macOS NSTableView Drag and Drop

[varsis]

- (BOOL)tableView:(NSTableView *)tv writeRowsWithIndexes:(NSIndexSet *)rowIndexes toPasteboard:(NSPasteboard*)pboard
{
    // Copy the row numbers to the pasteboard.
	NSData *data = [NSKeyedArchiver archivedDataWithRootObject:rowIndexes];
    [pboard declareTypes:[NSArray arrayWithObject:MyPrivateTableViewDataType] owner:self];
    [pboard setData:data forType:MyPrivateTableViewDataType];
    return YES;}

- (NSDragOperation)tableView:(NSTableView*)tv validateDrop:(id <NSDraggingInfo>)info proposedRow:(int)row proposedDropOperation:(NSTableViewDropOperation)op
{
    // Add code here to validate the drop
    NSLog(@"validate Drop");
    return NSDragOperationEvery;
}
- (BOOL)tableView:(NSTableView *)aTableView acceptDrop:(id <NSDraggingInfo>)info
            row:(int)row dropOperation:(NSTableViewDropOperation)operation
{
	
    NSPasteboard* pboard = [info draggingPasteboard];
	
	//NSArray *files = [pboard propertyListForType:NSFilenamesPboardType];
    NSData* rowData = [pboard dataForType:MyPrivateTableViewDataType];
    NSIndexSet* rowIndexes = [NSKeyedUnarchiver unarchiveObjectWithData:rowData];
    int dragRow = [rowIndexes firstIndex];


	//if (files != nil) {
	//NSLog (@"Before Insert");
	//[self addDragImage:files];
	//} else {
	NSLog (@"%i drag row",dragRow);
	NSLog (@"%i Drop into Row",row);
	int countIndex = [rowIndexes count];

	id current = [array objectAtIndex:[rowIndexes firstIndex]];
	[array removeObjectAtIndex:[rowIndexes firstIndex]];
	[array insertObject:current atIndex:row];
	//}
	NSLog (@"%i Drop into Row",[array count]);
	[table reloadData];
	NSLog (@"Reload Table and Set Object");
	return YES;

}

I have the above code to allow sorting within my NSTableView the problem is that when I add new objects into the array is causes problems. The application freezes up and crashes. The nstable display uses the following code:

- (id)tableView:(NSTableView *)tableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(int)row {
	    id theRecord, theValue; //define used variable
		theValue = [[NSObject init] alloc];

   if(row >= 0 && row < [array count]) {

   theRecord = [array objectAtIndex:row];// row of Dictionary
    theValue =  [theRecord objectForKey:[aTableColumn identifier]]; // Get Object With KEY of Column

	}

    return theValue;
	


}

Any help would be good. The thing it screws up on is getting the objectForKey: in the above code. (Like I can't access the record.)


chris

 

[kainjow]

From the NSMutableArray documentation:

Like NSArray, instances of NSMutableArray maintain strong references to their contents. If you do not use garbage collection, when you add an object to an array, the object receives a retain message. When an object is removed from a mutable array, it receives a release message. If there are no further references to the object, this means that the object is deallocated. If your program keeps a reference to such an object, the reference will become invalid unless you send the object a retain message before it’s removed from the array. For example, if anObject is not retained before it is removed from the array, the third statement below could result in a runtime error:

id anObject = [[anArray objectAtIndex:0] retain];
[anArray removeObjectAtIndex:0];
[anObject someMessage];

So, retain your object before you remove it.

 

[varsis]

From the NSMutableArray documentation:



So, retain your object before you remove it.

Thanks so much. That helps alot.

Chris