nsoutlineview의 드래그 앤 드롭 문제

Question

내가 가진 문제는 드래그 앤 드롭이있는 nsoutlineview가 있다는 것입니다 (드래그 앤 드롭 작업을위한 코드의 맨 아래 참조) 작동하지만, 한 행을 다른 행으로 끌어 올리면 드래그 된 행은 아이가됩니다. 또한 부모가되었던 곳에 머무르고, 두 행을 삭제하면 두 행이 삭제됩니다. 내 제가 의미하는 바를 보여주기 위해 문제를 녹음했습니다. 여기 링크가 있습니다. http://dvlp.me/6kya9

다음은 개요보기에서 드래그 앤 드롭이 작동하는 코드입니다.

헤더 파일.

@interface _NSControllerTreeProxy : NSObject 
{
    // opaque
}
//
// Number of objects at the root level.
//
- (unsigned int)count;

- (id)nodeAtIndexPath:(id)fp8;
- (id)objectAtIndexPath:(id)fp8;
@end

@interface _NSArrayControllerTreeNode : NSObject
{
    // opaque
}
- (unsigned int)count;
- (id)observedObject;
- (id)parentNode;
- (id)nodeAtIndexPath:(id)fp8;
- (id)subnodeAtIndex:(unsigned int)fp8;
- (BOOL)isLeaf;
- (id)indexPath;
- (id)objectAtIndexPath:(id)fp8;
@end

// some more detailed reverse engineering is available here
// http://www.blueboxmoon.com/wiki/?page=Binding%20Tree


@interface DragController : NSObject
{
    IBOutlet NSTreeController *groupTreeControl;
    IBOutlet NSOutlineView *treeTable;

    NSArray* dragType;

    _NSArrayControllerTreeNode* draggedNode;


}

- (void) resortGroups:(NSManagedObjectContext*)objectContext forParent:(NSManagedObject*)parent;
- (NSArray* ) getSubGroups:(NSManagedObjectContext*)objectContext forParent:(NSManagedObject*)parent;
- (BOOL) category:(NSManagedObject* )cat isSubCategoryOf:(NSManagedObject* ) possibleSub;

@end

#define INTERVAL 10

구현 파일.

@implementation DragController
- (void)awakeFromNib {  

    dragType = [NSArray arrayWithObjects:   @"factorialDragType", nil];

    [ dragType retain ]; 

    [ treeTable registerForDraggedTypes:dragType ];
    NSSortDescriptor* sortDesc = [[NSSortDescriptor alloc] initWithKey:@"position" ascending:YES];
    [groupTreeControl setSortDescriptors:[NSArray arrayWithObject: sortDesc]];
    [ sortDesc release ];
}   


//------------------------------------
#pragma mark NSOutlineView datasource methods -- see NSOutlineViewDataSource
//---------------------------------------------------------------------------   
- (BOOL) outlineView : (NSOutlineView *) outlineView 
          writeItems : (NSArray*) items 
        toPasteboard : (NSPasteboard*) pboard {

    [ pboard declareTypes:dragType owner:self ];        
    // items is an array of _NSArrayControllerTreeNode see http://theocacao.com/document.page/130 for more info
    draggedNode = [ items objectAtIndex:0 ];

    return YES; 
}




- (BOOL)outlineView:(NSOutlineView *)outlineView acceptDrop:(id <NSDraggingInfo>)info item:(id)item childIndex:(int)index {

    _NSArrayControllerTreeNode* parentNode = item;
    _NSArrayControllerTreeNode* siblingNode;
    _NSControllerTreeProxy* proxy = [ groupTreeControl arrangedObjects ];

    NSManagedObject* draggedGroup = [ draggedNode observedObject ];

    BOOL draggingDown = NO;
    BOOL isRootLevelDrag = NO;

    // ----------------------
    // Setup comparison paths
    // -------------------------
    NSIndexPath* draggedPath = [ draggedNode indexPath ];
    NSIndexPath* siblingPath =  [ NSIndexPath indexPathWithIndex:  index  ];
    if ( parentNode == NULL ) {     
        isRootLevelDrag = YES;
    } else {
        // A non-root drag - the index value is relative to this parent's children
        siblingPath = [ [ parentNode indexPath ] indexPathByAddingIndex: index ];
    }

    // ----------------------
    // Compare paths - modify sibling path for down drags, exit for redundant drags
    // -----------------------------------------------------------------------------    
    switch ( [ draggedPath compare:siblingPath] ) {
        case NSOrderedAscending:  // reset path for down dragging
            if ( isRootLevelDrag ) {
                siblingPath = [ NSIndexPath indexPathWithIndex: index  - 1];                             
            } else {
                siblingPath = [ [ parentNode indexPath ] indexPathByAddingIndex: index - 1 ]; 
            }
            draggingDown = YES;
            break;

        case NSOrderedSame:
            return NO;
            break;               
    }

    siblingNode = [ proxy nodeAtIndexPath:siblingPath ];    

