I'm trying to move a UIView - "A" (Subview) inside another UIView - "B" (SuperView) using the touches moved method. I'm able to move the UIView outside the superview. I want to restrict the UIView inside the Superview bounds. Is there any way there can be a generic method to test if the subview is inside the visible rect of the superview ???
It sounds like you want to constrain the movement of the subview (viewA) to be always completely contained by the superview (viewB). CGRectContainsRect is the right answer, but it must be applied carefully, since a subview frame is specified in it's superview's coordinate system.
// inside touches moved, compute the newViewAFrame based on the movement
// but only assign it if it meets the containment constraint:
if (CGRectContainsRect(viewB.bounds, newViewAFrame)) {
viewA.frame = newViewAFrame;
}
Notice that we don't mention viewB.frame in the check. viewB's position in it's parent is not relevant to whether viewB contains viewA.
Use clipsToBounds method or CGRectContainsRect
youSuperView.clipsToBounds = YES;
I think it will be helpful to you
I had the same problem and this post helped me a lot, so I'll share my answer (that seems to fit exactly what you need) :
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
if (SuperView.frame.contains(self.frame)) {
let oldCenter = self.center
self.center = touch.location(in: SuperView)
if(!SuperView.frame.contains(self.frame)) {
self.center = oldCenter
}
}
}
}
quite simple and you can use this in the methods touchesMoved and touchesEnded too, so it won't stop you when your UIView reach the limits (this is why oldCenter exists).
As mentioned by #dahn, if your view is INSIDE the SuperView, you must take care, because the coordinates of the first will be restrict to the frame of the second, so it may fail if the SuperView is not a full-screen view.
If it is not a full-screen view, the SuperView cannot be the dad of the SubView, because it will cause bugs. The solution is to keep the SuperView and the SubView both inside a third View (so their coordinate system will be the same and it will work fine).
Hope that helps someone someday :)
Swift 2.2:
let rect1 = CGRect(...)
let rect2 = CGRect(...)
There is a method to check this - CGRectContainsRect(rect1, rect2)
Related
My UIView already handles single-finger touches with gesture recognisers for tap and pan just fine.
However, I would like touches with two fingers to be passed through to the parent view, behind this view. (The parent is a WKWebView with a javascript generated map that I'd like the user to be able to pinch-zoom, even while this other view is in front. This works OK when the other view is not in front, but of course when the front view is there, it doesn't pass through the touches.)
I have tried to detect this using either of the following in the front view, but in both cases, allTouches is an empty set (zero touches):
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
if let event = event {
print("\(event)")
if let touches = event.allTouches {
print("\(event.allTouches)")
if touches.count > 1 {
return false
}
}
}
return super.point(inside: point, with: event)
}
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
if let event = event {
print("\(event)")
if let touches = event.allTouches {
print("\(event.allTouches)")
if touches.count > 1 {
return nil
}
}
}
return super.hitTest(point, with: event)
}
How can I continue to use my existing gesture recognisers, but pass through multi-finger touches to the superview?
More of a work-around than an actual answer, but here's what solved it for me...
Instead of the in-front child view covering all of the parent view with a transparent layer, I reduced it to only include the small area needed to actually present information and form fields to the user.
Then I changed the single-touch gestures to be added to the parent view, instead of to the child view.
So now NONE of the touches are captured by the child view (except for its form fields and buttons).
This is perhaps the better way to handle my particular situation anyhow. So I was probably asking the wrong question (X/Y issue!).
I have a form in a Mac app that needs to scroll. I have a scrollView embedded in a ViewController. I have the scrollView assigned with an identifier that links it to its own NSScrollView file. The constraints are set to the top, right, and left of the view controller, it also has the hight constraint set to the full height of the ViewController.
Here is my code:
import Cocoa
class ScrollView: NSScrollView {
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
// Drawing code here.
