I'm trying to release some strain on a view-based NSOutlineView for which I changed a single item property and which I initially reloaded just fine using [myOutlineView reloadData].
I tried [myOutlineView reloadItem: myOutlineViewItem] but it never calls - (NSView *)outlineView:(NSOutlineView *)ov viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item and consequently the data is not updated.
-(void)reloadOutlineViewObject
{
//[myOutlineView reloadData]; //Reload data just fines but is ressource-hungry
NSLog(#"%d",[myOutlineView rowForItem:myOutlineViewItem]; //Making sure my object is an item of the outlineView, which it is !
[myOutlineView reloadItem:myOutlineViewItem];
}
Am I missing something here ?
UPDATE
As pointed out in the comments, my outlineView is view-based.
UPDATE 2
Trying out some stuffs made me realized that the object I am reloading is a second-level object (cf object tree) and calling reloadItem:firstLevelObject reloadChildren:YES does work.
Would it be possible that we can only call reloadItem: on first-level object ? That would be highly inefficient in my case (I only have one two level item and plenty of second level) !
nil ->firstLevelA ->secondLevel1
->secondLevel2
->firstLevelB ->secondLevel3
->secondLevel4
Gonna try to subclass NSOutlineView and rewrite reloadItem: in the mean time.
UPDATE 3
I took a look at NSOutlineView in Cocotron to get start and felt that the code I needed to write to overwrite reloadItem would be quiet heavy. Anyone to confirm ?
I encountered this same problem with a view-based outline view, where calling -reloadItem: seems to just not do anything. This definitely seems like a big bug, though the documentation doesn't explicitly say that reloadItem will reacquire the views for that row.
My workaround was to call NSTableView's -reloadDataForRowIndexes:columnIndexes: instead, which seems to work as expected, triggering a call to the -outlineView:viewForTableColumn:item: delegate method for just that item. You can get the row that needs to be reloaded by calling -rowForItem: and passing in the item you want to reload.
This really isn't a bug - it was something I had explicitly designed. My thought was that reloadItem (etc) should just reload the outline view item properties, not the table cell at that item, since it doesn't carry enough specific information on what to reload (such as what specific cell you might want reloaded). I had intended for people to use reloadDataForRowIndexes:columnIndexes: to reload a particular view based tableview cell; we usually don't provide cover methods when the base class can easily do the same thing with just a few lines of code.
However, having said that, I know multiple people have gotten confused about this, and most people expect it to reload the cell too.
Please log a bug requesting Apple to change this.
thanks,
-corbin
Apple seems to have "fixed" it.
WWDC 2016, presentation 203 "What's New in Cocoa" at 30:35 in the video:
"NSOutlineView
Reloads cell views associated with the 'item' when reloadItem() is called"
reloadItem: works only on macOS 10.12.
From release notes:
https://developer.apple.com/library/content/releasenotes/AppKit/RN-AppKit/
NSOutlineView will now reload the cell views associated with ‘item’
when [outlineView reloadItem:] is called. The method simply calls
[outlineView reloadDataForRowIndexes:columnIndexes:] passing the
particular row that is to be reloaded, and all the columns. For
compatibility, this will only work for applications that link against
the 10.12 SDK.
So, if you want to reload row on earlier systems, you should use -reloadDataForRowIndexes:columnIndexes:.
Something like that:
let index = outlineView.row(forItem: obj)
let rowIndex = IndexSet(integer: index)
let cols = IndexSet(0 ... outlineView.numberOfColumns)
outlineView.reloadData(forRowIndexes: rowIndex, columnIndexes: cols)
Related
I'm implementing an example, in that example, I read in data from a database, put it in an array, sort it, and it's displayed using the RootViewController. The DB read and array load happen before the RVC code. So, it works, I get the data in the window created by the RVC and there's a nav controller there as well.
I want to add a button or something to the nav controller so that when you hit it, it sends a value back to the RootViewController.m file, then based on that value, I want to resort the array and display it once again in the RootViewController window.
I'm not sure how to do this. What changes would I have to make to the .xib and the RootViewController.m file?
Please, I'm a confused nube. %-0 Thank you very much.
There's a fair amount to this, so I'll give some general points and if any of them cause problems, it may be easier to work out smaller details.
In you RVC's viewDidLoad method, you can create a button and set it as the right or left button in your controller's navigationItem.
You can associate a tap on that button with a method in your controller that can do whatever you want when the button is tapped. (But a button doesn't send values, really, so you may have to explain more about that idea.)
I assume the RVC has a table view if you're showing array contents, so once the array (mutable array, I'd assume) is re-sorted, you can tell the table view to reload its data.
In answer to your secondary question, once you have resorted your array (or generally updated your data however you wish) you can force the table view to reload programmatically
[tableView reloadData];
Where 'tableView' is your instance variable pointing to your table view
When a user adds a new managed object, it shows up in a table, which scrolls down to the new entry, and the name of the new object (a default value) goes into editing mode.
