I'm using NSOutlineView (cell-based) for the first time. I need to return the index of the selected parent item.
In the picture above, there are two parent items. I want to return 1 if I select Colors 2. The application will return 1 if Colors is not expanded. If it's expanded, it will return 6.
- (void)outlineViewSelectionDidChange:(NSNotification *)notification {
NSOutlineView *outlineView = [notification object];
id item = [outlineView itemAtRow:[outlineView selectedRow]];
if ([item objectForKey:#"parent"]) {
NSInteger r = [outlineView selectedRow]; // returning 6
}
}
How can I return the index of the selected parent item correctly whether or not any of the parent items is expanded? It seems that my problem is related to this topic. Yet, since I'm not very familiar with NSOutlineView, I don't know what I can do to improve my code.
Muchos thankos.
The item returned by -[NSOutlineView itemAtRow:] is an NSTreeNode instance. These objects are created by Cocoa - I've never needed to create one myself - and are used to wrap the objects you passed to the outline view from your data source. They have two very useful properties: representedObject (of type id) and indexPath (of type NSIndexPath). The representedObject is the object that's being wrapped (one of your own model objects), whereas you can think of the indexPath of an item as a way of establishing its exact location in a fully expanded outline view - this is the what you're after. Once you've got your item, cast it to an NSTreeNode, then call its indexPath property. In the case you outline in your question the relevant index path will consist of just a single number (1), but index paths vary in length depending on where the associated item sits in the data 'tree`. For example the blue color that is revealed when you expand Colors 2 would have an index path of [0, 3]
- (void)outlineViewSelectionDidChange:(NSNotification *)notification {
NSOutlineView *outlineView = [notification object];
id item = [outlineView itemAtRow:[outlineView selectedRow]];
NSTreeNode *node = (NSTreeNode *)item;
NSIndexPath *ip = [node indexPath];
}
Related
I'm populating a NSOUtlineView with a NSTreeController.
The NSTreeController is a 3 levels hierarchy controller (CBMovie, CBDisc and CBEpisode), but only the first 2 levels are displayed in the outline view.
The implementation is the same for all objects: I've implemented methods to specify children, children count and if the object is a leaf. These methods are correctly called for all objects (also for those ones that are not displayed, the grandchildren: CBEpisode).
In the outline View, everything is displayed correctly for the first 2 level. But grandchildren are never displayed, I don't have the option to expand their parent to see them. I can only see CBMovie and CBDiscs.
I'm wondering if there is another setting I'm missing, about how deep the nodes can expand in NSTreeControllers or NSOutlineView configurations.
Below: Implementation in one of the three nodes.
Each node class has different path to its children. This is specified in the -(NSArray*)children method (correctly called).
-(NSArray*)children
{
return [[self Episodes] allObjects];
}
-(int)childrenCount
{
return [[self Episodes] count];
}
-(BOOL)isLeaf
{
return ![[self Episodes] count];
}
Output of logging code. The datasource, the NSTreeController, seems to have the correct structure.
CBMovie
CBDisc
CBEpisode
CBEpisode
CBMovie
CBDisc
CBDisc
CBDisc
CBDisc
CBMovie
CBDisc
CBEpisode
CBEpisode
This is how I populate the NSOutlineView (cell based). I don't use datasource methods, but I'm binding it programmatically.
NSMutableDictionary *bindingOptions = [[NSMutableDictionary alloc] initWithCapacity:2];
if (metadata.valueTransformer) {
[bindingOptions setObject:metadata.valueTransformer forKey:NSValueTransformerNameBindingOption];
}
[bindingOptions setObject:[NSNumber numberWithBool:NO] forKey:NSCreatesSortDescriptorBindingOption];
[bindingOptions setObject:[NSNumber numberWithBool:NO] forKey:NSRaisesForNotApplicableKeysBindingOption];
[newColumn bind:#"value" toObject:currentItemsArrayController withKeyPath:[NSString stringWithFormat:#"arrangedObjects.%#", metadata.columnBindingKeyPath] options:bindingOptions];
Examining the NSTreeController side
The NSTreeController is a 3 levels hierarchy controller, but only the first 2 levels are displayed in the outline view.
Have you confirmed that all three levels are loaded into your NSTreeController? You could do this by logging its contents to the console with the extension below. If the output produced by this code matches what appears in your outline-view, the problem is probably on the NSTreeController side, not the outline-view.
