My code:
#IBOutlet weak var scroller: NSScrollView!
var showSettingsButton = NSButton(frame: NSMakeRect(0, 860, 60, 40))
showSettingsButton.title = "Settings"
scroller.addSubview(showSettingsButton)
The button looks as intended by the scrollview keeps static, but when I scroll the ScrollView, the button just looks like this:
I want to put this button always in the down-left corner regardless of scroller's scrolling.
So which view should be the superView of this button?
It should be in your View. Put it underneath the Scroll View - Text View, but make sure it will be siblings with the Scroll View - Text View, and not a child.
If you're going to add it in code, add it like
view.addSubview(showSettingsButton)
For your requirement , you should subclass NSScrollView and override the "tile" method. There you can specify your buttons frame
When you want your Button not to scroll, why do you add it to the scroll view then?
Add it to view, the superview of scrollview. So make it a sibling of the scrollview. Just add the scrolliview first and the button next so that the button overwrites the scrollview and appears on top.
ViewController
-> View
-> ScrollView
-> TextView (and anything that you want to scroll)
-> Button
You may want to do parts of this programmatically because IB or Storyboard Editor respectivey may change the view hierarchy again by making the button a subview of your scroll view.
Related
I have the following layout (see below), which for most circumstances works just fine. The user is able to scroll within the blue UIScrollView (which for all intents and purposes is a UITableView, but this question generalises this), and then when they've reached the end of this scroll view, they can start scrolling again (they have to take their finger off, and on again, because the inner scroll view rubberbands otherwise), and the 'super' scroll view starts scrolling, revealing the rest of the image.
It's the whole (they have to take their finger off, and on again, because the inner scroll view rubberbands otherwise) that I don't want. Ideally, once the contained UIScrollView reaches the end of its content, I want the superview to take over scrolling straight away, so that the inner scroll view doesn't rubberband.
The same goes when the user is scrolling back up; when the red scrollview reaches the top of it's content, I want the inner blue scroll view to start scrolling up straight away, instead of the red scroll view rubberbanding at the top.
Any idea how? I am able to determine when the scroll views have reached the ends of their content, but I'm not sure how to apply this knowledge to achieve the effect I'm after. Thanks.
// Inner (blue) scroll view bounds checking
if (scrollView.contentOffset.y + scrollView.frame.size.height > scrollView.contentSize.height) { ... }
// Outer (red) scroll view bounds checking
if (scrollView.contentOffset.y < 0) { ... }
Yeah. Ive got a nifty trick for you.
Instead of having your red outlined view a scrollview make it a normal UIView that fills the screen. In that view lay out your scroll view (table view) and image view as they are in your illustration.
Place a scrollview that fills the bounds of the root view (i.e. also fills the screen) above all the other scrollview and image views. Set the content size of this view to be the total content height of all the views you want to scroll through. In otherwords there is an invisible scrollview sitting on top of all your other views and its content size height is inner scrollview (tableview) content size height + image view size height.
The heierarchy should look like this:
Then this scrollview on top that you have made with the really tall content size make its delegate be your view controller. Implement scrollViewDidScroll and we'll work some magic.
Scrollviews basically scroll by adjusting the bounds origin with funky formulas for momentum and stuff. So in our scrollviewDidScroll method we will simply adjust the bounds of the underlying views:
-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
//the scroll view underneath (in the container view) will have a max content offset equal to the content height
//but minus the bounds height
CGFloat maxYOffsetForUnderScrollView = self.underScrollView.contentSize.height - self.underScrollView.bounds.size.height;
CGRect scrolledBoundsForContainerView = self.view.bounds;
if (scrollView.contentOffset.y <= maxYOffsetForUnderScrollView) {
//in this scenario we are still within the content for the underScrollView
//so we make sure the container view is scrolled to the top and set the offset for the contained scrollview
self.containerView.bounds = scrolledBoundsForContainerView;
self.underScrollview.contentOffset = scrollView.contentOffset;
return;
}
//in this scenario we have scrolled throug the entirety of the contained scrollview
//set its offset to the max and change the bounds of the container view to scroll everything else.
self.underScrollView.contentOffset = CGPointMake(0, maxYOffsetForUnderScrollView);
scrolledBoundsForContainerView.origin.y = scrollView.contentOffset.y - maxYOffsetForUnderScrollView;
self.containerView.bounds = scrolledBoundsForContainerView;
}
You will find that as scrollViewDidScroll is called every frame of animation that this faux scrolling of the contained views looks really natural.
