Category for NSMatrix that allows moving rows and columns. Feel free to add anything else you find useful. Also check out DragMatrix, a very useful subclass of NSMatrix that can quickly be modified to accommodate dragging other types of cells (besides images).

Code for NSMatrix+CocoaDevUsersAdditions.h

#import <Cocoa/Cocoa.h>

@interface NSMatrix (CocoaDevUsersAdditions)

• (void)moveColumn:(int)srcCol toColumn:(int)dstCol;
• (void)moveRow:(int)srcRow toRow:(int)dstRow; @end

Code for NSMatrix+CocoaDevUsersAdditions.m

#import “NSMatrix+CocoaDevUsersAdditions.h”

@implementation NSMatrix (CocoaDevUsersAdditions)

• (void)moveColumn:(int)srcCol toColumn:(int)dstCol { if (srcCol == dstCol) return;

  int row = [self numberOfRows]; NSMutableArray *cellsInCol = NSMutableArray alloc] initWithCapacity:row];

  for (row–; row >= 0; row–) { [cellsInCol insertObject:[self cellAtRow:row column:srcCol] atIndex:0]; }

  [self removeColumn:srcCol]; [self insertColumn:dstCol withCells:cellsInCol];

  [cellsInCol release]; }

• (void)moveRow:(int)srcRow toRow:(int)dstRow { if (srcRow == dstRow) return;

  int col = [self numberOfColumns]; NSMutableArray *cellsInRow = [[NSMutableArray alloc] initWithCapacity:col];

  for (col–; col >= 0; col–) { [cellsInRow insertObject:[self cellAtRow:srcRow column:col] atIndex:0]; }

  [self removeRow:srcRow]; [self insertRow:dstRow withCells:cellsInRow];

  [cellsInRow release]; } @end

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Why make a copy of cellsInRow? Why not just pass in cellsInRow to -insertRow:withCells: ?

I think that immutable arrays don’t carry much of the “baggage” that mutable arrays do (e.g., current capacity, resizing capability). But I could be wrong. There won’t be any functional change if you don’t make a copy – I just thought it might help.

I think at best it will add a small overhead. I’ve changed the code :)

[[Category:CocoaDevUsersAdditions