#import "NSTreeController+Logging.h"
#implementation NSTreeController (Logging)
// Make sure this is declared in the associated header file.
-(void)logWithBlock:(NSString * (^)(NSTreeNode *))block {
NSArray *topNodes = [self.arrangedObjects childNodes];
[self logNodes:topNodes withIndent:#"" usingBlock:block];
}
// For internal use only.
-(void)logNodes:(NSArray *)nodes
withIndent:(NSString *)indent
usingBlock:(NSString * (^)(NSTreeNode *))block {
for (NSTreeNode * each in nodes) {
NSLog(#"%#%#", indent, block(each));
NSString *newIndent = [NSString stringWithFormat:#" %#", indent];
[self logNodes:each.childNodes withIndent:newIndent usingBlock:block];
}
}
#end
The above code does not need to be adjusted, all you need to do is call it with a customised block:
-(void)logIt {
[self.treeController logWithBlock:^NSString *(NSTreeNode * node) {
// This will be called for every node in the tree. This implementation
// will see the object's description logged to the console - you may
// want to do something more elaborate.
NSString *description = [[node representedObject] description];
return description;
}];
}
Examining the NSOutlineView side
If all the data seems to have loaded correctly into the NSTreeController you could have a look at how your NSOutlineView is populated. The delegate method -[NSOutlineViewDelegate outlineView:viewForTableColumn:item] is a good place to start. The item argument is the NSTreeNode instance, so, before you return the relevant view you can look at this node and make sure it's behaving as expected. In your case, you should scrutinize the properties of item objects that are representing CBDisc objects. (You may need to click on disclosure buttons to get this method to fire for the relevant objects.)
-(NSView *)outlineView:(NSOutlineView *)outlineView
viewForTableColumn:(NSTableColumn *)tableColumn
item:(id)item {
NSTreeNode *node = (NSTreeNode *)item;
NSManagedObject *representedObject = (NSManagedObject *)node.representedObject;
// Query the node
NSLog(#"%# <%#>", representedObject.description, [representedObject class]);
NSLog(#" node is a leafNode: %#", node.isLeaf ? #"YES" : #"NO");
NSLog(#" node has child-count of: %lu", (unsigned long)node.childNodes.count);
// Query the NSManagedObject
// your stuff here...
// This is app-specific - you'll probably need to change the identifier.
return [outlineView makeViewWithIdentifier:#"StandardTableCellView" owner:self];
}
So, I've figured out why.
Quite stupid: the main outline column containing the disclosure arrows was 20px width only and the arrows of the children had indentation.
I'm using the outline column for the arrows only and not the titles of the nodes, that's why it's so narrow.
I had disabled indentation and now I can see all arrows.
Is an NSValueTransform subclass a good choice for displaying Core Data attributes into UI views displaying:
A number string like (0,1,2,3,etc) into a string such as (Pending, Completed, Frozen, In progress, etc)
A number string like (0,1) into a app-based image (red.png if 0, green.png if 1)
Here's what Core Data displays for the two attributes, timer and status:
Here is what I want to be displayed instead, without changing the values in Core Data:
If not to use NSValueTransformer, in what other way is this possible?
I do not want to see the data permanently converted, only for the benefit of less data stored in Core Data and better UI view items.
I have also tried to modify the attributes in the managed object class (with out KVO notification) with no luck.
Yes, NSValueTransformer subclasses work just fine for this purpose.
You can also add read-only computed properties to your managed object class, and that should work, too. Those properties can even be added by a category in the controller code, if they don't make sense as part of the model code.
For example:
+ (NSSet*) keyPathsForValuesAffectingStatusDisplayName
{
return [NSSet setWithObject:#"status"];
}
- (NSString*) statusDisplayName
{
NSString* status = self.status;
if ([status isEqualToString:#"0"])
return #"Pending";
else if ([status isEqualToString:#"1"])
return #"Completed";
// ...
}
The +keyPathsForValuesAffectingStatusDisplayName method lets KVO and bindings know that when status changes, so does this new statusDisplayName property. See the docs for +keyPathsForValuesAffectingValueForKey: to learn how that works.
