Automatically grow document view of NSScrollView using auto layout? - cocoa

Is there a simple way to get an NSScrollView to adapt to its document view changing size when using auto layout?
I have tried to call both setNeedsUpdateConstraints: and setNeedsLayout: on the document view, the clip view and the scroll view, without any results.
fittingSize of the document view reports the correct size.
The problem is that the document view, which holds subviews, is not re-sized when the subviews change their size, even if they call invalidateIntrinsicContentSize. The contents of the document view are hence clipped to the original size of the document view as they grow. The document view is created in a nib and set as the scroll view's document view in an awakeFromBib method.
I was hoping that the document view frame would automatically be adjusted when its fittingSize changes, and the scrollbars updated accordingly.
NSPopover does something similar - provided that the subviews of the content controller's view have the constraints set right and various content hugging values are high enough (higher than the hidden popover window's hight constraint priority, for one).

The problem of course is that when adding the document view, Cocoa will automatically create some hard constraints in the view that the document view is inserted into, i.e., the clip view.
So the answer to my own question is simple, just use:
// Assume self.docView is an IBOutlet populated with
// an NSView subclass
self.docView.translatesAutoresizingMaskIntoConstraints = NO;
before you add the document view to the scroll view:
self.scrollView.documentView = self.docView;
Now, since there are no auto-generated constraints on the layout of the document view in the clip view, you will need to add them explicitly. Otherwise, the doc view's contents will just be rendered at their intrinsic size in the upper left corner of the scroll view.

Related

Custom NSView embedded in NSSscrollView

Is there a way for a custom NSView to know whether it is embedded in a NSScrollView or not?
I am creating a custom NSView for displaying some content.
When my view is placed in a window or another view, its size is fixed and the content is clipped to available size.
When my view is placed in a NSScrollView its size must be adjusted according to content so it can be scrolled if necessary.
I know I can add a member in my view that specifies the NSScrollView that hosts my view and set this member manually in code, but I was wondering if there is another way?
You didn't check the methods of NSView?
#property(readonly, strong) NSScrollView *enclosingScrollView;
or
var enclosingScrollView: NSScrollView? { get }
The nearest ancestor scroll view that contains the current view.
If the current view is not embedded inside a scroll view, the value of this property is nil. This property does not contain the current view if the current view is itself a scroll view. It always contains an ancestor scroll view.

How to call NSScrollView autoscroll-method programmatically

I have simple chat application with text messages view-based NSTableView as you can see at the picture below.
Each message contains NSTextView instance having height to fit all the text.
All I need is to start NSScrollView (which NSTableView-instance is enclosed by) autoscrolling while the user selecting text dragging mouse far enough. Unfortunately, autoscrolling doesn't appear. In case of dragging somewhere outside of the text views all succeed.
I tried to call autoscroll:-method directly by simply push NSEvent-instance from NSTextView-subclass "mouse dragged"-event (like in example from this article):
- (void)mouseDragged:(NSEvent *)event
{
[self.scrollView autoscroll:event];
}
As I've overrode all the mouse events and implemented all the text selecting, this method often invokes. But the autoscrolling doesn't seem to work.
UPDATE
I figured out that before calling -autoscroll:-method there must be -mouseDown: of the same object. But it breaks my text selecting mechanism. The point even not in being first responder, there must be nothing but the mouseDown:-method.
Normally, a text view is within a scroll view of its own. Even if that's big enough to show all of the text without scrolling, it's still there. A call of -autoscroll: on anything within that scroll view (possibly including that scroll view itself?) will just try to scroll that scroll view, not the scroll view that contains the table view.
Try calling -autoscroll: on a view higher up in the hierarchy. Either self.scrollView.superview, the table cell view, or the table view.
Note, though, that the table view's scroll view will keep scrolling even after the cell view containing the text view is fully on-screen. In fact, it may keep scrolling it so far that it's off the screen in the other direction. Basically, it doesn't know that you're trying to select within the text view so it doesn't know to stop when the selection extends all the way to the edge of the text view.
Another approach might be to try to use a "bare" text view with no enclosing scroll view. I don't think IB will let you do that, so you'd have to do it programmatically. Bare text views don't play well with auto layout, though.

View based NSTableView with each view contains 3 labels with should resize based on Text

I need to create a view based tableview in Popover as specified below:
Tableview should be placed in Popover(Popover height should be same as tableview).
Each row should contain a view.
Each row view will contain 3 labels.
Labels should be auto re sizable based on its text height.
Based on 3 labels height, Cell row height should resize.
Based on all cell rows, tableview height should resize.
Based on tableview height, Popover should resize.
I have done this in a static format, but i need to do it in more dynamic format(in future i should be able to add more rows using same classes and methods).
Main problem i am facing is, i am unable calculate the size of cell view in tableView:heigthOfRow: since i don't know the text of labels in this point of time.
So i just created tableview cells in loadView itself and saved in array, and fetching from array in tableview delegate methods. But i think this is wrong way of doing so.
Note: All data to tableview will be given while loading the view itself. Labels are not editable.
Cocoa system resizes the subviews based on superview ,I think scenario that you are looking for is to resize super view based on subview size.
Following 2 solutions i can suggest right awyay,
1.You can choose to post notification upon size change in each subview and make immediate superview observe that.
2.Use globals for size of each subview in your case 3 labels, and have an API to calculate finalRect in your view of view based table view.
Hope this helps:) have a nice day.

How to stop interface builder resetting user constraints on UIScrollView?

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.

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.

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