I want a control for iOS that slides left-to-right, similar to slide to unlock, but also slides right-to-left. I want something very similar to the control on Android's lock screen, where sliding left-to-right unlocks and sliding right-to-left silences.
It seems like this would be easiest to implement by subclassing UISlider, right? Would I need two sliders, or should I do it with just one?
Are there already any open source versions of this?
Ideas
Here's an idea of what the protocol might look like:
#interface DoubleSlider : UISlider
typedef enum {
DoubleSliderDirectionLeftToRight,
DoubleSliderDirectionRightToLeft
} DoubleSliderDirection;
#end
#protocol DoubleSliderDelegate <NSObject>
#optional
- (void)doubleSlider:(DoubleSlider *)doubleSlider
didBeginSlidingWithDirection:(DoubleSliderDirection)direction;
- (void)doubleSlider:(DoubleSlider *)doubleSlider
didEndSlidingWithDirection:(DoubleSliderDirection)direction;
#end
Related
iPhone "slide to unlock" animation
Slider which helps to unlock the iPhone
UISlider, slide to unlock
iPhone:Programming UISlider to position at clicked location
Custom Double Handle Slider
I can't think of any third party versions for this. I don't feel that UISlider would be a good place to begin. If I were you, I would subclass a UIScrollView instead.
Set it up at the bottom of the screen to have a height of 44 pixels or so. Lay down the images at the appropriate positions on the scrollView like in the image you posted.
Then, conform to the UIScrollViewDelegate and implement the scrollViewDidScroll: method to track when the user slides it left or right. Inside this method, check the contentOffset property of the UIScrollView. By trial and error, you can find out the exact content offsets where you feel that sliding the scrollview should trigger the actions you're looking for.
For example, if the contentOffset being 50 means that it's for DoubleSliderDirectionLeftToRight, you can fire off the delegate callback and then have the scrollview 'jump back' to the original position by using scrollRectToVisible:animated:
Sorry for the long winded and RTFM-ish answer, but I have no code to support this. This is just speculation, but I don't see why this solution would not work :)
Related
I have few other UI in my UIView and i have a UIButton on the top which i want to be hidden until unless the user scrolls to see the content on the very top and then display the UIButton.
Is there a way to implement this.
Thanks,
UIView (and thus everything sub-classing it) has a hidden property, this includes a UIButton. You can simply set this to YES/NO to hide/show something to the user.
After that the real question comes down to the show/hide criteria and how to measure it. If you are using a UIScrollView then you can add/implement UIScrollViewDelegate. This will give you methods like scrollViewDidScrollToTop: to check if the user scrolled to the top.
Keep track of the previous scroll offset so that with each scroll you can compute the delta, telling you whether the user scrolled up or down. With that, you can toggle the button's "hidden" property. Hope that helps.
In a post, Making Long Scrolls on the iPhone Not Suck, Aza Raskin describes an alternative scrollbar control that's better at getting around on very long pages:
It's not important that the scrollbar "remains for some amount of time" to activate it; I'm fine with simply swiping along the right edge of the iPhone's screen to grab hold of the scrollbar handle. The idea is that if I drag the handle 3/4 of the way down on the physical screen, I'd be 3/4 of the way down on the page.
Tthe Dropbox iPhone app (it's great, btw!) has exactly this kind of scrollbar for long PDF documents. Regular scrolling is done by dragging anywhere but on the handle; dragging the handle moves the view to that location. This seems to have been implemented "from scratch", as I don't think the SDK is flexible enough to customize the behavior of the existing scrollbar.
However, Dropbox uses the native document viewers to show documents on the iPhone, so somehow they add the scrollbar functionality to it. See the scrollbar handle? You can drag that to quickly get somewhere else in the document.
This concept is very similar to how index bars work in UITableView (ie. Contacts.app); the index appears as a bar on the right hand side of the table (for example, "a" through "z"), and you can touch a particular label to jump to the target section. In this case, however, a very long page doesn't have sections, and it should work for general-purpose scrolling, not jumping to sections.
So how can I go about implementing this method of scrolling? I'm looking for general ideas and specific implementation details. I'm also interested if an open-source implementation exists (this seems like a general-purpose problem/solution).
A general idea:
I grabbed the dropbox app (it is awesome) and played around with a bit. It looks like pdf viewing takes a bit from the photo app in that it conditionally displays a translucent navbar and toolbar on touches, in addition to supporting the scrollbar. I'm pretty sure what's going on is that they have a custom view controller intercepting touches and reacting accordingly.
On a touch:
If it's a tap, show/hide the
navbar and toolbar.
