(Somewhat hackily) implemented the new label rules on Mac OS X.

objc_darwin.h

@@ -33,6 +33,12 @@ struct xpoint {
 	intptr_t y;
 };
 
+struct xprefsize {
+	intptr_t width;
+	intptr_t height;
+	intptr_t yoff;
+};
+
 /* objc_darwin.m */
 extern id toNSString(char *);
 extern char *fromNSString(id);
@@ -86,10 +92,11 @@ extern uintptr_t listboxIndexesNext(id, uintptr_t);
 extern intptr_t listboxLen(id);
 
 /* prefsize_darwin.m */
-extern struct xsize controlPrefSize(id);
-extern struct xsize listboxPrefSize(id);
-extern struct xsize pbarPrefSize(id);
-extern struct xsize areaPrefSize(id);
+extern struct xprefsize controlPrefSize(id, BOOL);
+extern struct xprefsize labelPrefSize(id, BOOL);
+extern struct xprefsize listboxPrefSize(id, BOOL);
+extern struct xprefsize pbarPrefSize(id, BOOL);
+extern struct xprefsize areaPrefSize(id, BOOL);
 
 /* sysdata_darwin.m */
 extern void addControl(id, id);

prefsize_darwin.go

@@ -10,40 +10,46 @@ Cocoa doesn't provide a reliable way to get the preferred size of a control (you
 */
 
 // standard case: control immediately passed in
-func controlPrefSize(control C.id) (width int, height int) {
-	r := C.controlPrefSize(control)
-	return int(r.width), int(r.height)
+func controlPrefSize(control C.id, alternate C.BOOL) (width int, height int, yoff int) {
+	r := C.controlPrefSize(control, alternate)
+	return int(r.width), int(r.height), int(r.yoff)
+}
+
+// Labels have special yoff calculation
+func labelPrefSize(control C.id, alternate C.BOOL) (width int, height int, yoff int) {
+	r := C.labelPrefSize(control, alternate)
+	return int(r.width), int(r.height), int(r.yoff)
 }
 
 // NSTableView is actually in a NSScrollView so we have to get it out first
-func listboxPrefSize(control C.id) (width int, height int) {
-	r := C.listboxPrefSize(control)
-	return int(r.width), int(r.height)
+func listboxPrefSize(control C.id, alternate C.BOOL) (width int, height int, yoff int) {
+	r := C.listboxPrefSize(control, alternate)
+	return int(r.width), int(r.height), int(r.yoff)
 }
 
 // and for type checking reasons, progress bars are separate despite responding to -[sizeToFit]
-func pbarPrefSize(control C.id) (width int, height int) {
-	r := C.pbarPrefSize(control)
-	return int(r.width), int(r.height)
+func pbarPrefSize(control C.id, alternate C.BOOL) (width int, height int, yoff int) {
+	r := C.pbarPrefSize(control, alternate)
+	return int(r.width), int(r.height), int(r.yoff)
 }
 
 // Areas know their own preferred size
-func areaPrefSize(control C.id) (width int, height int) {
-	r := C.areaPrefSize(control)
-	return int(r.width), int(r.height)
+func areaPrefSize(control C.id, alternate C.BOOL) (width int, height int, yoff int) {
+	r := C.areaPrefSize(control, alternate)
+	return int(r.width), int(r.height), int(r.yoff)
 }
 
-var prefsizefuncs = [nctypes]func(C.id) (int, int){
+var prefsizefuncs = [nctypes]func(C.id, C.BOOL) (int, int, int){
 	c_button:      controlPrefSize,
 	c_checkbox:    controlPrefSize,
 	c_combobox:    controlPrefSize,
 	c_lineedit:    controlPrefSize,
-	c_label:       controlPrefSize,
+	c_label:       labelPrefSize,
 	c_listbox:     listboxPrefSize,
 	c_progressbar: pbarPrefSize,
 	c_area:        areaPrefSize,
 }
 