I need to check if the name of the new object is unique in the datastore, so I can't use a formatter for this. I think the perfect moment where I should validate this, is whenever the user tries to commit the entry's name value, using textShouldEndEditing:.
I subclassed NSTableView and overrid following methods, just to be able to check in the log if they get called.
- (BOOL)textShouldEndEditing:(NSText *)textObject {
NSLog(#"textSHOULDendEditing fired in MyTableView");
return [super textShouldEndEditing:textObject];
}
- (BOOL)control:(NSControl *)control textShouldEndEditing:(NSText *)fieldEditor {
NSLog(#"control:textShouldEndEditing fired in MyTableView");
return YES;
}
- (void)textDidEndEditing:(NSNotification *)aNotification {
NSLog(#"textDIDEndEditing fired in MyTableView");
}
textDidEndEditing: gets called fine, but textShouldEndEditing: does not.
In the NSTableView Class Reference, under Text Delegate Methods, both methods textShouldEndEditing: and textDidEndEditing: are listed. Someone please explain why one gets called and the other doesn't.
I think the NSTableView acts as the delegate for an NSTextField that gets instantiated as a black box delegate for the NSTextFieldCell. So what is referred to as delegate methods in the NSTableView Class Reference, actually implement the text manipulating methods for the NSTextField object.
I tried to declare the NSTextFieldCell as an outlet in my NSTableView. I also tried to declare several protocols in the NSTableView.
#import <AppKit/AppKit.h>
#import <Cocoa/Cocoa.h>
#interface MyTableView : NSTableView <NSTextDelegate, NSTextFieldDelegate, NSControlTextEditingDelegate, NSTableViewDelegate, NSTableViewDataSource> {
}
#end
Don't laugh, I even tried to declare my table view as its own delegate :P
After banging my head one entire day on this issue without finding any conclusive answer in Apple documentation, I decided to share the solution I've found in case somebody else struggles with the same problem.
According to the documentation, as the original poster mentioned, the methods control:textShouldBeginEditing and control:textShouldEndEditing of NSControlTextEditingDelegate should be called directly on the delegate:
This message is sent by the control directly to its delegate object.
Furthermore, a Technical Q&A was issued by Apple with the title Detecting the start and end edit sessions of a cell in NSTableView where it's clearly stated the following:
A: How do I detect start and end edit sessions of a cell in NSTableView?
In order to detect when a user is about to start and end an edit session of a cell in NSTableView, you need to be set as the delegate of that table and implement the following NSControl delegate methods:
- (BOOL)control:(NSControl *)control textShouldBeginEditing:(NSText *)fieldEditor;
- (BOOL)control:(NSControl *)control textShouldEndEditing:(NSText *)fieldEditor;
The table forwards the delegate message it is getting from the text view on to your delegate object using the control:textShouldEndEditing: method. This way your delegate can be informed of which control the text view field editor is acting on its behalf.
I found nothing in Apple's documentation stating anything different and if someone does, a documentation pointer would really be appreciated.
In fact, this appears to be true if a cell-based NSTableView is being used. But as soon as you change the table to a view-based table, the delegate method is not called any longer on the table delegate object.
A Solution
However, some heuristic tests I performed showed that those delegate methods get called on a view-based table delegate if (and as far as I know: and only if):
The table delegate is set.
The delegate of the editable control is set.
If you remove either delegate, the methods of the NSControlTextEditingDelegate protocol will not be called.
What's unexpected according to the (only) documentation is setting the delegate of the editable control. On the other hand setting the delegate object to receive delegate notifications sounds rather intuitive to me, and that's why I tried in the first place. But there's a catch! The curious thing, though, is that that's not sufficient. If the table delegate is removed, the NSControlTextEditingDelegate methods will not be called even if the delegate of the editable control is set (which is the weirdest thing to me).
Hope this helps somebody else not to lose time on this issue.
in your question you mention the insertion of a "managed object" and that was the problem. It seems that you are using a view based table, but the textShouldEndEditing: method only gets called for cell based tables.
I overrid -(void)awakeFromInsert; in the (subclassed) managed object, to construct a unique default value for the name-property.
Also, I ended up not overriding the -(BOOL)textShouldEndEditing: method in the table view. Instead, I check if a newly entered name-property is unique in the (subclassed) managed object's -(BOOL)validate<Key>:error:.
Together, the above two strategies result in unique name-properties in all managed objects.
Maybe I could have forced the NSTextFieldCell to go into editing mode, resulting in -(BOOL)textShouldEndEditing: to get called every time.
Some remarks though:
It seems -(BOOL)textShouldEndEditing: returns NO when the -(BOOL)validate<Key>:error: returns NO.
Both -(BOOL)textShouldEndEditing: and -(BOOL)validate<Key>:error: methods are called only when the user actually makes changes to the property.