If it's on
the scrubber, begin tracking the
touch and scrolling the
scrollview/webview (whatever they're
displaying with). I'm sure the
scrolling is something simple like
scrollView.contentOffset =
CGPointMake(0, (scrubber.y / [UIScreen mainScreen].bounds.size.height) *
scrollView.contentSize.height). 3)
Else, pass the touch on to the
enclosed view.
There may be other hidden magic with PDF displaying (I've never done it in cocoa touch) but something tells me this is their basic process.
I don't know of any iPhone specific solutions, but this is an old and well travelled topic in the world of Flash development... and you could probably extract a ton of pseudo code from that realm.
If you know the height of your window, and the height of your content, and the current offset of the content (which you do), then you have all the tools you need to create a custom UIView which can serve as a touch-responding slider. And then just paint it over the default scroller.
There's probably an open source implementation for this. I don't know any. Maybe shoot an email to Dropbox developers?
Anyway, the way I'd do this is:
#interface UICustomisedScrollView : UISCrollView
{
BOOL showingScroller;
UIView scroller; //Customise this, either in IB or in viewDidLoad
}
#implementation UICustomisedScrollView
- (BOOL)touchesShouldBegin:(NSSet *)touches withEvent:(UIEvent *)event inContentView:(UIView *)view {
showingScroller = !showingScroller;
if(showingScroller)
scroller.hidden = NO;
else
scroller.hidden = YES;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if(showingScroller) {
if(/*the touch is on the scroller*/) {
/* scrollview.setContentOffset(...) we want to scroll according to how much the user scrolls here */
}
//move scroller.frame.origin to where the touch is.
}
}
I'm guessing it won't be too difficult... But I haven't tested the above code yet. That's the general idea anyway =)
Try using a UIPanGestureRecognizer. In your action, can use the locationInView to determine the point the user is touching. Do this when the state is UIGestureRecognizerStateBegan and if it's close enough to the side of the view implement fast scrolling. Otherwise, implement slow scrolling.
Hej folks,
I got an UIView in my application and want to implement kind of a swipe gesture. I know how I detect this gesture (touchesBegan: and touchesEnded: for example is x coordinates are distanced more than 100 pixels or something else) but I really don´t now how to animate my needs. In fact my UIView will contain subviews which are 9 UIButtons. On swipe I want to change the set of buttons programatically...any solutions out there? Primarily need the animation!
EDIT: I thought about programatically moving the buttons off-screen to the left and at the same time move the new ones on-screen from the right side. But it seems I don't really know how to realize this...isn't it too much leaking at the same time? Please give me a hint!
It's seem that you want to recreate somethings like the springboard but with button instead of icon.
I can suggest you to use UIScrollView.
why you don't load just a new view with the other button set in your window after the swipe gesture was detected?
How to control scrolling sound of uipicker? Any available sample code?
There is no documented way. That being said:
[myPickerView setSoundsEnabled:NO];
Like Peter said, there's no public way to do this. However, if it's really critical you could implement your own picker-type object. Basically, all you need to do is create a UITableView and customize the cells as you like. Then create an image to add as a UIImageView subview that's the same size as the table. At its simplest, all you need is a little bit of gradient fade-to-black at the top and bottom so the cells of the table appear to fade in/out. You could also add a bit of a frame around the table, or anything else really, as you like.
If you take a look at a picker and think of the wheels as just UITableViews with a gradient at the top and bottom, you'll see that the curved effect is just that simple. If you look closely as you scroll the cells offscreen, you can see that they never change shape; they just fade out.
As for the sounds, you could then use any of the UIScrollViewDelegate and UITableViewDelegate methods to monitor when the "wheel" moves and check to see where the table cells are on-screen. Perhaps when a cell passes the mid-way point, you play your custom sound.
It would definitely take a little bit of work to implement this, but is certainly possible if it's critical for your app.
What method to I use to make my UIScrollView update when the sides of a UIPageControl are tapped? When swiping the UIScrollView, the UIPageControl is updated correctly, but if I tap the sides of the UIPageControl to go to the next page, only the dots update, but the UIScrollView won't swipe. I've looked in the docs and am unable to find any methods for this?
If you're unsure of what I mean, go to your iPhone home screen and tap either side of the white dots, right between the dock and the paged icons.
Just make sure you're giving your page control enough width, and you've hooked up its Value Changed outlet. If you do this, you should get messages when its value changes; look at the currentPage property on the control. It handles left- and right-margin taps properly.
The method you're looking for is:
UIScrollView scrollRectToVisible: animated:
If you do this on the UIPageControl valueChanged, it should be automatic.
See my answer here: Is UIPageControl Useless By Itself?
for a reusable class encapsulating the UIPageControl and UIScrollView.