I'm currently implementing drag and drop rearranging in a table view in my OS X app. While normal scrolling works fine, autoscroll while dragging it totally broken.
If I grab a cell and start dragging, autoscroll just tells the table to scroll to the top. If I manually scroll using the trackpad during dragging the table continually pops to the top. If I drag one of the top cells, the table will not autoscroll down when dragging near the bottom.
I subclassed NSScrollView and overrode the scrollClipView method. I see that it's being called by some internal autoscroll method with the coordinates of (0, 0).
Since I can't see what that internal method is doing, and Goggle and SO are turning up nothing, I'm a bit stuck.
Has anyone run into this issue before? From past experiences, I have the feeling it's something AutoLayout related, but I have no idea what. Or maybe it's something completely unrelated.
Any ideas on how to further troubleshoot?
I ran into the same issue. In my case, the problem was that I set the height of the NSTableCellView to 10,000 in Interface Builder so that the horizontal separators wouldn’t be displayed for empty rows below the actual rows.
However, the actual height of my NSTableCellViews loaded at run time was 43px.
So as soon as I started dragging a cell to re-order it, the NSScrollView was trying to scroll 10,000 pixels at a time instead of 43 at a time.
This seems like a bug, because my NSOutlineView subclass does implement the following method to dynamically set the height of each row.
func outlineView(_ outlineView: NSOutlineView, heightOfRowByItem item: Any) -> CGFloat
Apparently that method is ignored by the autoscroll mechanism during drag and drop operations, and only the value set in Interface Builder is used.
So I just changed the height of the dummy NSTableCellView to 43px in Interface Builder, and I’ll just live with the horizontal separators being displayed for empty rows.
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I'm experiencing a weird behavior in Interface Builder. I almost feel like it's a glitch, but I'm hoping that I'm just misunderstanding something, or that someone knows what weird AutoLayout behavior I'm experiencing, or something. I'll try to describe it as best I can...
I've got a ViewController in Interface Builder, with nothing but a UITextView. Nothing unusual about the TextView, I just dragged it in from the sidebar, and it's the first thing I added. But here's the thing: the text is offset by about 50 points. There's nothing in the Size Inspector that would explain it, the text is just spaced down. BUT, if I click and drag it around, the text pops back up to the top. Then I drop it in a new place, and the text is offset again.
Here's where it gets really weird: if I drag a UICollectionView into that same ViewController, it's fine (the default cell is right up in the top left corner), but as soon as I delete the TextView, the default cell gets moved 50 points down in the CollectionView! Now I have a CollectionView with an offset cell, and if I drag a new TextView back on, it's fine, but deleting the CollectionView adds the offset back to the new TextView! The location of the views is irrelevant (either at the time of adding or later), the older view will always be offset.
And, just for an extra dose of weird: whichever view is offset, if I click and drag it to move it around, the other view will be offset until I drop it in its new location. Oh, and deleting the ViewController entirely and starting again does nothing. The behavior remains.
What black magic is this?! This is the 8th ViewController I've added to my Storyboard (12th if you include abstract ViewControllers like TabBarControllers etc), and none of them had this issue. Why would this forced-offset exist, and how do I stop it? Is this some weird permutation of AutoLayout or something? Or does this sound like a genuine glitch, and I should post on a tech support forum?
EDIT: Just to be clear: the offset does appear when the app is run in the Simulator. IB shows that the frame isn't changing, the content is being offset within the frame, but whatever it is, it DOES show up in the final app.
The answer turned out to be turning off "Adjust Scroll View Insets" on the ViewController.
Sort of a weird behavior for the ViewController to present like that, adjusting a single ScrollView without any regard for its position or size, but at least it was an easy fix.
I have an NStableView embedded in an NSSplitview.
The table will display, but when it does, the first three or so rows are not visible until I reize the window and/or split view. Then, it will snap into place and function perfectly fine until I quit.
Has this ever happened to anyone? Is there a simple method I can call on the view or table to get it to redraw?
This is how it displays when the view is first loaded (note: the user can scroll the table up and see the top row highlighted, but never get to it)
after resizing the window, the table view suddenly snaps into place and appears as it should:
You could try a [_yourSplitView display] to force a redraw of the NSSplitView. If I remeber correctly the SplitView will redraw all its subviews.
Try experimenting with where you use this, as result may vary depending on where in the init order you call this.
I actually got this working by calling the subview and then just resetting the position of the splitview divider.
NSView *v = [vc view];
[self.superDisplayView addSubview:v];
[self.SourceListSplitView setPosition:250 ofDividerAtIndex:0];
I'm having trouble getting a UIScrollView to respect the constraints I put in interface builder.
All I need to be able to do is set the content size of the scroll view from within IB.
The UIScrollView contains a single UIView.