I add another Object to my NSOutlineView's NSOutlineViewDataSource and call [myOutlineView noteNumberOfRowsChanged]. If I read the documentation correctly this should get the OutlineView to realize I added one row and redraw itself properly. But instead nothing happens.
If I call [myOutlineView reloadData] it works, but according to the documentation reloadData has a much higher overhead than noteNumberOfRowsChanged (since it reloads all data ... duh)
I'm not using bindings, I supply NSOutlineViewDataSource myself.
Anyone know what I'm doing wrong?
From the reloadData: documentation:
If you just want to update the
scroller, use noteNumberOfRowsChanged;
if the height of a set of rows
changes, use
noteHeightOfRowsWithIndexesChanged:.
To me that sounds like that noteHeightOfRowsWithIndexesChanged: only ensures that the newly added object is visible within the view.
The discussion section of the reloadData: documentation also mentions a way to update a single row. But it seems that reloadData: is the only option if you add new objects.
I must be missing something simple, but I am having some trouble binding a tableView to an NSDictionaryController. Here is a model of my current scheme:
TableViewColumn --bindsTo-->DictionaryController.arrangedObjects.(value or key)
--bindsTo-->someClass.someClassMember.aDictionary.
I've tested the tableView by adding an entry to aDictionary on init, which is displayed correctly. But when another method produces an object that is then added to aDictionary, the TableView doesn't seem to update or even know that aDictionary now has two entries. I've tried everything I can think of. I am not directly accessing aDictionary....I've tried (in someClassMember) [self aDictionary setValue:forKey:], and [self setValue:forKeyPath:#"aDictionary"] and similar variations. The key is a string, so it should be KVC/KVO compliant, and I have '#synthesize'd aDictionary in someClassMember.
What am I missing? Why won't new entries to the dictionary show up in the tableView?
Thanks in advance
Try [self willChangeValueForKey:#"aDictionary"]; before adding the new item, and [self didChangeValueForKey:#"aDictionary"]; afterwards in someClass
I'm using an NSArrayController, NSMutableArray and NSTableView to show a list of my own custom objects (although this question probably applies if you're just showing a list of vanilla NSString objects too).
At various points in time, I need to clear out my array and refresh the data from my data source. However, just calling removeAllObjects on my NSMutableArray object does not trigger the KVO updates, so the list on screen remains unchanged.
NSArrayController has no removeAllObjects method available, which seems really weird. (It does have addObject, which I use to add the objects, ensuring the KVO is triggered and the UI is updated.)
The cleanest way I've managed to cause this happen correctly is:
[self willChangeValueForKey:#"myArray"];
[myArray removeAllObjects];
[self didChangeValueForKey:#"myArray"];
...so I'm kind of having to do the KVO notification manually myself (this is in my test app class, that contains the myArray property, which is NSMutableArray, as mentioned.)
This seems wrong - is there a better way? From my googling it seems a few people are confused by the lack of removeAllObjects in NSArrayController, but haven't seen any better solutions.
I have seen this solution:
[self removeObjectsAtArrangedObjectIndexes:
[NSIndexSet indexSetWithIndexesInRange:
NSMakeRange(0, [[self arrangedObjects] count])]];
but this looks even more unpleasant to me. At least my solution is at least marginally self-documenting.
Did Apple not notice that sometimes people might want to empty a list control being managed via an NSArrayController object? This seems kind of obvious, so I think I must be missing something...
Aside: of course, if I add new items to the array (via NSArrayController), then this triggers a KVO update with the NSArrayController/NSTableView, but:
Sometimes I don't put any items in the list, because there are none. So you just see the old items.
This is a bit yucky anyway.
You don't remove items from a table view. It doesn't have any items—it just displays another object's items.
If you bound the array controller's content array binding to an array property of some other object, then you should be working with that property of that object. Use [[object mutableArrayValueForKey:#"property"] removeAllObjects].
If, on the other hand, you haven't bound the array controller's content array binding, then you need to interact with its content directly. Use [[arrayController mutableArrayValueForKey:#"content"] removeAllObjects]. (You could also work with arrangedObjects instead of content. If one doesn't work, try the other—I've only ever done things the first way, binding the array controller to something else.)
Had this problem as well and solved it this way:
NSArrayController* persons = /* your array controller */;
[[persons content] removeAllObjects];
Swift
#IBOutlet var acLogs: NSArrayController!
acLogs.removeObjects(acLogs.content as! [AnyObject])
worked for me.
Solution in Swift:
if let ac = arrayController
{
let range:NSRange = NSMakeRange(0, ac.arrangedObjects.count);
let indexSet:NSIndexSet = NSIndexSet(indexesInRange: range);
ac.removeObjectsAtArrangedObjectIndexes(indexSet);
}
Just an update that works in Swift 4:
let range = 0 ..< (self.arrayController.arrangedObjects as AnyObject).count
self.arrayController.remove(atArrangedObjectIndexes: IndexSet(integersIn: range))