NSMatrix with multiple toggle buttons? - objective-c

Question

I am trying to create an NSMatrix of NSButtonCells where between zero and four buttons can be selected (toggled on). I have tried the following (test) code, but am not sure how I can provide the functionality I require. Perhaps it's not possible with NSMatrix and I need to look at an alternative control, or create my own?
#interface MatrixView : NSView
{
NSScrollView *_scrollView;
NSMatrix *_matrixView;
}
#end
#implementation MatrixView
- (id)initWithFrame:(NSRect)frameRect
{
NSLog(#"initWithFrame. frameRect=%#", NSStringFromRect(frameRect));
self = [super initWithFrame:frameRect];
if (self != nil)
{
_scrollView = [[NSScrollView alloc] initWithFrame:NSMakeRect(0, 0, frameRect.size.width, frameRect.size.height)];
[_scrollView setBorderType:NSNoBorder];
[_scrollView setHasVerticalScroller:YES];
[_scrollView setHasHorizontalScroller:NO];
[_scrollView setAutoresizingMask:NSViewWidthSizable|NSViewHeightSizable];
NSSize contentSize = [_scrollView contentSize];
contentSize.height = 300;
// Make it 3 x however-many-buttons-will-fit-the-height
CGFloat gap = 8.0;
CGFloat width = (contentSize.width / 3.0) - (gap * 2.0);
NSUInteger rows = (contentSize.height / (width + gap));
NSLog(#"width=%f, rows=%lu", width, rows);
NSButtonCell *prototype = [[NSButtonCell alloc] init];
[prototype setTitle:#"Hello"];
[prototype setButtonType:NSToggleButton];
[prototype setShowsStateBy:NSChangeGrayCellMask];
_matrixView = [[NSMatrix alloc] initWithFrame:NSMakeRect(0, 0, contentSize.width, contentSize.height)
mode:NSListModeMatrix
prototype:prototype
numberOfRows:rows
numberOfColumns:3];
[_matrixView setCellSize:NSMakeSize(width, width)];
[_matrixView setIntercellSpacing:NSMakeSize(gap, gap)];
[_matrixView setAllowsEmptySelection:YES];
[_matrixView sizeToCells];
[_scrollView setDocumentView:_matrixView];
[self addSubview:_scrollView];
[self setAutoresizesSubviews:YES];
[prototype release];
}
return self;
}
...

Answer 1

I got this to work with the following subclass of NSMatrix. I added one property, onCount, to keep track of how many buttons were in the on state:
#implementation RDMatrix
#synthesize onCount;
-(id) initWithParentView:(NSView *) cv {
NSButtonCell *theCell = [[NSButtonCell alloc ]init];
theCell.bezelStyle = NSSmallSquareBezelStyle;
theCell.buttonType = NSPushOnPushOffButton;
theCell.title = #"";
if (self = [super initWithFrame:NSMakeRect(200,150,1,1) mode:2 prototype:theCell numberOfRows:4 numberOfColumns:4]){
[self setSelectionByRect:FALSE];
[self setCellSize:NSMakeSize(40,40)];
[self sizeToCells];
self.target = self;
self.action = #selector(buttonClick:);
self.drawsBackground = FALSE;
self.autoresizingMask = 8;
self.allowsEmptySelection = TRUE;
self.mode = NSHighlightModeMatrix;
self.onCount = 0;
[cv addSubview:self];
return self;
}
return nil;
}
-(IBAction)buttonClick:(NSMatrix *)sender {
NSUInteger onOrOff =[sender.selectedCells.lastObject state];
if (onOrOff) {
self.onCount += 1;
}else{
self.onCount -= 1;
}
NSLog(#"%ld",self.onCount);
if (self.onCount == 5) {
[sender.selectedCells.lastObject setState:0];
self.onCount -= 1;
}
}
When you try to select the 5th button it will flash on, but then go off. This could be a problem depending on how you are using the state of these buttons. I just logged them with this method:
-(IBAction)checkMatrix:(id)sender {
NSIndexSet *indxs = [self.mat.cells indexesOfObjectsPassingTest:^BOOL(NSButtonCell *cell, NSUInteger idx, BOOL *stop) {
return cell.state == NSOnState;
}];
NSLog(#"%#",indxs);
}
After Edit: I didn't like the way my first method flashed the button on briefly before turning it off again when you try to click the 5th button. I found what I think is a better solution that involves overriding mouseDown in the matrix subclass (if you want to try this, you should delete the setAction and setTarget statements and delete the buttonClick method):
-(void)mouseDown:(NSEvent *) event {
NSPoint matPoint = [self convertPoint:event.locationInWindow fromView:nil];
NSInteger row;
NSInteger column;
[self getRow:&row column:&column forPoint:matPoint];
NSButtonCell *cell = [self cellAtRow:row column:column];
if (self.onCount < 4 && cell.state == NSOffState) {
cell.state = NSOnState;
self.onCount += 1;
}else if (cell.state == NSOnState) {
cell.state = NSOffState;
self.onCount -= 1;
}
}