But wait! I hear you say. That scroll view on top now intercepts ALL touches, and the views underneath it need to be touched as well. I have an interesting solution for that as well.
Set the scrollview on top to be off screen somewhere (i.e. set its frame off screen, but still the same size.) and then in your viewDidLoad method you add the scrollview's panGestureRecogniser to the main view. This will mean that you get all the iOS natural scrolling momentum and stuff without actually having the view on the screen. The contained scroll view will now probably go juddery as its pan gesture recognizer will get called as well (they work differently to UIEvent handling) so you will need to remove it.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self.view addGestureRecognizer:self.scrollview.panGestureRecognizer];
[self.underScrollview removeGestureRecognizer:self.underScrollView.panGestureRecognizer];
//further code to set up content sizes and stuff
}
I had fun making this so heres a link to the sample project on github:
https://github.com/joelparsons/multipleScrollers
EDIT:
To show the scrollbar for the top scrollview when its off the screen no matter where you put it you can set the scrollIndicatorInsets to an inset created like this:
CGPoint scrollviewOrigin = self.scrollview.frame.origin;
self.scrollview.scrollIndicatorInsets = UIEdgeInsetsMake(-scrollviewOrigin.y,0,scrollviewOrigin.y,scrollviewOrigin.x);
*caveat that the scrollview still has to be the right height but I'm sure you get the idea.
And then to make the bar draw outside the scrollview's visible bounds you have to turn off clips to bounds
self.scrollview.clipsToBounds = NO;
OMG. jackslash, you saved my life.
In my case, I need to use three depth of scroll views.
Parent Scroll View
that has a scroll view as one of the children
Child Scroll View: shown as 'Explanation Scroll View / Review Table View / Information Scroll View' in the below image)
Hidden Scroll View
which is distribute own content offset to 'Parent Scroll View' and 'Child Scroll View'
which has content size of whole flatten contents
Screenshot of view hierarchy
After setting view hierarchy, I just need to sync whole flatten content size and distribute content offset properly.
Observable.combineLatest(
overviewStackView.rx.observe(CGRect.self, #keyPath(UIStackView.frame)).unwrap(),
explanationScrollView.rx.observe(CGSize.self, #keyPath(UIScrollView.contentSize)).unwrap()
)
.subscribe(onNext: { [weak self] overviewStackViewFrame, explanationScrollViewContentSize in
guard let self = self else { return }
let totalContentHeight = overviewStackViewFrame.height + self.segmentedControl.frame.height + explanationScrollViewContentSize.height
self.hiddenScrollView.contentSize.height = totalContentHeight
})
.disposed(by: disposeBag)
hiddenScrollView.rx.didScroll
.subscribe(onNext: { [weak self] _ in
guard let self = self else { return }
let currentHiddenScrollViewOffsetY = self.hiddenScrollView.contentOffset.y
let parentScrollViewMaxOffsetY = self.overviewStackView.frame.height
let expectedChildScrollViewOffsetY = max(currentHiddenScrollViewOffsetY - parentScrollViewMaxOffsetY, 0)
self.parentScrollView.contentOffset.y = min(parentScrollViewMaxOffsetY, currentHiddenScrollViewOffsetY)
self.explanationScrollView.contentOffset.y = expectedChildScrollViewOffsetY
})
.disposed(by: disposeBag)
I can't figure out how to actually use NSScrollview. I dragged the scroll view object onto an NSWindow in the interface builder. I then dragged some NSButtons onto the scroll view. My question is:
How do I actually make it scroll down, for example, 2x the original height?
Of course the user can scroll automatically using their UI. I assume what you want to do is to scroll programmatically.
A bit of background: An NSScrollView has a documentView, which is the underlying view that the scroll view shows a part of, and a clipView, which is the view that is shown on the screen. So the clip view is like a window into the document view. To scroll programmatically you tell the document view to scroll itself in the clip view.
