progress = 0.5;

Pinwheel

It works, but the shininess on the bar is now upside-down: can I mirror it vertically as well? – Sixtyfourmo

Ah, got it! pv.transform = CGAffineTransformScale(CGAffineTransformMakeRotation(M_PI), 1.0, -1.0); Thanks! – Sixtyfourmo

@Autopulated - That works just fine, or you can use the updated code in my response. – Pinwheel

Answer 2

You can rotate the UIProgressView:

progressView.transform = CGAffineTransformMakeRotation(DegreesToRadians(180));

where DegreesToRadians is:

#define DegreesToRadians(d) ((d) * M_PI / 180.0)

To change the progress value, use positive numbers.

Haggle

Answer 3

A simpler version is to flip it horizontally.

progressView.transform = CGAffineTransformMakeScale(-1.0f, 1.0f);

Seibel

Answer 4

In iOS 9+, you can use semanticContentAttribute:

progressView.semanticContentAttribute = .forceRightToLeft

Roughish

Answer 5

Swift answer:

progressView.transform = CGAffineTransform(rotationAngle: .pi)

Writ

Answer 6

You can rotate the view by 180°:

progressView.transform = CGAffineTransformMakeRotation(-M_PI);

Tenon

Answer 7

In iOS 7 with storyboards, you can set the Progress Tint to the Track Tint and vice versa, then subtract the regular value from one and set that to the current progress. Probably better to do it the other (rotation) way, but I thought I would throw this out there.

Alps

Answer 8

Swift 5 Version

progressView.transform = CGAffineTransform(scaleX: -1.0, y: 1.0)

Sesame

Answer 9

This works for me using latest SWIFTUI version:

ProgressView(configuration)
.scaleEffect(x: -1, y: 3, anchor: .center)

Ping

Answer 10

SwiftUI solution:

                ProgressView(value: progress)
                    .accentColor(.purple)
                    .frame(alignment: .leading)
                    .rotationEffect(.degrees(180))

Dives