objective c - Drawing issues after subclassing NSCollectionView -

objective c - Drawing issues after subclassing NSCollectionView -

ok, here's have done:

i have nscollectionview i wanted able enable "selecting" items, , drawing custom border when items selected i subclassed nscollectionviewitem (to enable selection) i subclassed nsview nscollectionviewitem view, in order draw border the code

the view item

@implementation mslibrarycollectionviewitem - (void)setselected:(bool)flag { [super setselected:flag]; [(mslibrarycollectionviewview*)[self view] setselected:flag]; [(mslibrarycollectionviewview*)[self view] setneedsdisplay:yes]; }

the custom view

@implementation mslibrarycollectionviewview /*************************************** initialisation ***************************************/ - (mslibrarycollectionviewview*)initwithframe:(nsrect)frame { self = [super initwithframe:frame]; if (self) { // initialization code here. } homecoming self; } /*************************************** drawing ***************************************/ - (void)drawrect:(nsrect)rect { if ([self selected]) { //[[nscolor redcolor] setfill]; //nsrectfill(rect); //[super drawrect:rect]; nscolor* gs = [nscolor colorwithcalibratedred:0.06 green:0.45 blue:0.86 alpha:1.0]; nscolor* ge = [nscolor colorwithcalibratedred:0.12 green:0.64 blue:0.94 alpha:1.0]; nsgradient* g = [[nsgradient alloc] initwithstartingcolor:ge endingcolor:gs]; nscolor *bordercolor = [nscolor colorfromgradient:g]; nsrect framerect = [self bounds]; if(rect.size.height < framerect.size.height) return; nsrect newrect = nsmakerect(rect.origin.x+5, rect.origin.y+5, rect.size.width-10, rect.size.height-10); nsbezierpath *textviewsurround = [nsbezierpath bezierpathwithroundedrect:newrect xradius:7 yradius:7]; [textviewsurround setlinewidth:2.0]; [bordercolor set]; [textviewsurround stroke]; } }

however, seems wrong drawing. example:

when resizing collection view's container, weird line appears @ outer box when collection view item not 100% visible (e.g. because it's been scrolled down), selection border doesn't appear @ (while expect draw visible portion). some examples

what's going on?

p.s. i'm not guru drawing , custom views in cocoa - ideas/help more welcome!

you switched asking collection view talking outline view, assume mental hiccup.

when outline view item not 100% visible (e.g. because it's been scrolled down), selection border doesn't appear @ (while expect draw visible portion).

that's because of code in -drawrect:.

if(rect.size.height < framerect.size.height) return;

it's avoiding drawing partial selection outline.

regarding weird line, uncertainty has collection item view's custom drawing. stop happening if disable custom drawing? experiment using ordinary color rather using third-party +colorfromgradient: code you're using.

by way, line:

nsrect newrect = nsmakerect(rect.origin.x+5, rect.origin.y+5, rect.size.width-10, rect.size.height-10);

could written more as:

nsrect newrect = nsinsetrect(rect, 5, 5);

objective-c cocoa nsview nscollectionview nscollectionviewitem