GstPipelineStudio/src/app.rs

// app.rs
//
// Copyright 2021 Stéphane Cerveau <scerveau@collabora.com>
//
// This file is part of GstPipelineStudio
//
// SPDX-License-Identifier: GPL-3.0-only

use glib::SignalHandlerId;
use glib::Value;
use gtk::gdk;
use gtk::prelude::*;
use gtk::{gio, gio::SimpleAction, glib, graphene};
use gtk::{
    Application, ApplicationWindow, Builder, Button, FileChooserAction, FileChooserDialog, Paned,
    PopoverMenu, ResponseType, Statusbar, Viewport, Widget,
};
use log::error;
use once_cell::unsync::OnceCell;
use std::cell::RefCell;
use std::collections::HashMap;
use std::fs::File;
use std::io::{Read, Write};
use std::ops;
use std::rc::{Rc, Weak};

use crate::gps as GPS;
use crate::logger;
use crate::settings::Settings;
use crate::ui as GPSUI;

use crate::{GPS_DEBUG, GPS_ERROR, GPS_INFO, GPS_TRACE, GPS_WARN};

use crate::graphmanager as GM;
use crate::graphmanager::PropertyExt;
use std::fmt;
#[derive(Debug)]
pub struct GPSAppInner {
    pub window: gtk::ApplicationWindow,
    pub graphview: RefCell<GM::GraphView>,
    pub builder: Builder,
    pub player: RefCell<GPS::Player>,
    pub plugin_list_initialized: OnceCell<bool>,
    pub signal_handlers: RefCell<HashMap<String, SignalHandlerId>>,
}

#[derive(Debug)]
pub enum AppState {
    Ready,
    Playing,
    Paused,
    Stopped,
    Error,
}

impl fmt::Display for AppState {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{:?}", self)
    }
}

// This represents our main application window.
#[derive(Debug, Clone)]
pub struct GPSApp(Rc<GPSAppInner>);

// Deref into the contained struct to make usage a bit more ergonomic
impl ops::Deref for GPSApp {
    type Target = GPSAppInner;

    fn deref(&self) -> &GPSAppInner {
        &*self.0
    }
}

// Weak reference to our application struct
//
// Weak references are important to prevent reference cycles. Reference cycles are cases where
// struct A references directly or indirectly struct B, and struct B references struct A again
// while both are using reference counting.
pub struct GPSAppWeak(Weak<GPSAppInner>);
impl GPSAppWeak {
    // Upgrade to a strong reference if it still exists
    pub fn upgrade(&self) -> Option<GPSApp> {
        self.0.upgrade().map(GPSApp)
    }
}

impl GPSApp {
    fn new(application: &gtk::Application) -> anyhow::Result<GPSApp> {
        let glade_src = include_str!("ui/gps.ui");
        let builder = Builder::from_string(glade_src);
        let window: ApplicationWindow = builder
            .object("mainwindow")
            .expect("Couldn't get the main window");
        window.set_application(Some(application));
        window.set_title(Some("GStreamer Pipeline Studio"));

        let player = GPS::Player::new().expect("Unable to initialize GStreamer subsystem");
        let app = GPSApp(Rc::new(GPSAppInner {
            window,
            graphview: RefCell::new(GM::GraphView::new()),
            builder,
            player: RefCell::new(player),
            plugin_list_initialized: OnceCell::new(),
            signal_handlers: RefCell::new(HashMap::new()),
        }));
        let app_weak = app.downgrade();
        app.player.borrow().set_app(app_weak);
        app.graphview.borrow_mut().set_id(0);

        let settings = Settings::load_settings();

        if settings.app_maximized {
            app.window.maximize();
        } else {
            app.window
                .set_size_request(settings.app_width, settings.app_height);
        }
        app.set_paned_position(&settings, "graph_dashboard-paned", 100);
        app.set_paned_position(&settings, "graph_logs-paned", 100);
        app.set_paned_position(&settings, "elements_preview-paned", 100);
        app.set_paned_position(&settings, "elements_properties-paned", 100);
        app.set_paned_position(&settings, "playcontrols_position-paned", 100);