I ended up using what at first appeared to be blocking the display of different info in those cells, using:
#pragma mark - Table View Delegate
- (NSView *)tableView:(NSTableView *)tableView viewForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)row
{
/* tableColumn = (string) #"AutomaticTableColumnIdentifier.0"
row = (int) 0 */
NSString *identifier = [tableColumn identifier];
NSTableCellView *cellView = [tableView makeViewWithIdentifier:identifier owner:self];
NSManagedObject *item = [self.itemArrayController.arrangedObjects objectAtIndex:row];
if ([identifier isEqualToString:#"AutomaticTableColumnIdentifier.0"]) {
/* subviews returns array with 0 = Image View &
1 = Text Field */
/* First, set the correct timer image */
... logic ...
NSImageView *theImage = (NSImageView *)[[cellView subviews] objectAtIndex:0];
theImage.image = [NSImage imageNamed:#"green.gif"];
/* Second, display the desired status */
NSTextField *theTextField = (NSTextField *)[[result subviews] objectAtIndex:1];
... logic ...
theTextField.stringValue = #"Pending";
}
return cellView;
}
Apple's documentation states (somewhere) that bindings with an Array Controller can work in combination with manually populating the table view cells. It seems best and easiest to start with bindings and then refine display values manually.
I need to perform an operation on all objects in my NSOutlineView when I close the window.
(Both parents and children, and children of children).
It doesn't matter if the items are expanded or not, I just need to perform a selector over all items in the outline view.
thanks
Assuming you're using NSOutlineViewDataSource and not bindings, you could do it like this:
- (void)iterateItemsInOutlineView: (NSOutlineView*)outlineView
{
id<NSOutlineViewDataSource> dataSource = outlineView.dataSource;
NSMutableArray* stack = [NSMutableArray array];
do
{
// Pop an item off the stack
id currentItem = stack.lastObject;
if (stack.count)
[stack removeLastObject];
// Push the children onto the stack
const NSUInteger childCount = [dataSource outlineView: outlineView numberOfChildrenOfItem: currentItem];
for (NSUInteger i = 0; i < childCount; ++i)
[stack addObject: [dataSource outlineView: outlineView child: i ofItem: currentItem]];
// Visit the current item.
if (nil != currentItem)
{
// Do whatever you want to do to each item here...
}
} while (stack.count);
}
This should achieve a full traversal of all the objects vended by your NSOutlineViewDataSource.
FYI: If you're using cocoa bindings, this won't work as is. If that's the case, though, you could use a similar approach (i.e. surrogate-stack traversal) against the NSTreeController (or whatever else) you're binding to.
HTH
I have anNSTableView showing the contents of a directory. I watch for FSEvents, and each time I get an event I reload my table view.
Unfortunately, the current selection then disappears. Is there a way to avoid that?
Well, you can save selection before calling reloadData and restore it after that.
NSInteger row = [self.tableView selectedRow];
[self.tableView reloadData];
[self.tableView selectRowIndexes:[NSIndexSet indexSetWithIndex:row] byExtendingSelection:NO];
This worked for me in some cases. But if you insert some items BEFORE the selected row, you should andjust your row variable by adding count of added items to it.
Swift 4.2
Create an extension and add a method which preserves selection.
extension NSTableView {
func reloadDataKeepingSelection() {
let selectedRowIndexes = self.selectedRowIndexes
self.reloadData()
self.selectRowIndexes(selectedRowIndexes, byExtendingSelection: false)
}
}
Do this in case you use the traditional way of populating table views (not NSArrayController).
It depends on how you populate your NSTableView.
If you have the table view bound to an NSArrayController, which in turn contain the items that your table view is displaying, then the NSArrayController has an option to preserve the selection. You can select it (or not) from within Interface Builder as a property on the NSArrayController. Or you can use the setPreservesSelection method in code.
However, if you completely replace the array of items that the NSArrayController manages each time you get your FSEvents, then maybe the preservation of selection cannot work. Unfortunately the Apple docs on this property of NSArrayController are a bit vague as to when it can and cannot preserve the selection.
If you are not using an NSArrayController, but maybe using a dataSource to populate the table view, then I think you'll have to manage the selection yourself.
In the case of using Data Source, Apple Documentation in the header file on reloadData() is that
The selected rows are not maintained.
To get around, you can use reloadDataForRowIndexes(rowIndexes: NSIndexSet, columnIndexes: NSIndexSet). As mentioned in the same header file
For cells that are visible, appropriate dataSource and delegate methods will be called and the cells will be redrawn.
Thus the data will be reloaded, and the selection is kept as well.
A variant on #silvansky's answer.