Constraints on the UIScrollView:
Constraints on the UIView:
I've read through the documentation, and so have set things up as follows:
the UIScrollView has constraints pinning it to its superview, thus defining its size from outside
the UIView (content) has a fixed size (through width and height constraints)
the UIView is pinned to the UIScrollView, thus defining the content size
However, IB won't let me enter these constraints. If I change the 'Bottom Space' constraint between the view and the scroll view, shown in the image as -2196, to 0 (thus pinning the lower edge of the scroll view), then the 'Top Space' constraint resets to a non-zero value. The same happens in reverse. (I haven't yet tried in Xcode 5, which has a far saner approach to invalid constraints in that it doesn't just throw yours away when it feels like it.)
What am I missing?
Every time I've tried to do something even mildly sophisticated with constraints in Xcode 4's Interface Builder, I've eventually given up and either written the constraints in code or switched back to springs'n'struts and layoutSubviews (usually after crashing Xcode a few times).
That said, there is another approach to laying out a scroll view with content in IB. Just make the scroll view as big as its content size, and rely on the view controller (or some containing view controller) to resize the scroll view (or its superview) and let the constraints shrink down the scroll view's frame at runtime. The window's root view controller will always set its view's frame to the screen size, regardless of its size in the nib or storyboard, and that resizing flows down the view hierarchy.
I described this approach in more detail in this answer.
If your scroll view's content size is really supposed to be 2196 points tall, this probably won't work so well. I don't have anything better to suggest in that case.
I have a 10.6 app that I am building on Lion with Xcode 4.3
There is a horizontal split view in the main view, containing the following:
The top view contains an NSSearchField with an NSTableView below it.
The bottom view contains a WebView.
I have it working, but when I resize the split view the top view behaves oddly.
What I want to happen is for the search field to remain where it is, the tableview to remain where it is, but to expand if the split view is dragged down. If dragged up, I want the webview to overwrite the search field and table view.
You can see what I mean in this clip: http://dl.dropbox.com/u/160638/Work/TENSOFT/resizemostlyokay.mov
This keeps the things in the right place when I drag up, but doesn't expand the table when I drag down. The view is expanded, but not the table.
So, I changed the autosizing constraint on the table view / scroll view to make it expand when the view is resized. This is what happens: http://dl.dropbox.com/u/160638/Work/TENSOFT/resizeproblem.mov
When the split bar is moved upwards the table view is moved upwards inside the top view until it overwrites the search field. It doesn't move back when the bar is moved back down.
I cannot find a way to make this work by changing the autosizing constraints. This is usually pretty easy stuff, so either I'm missing something obvious or...?
Has anyone seen this behaviour before when creating SL apps on Lion with Xcode 4.3?
FYI, if I replicate this in a new 10.7 project using auto-layout everything works fine.
Regards
Darren.
When you allow an NSSplitView to make one of its subviews very small so that the subviews effectively overlap you get layout issues and this is one of the reasons that Apple introduced auto-layout (watch the WWDC video about auto-layout and I think they demo this problem near the beginning).
If I were you I'd set a minimum size for the top pane so that, for example, it stops resizing when it is 100px high. You can then allow it to collapse so that the user can still show just the WebView.
I've got an NSTableView with a single column, populated with NSTableViewDataSource methods (no bindings involved.) The NSTableView is inside an NSScrollView, as is the default behavior when you drag an NSTableView in from the library in Interface Builder. The contents of the tableview are populated based upon a search string that the user types, and are not changed after that point.
I am only implementing these two methods of the DataSource protocol:
- (NSInteger)numberOfRowsInTableView:(NSTableView *)tableView;
- (id)tableView:(NSTableView *)tableView objectValueForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row;
After typing my search string, the focus is still in the NSTextField, but I can naturally scroll the tableview with my mouse's scroll wheel or with the arrows on the scroll bar. Neither causes the tableview to receive the focus ring. However, if I scroll down such that I am not at the top of the tableview and then click to highlight an individual row in the tableview, the tableview instead jumps back to the top, and then selects whatever row is under my mouse at that point. If I click on rows after that point, it works as expected.
In other words, if the NSTableView has the focus ring around it, clicking on a row highlights the expected row. If it does not have the focus ring around it, clicking on a row selects whatever row is at that position after scrolling to the top.
Any insight? I am running Snow Leopard, but I believe it happened when I was running Leopard as well.
Could it be that when the search NSTextField loses focus, it somehow fires a reloadData (or similar method) on the table view, which would empty out the view (resetting its scrolling position to the top) and then re-populating it instantaneously?
I had a similar bug once, and the cause was that my window controller was handling awakeFromNib and was setting the scroll position on the list so it would be in the right position when first loaded. However, I eventually realised that it was also getting awakeFromNib messages from the nib-based table view cells which are created as needed, which would sometimes mess with the table scroll value unexpectedly while scrolling. My fix was to make the window controller only set scroll position when handling the first awakeFromNib.