        Ok(app)
    }

    fn set_paned_position(
        &self,
        settings: &Settings,
        paned_name: &str,
        paned_default_position: i32,
    ) {
        let paned: Paned = self
            .builder
            .object(paned_name)
            .unwrap_or_else(|| panic!("Couldn't get {}", paned_name));
        paned.set_position(
            *settings
                .paned_positions
                .get(paned_name)
                .unwrap_or(&paned_default_position),
        );
    }

    fn save_paned_position(&self, settings: &mut Settings, paned_name: &str) {
        let paned: Paned = self
            .builder
            .object(paned_name)
            .unwrap_or_else(|| panic!("Couldn't get {}", paned_name));
        settings
            .paned_positions
            .insert(paned_name.to_string(), paned.position());
    }

    pub fn on_startup(application: &gtk::Application) {
        // Create application and error out if that fails for whatever reason
        let app = match GPSApp::new(application) {
            Ok(app) => app,
            Err(err) => {
                error!("Error creating application: {}", err);
                return;
            }
        };

        // When the application is activated show the UI. This happens when the first process is
        // started, and in the first process whenever a second process is started
        let app_weak = app.downgrade();
        application.connect_activate(glib::clone!(@weak application => move |_| {
            let app = upgrade_weak!(app_weak);
            app.build_ui(&application);
        }));

        let app_weak = app.downgrade();
        let slider: gtk::Scale = app
            .builder
            .object("scale-position")
            .expect("Couldn't get status_bar");
        let slider_update_signal_id = slider.connect_value_changed(move |slider| {
            let app = upgrade_weak!(app_weak);
            let player = app.player.borrow();
            let value = slider.value() as u64;
            GPS_TRACE!("Seeking to {} s", value);
            if player.set_position(value).is_err() {
                GPS_ERROR!("Seeking to {} failed", value);
            }
        });
        let app_weak = app.downgrade();
        let timeout_id =
            glib::timeout_add_local(std::time::Duration::from_millis(500), move || {
                let app = upgrade_weak!(app_weak, glib::Continue(false));
                let player = app.player.borrow();

                let label: gtk::Label = app
                    .builder
                    .object("label-position")
                    .expect("Couldn't get status_bar");
                let slider: gtk::Scale = app
                    .builder
                    .object("scale-position")
                    .expect("Couldn't get status_bar");
                let position = player.position();
                let duration = player.duration();
                slider.set_range(0.0, duration as f64 / 1000_f64);
                slider.block_signal(&slider_update_signal_id);
                slider.set_value(position as f64 / 1000_f64);
                slider.unblock_signal(&slider_update_signal_id);

                // Query the current playing position from the underlying player.
                let position_desc = player.position_description();
                // Display the playing position in the gui.
                label.set_text(&position_desc);
                // Tell the callback to continue calling this closure.
                glib::Continue(true)
            });

        let timeout_id = RefCell::new(Some(timeout_id));
        let app_container = RefCell::new(Some(app));

        application.connect_shutdown(move |_| {
            let app = app_container
                .borrow_mut()
                .take()
                .expect("Shutdown called multiple times");
            let window: ApplicationWindow = app
                .builder
                .object("mainwindow")
                .expect("Couldn't get the main window");
            let mut settings = Settings::load_settings();
            settings.app_maximized = window.is_maximized();
            settings.app_width = window.width();
            settings.app_height = window.height();
            app.save_paned_position(&mut settings, "graph_dashboard-paned");
            app.save_paned_position(&mut settings, "graph_logs-paned");
            app.save_paned_position(&mut settings, "elements_preview-paned");
            app.save_paned_position(&mut settings, "elements_properties-paned");
            app.save_paned_position(&mut settings, "playcontrols_position-paned");

