Changed how the preferred size of controls is determined to accomodate NSTableView, NSScrollView, and NSProgressIndicator. Updated TODOs to mark other weirdnesses (such as Label text that used to get cropped) that no longer happen because of this. Now for putting Listboxes in NSScrollViews.

prefsize_darwin.go

@@ -5,18 +5,40 @@ package ui
 // #include "objc_darwin.h"
 import "C"
 
-// -[NSCell cellSize] is documented as determining the minimum size needed to draw its receiver. This will work for our case; it appears to be what GTK+ does as well.
-// See also: http://stackoverflow.com/questions/1056079/is-there-a-way-to-programmatically-determine-the-proper-sizes-for-apples-built
-// TODO figure out what to do if one of our controls returns the sentinel (10000, 10000) that indicates we can't use -[NSCell cellSize]
+/*
+Cocoa doesn't provide a reliable way to get the preferred size of a control (you're supposed to use Interface Builder and have it set up autoresizing for you). The best we can do is call [control sizeToFit] (which is defined for NSControls and has a custom implementation for the other types here) and read the preferred size. Though this changes the size, we're immediately overriding the change on return from sysData.preferredSize(), so no harm done. (This is similar to what we are doing with GTK+, except GTK+ does not actually change the size.)
+*/
 
 var (
-	_cell = sel_getUid("cell")
-	_cellSize = sel_getUid("cellSize")
+	_sizeToFit = sel_getUid("sizeToFit")
+	// _frame in sysdata_darwin.go
+	// _documentView in listbox_darwin.go
 )
 
+// standard case: control immediately passed in
+func controlPrefSize(control C.id) (width int, height int) {
+	C.objc_msgSend_noargs(control, _sizeToFit)
+	r := C.objc_msgSend_stret_rect_noargs(control, _frame)
+	return int(r.width), int(r.height)
+}
+
+// NSTableView is actually in a NSScrollView so we have to get it out first
+func listboxPrefSize(control C.id) (width int, height int) {
+//	return controlPrefSize(C.objc_msgSend_noargs(control, _documentView))
+	return controlPrefSize(control)
+}
+
+var prefsizefuncs = [nctypes]func(C.id) (int, int){
+	c_button:			controlPrefSize,
+	c_checkbox:		controlPrefSize,
+	c_combobox:		controlPrefSize,
+	c_lineedit:		controlPrefSize,
+	c_label:			controlPrefSize,
+	c_listbox:			listboxPrefSize,
+	c_progressbar:		controlPrefSize,
+}
+
 func (s *sysData) preferredSize() (width int, height int) {
 if classTypes[s.ctype].make == nil { return 0, 0 }	// prevent lockup during window resize
-	cell := C.objc_msgSend_noargs(s.id, _cell)
-	cs := C.objc_msgSend_stret_size_noargs(cell, _cellSize)
-	return int(cs.width), int(cs.height)
+	return prefsizefuncs[s.ctype](s.id)
 }

todo.md

@@ -32,7 +32,7 @@ important things:
 - NSPopUpButton doesn't seem to allow no initial selection? need to be sure
 - NSComboBox scans the entered text to see if it matches one of the items and returns the index of that item if it does; find out how to suppress this so that it returns -1 unless the item was chosen from the list (like the other platforms)
 - figure out what to do about deleting a nonexistent item; each backend responds differently by default
-- some Cocoa controls don't seem to resize correctly: Buttons have space around the edges and don't satisfy stretchiness; Labels in the grid test window get cropped
+- some Cocoa controls don't seem to resize correctly: Buttons have space around the edges and don't satisfy stretchiness
 - find out how to deselect the first item in the NSTableView when first creating the Listbox (to make it work like on other platforms)
 - there's no GTK+ error handling whatsoever; we need to figure out how it works
 - make sure GTK+ documentation point differences don't matter