(Similar to this question, which is unanswered: Tableview scroll to top not going all the way, as well as this one, also unanswered: Show navigation bar's large title and search bar on scroll to top collection view iOS 11 Swift 4)
I am trying to replicate scrolling to the top of a UITableView on status bar tap, but when I've tapped the UITabBar item and I'm already in that view. I have the tapping part working, but the scrolling to top is not working as I want it to.
The tableview is embedded in a navigationbar with large titles, and the searchbar is in the header, so it expands and collapses with scroll (the default behavior).
I am using the following to scroll, which, as expected, scrolls to the first table view cell, not expanding the navigation bar and/or the search bar:
[tv scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]
atScrollPosition:UITableViewScrollPositionTop animated:YES];
I can't seem to figure out how to scroll to the top and expand the navigation bar and the search bar. Manually calculating the content offset of the tableview doesn't work, as the offsets of the tableview are obviously different when the tableview is scrolled. Furthermore, I can't store the offset, as different screen sizes have different content offsets for an expanded navigationbar and searchbar.
Has anyone been able to figure this out?
Well, I'm a bit late to the action here but for future reference:
For iOS 10+ (sufficient, since growing navigationBars were introduced in 11) you can use
scrollView.perform(NSSelectorFromString("_scrollToTopIfPossible:"), with: true)
This is private API. I've searched for a couple of hours and tried a lot of stuff but in the end this is the only thing that worked. Note that WhatsApp seems to be using the same method. Maybe they have a special deal with Apple or hide the api call (cough base64 cough).
#implementation UIWindow (SCROLL)
- (void)performScrollToTop {
SEL selector = NSSelectorFromString(#"_scrollToTopViewsUnderScreenPointIfNecessary:resultHandler:");
if ([self respondsToSelector:selector] == false) {
return;
}
NSMethodSignature *signature = [UIWindow instanceMethodSignatureForSelector:selector];
if (signature == nil) {
return;
}
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIWindow instanceMethodSignatureForSelector:selector]];
[invocation setTarget:self];
[invocation setSelector:selector];
CGRect statusBarFrame = UIApplication.sharedApplication.statusBarFrame;
CGPoint point = CGPointMake(statusBarFrame.size.width / 2.0, statusBarFrame.size.height + 1.0);
[invocation setArgument:&point atIndex:2];
[invocation invoke];
}
#end
Related
I've stumbled upon a behavior in NSTextView that does not seem intended, or that I at least do not understand the reasoning behind.
When you have a large body of text in an NSTextView and you resize the control/window, the wrapping of words only happens fluently and immediately while resizing when the text is scrolled near the top. If you scroll far down in the text, it does not, and it doesn't seem to "commit" the wrapping until you release and finish resizing.
Is there some internal limitation, or is this a bug?
The issue seems to be reproducible:
macOS 10.15.4, Xcode 11.4.1
Create a new macOS App project
Put an NSTextView on the default generated view controller (doesn't matter which of the 3: rich, plain or default) and constrain it so that it resizes with the window (top, bottom, leading, trailing)
Run the application and paste a large body of text into the text view (for example: http://www.gutenberg.org/cache/epub/12281/pg12281.txt)
Scroll to the top of the NSTextView and observe how the text wraps while resizing the window
Scroll to the bottom and observe how it only wraps after resizing the window
Hoping there's any Cocoa detectives out there who can provide some enlightenment on this one.
EDIT:
As per the docs, it states that "the layout manager reserves the right to perform layout for larger ranges". I take it that this means it is indeed intended as a performance consideration.
Is there any way to determine what the limit is, though?
EDIT: You could try subclassing NSScrollView to render the text into multiple containers.
