[Gtk-sharp-list] How to get CSS style properties from widgets?

[Manuel Roth]

Hello everyone,

I'm using CSS styling in GTK3 / GTK# and trying to read style properties
by CssProvider.GetStyleProperty(...).

The function returns false all the time. Can you please help me? Minimum
sample is below.

Kind Regards,
Manuel


/***********************************
Setup details / versions:
***********************************/
- Ubuntu: 17.04 64 bit
- libgtk3.0-cil and libgtk3.0-cil-dev: 2.99.3-2
- libgtk-3-0:amd64, libgtk-3-bin, libgtk-3-common, libgtk-3-dev:amd64:
3.22.11-0ubuntu3
- NuGet package: id="gtk-sharp-3" version="3.22.6.4" targetFramework="net45"


/***********************************
Sample code:
***********************************/
using System;
using GLib;
using Gdk;
using Gtk;

namespace Gtk3Test
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            Gtk.Application.Init();
            GtkWindow win = new GtkWindow();
            win.ShowAll();
            Gtk.Application.Run();
        }
    }

    public class GtkWindow : Gtk.Window
    {
        private Fixed _fixed1;
        private Button _btnTest;
        private CssProvider _cssProvider = new CssProvider();

        public GtkWindow()
            :base("test window")
        {
            _cssProvider.LoadFromData("#btnTest {font-size: 23px}");

            BuildContent();

            RegisterEventhandlers();

            WidthRequest = 200;
            HeightRequest = 200;
        }

        void RegisterEventhandlers()
        {
            _btnTest.Clicked += (sender, args) =>
            {
                var val = new Value();
                var paramSpec = new ParamSpec("font-size", null, null,
GType.Int64, true, true);
                var success =
_cssProvider.GetStyleProperty(_btnTest.WidgetPath, StateFlags.Normal,
paramSpec.Handle, val);
                                   
                if (!success)
                {
                    var s = "What am i doing wrong? I'd expect true and
the value of 23...";
                }
            };

            DeleteEvent += (o, args) =>
            {
                Gtk.Application.Quit();
                args.RetVal = true;   
            };
        }

        void BuildContent()
        {
            _fixed1 = new Fixed()
            {
                Name = "fixed1",
            };
            _fixed1.StyleContext.AddProvider(_cssProvider,
StyleProviderPriority.Application);
            Add(_fixed1);

            _btnTest = new Button(_fixed1)
            {
                Name = "btnTest",
                Label = "Test"
            };           
            _btnTest.StyleContext.AddProvider(_cssProvider,
StyleProviderPriority.Application);
            _fixed1.Add(_btnTest);
        }
    }
}