support for GTK 3.98.3

README.adoc

@@ -1,6 +1,6 @@
 = High level GTK3 (and GTK4) bindings for the Nim programming language
 (c) Stefan Salewski                                     
-//Version 0.7.3
+//Version 0.7.4
 :experimental:
 :imagesdir: http://ssalewski.de/tmp
 :source-highlighter: pygments
@@ -25,7 +25,9 @@ with code inserted from files directly.
 NOTE: This work is partly based on earlier works of J. Mansour and has been supported by A. Rumpf, E. Bassi and other _Nim_ and _GTK/Gnome_ developers.
 The `combinatorics` module was kindly provided by R. Behrends.
 
-NOTE: Starting with current version v0.7.3 we allow passing a type descriptor as first parameter to the
+NOTE: With current version 0.7.4 we support latest GTK 3.98.3 which may become GTK 4 at the end of 2020.
+
+NOTE: Starting with version v0.7.3 we allow passing a type descriptor as first parameter to the
 new() procs like `newButton(MyButtonSubclass)` to support subclassing and extending Widgets in OOP style.
 See <<Extending or sub-classing Widgets>> for an complete example. The init() procs which were used
 before for this task are now deprecated and will be removed later. This new approach generally saves
@@ -2723,6 +2725,7 @@ proc main =
   ##  Wait until error or EOS
   bus = gst.getBus(pipeline)
   msg = gst.timedPopFiltered(bus, gst.Clock_Time_None, {gst.MessageFlag.error, gst.MessageFlag.eos})
+  echo msg.getType
   discard gst.setState(pipeline, gst.State.null) # is this necessary?
 
 main()
@@ -2752,8 +2755,10 @@ button, but called after gtk4.main(). A bit strange indeed, see forum note of Mr
 .headerbar.nim
 ----
 # https://github.com/GNOME/gtk/blob/mainline/tests/testheaderbar.c
+# this is still based on the original testheaderbar.c, which was recently replaced by testheaderbar2.c
+# and testheaderbar.c is not a very good Nim GTK4 example unfortunately -- too comlicated and strange code.
 # nim c headerbar.nim
-import gintro/[gtk4, glib, gobject, gio]
+import gintro/[gtk4, glib, gobject]
 
 const
   Css = """
@@ -2775,7 +2780,7 @@ const
 # we try to avoid use of global header variable as done in C code
 type
   MyWindow = ref object of gtk4.Window
-    header: gtk4.Headerbar
+    header: gtk4.Widget
 
 proc response(d: gtk4.FileChooserDialog; responseID: int) = gtk4.destroy(d)
 
@@ -2787,11 +2792,11 @@ proc onBookmarkClicked(button: Button; data: MyWindow) =
   chooser.connect("response", response)
   chooser.show
 
-proc changeSubtitle(button: Button; w: MyWindow) =
-  if w.header.subtitle == "":
-    w.header.setSubtitle("(subtle subtitle)")
-  else:
-    w.header.setSubtitle("") # can we pass nil?
+#proc changeSubtitle(button: Button; w: MyWindow) =
+#  if w.header.subtitle == "":
+#    w.header.setSubtitle("(subtle subtitle)")
+#  else:
+#    w.header.setSubtitle("") # can we pass nil?
 
 proc toggleFullscreen(button: Button; window: MyWindow) =
   var fullscreen {.global.}: bool
@@ -2807,68 +2812,85 @@ proc toIntVal(i: int): Value =
   discard init(result, gtype)
   setInt(result, i)
 