            Settings::save_settings(&settings);

            let pop_menu: PopoverMenu = app
                .builder
                .object("app_pop_menu")
                .expect("Couldn't get app_pop_menu");
            pop_menu.unparent();
            if let Some(timeout_id) = timeout_id.borrow_mut().take() {
                timeout_id.remove();
            }

            app.drop();
        });
    }

    fn setup_app_actions(&self, application: &gtk::Application) {
        application.add_action(&gio::SimpleAction::new("new-window", None));
        application.set_accels_for_action("app.new-window", &["<primary>n"]);

        application.add_action(&gio::SimpleAction::new("open", None));
        application.set_accels_for_action("app.open", &["<primary>o"]);

        application.add_action(&gio::SimpleAction::new("save_as", None));
        application.set_accels_for_action("app.save", &["<primary>s"]);

        application.add_action(&gio::SimpleAction::new("delete", None));
        application.set_accels_for_action("app.delete", &["<primary>d", "Delete"]);

        application.add_action(&gio::SimpleAction::new("preferences", None));
        application.set_accels_for_action("app.preferences", &["<primary>p"]);

        application.add_action(&gio::SimpleAction::new("about", None));
        application.set_accels_for_action("app.about", &["<primary>a"]);

        application.add_action(&gio::SimpleAction::new("favorite.remove", None));

        application.add_action(&gio::SimpleAction::new("graph.check", None));
        application.add_action(&gio::SimpleAction::new("graph.pipeline_details", None));

        application.add_action(&gio::SimpleAction::new("port.delete", None));
        application.add_action(&gio::SimpleAction::new("port.properties", None));

        application.add_action(&gio::SimpleAction::new("node.add-to-favorite", None));
        application.add_action(&gio::SimpleAction::new("node.delete", None));
        application.add_action(&gio::SimpleAction::new("node.request-pad-input", None));
        application.add_action(&gio::SimpleAction::new("node.request-pad-output", None));
        application.add_action(&gio::SimpleAction::new("node.properties", None));
    }

    pub fn app_pop_menu_at_position(
        &self,
        widget: &impl IsA<Widget>,
        x: f64,
        y: f64,
    ) -> PopoverMenu {
        let mainwindow: ApplicationWindow = self
            .builder
            .object("mainwindow")
            .expect("Couldn't get the main window");

        let pop_menu: PopoverMenu = self
            .builder
            .object("app_pop_menu")
            .expect("Couldn't get app_pop_menu");

        if let Some((x, y)) = widget.translate_coordinates(&mainwindow, x, y) {
            let point = graphene::Point::new(x as f32, y as f32);
            pop_menu.set_pointing_to(Some(&gdk::Rectangle::new(
                point.to_vec2().x() as i32,
                point.to_vec2().y() as i32,
                0,
                0,
            )));
        }
        pop_menu
    }

    fn app_menu_action(&self, action_name: &str) -> SimpleAction {
        let application = gio::Application::default()
            .expect("No default application")
            .downcast::<gtk::Application>()
            .expect("Unable to downcast default application");

        application
            .lookup_action(action_name)
            .unwrap_or_else(|| panic!("Unable to find action {}", action_name))
            .dynamic_cast::<SimpleAction>()
            .expect("Unable to dynamic cast to SimpleAction")
    }

    fn disconnect_app_menu_action(&self, action_name: &str) {
        let action = self.app_menu_action(action_name);

        if let Some(signal_handler_id) = self.signal_handlers.borrow_mut().remove(action_name) {
            action.disconnect(signal_handler_id);
        }
    }

    pub fn connect_app_menu_action<
        F: Fn(&SimpleAction, std::option::Option<&glib::Variant>) + 'static,
    >(
        &self,
        action_name: &str,
        f: F,
    ) {
        let action = self.app_menu_action(action_name);
        self.disconnect_app_menu_action(action_name);
        let signal_handler_id = action.connect_activate(f);
        self.signal_handlers
            .borrow_mut()
            .insert(String::from(action_name), signal_handler_id);
    }

