I have the following hierarchy of views
MainView -> SubViewA -> ChildA,ChildB,ChildC
The logElementTree() is unable to print the subview elements for the View "SubViewA". (All the views have accessibilityLabel)
Related
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.
I am adding a subview programmatically and adding it to the main windows context view to cover up the entire context view like so:
loadingView = [[LoadingView alloc] initWithFrame:[mainWindow.contentView frame]];
NSLog(#"%#", [mainWindow.contentView subviews]);
[mainWindow.contentView addSubview:loadingView];
NSLog(#"%#", [mainWindow.contentView subviews]);
[mainWindow makeFirstResponder:loadingView];
The NSLog's confirm that loadingView is being added last in the contentView subviews. I have also tried:
loadingView = [[LoadingView alloc] initWithFrame:[mainWindow.contentView frame]];
[mainWindow.contentView addSubview:loadingView positioned:NSWindowAbove relativeTo:nil];
[mainWindow makeFirstResponder:loadingView];
That didn't work either. For some reason the two tableviews (created in IB) at the bottom of the window are on top of the new view I've added. Here's a snapshot of the window, note that the red part is what should be on top with the progress bar and a few labels:
It's also worth noting that the view has it's alpha set to 0.9 which is why you can somewhat see behind it.
GW
If you place one view above another, the objects in the previous view will be visible in above view. What you need do is remove previous views from window and then add a new subview.
Try using:
//Create IBOutlet of your tableview in your .h file
IBOutlet NSTableView* yourTableView;
// Add this line where you are adding your subview to remove the tableview from superview.
[yourTableView removeFromSuperview];
// Then add your loading view as the subview
loadingView = [[LoadingView alloc] initWithFrame:[mainWindow.contentView frame]];
[mainWindow.contentView addSubview:loadingView];
Then whenever your want your tableView back use:
[window contentView]addSubview: yourTableView];
As long as you use nil here, you will not get predictable results.
[mainWindow.contentView addSubview:loadingView positioned:NSWindowAbove relativeTo:nil];
If you have not already done so, put all the other views inside a containing view.
Make the containing view the only view that is a direct child of the window content view.
Now add your subview with the above method and replace nil with a reference to the containing view.
In OS X, overlapping siblings have certain nuances when it comes to drawing. In your case, the loadingView and the two table views are siblings because they are all added as subviews of the window's content view and they overlap hence the nuances are coming into play.
From Apple's Documentation
For performance reasons, Cocoa does not enforce clipping among sibling
views or guarantee correct invalidation and drawing behavior when
sibling views overlap. If you want a view to be drawn in front of
another view, you should make the front view a subview (or descendant)
of the rear view.
I don't have the definitive solution for this but reading these should help improve your understanding for the long term.
http://www.cocoabuilder.com/archive/cocoa/327817-overlapping-sibling-views.html
Is there a proper way to handle overlapping NSView siblings?
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 have two views
the top view has some opaque and some transparent regions
the bottom view has some clickable buttons.
The top view is completely covering the bottom view, but since top view has transparent areas, bottom view can still be seen.
BUT, i cannot detect button clicks on the bottom view anymore since topview is blocking it, what should I do?
Is there anyway to let top view pass the touches to bottom view?
My solution for my own question, hope it helps someone.
In the front view, listen for touchesEnded:withEvent delegate.
When this delegate fires, you knows that a user is touching the front view.
Next you need to check whether the finger position touches special areas in the BOTTOM view.
What to do is:
1) Convert the point to relative to the bottom view:
UITouch *touch = [touches anyObject];
CGPoint touchPointInLowerView = [touch locationInView:self.lowerViewController.view];
BOOL isLowerButtonClicked = [self.lowerViewController isFingerOnYourButton:touchPointInLowerView];
if(isLowerButtonClicked)
{
// lower button clicked
}
2) In the lower view
- (BOOL) isFingerOnYourButton:(CGPoint)point
{
return CGRectContainsPoint(self.aButton.frame, point);
}
voila. In this way, we can detect clicks in bottom view even it is blocked by another interactive view on top.
Turn off user interaction in the top view that is blocking the view underneath:
topView.userInteractionEnabled = NO;
If you don't want the top view (or any of its subviews) to respond to touches at all, you can set the userInteractionEnabled property to NO for that view and be done with it.
Otherwise, your best bet is to override pointInside:withEvent: or hitTest:withEvent: in the top view's class. If the top view and the bottom view are siblings, it should enough to return NO from pointInside:withEvent:; if they are further separated in the view hierarchy, you may have to override hitTest:withEvent: to explicitly return the bottom view for the transparent areas.