NSRect documentView.NSMakeSize(0, 0, 1058.width, 1232.height)
}
override func scrollWheel(with event: NSEvent) {
switch event.phase {
case NSEvent.Phase.began:
Swift.print("Began")
// case NSEvent.Phase.changed:
// Swift.print("Changed")
case NSEvent.Phase.ended:
Swift.print("Ended")
default:
break
}
switch event.momentumPhase {
case NSEvent.Phase.began:
Swift.print("Momentum Began")
// case NSEvent.Phase.changed:
// Swift.print("Momentum Changed")
case NSEvent.Phase.ended:
Swift.print("Momentum Ended")
default:
break
}
super.scrollWheel(with: event)
}
I cant seem to get my app to scroll at all. I think I am not setting the frame correctly. What is the best way to do set the frame correctly? Am I coding the NSScrollView correctly?
I think you are making your life very hard because you are doing things that are not exactly recommended by Apple. First of all, you should not subclass NSScrollView. Rather you should read first Introduction to Scroll View Programming Guide for Cocoa by Apple to understand how you should create the correct hierarchy of views for an NSScrollView to work correctly.
A second recommendation is for you to check this nice article about how you should set up an NSScrollView in a playground, so that you can play with the code you want to implement.
Third, using Autolayout and NSScrollView has caused a lot of grief to a lot of people. You need to set up the AutoLayout just right, so that everything is going to work as expected. I recommend that you check this answer by Ken Thomases, which clearly explains how you need to set up auto layout constraints for an NSScrollView to work properly.
I just got over the "hump" with a NSScrollView inside a NSWindow. In order for scrolling to occur the view inside the NSScrollview needs to be larger than the content window. That's hard to set with dynamic constraints. Statically setting the inner view to a larger width/height than the window "works" but the static sizes usually are not what you want.
Here is my interface builder view hierarchy and constraints, not including the programmatically added boxes
In my app the user is adding "boxes" (custom draggable views) inside the mainView, which is inside a scrollview in a NSwindow.
Here's the functionality I wanted:
If I expanded the NSWindow, I wanted the mainView inside the scrollview to expand to fill the whole window. No scrolling needed in this case if all the boxes are visible.
If I shrank the NSWindow, I wanted the mainView inside the scrollview to shrink just enough to include all my mainView subviews ("boxes"), but not any further (i added a minBorder of 20). This results in scrolling if a box's position is further right/up than the nswindow's width/height.
I found the trick is to calculate the size of the mainView I want based on the max corner of each draggable boxview, or the height/width of the content frame of the nswindow, whichever is larger.
Below is my code, including some debugging prints.
Be careful of which subviews you use to calculate the max size. If you include a subview that's dynamically attached to the right/top of the window, then your window will never shrink. If you add +20 border to that, you might infinite loop. Not a problem in my case.
extension MapWindowController: NSWindowDelegate {
func windowDidEndLiveResize(_ notification: Notification) {
if let frame = window?.frame, let content = window?.contentRect(forFrameRect: frame) {
print("window did resize \(frame)")
var maxX: CGFloat = content.width
var maxY: CGFloat = content.height
for view in mainView?.subviews ?? [] {
let frameMaxX = view.frame.maxX + minBorder
let frameMaxY = view.frame.maxY + minBorder
if frameMaxX > maxX {
maxX = frameMaxX
}
if frameMaxY > maxY {
maxY = frameMaxY
}
}
print("view maxX \(maxX) maxY \(maxY)")
print("window width \(content.width) height \(content.height)")
mainView?.setFrameSize(NSSize(width: maxX, height: maxY))
}
}
}
I have two UIimageview images which are draggable using touchesBegan and touchesMoved however they can be dragged anywhere on the screen without any limitations. I am trying to limit the UIimageview to be only draggable inside the UIimage (certain area).
Any idea what is the best approach?
Thanks
Use CGRectContainsPoint to limit the area.
For example:
let point = touch.location(in: self) // or elsewhere
if CGRectContainsPoint(image.frame, point) {
// could drag
} else {
// stop dragging
}
Is there a way I can set my scrollview not to clip its contents? (Which is a NSTextView)
I have a subclass of NSScrollView and want its content not to be clipped to its bounds.
I have tried overriding:
- (BOOL) wantsDefaultClipping{
return NO;
}
in MyScrollView and in MytextView without any effect.
In the iOS I would simply would do: myuitextView.clipsToBounds=NO; how can I do this in Cocoa?