NSTextStorage *storage = [[NSTextStorage alloc] initWithString:string];
NSLayoutManager *manager = [[NSLayoutManager alloc] init];
[storage addLayoutManager:manager];
NSInteger i = 0;
while (YES) {
NSTextContainer *container = [[NSTextContainer alloc] initWithSize:CGSizeMake(width, height)];
[manager addTextContainer:container];
NSTextView *textView = [[NSTextView alloc] initWithFrame:CGRectMake(x, y, width, height) textContainer:container];
[self.contentView addSubview:textView];
i++;
NSRange range = [manager glyphRangeForTextContainer:container];
if ( range.length + range.location == string.length )
break;
}
Then, while resizing the window, you can call NSLayoutManager to ensure the layout only for visible containers.
When I am displaying some view in UIPopoverPresentationController and presenting it as popover
popoverCon?.modalPresentationStyle = UIModalPresentationStyle.popover
the content have moved upward toward and a some part is being display in the arrow.
Further I had border around the popover
popoverCon?.view.layer.borderColor = .orange
popoverCon?.view.layer.borderWidth = 1.0;
popoverCon?.view.layer.cornerRadius = 10.0;
popoverCon?.view.layer.masksToBounds = false;
it is not showing toward the part where arrow is but it displays a little of the border line in the tip of the arrow.
This was working fine until iOS 12 but in iOS 13 this issue is coming.
Any suggestions on how I can solve this?
The top of my tableView content was cut off by the arrow. This is how I fixed it in my case (code inserted in my tableViewController Swift file):
override func viewSafeAreaInsetsDidChange() {
if #available(iOS 11.0, *) {
super.viewSafeAreaInsetsDidChange()
self.tableView.contentInset = UIEdgeInsets(top: self.tableView.safeAreaInsets.top, left: 0, bottom: 0, right: 0)
}
}
My solution in Obj-C, for those who need an obj-c solution.
I had previously only popovercontroller, that was creating the error like shown in the question. I renamed it to childController for clarity and created a containing popoverController to make the solution given by #SaintMSent work in my situation of only one view originally. Also used https://stackoverflow.com/a/47076040/2148757 solution and https://useyourloaf.com/blog/self-sizing-child-views/ to resize appropriately since all of my childControllers set the preferred content size frequently.
//Create container popover controller and add child to it
UIViewController* popoverController = [[MyParentPopoverController alloc] init];
[popoverController.view addSubview:childController.view];
[popoverController addChildViewController:childController];
[popoverController setPreferredContentSize:childController.preferredContentSize];
//set popover settings on container
popoverController.modalPresentationStyle = UIModalPresentationPopover;
popoverController.popoverPresentationController.sourceRect = sourceRect;
popoverController.popoverPresentationController.sourceView = buttonView;
popoverController.popoverPresentationController.permittedArrowDirections = direction;
//Fix ios13 'bug' that Apple claims is a feature
UILayoutGuide* guide = popoverController.view.safeAreaLayoutGuide;
childController.view.translatesAutoresizingMaskIntoConstraints = NO;
[childController.view.leadingAnchor constraintEqualToAnchor:guide.leadingAnchor].active = YES;
[childController.view.trailingAnchor constraintEqualToAnchor:guide.trailingAnchor].active = YES;
[childController.view.topAnchor constraintEqualToAnchor:guide.topAnchor].active = YES;
[childController.view.bottomAnchor constraintEqualToAnchor:guide.bottomAnchor].active = YES;
[popoverController.view layoutIfNeeded];
//Show the popover
...
#interface MyParentPopoverController : UIViewController
#end
#implementation MyParentPopoverController
-(void)preferredContentSizeDidChangeForChildContentContainer:(id <UIContentContainer>)container {
[super preferredContentSizeDidChangeForChildContentContainer:container];
[self setPreferredContentSize:container.preferredContentSize];
}
#end
Note: I didn't check for ios11 compatibility because my user base is restricted to not use it.
