git-gui: use themed tk widgets with Tk 8.5

This patch enables the use of themed Tk widgets with Tk 8.5 and above.
These make a significant difference on Windows in making the
application appear native. On Windows and MacOSX ttk defaults to the
native look as much as possible. On X11 the user may select a theme
using the TkTheme XRDB resource class by adding an line to the
.Xresources file. The set of installed theme names is available using
the Tk command 'ttk::themes'. The default on X11 is similar to the current
un-themed style - a kind of thin bordered motif look.

A new git config variable 'gui.usettk' may be set to disable this if
the user prefers the classic Tk look. Using Tk 8.4 will also avoid the
use of themed widgets as these are only available since 8.5.

Some support is included for Tk 8.6 features (themed spinbox and native
font chooser for MacOSX and Windows).

Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/branch_create.tcl

@@ -16,48 +16,48 @@ field opt_fetch     1; # refetch tracking branch if used?
 field reset_ok      0; # did the user agree to reset?
 
 constructor dialog {} {
-	global repo_config
+	global repo_config use_ttk NS
 
-	make_toplevel top w
+	make_dialog top w
+	wm withdraw $w
 	wm title $top [append "[appname] ([reponame]): " [mc "Create Branch"]]
 	if {$top ne {.}} {
 		wm geometry $top "+[winfo rootx .]+[winfo rooty .]"
 	}
 
-	label $w.header -text [mc "Create New Branch"] -font font_uibold
+	${NS}::label $w.header -text [mc "Create New Branch"] \
+		-font font_uibold -anchor center
 	pack $w.header -side top -fill x
 
-	frame $w.buttons
-	button $w.buttons.create -text [mc Create] \
+	${NS}::frame $w.buttons
+	${NS}::button $w.buttons.create -text [mc Create] \
 		-default active \
 		-command [cb _create]
 	pack $w.buttons.create -side right
-	button $w.buttons.cancel -text [mc Cancel] \
+	${NS}::button $w.buttons.cancel -text [mc Cancel] \
 		-command [list destroy $w]
 	pack $w.buttons.cancel -side right -padx 5
 	pack $w.buttons -side bottom -fill x -pady 10 -padx 10
 
-	labelframe $w.desc -text [mc "Branch Name"]
-	radiobutton $w.desc.name_r \
-		-anchor w \
+	${NS}::labelframe $w.desc -text [mc "Branch Name"]
+	${NS}::radiobutton $w.desc.name_r \
 		-text [mc "Name:"] \
 		-value user \
 		-variable @name_type
+	if {!$use_ttk} {$w.desc.name_r configure -anchor w}
 	set w_name $w.desc.name_t
-	entry $w_name \
-		-borderwidth 1 \
-		-relief sunken \
+	${NS}::entry $w_name \
 		-width 40 \
 		-textvariable @name \
 		-validate key \
 		-validatecommand [cb _validate %d %S]
 	grid $w.desc.name_r $w_name -sticky we -padx {0 5}
 
-	radiobutton $w.desc.match_r \
-		-anchor w \
+	${NS}::radiobutton $w.desc.match_r \
 		-text [mc "Match Tracking Branch Name"] \
 		-value match \
 		-variable @name_type
+	if {!$use_ttk} {$w.desc.match_r configure -anchor w}
 	grid $w.desc.match_r -sticky we -padx {0 5} -columnspan 2
 
 	grid columnconfigure $w.desc 1 -weight 1
@@ -66,34 +66,34 @@ constructor dialog {} {
 	set w_rev [::choose_rev::new $w.rev [mc "Starting Revision"]]
 	pack $w.rev -anchor nw -fill both -expand 1 -pady 5 -padx 5
 
-	labelframe $w.options -text [mc Options]
+	${NS}::labelframe $w.options -text [mc Options]
 
-	frame $w.options.merge
-	label $w.options.merge.l -text [mc "Update Existing Branch:"]
+	${NS}::frame $w.options.merge
+	${NS}::label $w.options.merge.l -text [mc "Update Existing Branch:"]
 	pack $w.options.merge.l -side left
-	radiobutton $w.options.merge.no \
+	${NS}::radiobutton $w.options.merge.no \
 		-text [mc No] \
 		-value none \
 		-variable @opt_merge
 	pack $w.options.merge.no -side left
-	radiobutton $w.options.merge.ff \
+	${NS}::radiobutton $w.options.merge.ff \
 		-text [mc "Fast Forward Only"] \
 		-value ff \
 		-variable @opt_merge
 	pack $w.options.merge.ff -side left
-	radiobutton $w.options.merge.reset \
+	${NS}::radiobutton $w.options.merge.reset \
 		-text [mc Reset] \
 		-value reset \
 		-variable @opt_merge
 	pack $w.options.merge.reset -side left
 	pack $w.options.merge -anchor nw
 
-	checkbutton $w.options.fetch \
+	${NS}::checkbutton $w.options.fetch \
 		-text [mc "Fetch Tracking Branch"] \
 		-variable @opt_fetch
 	pack $w.options.fetch -anchor nw
 
-	checkbutton $w.options.checkout \
+	${NS}::checkbutton $w.options.checkout \
 		-text [mc "Checkout After Creation"] \
 		-variable @opt_checkout
 	pack $w.options.checkout -anchor nw
@@ -109,6 +109,7 @@ constructor dialog {} {
 	bind $w <Visibility> [cb _visible]
 	bind $w <Key-Escape> [list destroy $w]
 	bind $w <Key-Return> [cb _create]\;break
+	wm deiconify $w
 	tkwait window $w
 }