This one has no need to keep track of count of items inserted/deleted. And it maintains multiple selection.
The idea is to...
1. create an array of selected objects/nodes from the current selection.
2. refresh the table using reloadData
3. for each object obtained in step 1, find/record it's new index
4. tell the table view/outline view to select the updated index set
- (void)refresh {
// initialize some variables
NSIndexSet *selectedIndexes = [self.outlineView selectedRowIndexes];
NSMutableArray *selectedNodes = [NSMutableArray array];
NSMutableIndexSet *updatedSelectedIndex = [NSMutableIndexSet indexSet];
// 1. enumerate all selected indexes and record the nodes/objects
[selectedIndexes enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL *stop) {
[selectedNodes addObject:[self.outlineView itemAtRow:idx]];
}];
// 2. refresh the table which may add new objects/nodes
[self.outlineView reloadData];
// 3. for each node in step 1, find the new indexes
for (id selectedNode in selectedNodes) {
[updatedSelectedIndex addIndex:[self.outlineView rowForItem:selectedNode]];
}
// 4. tell the outline view to select the updated index set
[self.outlineView selectRowIndexes:updatedSelectedIndex byExtendingSelection:NO];
}
I am working on an app that is not core data based - the data feed is a series of web services.
Two arrays are created from the data feed. The first holds season data, each array object being an NSDictionary. Two of the NSDictionary entries hold the data to be displayed in the popup ('seasonName') and an id ('seasonID') that acts as a pointer (in an external table) by matches defined for that season.
The second array is also a collection of NSDictionaries. Two of the entries hold the data to be displayed in the popup ('matchDescription') and the id ('matchSeasonId') that points to the seasonId defined in the NSDictionaries in first array.
I have two NSPopUps. I want the first to display the season names and the second to display the matches defined for that season, depending on the selection in the first.
I'm new at bindings, so excuse me if I've missed something obvious.
I've tried using ArrayControllers as follows:
SeasonsArrayController:
content bound to appDelegate seasonsPopUpArrayData.
seasonsPopup:
content bound to SeasonsArrayController.arrangedObjects; content value bound to SeasonsArrayController.arrangedObjects.seasonName
I see the season names fine.
I can obviously follow a similar route to see the matches, but I then see them all, instead of restricting the list to the matches for the season highlighted.
All the tutorials I can find seem to revolve around core data and utilise the relationships defined therein. I don't have that luxury here.
Any help very gratefully received.
This is not an answer - more an extension of the previous problem.
I created MatchesArrayController and subclassed it from NSArrayController to allow some customisation.
Following the example in 'Filtering Using a Custom Array Controller' from 'Cocoa Bindings Topics', I followed the same idea as above:
MatchessArrayController: content bound to appDelegate matchesPopUpArrayData.
matchesPopup: content bound to MatchesArrayController.arrangedObjects; content value bound to MatchesArrayController.arrangedObjects.matchDescription.
I've derived the selected item from seasonPopUp:sender and used this to identify the seasonId.
The idea is to change the arrangedObjects in MatchesArrayController by defining the following in;
- (NSArray *)arrangeObjects:(NSArray *)objects
{
if (searchString == nil) {
return [super arrangeObjects:objects];
}
NSMutableArray *filteredObjects = [NSMutableArray arrayWithCapacity:[objects count]];
NSEnumerator *objectsEnumerator = [objects objectEnumerator];
id item;
while (item = [objectsEnumerator nextObject]) {
if ([[[item valueForKeyPath:#"matchSeasonId"] stringValue] rangeOfString:searchString options:NSAnchoredSearch].location != NSNotFound) {
[filteredObjects addObject:item];
}
}
return [super arrangeObjects:filteredObjects];
}
- (void)searchWithString:(NSString *)theSearchString {
[self setSearchString:theSearchString];
[self rearrangeObjects];
}
- (void)setSearchString:(NSString *)aString
{
[aString retain];
[searchString release];
searchString=aString;
}
I've used NSLog to check that things are happening the way they are supposed to and all seems ok.
However, it still doesn't do what I want.
[self rearrangeObjects]; is supposed to invoke the arrangeObjects method but doesn't. I have to call it explicity
(i.e.[matchesArrayController arrangeObjects:matchesPopUpArrayData]; )
Even then, although filteredObjects gets changed the way it is supposed to, the drop down list does not get updated the way I want it to.