It is definitely a feature, they want you to use safe area since iOS 11, actually, but it seems now they want to force you to use it
Had the same problem as you, this worked for me
https://useyourloaf.com/blog/safe-area-layout-guide/
Definitely a bug. When you have a situation where you use UIPopoverArrowDirectionAny you will see that the problem only exists when the arrow is at the top or left of the popover and not when the arrow appears at the right or the bottom of the popover. If you make adjustments in your code to compensate it will work if you use UIPopoverArrowDirectionUp or UIPopoverArrowDirectionLeft but will not display correctly using that adjustment when using UIPopoverArrowDirectionAny and the popup appears above or to the right of the target rectangle.
I don't have an 'answer' yet, but I have identified what's going on and why it's so hard to fix.
ios13 UIPopoverViewController showing UITableViewController - Safe Area problems / Missing parts of table
Basically, any UITableView that has headers or footers is going to be broken in iOS 13 unless there's some way to alter the _UITableViewHeaderFooterViewBackground
That is notoriously problematic and doesn't play nicely with Auto-Layout - it's been known about for years, but Apple have never fixed it or made it easier to deal with and more publicly known.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=1&cad=rja&uact=8&ved=0ahUKEwibouuozfvkAhVCXRUIHVGsBegQtwIIKjAA&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DajsCY8SjJ1Y&usg=AOvVaw3_U_jy9EWH2dJrM8p-XhDQ
https://spin.atomicobject.com/2016/10/12/auto-layout-uitableview/
I'm unable to push my app to the App Store until I get this sorted.. I hope someone can identify how to manipulate this view so that it stops pushing the boundaries of the table out of whack with AutoLayout which causes this safe area intrusion.
Searching on the internet I got help from following link
Twitter
so I had to add safe area and manage my views accordingly
CGFloat topPadding = 0.0;
if (#available(iOS 11.0, *)) {
topPadding = self.view.safeAreaLayoutGuide.layoutFrame.origin.y;
}
Swift:
var topPadding: CGFloat = 0.0
if #available(iOS 11.0, *) {
topPadding = self.view.safeAreaLayoutGuide.layoutFrame.origin.y
}
but I haven't got solution to the border problem of mine yet.
Edit:
Temporarily I did solved the border problem by creating an invisible view on popover and giving it same frame as safe area and drawing its border.
You should use constraints. And also pay attention to topAnchor. It must be safeAreaLayoutGuide.topAnchor. In my case, it works correctly. For example:
[NSLayoutConstraint activateConstraints:#[
[toolbar.leftAnchor constraintEqualToAnchor:self.view.leftAnchor],
[toolbar.rightAnchor constraintEqualToAnchor:self.view.rightAnchor],
[toolbar.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor],
[toolbar.heightAnchor constraintEqualToConstant:50]
]];
Embed the contents of the popover in another view with "safe area relative margins" on. This should have -21,-21 as the origin. Turn off vertical and horizontal auto resizing. Seems to work, although you lose auto-stretching.
Setup your popover's content UIViewController like such:
NSLayoutConstraint.activate([
myContentView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
myContentView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
myContentView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
myContentView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor)
])
How does one go about having auto-layout automatically wrap an NSTextField to multiple lines as the width of the NSTextField changes?
I have numerous NSTextFields displaying static text (i.e.: labels) in an inspector pane. As the inspector pane is resized by the user, I would like the right hand side labels to reflow to multiple lines if need be.
(The Finder's Get Info panel does this.)
But I haven't been able to figure out the proper combination of auto layout constraints to allow this behavior. In all case, the NSTextFields on the right refuse to wrap. (Unless I explicitly add a height constraint that would allow it to.)
The view hierarchy is such that each gray band is a view containing two NSTextFields, the property name on the left and the property value on the right. As the user resizes the inspector pane, I would like the property value label to auto-resize it's height as need-be.
Current situation:
What I would like to have happen:
(Note that this behavior is different than most Stack Overflow questions I came across regarding NSTextFields and auto layout. Those questions wanted the text field to grow while the user is typing. In this situation, the text is static and the NSTextField is configured to look like a label.)