You have two options on how to scroll programmatically:
- (void)scrollPoint:(NSPoint)aPoint –– This scrolls the document so the given point is at the origin of the clip view that encloses it.
- (BOOL)scrollRectToVisible:(NSRect)aRect –– This scrolls the document the minimum distance so the entire rectangle is visible. Note: This may not need to scroll at all in which case it returns NO.
So, for example, here is an example from Apple's Scroll View Programming Guide on how to scroll to the bottom of the document view. Assuming you have an IBOutlet called scrollView connected up to the NSScrollView in your nib file you can do the following:
- (void)scrollToBottom
{
NSPoint newScrollOrigin;
if ([[scrollview documentView] isFlipped]) {
newScrollOrigin = NSMakePoint(0.0,NSMaxY([[scrollview documentView] frame])
-NSHeight([[scrollview contentView] bounds]));
} else {
newScrollOrigin = NSMakePoint(0.0,0.0);
}
[[scrollview documentView] scrollPoint:newScrollOrigin];
}
I want to make a View with three subviews stacked on top of each other with the middle subview scrollable with the others fixed.
How can I achieve this programmatically? I have tried
to set the contentsize of the root view to the size of the scrollable view but that makes all the views scroll.
-set the contentsize of the middle subview without setting any property for the root view but that makes all the views unscrollable.
Please help. I am new to iOS.
Thanks in advance
You can use the scrollViewDidScroll: delegate callback on the UIScrollView to adjust your view's position. In the callback, get the contentOffset of the scrollview and use that to set your fixed view's position.
For example, if you want your fixed view to always remain 100 px from the top of the scrollview, set its initial frame to (0, 100, width, height), and then in the callback set the frame to (0, contentOffset.y + 100, width, height).
The result is that the subview will appear fixed at a given height.
If your UIScrollView has a superview (i.e. a container view), you can add your 'fixed' view as a subview of the superview instead of the UIScrollView. You'll only have to calculate your frame coordinates once.
You can do it moving sub view from UIScrollView to super view of scrollview like:
Place/set your button over scroll view (not inside scroll view) as shown here in this snapshot. And also set button constraints (position) with respect to super view of your scrollview.
Here is ref. snapshot of hierarchy of position of each view over each-other.
I have a view 200 x 150 px which i would like to present on the tap of a button. If i use addSubview: then the view shows up in the correct position, but i can still tap other buttons on the superview, which is behaviour i don't want.
If i use presentModalViewController then the view takes up the whole screen, which is what i don't want either... this happens even if i set wantsFullScreenLayout to NO.
How can i present the view so that the user can only interact with controls on the presented view?
Thanks
Make the view the size of the screen (taking the status bar into account). That view should have a translucent background color (or clear). Have the 200x150 view be on the bottom of that view to have the appearance of a UIActionSheet, where the background dims and the user cannot interact with other elements on the screen.
Then, you can use presentModalViewController to present the view.
Addition
In the view controller's .m file, define awakeFromNib:
-(void)awakeFromNib
{
self.view.backgroundColor = [UIColor clearColor];
}
I have a button that sits on top of an NSScrollView, not within. When the scrollview scrolls, the button get's clipped with part of the button going along with the scrolling and the other part staying positioned.
To better describe the issue here's a video of the issue:
http://dl.dropbox.com/u/170068/ScrollTest.mov
The planned goal was to have a button sit in the top right corner of a text view but stay there when the text view scrolls. So if anyone has any thoughts on how to achieve this it would be greatly appreciated.
You should subclass NSScrollView and override "tile" method to position sub-controls of the scroll view.
- (void)tile
{
[super tile];
if (subControl)
{
NSRect subControlFrame = [subControl frame];
// adjust control position here in the scrollview coordinate space
// move controls
[subControl setFrame:subControlFrame];
}
}
I have used this way to implement a custom ScrollView with zoom control and background color selector embedded.
Overlapping views isn't recommended for non-layer-backed views. I think Interface Builder will even warn you about this. The easiest way to work around this would be to make your button layer-backed.