-proc quit(b: Button) = gtk4.mainQuit()
+var done = false
+
+proc quit_cb(b: Button) = # we can not pass a var parameter
+ #gtk4.mainQuit()
+ done = true
+ wakeup(defaultMainContext()) # g_main_context_wakeup (NULL);
 
 proc changeHeader(button: ToggleButton; window: MyWindow) =
   if button != nil and button.getActive:
-    window.header = cast[HeaderBar](newBox(gtk4.Orientation.horizontal,
-        10)) # intended cast, see C code!
-    addClass(getStyleContext(window.header), "titlebar")
-    addClass(getStyleContext(window.header), "header-bar")
-    window.header.setProperty("margin", toIntVal(10))
+    window.header = (newBox(gtk4.Orientation.horizontal,
+        10))
+    addCssClass(window.header, "titlebar")
+    addCssClass(window.header, "header-bar")
+    #window.header.setProperty("margin_start", toIntVal(10))
+    #window.header.setProperty("margin_end", toIntVal(10))
+    #window.header.setProperty("margin_top", toIntVal(10))
+    #window.header.setProperty("margin_bottom", toIntVal(10))
+    window.header.setMarginStart(10)
+    window.header.setMarginEnd(10)
+    window.header.setMarginTop(10)
+    window.header.setMarginBottom(10)
     let label = newLabel("Label")
-    window.header.add(label)
+    gtk4.Box(window.header).append(label)
     let levelBar = newLevelBar()
     levelBar.setValue(0.4)
     levelBar.setHexpand
-    window.header.add(levelBar)
+    gtk4.Box(window.header).append(levelBar)
   else:
     window.header = newHeaderBar()
-    addClass(getStyleContext(window.header), "titlebar")
-    window.header.setTitle("Example header")
+    #addClass(getStyleContext(window.header), "titlebar")
+    addCssClass(window.header, "titlebar")
+    #window.header.setTitle("Example header")
     var button = newButton("_Close")
     button.setUseUnderline
-    addClass(getStyleContext(button), "suggested-action")
-    button.connect("clicked", quit)
-    window.header.packEnd(button)
+    addCssClass(button, "suggested-action")
+    button.connect("clicked", quit_cb)
+    gtk4.HeaderBar(window.header).packEnd(button)
     button = newButton()
     let image = newImageFromIconName("bookmark-new-symbolic")
     button.connect("clicked", onBookmarkClicked, window)
-    button.add(image)
-    window.header.packStart(button)
+    button.setChild(image)
+    gtk4.HeaderBar(window.header).packStart(button)
   window.setTitlebar(window.header)
 
 proc main =
   gtk4.init()
-  var window: MyWindow
-  initWindow(window)
-  addClass(getStyleContext(window), "main")
+  #var window: MyWindow
+  let window = newWindow(MyWindow)
+  addCssClass(window, "main") # gtk_widget_add_css_class (window, "main");
   let provider = newCssProvider()
   provider.loadFromData(Css)
   addProviderForDisplay(getDisplay(window), provider, STYLE_PROVIDER_PRIORITY_USER)
   changeHeader(nil, window)
   let box = newBox(Orientation.vertical, 0)
-  window.add(box)
+  window.setChild(box) # gtk_window_set_child (GTK_WINDOW (window), box);
+  #window.add(box)
   let content = newImageFromIconName("start-here-symbolic")
   content.setPixelSize(512)
-  box.add(content)
+  content.setVexpand
+  box.append(content)
   let footer = newActionBar()
   footer.setCenterWidget(newCheckButtonWithLabel("Middle"))
   let button = newToggleButtonWithLabel("Custom")
   button.connect("clicked", changeHeader, window)
   footer.packStart(button)
-  var button1 = newButton("Subtitle")
-  button1.connect("clicked", changeSubtitle, window)
-  footer.packEnd(button1)
-  button1 = newButton("Fullscreen")
+  #var button1 = newButton("Subtitle")
+  #button1.connect("clicked", changeSubtitle, window)
+  #footer.packEnd(button1)
+  var button1 = newButton("Fullscreen")
   footer.packEnd(button1)
   button1.connect("clicked", toggleFullscreen, window)
-  box.add(footer)
+  box.append(footer)
   window.show
-  gtk4.main()
+  #gtk4.main()
+  while not done:
+    discard iteration(defaultMainContext(), true) # g_main_context_iteration (NULL, TRUE);
   destroy(window) # this is special for this example, see  https://discourse.gnome.org/t/tests-testgaction-c/2232/6
 
-main() # 118 lines
+main() # 137 lines
 ----
 
 NOTE: Related work: https://github.com/jdmansour/nim-smartgi