Update 1.0
Taking #hamstergene's suggestion, I subclassed NSTextField and made a little sample application. For the most part, it now works, but there's now a small layout issue that I suspect is a result of the NSTextField's frame not being entirely in sync with what auto-layout expects it to be. In the screenshot below, the right-hand side labels are all vertically spaced with a top constraint. As the window is resized, the Where field is getting properly resized and wrapped. However, the Kind text field does not get pushed down until I resize the window "one more pixel".
Example: If I resize the window to just the right width that the Where textfield does it's first wrap, then I get the results in the middle image. If I resize the window one more pixel, then the Kind field's vertical location is properly set.
I suspect that's because auto-layout is doing it's pass and then the frames are getting explicitly set. I imagine auto-layout doesn't see that on that pass but does it it on the next pass, and updates the positions accordingly.
Assuming that's the issue, how do I inform auto-layout of these changes I'm doing in setFrameSize so that it can run the layout again. (And, most importantly, not get caught in recursive state of layout-setFrameSize-layout-etc...)
Solution
I've come up with a solution that appears to work exactly how I was hoping. Instead of subclassing NSTextField, I just override layout in the superview of the NSTextField in question. Within layout, I set the preferredMaxLayoutWidth on the text field and then trigger a layout pass. That appears to be enough to get it mostly working, but it leaves the annoying issue of the layout being briefly "wrong". (See note above).
The solution to that appears to be to call setNeedsDisplay and then everything Just Works.
- (void)layout {
NSTextField *textField = ...;
NSRect oldTextFieldFrame = textField.frame;
[textField setPreferredMaxLayoutWidth:NSWidth(self.bounds) - NSMinX(textField.frame) - 12.0];
[super layout];
NSRect newTextFieldFrame = textField.frame;
if (oldTextFieldFrame.size.height != newTextFieldFrame.size.height) {
[self setNeedsDisplay:YES];
}
}
The simplest way to get this working, assuming you're using an NSViewController-based solution is this:
- (void)viewDidLayout {
[super viewDidLayout];
self.aTextField.preferredMaxLayoutWidth = self.aTextField.frame.size.width;
[self.view layoutSubtreeIfNeeded];
}
This simply lets the constraint system solve for the width (height will be unsolvable on this run so will be what ever you initially set it to), then you apply that width as the max layout width and do another constraint based layout pass.
No subclassing, no mucking with a view's layout methods, no notifications. If you aren't using NSViewController you can tweak this solution so that it works in most cases (subclassing textfield, in a custom view, etc.).
Most of this came from the swell http://www.objc.io/issue-3/advanced-auto-layout-toolbox.html (look at the Intrinsic Content Size of Multi-Line Text section).
If inspector pane width will never change, just check "First Runtime Layout Width" in IB (note it's 10.8+ feature).
But allowing inspector to have variable width at the same time is not possible to achieve with constraints alone. There is a weak point somewhere in AutoLayout regarding this.
I was able to achieve reliable behaviour by subclassing the text field like this:
- (NSSize) intrinsicContentSize;
{
const CGFloat magic = -4;
NSSize rv;
if ([[self cell] wraps] && self.frame.size.height > 1)
rv = [[self cell] cellSizeForBounds:NSMakeRect(0, 0, self.bounds.size.width + magic, 20000)];
else
rv = [super intrinsicContentSize];
return rv;
}
- (void) layout;
{
[super layout];
[self invalidateWordWrappedContentSizeIfNeeded];
}
- (void) setFrameSize:(NSSize)newSize;
{
[super setFrameSize:newSize];
[self invalidateWordWrappedContentSizeIfNeeded];
}
- (void) invalidateWordWrappedContentSizeIfNeeded;
{
NSSize a = m_previousIntrinsicContentSize;
NSSize b = self.intrinsicContentSize;
if (!NSEqualSizes(a, b))
{
[self invalidateIntrinsicContentSize];
}
m_previousIntrinsicContentSize = b;
}
In either case, the constraints must be set the obvious way (you have probably already tried it): high vertical hugging priority, low horizontal, pin all four edges to superview and/or sibling views.
