Add stateful action with parameter

[hja3]

Hello.

I couldn't find a way to add a stateful action with parameter to GActionMap out of the box.

The following does the trick getting the radio menu items to work, but requires a custom overload of add_stateful_action.

Perhaps there is something I have overlooked?

using Gtk4, Gtk4.GLib

function Gtk4.add_stateful_action(m::GActionMap, name::AbstractString,
                             initial_state, handler::Function,
                             parameter::Bool = false)
    pvtype = parameter ? GVariantType(typeof(initial_state)) : nothing
    action = GSimpleAction(name, pvtype, GVariant(initial_state))
    push!(m, GAction(action))
    signal_connect(handler, action, :change_state)
    action
end

const menu_xml = """
<?xml version='1.0' encoding='UTF-8'?>
<!-- Created with Cambalache 0.16.0 -->
<interface>
  <!-- interface-name menus.ui -->
  <requires lib="gio" version="2.0"/>
  <menu id="menubar">
    <submenu>
      <attribute name="label">Menu</attribute>
      <item>
        <attribute name="action">app.check</attribute>
        <attribute name="label">Check</attribute>
      </item>
      <item>
        <attribute name="action">app.radio</attribute>
        <attribute name="label">Radio 1</attribute>
        <attribute name="target">1</attribute>
      </item>
      <item>
        <attribute name="action">app.radio</attribute>
        <attribute name="label">Radio 2</attribute>
        <attribute name="target">2</attribute>
      </item>
    </submenu>
  </menu>
</interface>
"""

function on_check_changed(a, v) ::Nothing
    println("check changed: ", v[Bool])
    Gtk4.GLib.set_state(a, v)
end

function on_radio_changed(a, v) ::Nothing
    println("radio changed: ", v[String])
    Gtk4.GLib.set_state(a, v)
end

function activate(app)
    # main window
    window = GtkApplicationWindow(app)
    add_action(GActionMap(window), "close", _ -> destroy(window))

    # build menu
    add_stateful_action(GActionMap(app), "check", true, on_check_changed)
    add_stateful_action(GActionMap(app), "radio", "1", on_radio_changed, true)
    builder = GtkBuilder(menu_xml, length(menu_xml))
    Gtk4.G_.set_menubar(app, builder["menubar"])
    window.show_menubar = true

    show(window)
end

function julia_main() ::Cint
    app = GtkApplication("julia.menubar.example")
    Gtk4.signal_connect(activate, app, :activate)

    # When all windows are closed, loop automatically stops running
    Gtk4.run(app)

    return 0
end

[jwahlstrand]

You didn't overlook anything, that was just not implemented! I will add your suggested method, unless you want to create a PR?

[hja3]

I am not experienced with the GitHub workflow, sorry. I would be grateful if you could add it.

The version I eventually settled on here refactors both stateless and stateful actions to handle parameters, with the non-parameter method forwarding to the parameter method in each case. Please feel free to use this code if you think it is a good approach:

using Gtk4, Gtk4.GLib
import Gtk4: add_action, add_stateful_action

# stateless, with parameter
function add_action(m::GActionMap, name::AbstractString,
                    parameter::Type{T}, handler::Function) where T
    pvtype = parameter == Nothing ? nothing : GVariantType(parameter)
    action = GSimpleAction(name, pvtype)
    push!(m, GAction(action))
    signal_connect(handler, action, :activate)
    action
end

# stateless, without parameter
function add_action(m::GActionMap, name::AbstractString, handler::Function)
    add_action(m, name, Nothing, handler)
end

# stateful, with parameter
function add_stateful_action(m::GActionMap, name::AbstractString,
                             parameter::Type{T}, initial_state,
                             handler::Function) where T
    pvtype = parameter == Nothing ? nothing : GVariantType(parameter)
    action = GSimpleAction(name, pvtype, GVariant(initial_state))
    push!(m, GAction(action))
    signal_connect(handler, action, :change_state)
    action
end

# stateful, without parameter
function add_stateful_action(m::GActionMap, name::AbstractString,
                             initial_state, handler::Function)
    add_stateful_action(m, name, Nothing, initial_state, handler)
end

const menu_xml = """
<?xml version='1.0' encoding='UTF-8'?>
<!-- Created with Cambalache 0.16.0 -->
<interface>
  <!-- interface-name menus.ui -->
  <requires lib="gio" version="2.0"/>
  <menu id="menubar">
    <submenu>
      <attribute name="label">Menu</attribute>
      <item>
        <attribute name="action">app.action</attribute>
        <attribute name="label">Action</attribute>
      </item>
      <item>
        <attribute name="action">app.action-param</attribute>
        <attribute name="label">Foo</attribute>
        <attribute name="target">foo</attribute>
      </item>
      <item>
        <attribute name="action">app.action-param</attribute>
        <attribute name="label">Bar</attribute>
        <attribute name="target">bar</attribute>
      </item>
      <item>
        <attribute name="action">app.check</attribute>
        <attribute name="label">Check</attribute>
      </item>
      <item>
        <attribute name="action">app.radio</attribute>
        <attribute name="label">Radio 1</attribute>
        <attribute name="target" type="x">1</attribute>
      </item>
      <item>
        <attribute name="action">app.radio</attribute>
        <attribute name="label">Radio 2</attribute>
        <attribute name="target" type="x">2</attribute>
      </item>
    </submenu>
  </menu>
</interface>
"""

function on_action(a, v) ::Nothing
    println("action")
end

function on_action_param(a, v) ::Nothing
    println("action, param: ", v[String])
end

function on_check_changed(a, v) ::Nothing
    println("check changed: ", v[Bool])
    Gtk4.GLib.set_state(a, v)
end

function on_radio_changed(a, v) ::Nothing
    println("radio changed: ", v[Int])
    Gtk4.GLib.set_state(a, v)
end

function activate(app)
    # main window
    window = GtkApplicationWindow(app)

    # build menu
    add_action(GActionMap(app), "action", on_action)
    add_action(GActionMap(app), "action-param", String, on_action_param)
    add_stateful_action(GActionMap(app), "check", true, on_check_changed)
    add_stateful_action(GActionMap(app), "radio", Int, 1, on_radio_changed)
    builder = GtkBuilder(menu_xml, length(menu_xml))
    Gtk4.G_.set_menubar(app, builder["menubar"])
    window.show_menubar = true

    show(window)
end

function julia_main() ::Cint
    app = GtkApplication("julia.menubar.example")
    Gtk4.signal_connect(activate, app, :activate)

    # When all windows are closed, loop automatically stops running
    Gtk4.run(app)

    return 0
end