EDIT
This is an example of what I want to achieve but in the mac
The scrollview is white, the scroller will never go outside its bounds but the text does since I did myuitextView.clipsToBounds=NO
See picture here
EDIT2
I wouldn't mind clip my view like #Josh suggested. But the real behaviour I would like to have can be explained with this picture:
Do you see the word *****EDIT***** that has being cut in the very first line?
I want the text not to be cut this way, rather I want it to completely appear and I will put a semitransparent image so it looks like it fades off when it's outside the frame.
Q: Why don't I simply put a semitransparent NSImageView on it so it looks like what I want?
A: Because 1.Scroller will be faded as well. Even if I correctly place the semitransparent NSImageView so the scroller looks fine, the cursor/caret will be able to go underneath the semitransparent NSImageView again it does not look good.
I would like to be able to control the area is clipped by NSClipView. I think that would solve my problem. Is there any alternative I have? maybe I can control the caret position or scrolling position through NSTextView so caret will never go near the top/bottom frame limits? or any work-around?
Any advice is appreciated.
Now that it's 2016 and we're using vibrant titlebars with full size content views, I'll add my thoughts to how someone might accomplish this. Hopefully, this will help anyone who came here looking for help on this, as it helped me.
This answers the question in regards to scrolling under the titlebar, but you could easily modify this technique to scroll under other things using the insets and caret position.
To get a scroll view (with or without an NSTextView inside of it) to scroll behind a titlebar, you can use:
// For transparent title.
window.titlebarAppearsTransparent = true
window.styleMask = window.styleMask | NSFullSizeContentViewWindowMask
window.appearance = NSAppearance(named: NSAppearanceNameVibrantLight)
This effectively overlays the titlebar of the NSWindow onto the window's contentView.
To constrain something to the top of the window without knowing the height of the titlebar:
// Make a constraint for SOMEVIEW to the top layout guide of the window:
let topEdgeConstraint = NSLayoutConstraint(
item: SOMEVIEW, attribute: NSLayoutAttribute.Top,
relatedBy: NSLayoutRelation.Equal,
toItem: window.contentLayoutGuide,
attribute: NSLayoutAttribute.Top, multiplier: 1.0, constant: 0.0)
// Turn the constraint on automatically:
topEdgeConstraint.active = true
This allows you to constrain the top of an element to the bottom of the titlebar (and or toolbar + any accessory views it may have). This was shown at WWDC in 2015: https://developer.apple.com/videos/play/wwdc2014/220/
To get the scrollview to scroll under the titlebar but show its scrollbars inside the unobscured part of the window, pin it to the top of the content view in IB or via code, which will cause it to be under the titlebar. Then, tell it to automatically update it's insets:
scrollView.automaticallyAdjustsContentInsets = true
Finally, you can subclass your window and handle the cursor/caret position. There is a presumed bug (or developer error on my part) that doesn't make the scrollview always scroll to the cursor/caret when it goes above or below the content insets of the scrollview.
To fix this, you must manually find the caret position and scroll to see it when the selection changes. Forgive my awful code, but it seems to get the job done. This code belongs in an NSWindow subclass, so self is referring to the window.
// MARK: NSTextViewDelegate
func textViewDidChangeSelection(notification: NSNotification) {
scrollIfCaretIsObscured()
textView.needsDisplay = true // Prevents a selection rendering glitch from sticking around
}
// MARK: My Scrolling Functions
func scrollIfCaretIsObscured() {
let rect = caretRectInWindow()
let y: CGFloat = caretYPositionInWindow() - rect.height
// Todo: Make this consider the text view's ruler height, if present:
let tbHeight: CGFloat
if textView.rulerVisible {
// Ruler is shown:
tbHeight = (try! titlebarHeight()) + textViewRulerHeight
} else {
// Ruler is hidden
tbHeight = try! titlebarHeight()
}
if y <= tbHeight {
scrollToCursor()
}
}
func caretYPositionInWindow() -> CGFloat {
let caretRectInWin: NSRect = caretRectInWindow()
let caretYPosInWin: CGFloat = self.contentView!.frame.height - caretRectInWin.origin.y
return caretYPosInWin
}
func caretRectInWindow() -> CGRect {
// My own version of something based off of an old, outdated
// answer on stack overflow.
