NSTableView displaying incorrectly in NSSplitView - xcode

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];

Related

NSTableView in NSScrollView doesn't autoscroll when dragging

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.

How to place an NSButton over an NSTableView

1) No table behind button
2) Table loaded
3) After scrolling
If I place a button over an NSTableView I get artifacts being left behind after scrolling. Does anyone know how to fix this?
My current solution is just to split the section with the table into 2. The lower portion is a disabled button in the background.
Try the NSScrollView method
- (void)addFloatingSubview:(NSView *)view forAxis:(NSEventGestureAxis)axis
All tableviews should normally be inside a ScrollView.
I had a similar problem and solved it, see Why does an NSTextField leave artifacts over an NSTableView when the table scrolls?. Essentially OSX will draw the contents of the table and let the parent scroll view move the cached contents avoiding redraws to be performant. By subclassing the parent scroll view it can be forced to refresh the table hooking the reflectScrolledClipView: method. Then the whole table, including overlays, will be redrawn with each scroll.
That's because the scroll view is set to copy its contents when scrolling and only redraw the newly-uncovered part as a performance optimization. To turn that off, use
myTableView.enclosingScrollView.contentView.copiesOnScroll = NO;
though that will make scrolling use more CPU (you can also do this in the XIB, look for a 'copies on scroll' checkbox).
Probably a better approach would be to switch the scroll view and the button to be layer-backed:
myTableView.enclosingScrollView.wantsLayer = YES;
myButtonView.wantsLayer = YES;
(Again, you can set this in the 'Layers' inspector of the XIB file, where you can click a checkbox next to each view to give it a layer) Now, the scroll view will only copy stuff from its own layer (which no longer includes your button). Also, now all the compositing of the text view will be done using in the graphics card. This works fine with an opaque push button, however, if you put text on a transparent background in its own layer (e.g. if you have a transparent pushbutton with a title), you lose sub-pixel anti-aliasing.

NSView added as subview doesn't show

I have a puzzling problem. Working on a cocoa app in mac os x 10.7.
My app main window contains a split view. In a certain use context in one of the subviews of the split view is loaded a custom view with some labels (nstextfield) and a split view (instantiating a view controller that loads a nib and getting view from that controller). Frame of the custom view is set to split view subview bounds and everything works fine.
Problem is that one of the subviews of the second split view should be loaded (same method: view controller-nib-view-frame/bounds) with a custom view containing a table view and a button, but in this case nothing shows. Everything is done the same way but last custom view is not visible. Any idea?
Thanks
(edit)
this is the code I use to instantiate controller for the view to be added, get the view, and add it as subview to a subview of the split view
- (void)loadSubview {
self.subviewToAddController = [[viewController alloc] initWithNibName:nil bundle:nil];
//nib name is coded in the controller class definition
[[self.subviewToAddController view] setFrame:[self.splitViewContainerSubView bounds]];
//container subView is an outlet
[self.splitViewContainerSubView addSubview:[self.subviewToAddController view]];
}
However I don't think the problem is in this code because if I ask the container subview for its own subviews I can see the new subview is present in the list. It just doesn't show. If I add it as a subview of the split view (a test a just made) or as subview of the subview of the most external split view it is correctly showed too (sorry for the confused explanation, I would need a diagram but in this moment I can't make it)
To elaborate more my doubt (I didn't want to misled so I didn't mention before) can't it be a problem of coordinates, so view is correctly loaded and added as subview but is not visible because hidden by something or showed out of visible area?
(update)
Sorry it took so long to post an update.
After more testing I found out the problem is related to autolayout. No idea what the exact problem is and how to solve it. I ended up turning it off for the nibs the were in troubles and use the old way to set interface objects position and size/resize. Not the best way but for now I can go on.
My best guess is that you didn't set the autoresizing masks of the view properly.

How to resize UI Table View of a UI Table View Controller programmatically?

I subclassed UITableViewController and called it FeaturedGamesViewController. Ok, I also have a navigation controller to which I added this FeaturedGamesViewController as the root. All pretty standard stuff that you do in the App Delegate.
Also note that there is no NIB file created for FeaturedGamesViewController. Just subclassing UITableViewController and calling initWithStyle sets the style of the table and sets the dataSource and delegate and size automatically. Data Source and Delegate are obviously set to FeaturedGamesViewController.
- (id)init
{
// Call the superclass's designated initializer
[super initWithStyle:UITableViewStyleGrouped];
}
OK, You see that I have set the table size to "Grouped". In Landscape view on my iPad it has about 20 pixels of space to the top, left and right (Sorry can't post screen shot because I am new here and the system won't let me until I have accumulated a certain number of points)
I DO NOT want that! This is Landscape so I expect it to fill up the all the space between the navigation bar and the tab bar below. What is worse is that I have faked a grid with a Custom UITableViewCell but the space to the left and right make it so that if you click on that space, the entire row is selected thus betraying the sense that this is a grid.
Now I figure I should resize the table view in viewDidLoad or something but I don't know how. I cannot do initWithFrame because of potential memory leaks (and possibly resetting dataSource and delegate and autoresizeMask properties that were already set) so there must be a setter or something to reset the origin of the tableview to just beneath the Navigation bar and filling up the entire screen with size 1024X748. How do you do dynamically reset the size of the table view?
Then I got really frustrated and I decided to do it via a Nib file, that way I can set the the orientation to landscape and set simulated Navigation and Tab bars and fill the rest of the space with the table view. This worked! If you are curious how to create a table view with a Nib after you have subclassed UITableViewController WITHOUT a nib, here is how:
http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/TableView_iPhone/CreateConfigureTableView/CreateConfigureTableView.html#//apple_ref/doc/uid/TP40007451-CH6-SW10
Go to the paragraph right before "Creating a Table View Programmatically".
OK, when I did that, my landscape view of the "grid" looks filled up the entire space between the navigation bar at the top and the tab bar at the bottom just like I wanted.
I was fiddling with this some more and I found out that in my "non nib" version (the problematic one), I had set the table style to "grouped". When I changed it to "plain", it worked!!! But here is the thing though: In the nib version, "grouped" or "plain" gives the correct layout with the table occupying the whole space. So what gives?
Sorry for the long question but I guess what I am asking is:
1) How do you programmatically reset the size of the table view without introducing potential memory leaks or affecting other properties already set for you (ex: dataSource, delegate, autoResizeMask - these are set for you just because you subclassed UITableViewController)?
2) How do you do that for any view in general?
3) Why does "plain" style fill the layout as desired whereas "grouped" style gives the weird layout. Note that it this is not a problem in the Nib version.
Thanks for your patience!
Answer for (2), and hence for (1):
A UIView's frame is in a local coordinate system of its superview. A common way to make a view fit its superview is
CGRect bounds = [[self superview] bounds];
[self setFrame:bounds];
You should do this inside layoutSubviews.

NSTableView jumps on selection… why?

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.

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