    //  NSLog(@"returning early");
    //  return NO;  // TODO robustify


    // ------------------------------------------------------------ 
    // SPECIAL CASE: Dragging to the bottom
    // ------------------------------------------------------------
    // - K                               - K                            - C                              - C
    // - - U                             - - C     OR     - U                                - F
    // - - C     ====>     - - F                    - F                              - K
    // - - F               - U              - K                              - U
    // ------------------------------------------------------------ 
    if ( isRootLevelDrag  && siblingNode == NULL ) {        
        draggingDown = YES;
        siblingPath = [ NSIndexPath indexPathWithIndex: [ proxy count ] - 1 ];          
        siblingNode = [ proxy nodeAtIndexPath:siblingPath ] ;
    }

    // ------------------------------------------------------------ 
    // Give the dragged item a position relative to it's new sibling
    // ------------------------------------------------------------ 
    NSManagedObject* sibling = [ siblingNode observedObject ];   
    NSNumber* bystanderPosition = [ sibling valueForKey:@"position"];
    int newPos =   ( draggingDown ? [ bystanderPosition intValue ]  + 1 : [ bystanderPosition intValue ]  - 1 );
    [draggedGroup setValue:[ NSNumber numberWithInt:newPos ] forKey:@"position"];   

    // ----------------------------------------------------------------------------------------------
    // Set the new parent for the dragged item, resort the position attributes and refresh the tree
    // ----------------------------------------------------------------------------------------------    
    [ draggedGroup setValue:[ parentNode observedObject ] forKey:@"parent" ];
    [ self resortGroups:[draggedGroup managedObjectContext] forParent:[ parentNode observedObject ] ];          
    [ groupTreeControl rearrangeObjects ];  
    return YES;             
}






- (NSArray* ) getSubGroups:(NSManagedObjectContext*)objectContext forParent:(NSManagedObject*)parent {
    NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"projects" inManagedObjectContext:objectContext];

    [request setEntity:entity];
    NSSortDescriptor* aSortDesc = [[NSSortDescriptor alloc] initWithKey:@"position" ascending:YES];
    [request setSortDescriptors:[NSArray arrayWithObject: aSortDesc] ];
    [aSortDesc release];

    NSPredicate* validationPredicate = [NSPredicate predicateWithFormat:@"parent == %@", parent ];

    [ request setPredicate:validationPredicate ];

    NSError *error = nil;  // TODO - check the error bozo
    return [objectContext executeFetchRequest:request error:&error];    
}




- (void) resortGroups:(NSManagedObjectContext*)objectContext forParent:(NSManagedObject*)parent {

    NSArray *array = [ self getSubGroups:objectContext forParent:parent ];

    // Reset the indexes...
    NSEnumerator *enumerator = [array objectEnumerator];
    NSManagedObject* anObject;
    int index = 0;
    while (anObject = [enumerator nextObject]) {
        // Multiply index by 10 to make dragging code easier to implement ;) ....
        [anObject setValue:[ NSNumber numberWithInt:(index * INTERVAL ) ] forKey:@"position"];    
        index++;
    }   


}

- (NSDragOperation)outlineView:(NSOutlineView *)outlineView validateDrop:(id <NSDraggingInfo>)info proposedItem:(id)item proposedChildIndex:(int)index {

    _NSArrayControllerTreeNode* newParent = item;

    // drags to the root are always acceptable
    if ( newParent == NULL ) {  
        return  NSDragOperationGeneric; 
    }

    // Verify that we are not dragging a parent to one of it's ancestors
    // causes a parent loop where a group of nodes point to each other and disappear
    // from the control 
    NSManagedObject* dragged = [ draggedNode observedObject ];      
    NSManagedObject* newP = [ newParent observedObject ];

    if ( [ self category:dragged isSubCategoryOf:newP ] ) {
        return NO;
    }       

    return NSDragOperationGeneric;
}

- (BOOL) category:(NSManagedObject* )cat isSubCategoryOf:(NSManagedObject* ) possibleSub {

    // Depends on your interpretation of subCategory ....
    if ( cat == possibleSub ) { return YES; }

    NSManagedObject* possSubParent = [possibleSub valueForKey:@"parent"];   

    if ( possSubParent == NULL ) {  return NO; }

    while ( possSubParent != NULL ) {       
        if ( possSubParent == cat ) { return YES;   }

        // move up the tree
        possSubParent = [possSubParent valueForKey:@"parent"];          
    }   

    return NO;
}




// This method gets called by the framework but the values from bindings are used instead
- (id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)tableColumn byItem:(id)item { 
    return NULL;
}

/* 
 The following are implemented as stubs because they are required when 
 implementing an NSOutlineViewDataSource. Because we use bindings on the
 table column these methods are never called. The NSLog statements have been
 included to prove that these methods are not called.
 */
- (int)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item {
    NSLog(@"numberOfChildrenOfItem");
    return 1;
}

- (BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item {
    NSLog(@"isItemExpandable");
    return NO;
}

- (id)outlineView:(NSOutlineView *)outlineView child:(int)index ofItem:(id)item {
    NSLog(@"child of Item");
    return NULL;
}



@end

Answer 1

방금 약간의 검색을했고 그것을 고치는 방법을 찾았습니다. Nstreecontroller의 속성에서 Fetch Perceicate를 다음과 같이 설정합니다. parent == nil.