-func (s *sysData) preferredSize() (width int, height int) {
-	return prefsizefuncs[s.ctype](s.id)
+func (s *sysData) preferredSize() (width int, height int, yoff int) {
+	return prefsizefuncs[s.ctype](s.id, toBOOL(s.alternate))
 }

prefsize_darwin.m

@@ -2,12 +2,15 @@
 
 #include "objc_darwin.h"
 #import <AppKit/NSControl.h>
+#import <AppKit/NSView.h>
+#import <AppKit/NSTextField.h>
 #import <AppKit/NSScrollView.h>
 #import <AppKit/NSTableView.h>
 #import <AppKit/NSProgressIndicator.h>
 
 #define to(T, x) ((T *) (x))
 #define toNSControl(x) to(NSControl, (x))
+#define toNSTextField(x) to(NSTextField, (x))
 #define toNSScrollView(x) to(NSScrollView, (x))
 #define toNSTableView(x) to(NSTableView, (x))
 #define toNSProgressIndicator(x) to(NSProgressIndicator, (x))
@@ -16,58 +19,87 @@
 #define listboxInScrollView(x) toNSTableView(inScrollView((x)))
 #define areaInScrollView(x) inScrollView((x))
 
-struct xsize controlPrefSize(id control)
+struct xprefsize controlPrefSize(id control, BOOL alternate)
 {
 	NSControl *c;
 	NSRect r;
-	struct xsize s;
+	struct xprefsize s;
 
 	c = toNSControl(control);
 	[c sizeToFit];
 	r = [c frame];
 	s.width = (intptr_t) r.size.width;
 	s.height = (intptr_t) r.size.height;
+	s.yoff = 0;		// no yoff for most controls
 	return s;
 }
 
-struct xsize listboxPrefSize(id scrollview)
+struct xprefsize labelPrefSize(id control, BOOL alternate)
+{
+	NSControl *c;
+	NSRect r;
+	struct xprefsize s;
+
+	c = toNSControl(control);
+	[c sizeToFit];
+	r = [c frame];
+	s.width = (intptr_t) r.size.width;
+	s.height = (intptr_t) r.size.height;
+	s.yoff = 0;		// no yoff for standalone labels
+	if (!alternate) {
+		// TODO this seems really hacky
+		// temporarily enable the border, compute its height, and take the height difference
+		[toNSTextField(c) setBordered:YES];
+		[c sizeToFit];
+		r = [c frame];
+		[toNSTextField(c) setBordered:NO];
+		// - 1 since the sizes are exclusive (????? TODO)
+		s.yoff = ((intptr_t) r.size.height) - s.height - 1;
+	}
+	return s;
+}
+
+struct xprefsize listboxPrefSize(id scrollview, BOOL altenrate)
 {
 	NSTableView *c;
 	NSRect r;
-	struct xsize s;
+	struct xprefsize s;
 
 	c = listboxInScrollView(toNSScrollView(scrollview));
 	[c sizeToFit];
 	r = [c frame];
 	s.width = (intptr_t) r.size.width;
 	s.height = (intptr_t) r.size.height;
+	s.yoff = 0;		// no yoff for listboxes
 	return s;
 }
 
-struct xsize pbarPrefSize(id control)
+struct xprefsize pbarPrefSize(id control, BOOL alternate)
 {
 	NSProgressIndicator *c;
 	NSRect r;
-	struct xsize s;
+	struct xprefsize s;
 
 	c = toNSProgressIndicator(control);
 	[c sizeToFit];
 	r = [c frame];
 	s.width = (intptr_t) r.size.width;
 	s.height = (intptr_t) r.size.height;
+	s.yoff = 0;		// no yoff for progress bars
 	return s;
 }
 
-struct xsize areaPrefSize(id scrollview)
+struct xprefsize areaPrefSize(id scrollview, BOOL alternate)
 {
 	NSView *c;
 	NSRect r;
-	struct xsize s;
+	struct xprefsize s;
 
 	c = areaInScrollView(toNSScrollView(scrollview));
 	// don't size to fit; the frame size is already the size we want
 	r = [c frame];
 	s.width = (intptr_t) r.size.width;
 	s.height = (intptr_t) r.size.height;
+	s.yoff = 0;		// no yoff for areas
 	return s;
 }