[kwlug-disc] Question Involving GTK 3 Programming in Python

[Paul Nijjar]

You prepend 'self.' in front of instance variables:

class ScrapAppWindow(Gtk.Window):

    # ... snip ...

    def __init__(self):
        Gtk.Window.__init__(self, title="Scrap App")
        self.set_border_width(10)

        material_label = Gtk.Label(label="Please Select Material")

        material_store = Gtk.ListStore(str)

        material_store.append(["#1 Bright Copper"])
        material_store.append(["#1 Copper"])

        # ... snip ...

        # This will make self.material_combo available in the class, I think
        self.material_combo = Gtk.ComboBox.new_with_model(material_store)
        self.material_combo.connect("changed", self.on_material_combo_changed)
        renderer_text = Gtk.CellRendererText()
        self.material_combo.pack_start(renderer_text, True)
        self.material_combo.add_attribute(renderer_text, "text", 0)

        plot_button = Gtk.Button.new_with_label("Plot Graph")
        plot_button.connect("clicked", self.on_plot_graph_clicked)

        vbox = Gtk.Box(orientation = Gtk.Orientation.VERTICAL, spacing=10)
        vbox.pack_start(material_label, True, True, 0)
        vbox.pack_start(self.material_combo, True, True, 0)
        vbox.pack_start(plot_button, True, True, 0)

        self.add(vbox)
        self.show_all()

Then your on_plot_graph_clicked() function becomes something like:

def on_plot_graph_clicked(self, button):
������� print('"Plot Graph" Button was clicked.')

������� selected_material = None

������� tree_iter = self.material_combo.get_active_iter()
������� if tree_iter is not None:
����������� model = self.material_combo.get_model()
����������� selected_material = model[tree_iter][0]

������� if (selected_material is None) or (selected_material=="All
Materials"):
����������� dialog = Gtk.MessageDialog(
������������� transient_for=self,
��������������� flags=0,
��������������� message_type=Gtk.MessageType.INFO,
��������������� buttons=Gtk.ButtonsType.OK,
��������������� text="Please select a material.",
����������� )
����������� dialog.run()
  ��������� print("Plot Graph dialog closed.")
����������� dialog.destroy()
������� else:
����������� print("Calling plotgraph(%s)."� % selected_material)
����������� plotgraph(selected_material)


(I did not test this, and I could be very very wrong, but I believe this is how you set up classes in Python. See: https://www.digitalocean.com/community/tutorials/understanding-class-and-instance-variables-in-python-3

- Paul

> On 2021-04-29 3:41 p.m., Paul Nijjar via kwlug-disc wrote:
> >
> > You have a class ScrapAppWindow. My (possibly wrong) idea would be to
> > make material_combo a class variable, rather than a variable that is
> > local to the init() function. Then it will be accessible from your
> > other functions.
> >
> > - Paul
> >
> >
> Your suggestion is a good one Paul.� However I am at a total loss on how to
> implement your suggestion in Python.
> 
> I did manage to get the Plot Graph button working by passing the
> material_combo variable to the on_plot_graph_clicked method. Sample code
> follows:
> 
> def on_plot_graph_clicked(self, button, combo):
> ������� print('"Plot Graph" Button was clicked.')
> 
> ������� selected_material = None
> 
> ������� tree_iter = combo.get_active_iter()
> ������� if tree_iter is not None:
> ����������� model = combo.get_model()
> ����������� selected_material = model[tree_iter][0]
> 
> ������� if (selected_material is None) or (selected_material=="All
> Materials"):
> ����������� dialog = Gtk.MessageDialog(
> ��������������� transient_for=self,
> ��������������� flags=0,
> ��������������� message_type=Gtk.MessageType.INFO,
> ��������������� buttons=Gtk.ButtonsType.OK,
> ��������������� text="Please select a material.",
> ����������� )
> ����������� dialog.run()
> ����������� print("Plot Graph dialog closed.")
> ����������� dialog.destroy()
> ������� else:
> ����������� print("Calling plotgraph(%s)."� % selected_material)
> ����������� plotgraph(selected_material)
> 
> I calling the on_plot_graph_clicked method using this line.
> 
> plot_button.connect("clicked", self.on_plot_graph_clicked, material_combo)
> 
> My solution works, but becomes unwieldy very quickly with multiple combo
> boxes.
> 
> John Driezen
> jdriezen at sympatico.ca
> 
> On 2021-04-29 3:41 p.m., Paul Nijjar via kwlug-disc wrote:
> > You have a class ScrapAppWindow. My (possibly wrong) idea would be to
> > make material_combo a class variable, rather than a variable that is
> > local to the init() function. Then it will be accessible from your
> > other functions.
> > 
> > - Paul
> > 
> > 
> 
> _______________________________________________
> kwlug-disc mailing list
> kwlug-disc at kwlug.org
> https://kwlug.org/mailman/listinfo/kwlug-disc_kwlug.org

-- 
Events: https://feeds.off-topic.kwlug.org 
Blog: http://pnijjar.freeshell.org