Best way to set input background color in Python GTK3 and revert to default

Question

What is the best way to set the background color for a single record and return it to the default color?

My script is now working, but I am very sure that this is not the best way.
Also, I still have two problems:

• If I insert text that does not contain the string “red” or “green” and select this text, I cannot see it because it is white.
• I think there are better ways that I insert self.entry_default_background_color_strinto CSS text.

---

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from gi.repository import Gdk

class Window(Gtk.Window):

    def __init__(self):

        self.screen = Gdk.Screen.get_default()
        self.gtk_provider = Gtk.CssProvider()
        self.gtk_context = Gtk.StyleContext()
        self.gtk_context.add_provider_for_screen(self.screen, self.gtk_provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)


        Gtk.Window.__init__(self, title="Check Input")
        self.set_size_request(300, 80)
        self.mainbox = Gtk.VBox()
        self.add(self.mainbox)

        # entry
        self.name_entry      = Gtk.Entry()
        self.name_entry.set_name("name_entry")
        self.mainbox.pack_start(self.name_entry, True, True, 0)
        self.name_entry.connect("changed", self.check_input)

        entry_context = self.name_entry.get_style_context()
        self.entry_default_background_color = entry_context.get_background_color(Gtk.StateType.NORMAL)
        self.entry_default_background_color_str = self.entry_default_background_color.to_string()

        self.show_all()


    def check_input(self, _widget=None):        
            if "red" in self.name_entry.get_text():
                self.gtk_provider.load_from_data('#name_entry { background: red; }')
            elif "green" in self.name_entry.get_text():
                self.gtk_provider.load_from_data('#name_entry { background: green; }')
            else:
                self.gtk_provider.load_from_data('#name_entry { background: ' + self.entry_default_background_color_str + '; }')


def main():
    window = Window()
    Gtk.main()


if __name__ == "__main__":
    main()

Answer 1

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---

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:

if "red" in self.name_entry.get_text():
    self.gtk_provider.load_from_data('#name_entry { background-image: linear-gradient(red); }')
elif "green" in self.name_entry.get_text():
    self.gtk_provider.load_from_data('#name_entry { background-image: linear-gradient(green); }')

---

2. , , self.entry_default_background_color_str CSS.

, : . , CssProvider css, , , , , .

:

if "red" in self.name_entry.get_text():
    self.gtk_provider.load_from_data('#name_entry { background-image: linear-gradient(red); }')
elif "green" in self.name_entry.get_text():
    self.gtk_provider.load_from_data('#name_entry { background-image: linear-gradient(green); }')
else:
    self.gtk_provider.load_from_data('#name_entry {}')

---

?

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def __init__(self):

    screen = Gdk.Screen.get_default()
    gtk_provider = Gtk.CssProvider()
    gtk_context = Gtk.StyleContext()
    gtk_context.add_provider_for_screen(screen, gtk_provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)

    # Create the window
    Gtk.Window.__init__(self, title="Check Input")
    self.set_size_request(300, 80)
    self.mainbox = Gtk.VBox()
    self.add(self.mainbox)

    # Load the CSS
    gtk_provider.load_from_data("""
    #name_entry.red { background-image: linear-gradient(red); }
    #name_entry.green { background-image: linear-gradient(green); }
    """)

    # Create the entry and give it a name which will be the ID
    name_entry = Gtk.Entry()
    name_entry.set_name("name_entry")
    self.mainbox.pack_start(name_entry, True, True, 0)

    # Add the listener
    name_entry.connect("changed", self.check_input)

    self.show_all()


def check_input(self, entry):
    # Get the style context for this widget
    entry_style_context = entry.get_style_context()

    # Check if our text contains red
    if "red" in entry.get_text():
        # Add the red class, so now the styling with .red is applied
        entry_style_context.add_class("red")

    # Check if our text contains green
    elif "green" in entry.get_text():
        # Add the red class, so now the styling with .green is applied
        entry_style_context.add_class("green")
    else:
        # When the text doesn't contain it remove the color classes to show the default behaviour
        entry_style_context.remove_class("red")
        entry_style_context.remove_class("green")