Set in the size inspector tab in section Text Field Preferred Width to "First Runtime layout Width"
This works for me and is a bit more elegant. Additionally i've made a little sample project on Github
public class DynamicTextField: NSTextField {
public override var intrinsicContentSize: NSSize {
if cell!.wraps {
let fictionalBounds = NSRect(x: bounds.minX, y: bounds.minY, width: bounds.width, height: CGFloat.greatestFiniteMagnitude)
return cell!.cellSize(forBounds: fictionalBounds)
} else {
return super.intrinsicContentSize
}
}
public override func textDidChange(_ notification: Notification) {
super.textDidChange(notification)
if cell!.wraps {
validatingEditing()
invalidateIntrinsicContentSize()
}
}
}
How do I make a scroll view start over again?
IE: my UIScrollView is 1000px wide. The user will swipe through the view to find a topic. When the user reaches the last topic (say topic 10) how do I have the UIScrollView start back at the beginning (topic 1) without having to scroll backwards?
So, the view will just continue in a circle forever, if the user wishes.
This is the method that you are going to use:
- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated
after you detect that user reaches the last topic.
I am assuming you are using a paging UIScrollView with topics as pages. The trick is to duplicate the end pages, and then when the user swipes to the last page in the scrollview (which is a duplicate of the first page) and the deceleration stops you want to change the content offset back to the first page.
When I needed to do this, I found this post. I used setContentOffset in scrollViewDidEndDecelerating rather than scrollRectToVisible, but either approach will work.
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sender
{
if (scrollView.contentOffset.x == 0) {
[scrollView setContentOffset:contentOffsetOfLastTopic animated:NO];
}
else if (scrollView.contentOffset.x == contentOffsetOfLastPage) {
[scrollView setContentOffset:contentOffsetOfFirstTopic animated:NO];
}
}
I have a NSTableView which contains my custom NSCell subclass, IconCell.
The IconCell contains three elements : an image, text, and a button.
Here's a simplified version of my drawing code (closeButton is the button):
- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView
{
NSPoint cellPoint = cellFrame.origin;
[controlView lockFocus];
CGFloat buttonWidth = [closeButton frame].size.width;
[someNSImage drawInRect:NSMakeRect(cellPoint.x, cellPoint.y, ICON_WIDTH, ICON_HEIGHT) fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0 respectFlipped:YES hints:nil];
[someNSString drawInRect:NSMakeRect(cellPoint.x+ICON_WIDTH+PADDING, cellPoint.y, cellFrame.size.width - ICON_WIDTH - buttonWidth, cellFrame.size.height) withAttributes:someTextAttributes];
[(NSButtonCell*)[closeButton cell] drawWithFrame:NSMakeRect(cellPoint.x + cellFrame.size.width - buttonWidth, cellPoint.y, buttonWidth, cellFrame.size.height) inView:controlView];
[controlView unlockFocus];
}
The drawing part works fine and produces something like the following:
which is what I want.
Moreover, I want one of two things to happen when the user interacts with the cell: if the user clicks anywhere on the cell, EXCEPT the close button, it should do actionA. If the user clicks on the close button, it should do actionB.
The problem I'm having is that the close button seems "invisible" -- if I click on it, it doesn't move (whereas a working button should show its pushed down state), and in general it behaves as if it wasn't there, and actionA is triggered instead of actionB.
This is how I set the two actions:
[tableView setAction:#selector(actionA)];
and
[closeButton setAction:#selector(actionB)];
What am I doing wrong?
You're just drawing a picture of the button in the cell. This isn't the same thing as placing the actual button into the cell.
Cells aren't full views, so this is more complicated than you may think at first. If you really have to do this with cells, it's explained here: NSButtonCell inside custom NSCell.
But... if you can limit yourself to 10.7+, they've added view-based tableviews. These are much simpler, since you can put a full NSButton inside of your NSTableViewCellView. This is explained in the Table View Programming Guide. Highly recommended if you can limit yourself to 10.7+.