objective c - constraints cause an ambiguousLayout -

i have nswindow instance have setupui method.

-(void) setupui {     nsview* subview = [[nsview alloc] initwithframe:nszerorect];     subview.wantslayer = yes;     subview.layer.backgroundcolor = [[nscolor greencolor] cgcolor];     [self.contentview addsubview:subview];     [self.contentview settranslatesautoresizingmaskintoconstraints:no];     [self.contentview addconstraint:[nslayoutconstraint constraintwithitem:self.contentview                               attribute:nslayoutattributeleading                               relatedby:nslayoutrelationequal                                  toitem:subview                               attribute:nslayoutattributeleading                              multiplier:1                                constant:0]];     [self.contentview addconstraint:[nslayoutconstraint constraintwithitem:self.contentview                               attribute:nslayoutattributetop                               relatedby:nslayoutrelationequal                                  toitem:subview                               attribute:nslayoutattributetop                              multiplier:1                                constant:0]];     [self.contentview addconstraint:[nslayoutconstraint constraintwithitem:self.contentview                               attribute:nslayoutattributetrailing                               relatedby:nslayoutrelationequal                                  toitem:subview                               attribute:nslayoutattributetrailing                              multiplier:1                                constant:0]];     [self.contentview addconstraint:[nslayoutconstraint constraintwithitem:self.contentview                               attribute:nslayoutattributebottom                               relatedby:nslayoutrelationequal                                  toitem:subview                               attribute:nslayoutattributebottom                              multiplier:1                                constant:0]];  } 

when call [self.contentview hasambiguouslayout], returns yes. why happened? code snippet seems same xib has created while using pin panel.

and subview green color doesn't appear in window.

thanks in advance.

the property of translatesautoresizingmaskintoconstraints of nswindow's contentview default yes. can't guess happen knowledge of frame, autoresizingmask, autolayout if set no because behavior have tried makes me terribly confused.

in word, leave top contentview's translatesautoresizingmaskintoconstraints yes, of other subviews no if want use autolayout.

when create view, constructed autoresizingmask of 0 , translatesautoresizingmaskintoconstraints of yes. if translatesautoresizingmaskintoconstraints yes, use frame, autoresizingmask , constraints(autolayout) position view.

consider situation below.

nsview* subview = [[nsview alloc] initwithframe:nsmakerect(100, 100, 200, 200)]; subview.wantslayer = yes; subview.layer.backgroundcolor = [[nscolor greencolor] cgcolor]; [subview settranslatesautoresizingmaskintoconstraints:yes]; [self.contentview addsubview:subview];  [subview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributewidth                           relatedby:nslayoutrelationequal                              toitem:nil                           attribute:nslayoutattributenotanattribute                          multiplier:1                            constant:50]]; [subview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributeheight                           relatedby:nslayoutrelationequal                              toitem:nil                           attribute:nslayoutattributenotanattribute                          multiplier:1                            constant:50]]; 

the translatesautoresizingmaskintoconstraints of subview yes. use point(100, 100) position it. use size(200, 200) size it. create nsautoresizingmasklayoutconstraint make unresizable because default autoresizingmask 0 means view can't change width , height. create nslayoutconstraint autolayout because have called "addconstraint". , break nslayoutconstraint because nslayoutconstraint , nsautoresizingmasklayoutconstraint conflicted. terribly terrible.

but if call [subview settranslatesautoresizingmaskintoconstraints:no], not use point, size, nsautoresizingmasklayoutconstraint, use nslayoutconstraint autolayout. because size it, not position it. it's ambiguous layout. terribly terrible.

the code below true.

nsview* subview = [[nsview alloc] initwithframe:nsmakerect(100, 100, 200, 200)]; subview.wantslayer = yes; subview.layer.backgroundcolor = [[nscolor greencolor] cgcolor]; [subview settranslatesautoresizingmaskintoconstraints:no]; [self.contentview addsubview:subview];  [subview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributewidth                           relatedby:nslayoutrelationequal                              toitem:nil                           attribute:nslayoutattributenotanattribute                          multiplier:1                            constant:50]]; [subview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributeheight                           relatedby:nslayoutrelationequal                              toitem:nil                           attribute:nslayoutattributenotanattribute                          multiplier:1                            constant:50]]; [self.conteview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributeleading                           relatedby:nslayoutrelationequal                              toitem:self.contentview                           attribute:nslayoutattributeleading                          multiplier:1                            constant:0]]; [self.conteview addconstraint:[nslayoutconstraint constraintwithitem:subview                           attribute:nslayoutattributetop                           relatedby:nslayoutrelationequal                              toitem:self.contentview                           attribute:nslayoutattributetop                          multiplier:1                            constant:0]]; 

i think cocoa's layout such terrible thing, many reasons.

in qt, qhboxlayout can easily. not tell me there nsstackview in cocoa, feel tired debug when goes wrong without rhyme or reason.

but have work cocoa.

is there can tell me why can't set contentview's translatesautoresizingmaskintoconstraints no?

thanks in advance.