// Credit: http://stackoverflow.com/questions/6948914/nspopover-below-caret-in-nstextview
let caretRect: NSRect = textView.firstRectForCharacterRange(textView.selectedRange(), actualRange: nil)
let caretRectInWin: NSRect = self.convertRectFromScreen(caretRect)
return caretRectInWin
}
/// Scrolls to the current caret position inside the text view.
/// - Parameter textView: The specified text view to work with.
func scrollToCursor() {
let caretRectInScreenCoords = textView.firstRectForCharacterRange(textView.selectedRange(), actualRange: nil)
let caretRectInWindowCoords = self.convertRectFromScreen(caretRectInScreenCoords)
let caretRectInTextView = textView.convertRect(caretRectInWindowCoords, fromView: nil)
textView.scrollRectToVisible(caretRectInTextView)
}
enum WindowErrors: ErrorType {
case CannotFindTitlebarHeight
}
/// Calculates the combined height of the titlebar and toolbar.
/// Don't try this at home.
func titlebarHeight() throws -> CGFloat {
// Try the official way first:
if self.titlebarAccessoryViewControllers.count > 0 {
let textViewInspectorBar = self.titlebarAccessoryViewControllers[0].view
if let titlebarAccessoryClipView = textViewInspectorBar.superview {
if let view = titlebarAccessoryClipView.superview {
if let titleBarView = view.superview {
let titleBarHeight: CGFloat = titleBarView.frame.height
return titleBarHeight
}
}
}
}
throw WindowErrors.CannotFindTitlebarHeight
}
Hope this helps!
I would simply try to observe the document view's frame and match the scroll view's frame when the document resizes.
This is a little hairy. AFAIK, NSViews can't draw outside their own frame. At any rate I've never seen it done, and I was somewhat surprised when I realized that UIView allows it by default. But what you probably want to do here is not manipulate clipping rectangles (doing any such thing inside NSScrollView will probably not do what you want or expect), but instead try to cover up the vertically-truncated text lines with either layers or views that are the same color as the background. Perhaps you could subclass NSClipView and override viewBoundsChanged: and/or viewFrameChanged: in order to notice when the text view is being shifted, and adjust your "shades" accordingly.
You might consider using a translucent layer to achieve this appearance, without actually drawing outside your view. I'm not certain of the rules on iOS, but on the Mac, a view drawing outside its bounds can cause interference with surrounding drawing.
However, you can set the clipping region to be whatever you like inside your scroll view subclass's drawRect: using -[NSBezierPath setClip:]:
- (void)drawRect:(NSRect)dirtyRect {
[NSGraphicsContext saveGraphicsState];
[[NSBezierPath bezierPathWithRect:[[self documentView] frame]] setClip];
//...
[NSGraphicsContext restoreGraphicsState];
}
It might be possible (since you asked) to use this code in an NSClipView subclass, but there's not much info about that, and I think you may have a hard time making it interact properly with its scroll view. If it were me, I'd try subclassing NSScrollView first.
I have a UIScrollView that contains a custom UIView. Inside the custom UIView, I'd like to know the rectangle in which it's visible (i.e. not clipped).
The quick-n-dirty solution is to have the custom UIView assume that the parent is a UIScrollView and get the content size through it, but I'm looking for a better solution that doesn't involve make such assumptions.
This should do the trick
CGRect visibleRect = CGRectIntersection(self.frame, superview.bounds);
Use that in the UIView and it should get you the rectangle (if any) that represents the visible section of that view in it's superview (The UIScrollView). I'm assuming here that there is no view between them in the hierarchy, but if there is, fiddling the code should be trivial.
Hope I could help!
It would help if you would give more info on what is that you are trying to accomplish.
If you want to know the size of the super view you can do this:
CGRect superFrame = [self superview].frame;
Swift 3
extension UIView {
var visibleRect: CGRect? {
guard let superview = superview else { return nil }
return frame.intersection(superview.bounds)
}
}