How to disable the mouse hover expand effect on a NSTextView's NSScrollView scroller? - objective-c

Question

I have a NSTextView and here's the normal size of the scroller:
And here's what happens when I hover the scroller of the textview:
However, I don't want to have this 'expand' effect. How can I remove it? I've tried to search around on how to perform this, but I couldn't find anything. I just want to have the regular scroller size (the thinner one) all the time, even if the user hovers it. Is this possible?
Thanks

Answer 1

I recommend subclassing the NSScroller and override – drawArrow:highlight: / – drawKnobSlotInRect:highlight: / – drawKnob methods so you have a stable scroller appearance.
P.S. Don't forget to set your new scroller class in XIB-file for the scrollers.
UPDATE
Here is the sample code:
- (void)drawKnob
{
// call the default implementation for Overlay Scrollers
if (self.scrollerStyle == NSScrollerStyleOverlay)
{
[super drawKnob];
return;
}
if (_style == NSScrollerKnobStyleLight || _style == NSScrollerKnobStyleDefault)
[[NSColor colorWithCalibratedWhite:1.0 alpha:0.8] setFill];
else [[NSColor colorWithCalibratedWhite:0 alpha:0.4] setFill];
// Note: you can specify the rect with fixed width here
NSRect knobRect = [self rectForPart:NSScrollerKnob];
// VERTICAL SCROLLER
NSInteger fullWidth = knobRect.size.width;
knobRect.size.width = round(knobRect.size.width/2);
knobRect.origin.x += (NSInteger)((fullWidth - knobRect.size.width)/2);
// draw...
NSBezierPath * thePath = [NSBezierPath bezierPath];
[thePath appendBezierPathWithRoundedRect:knobRect xRadius:4 yRadius:4];
[thePath fill];
}
//---------------------------------------------------------------
- (void)drawKnobSlotInRect:(NSRect)slotRect highlight:(BOOL)flag
{
// call the default implementation for Overlay Scrollers
// draw nothing for usual
if (self.scrollerStyle == NSScrollerStyleOverlay)
{
[super drawKnobSlotInRect:slotRect highlight:flag];
}
}
//---------------------------------------------------------------
- (void)drawArrow:(NSScrollerArrow)whichArrow highlight:(BOOL)flag
{
// call the default implementation for Overlay Scrollers
// draw nothing for usual
if (self.scrollerStyle == NSScrollerStyleOverlay)
{
[super drawArrow:whichArrow highlight:flag];
}
}

Answer 2

I don't know what exact style you want, but this category might help you.
#implementation NSScrollView (SetScrollStyle)
- (void) setHidingScroll
{
[self setScrollerStyle:NSScrollerStyleOverlay];
[[self verticalScroller] setControlSize: NSSmallControlSize];
[[self verticalScroller] setKnobStyle:NSScrollerKnobStyleDark];
[self setScrollerKnobStyle:NSScrollerKnobStyleDark];
[[self verticalScroller] setScrollerStyle:NSScrollerStyleOverlay];
}
and usage
[scrollView setHidingScroll];