Target Ubuntu 14.04 (gtk 3.10) build

Makefile

@@ -21,6 +21,11 @@ ibus-xml:
 
 	$(shell SCHEMES=("ml" "ta" "hi" "te" "ka" "bn"); for s in $${SCHEMES[@]}; do echo $s; ./${BIN} -s $$s -lang $$s -xml component/varnam-$$s.xml -prefix ${INSTALL_PREFIX}; done)
 
+ubuntu-14:
+	CGO_CFLAGS="-w" go build -tags "pango_1_36,gtk_3_10,glib_2_40,cairo_1_13,gdk_pixbuf_2_30,gtk_deprecated" -ldflags "-s -w" -o ${BIN} .
+	$(MAKE) ibus-xml
+	$(MAKE) install-script
+
 ubuntu-18:
 	go build -tags pango_1_42,gtk_3_22 -ldflags "-s -w" -o ${BIN} .
 	$(MAKE) ibus-xml

preferences.go

@@ -130,8 +130,11 @@ func makeSettingsPage() *gtk.Box {
 	settingsPage, err := gtk.BoxNew(gtk.ORIENTATION_VERTICAL, 6)
 	checkError(err)
 
-	settingsPage.SetMarginStart(12)
-	settingsPage.SetMarginEnd(12)
+	// gtk_widget_set_margin_left & right is deprecated since 3.12
+	// It got removed in 3.98: https://github.com/GNOME/gtk/blob/main/NEWS.pre-4.0#L939
+	// Our minimum GTK support needed is 3.10 (Ubuntu 14.04)
+	settingsPage.SetMarginLeft(12)
+	settingsPage.SetMarginRight(12)
 	settingsPage.SetMarginBottom(12)
 
 	/* Dictionary Match Exact Preference */
@@ -326,8 +329,8 @@ func makeRLWPage() *gtk.Box {
 	rlwPage, err := gtk.BoxNew(gtk.ORIENTATION_VERTICAL, 6)
 	checkError(err)
 
-	rlwPage.SetMarginStart(12)
-	rlwPage.SetMarginEnd(12)
+	rlwPage.SetMarginLeft(12)
+	rlwPage.SetMarginRight(12)
 	rlwPage.SetMarginTop(12)
 	rlwPage.SetMarginBottom(12)
 
@@ -419,8 +422,8 @@ func showPrefs() {
 
 	notebook.SetScrollable(true)
 
-	notebook.SetMarginStart(12)
-	notebook.SetMarginEnd(12)
+	notebook.SetMarginLeft(12)
+	notebook.SetMarginRight(12)
 	notebook.SetMarginBottom(12)
 
 	settingsLabel, err := gtk.LabelNew("Settings")
@@ -433,13 +436,6 @@ func showPrefs() {
 
 	win.Add(notebook)
 
-	settingsPage, err := gtk.BoxNew(gtk.ORIENTATION_VERTICAL, 6)
-	checkError(err)
-
-	settingsPage.SetMarginStart(12)
-	settingsPage.SetMarginEnd(12)
-	settingsPage.SetMarginBottom(12)
-
 	// Recursively show all widgets contained in this window.
 	mainWin.ShowAll()