Re: [Tcllib-devel] BWidget patch 2825354 - fork or L in tree widget - please discuss

[Koen D. <ko...@re...>]

Jeff Hobbs wrote:
> In there, you will see that the node to the top is actually drawn, and 
> in the one in sources (with newer BWidget), it isn't.  I actually prefer 
> the newer lack of top anchor look, and it does have the single node case 
> to start.  I think this also applies to how the tree is used.  When it 
> has the classic single root node, it is better without the top anchor 
> line displayed, but I could see it as ok with multiple root nodes.
> 
> In the end, this can simply be made an option, like -showrootanchor or 
> something.

Ok, I already thought that the Windows style you were referring to always had exactly one top node, which is not the case for BWidget (where the real "root" node is actually invisible).

I propose to make the line dependent on whether there are multiple top nodes. (Harald, the patch for that is below.) It seems we could agree on that, and I prefer it to an extra option (= extra documentation, which will probably difficult to understand without trying out.)

--Koen


Index: tree.tcl
===================================================================
RCS file: /cvsroot/tcllib/bwidget/tree.tcl,v
retrieving revision 1.59
diff -b -u -r1.59 tree.tcl
--- tree.tcl	30 Jun 2009 16:17:37 -0000	1.59
+++ tree.tcl	24 Jul 2009 13:26:22 -0000
@@ -1369,12 +1369,9 @@
         set yp $y1
         set y1 [_draw_node $path $node $x0 [expr {$y1+$deltay}] $deltax $deltay $padx $showlines]
     }
-    if { $showlines && [llength $nodes] } {
-	if {$y0 < 0} {
-	    # Adjust the drawing of the line to the first root node
-	    # to start at the vertical point (not go up).
-	    incr y0 $deltay
-	}
+    # Only draw a line to the virtual root node when there are multiple top nodes.
+    set len [llength $nodes]
+    if { $showlines && $len && !($y0 < 0 && $len < 2) } {
         set id [$path.c create line $x0 $y0 $x0 [expr {$yp+$deltay}] \
                     -fill    [Widget::getoption $path -linesfill]   \
                     -stipple [Widget::getoption $path -linestipple] \