    fn connect_button_action<F: Fn(&Button) + 'static>(&self, button_name: &str, f: F) {
        let button: Button = self
            .builder
            .object(button_name)
            .unwrap_or_else(|| panic!("Couldn't get app_button {}", button_name));
        button.connect_clicked(f);
    }

    fn get_file_from_dialog<F: Fn(GPSApp, String) + 'static>(app: &GPSApp, save: bool, f: F) {
        let mut message = "Open file";
        let mut ok_button = "Open";
        let cancel_button = "Cancel";
        let mut action = FileChooserAction::Open;
        if save {
            message = "Save file";
            ok_button = "Save";
            action = FileChooserAction::Save;
        }
        let window: ApplicationWindow = app
            .builder
            .object("mainwindow")
            .expect("Couldn't get main window");
        let file_chooser: FileChooserDialog = FileChooserDialog::new(
            Some(message),
            Some(&window),
            action,
            &[
                (ok_button, ResponseType::Ok),
                (cancel_button, ResponseType::Cancel),
            ],
        );
        let app_weak = app.downgrade();
        file_chooser.connect_response(move |d: &FileChooserDialog, response: ResponseType| {
            let app = upgrade_weak!(app_weak);
            if response == ResponseType::Ok {
                let file = d.file().expect("Couldn't get file");
                let filename = String::from(
                    file.path()
                        .expect("Couldn't get file path")
                        .to_str()
                        .expect("Unable to convert to string"),
                );
                f(app, filename);
            }

            d.close();
        });

        file_chooser.show();
    }

    pub fn set_app_state(&self, state: AppState) {
        let status_bar: Statusbar = self
            .builder
            .object("status_bar")
            .expect("Couldn't get status_bar");
        status_bar.push(status_bar.context_id("Description"), &state.to_string());
    }

    pub fn set_app_preview(&self, paintable: &gdk::Paintable, n_sink: usize) {
        let picture = gtk::Picture::new();
        picture.set_paintable(Some(paintable));
        let notebook_preview: gtk::Notebook = self
            .builder
            .object("notebook-preview")
            .expect("Couldn't get box_preview");
        if n_sink == 0 {
            loop {
                let i = notebook_preview.n_pages();
                if i == 0 {
                    break;
                }
                notebook_preview.remove_page(Some(i - 1));
            }
        }
        let box_preview = gtk::Box::builder()
            .orientation(gtk::Orientation::Vertical)
            .halign(gtk::Align::Center)
            .valign(gtk::Align::Center)
            .build();
        box_preview.append(&picture);
        let label = gtk::Label::new(Some(&format!("Preview{}", n_sink)));
        notebook_preview.insert_page(&box_preview, Some(&label), None);
    }

    pub fn build_ui(&self, application: &Application) {
        let drawing_area_window: Viewport = self
            .builder
            .object("drawing_area")
            .expect("Couldn't get drawing_area");

        drawing_area_window.set_child(Some(&*self.graphview.borrow()));

        // Setup the logger to get messages into the TreeView
        let (ready_tx, ready_rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
        let app_weak = self.downgrade();
        logger::init_logger(
            ready_tx,
            Settings::default_log_file_path()
                .to_str()
                .expect("Unable to convert log file path to a string"),
        );
        GPSUI::logger::setup_logger_list(self);
        let _ = ready_rx.attach(None, move |msg: String| {
            let app = upgrade_weak!(app_weak, glib::Continue(false));
            GPSUI::logger::add_to_logger_list(&app, &msg);
            glib::Continue(true)
        });

        let window = &self.window;

        window.show();
        self.set_app_state(AppState::Ready);
        self.setup_app_actions(application);

        let pop_menu: PopoverMenu = self
            .builder
            .object("app_pop_menu")
            .expect("Couldn't get app_pop_menu");
        pop_menu.set_parent(window);

        let app_weak = self.downgrade();
        self.connect_app_menu_action("new-window", move |_, _| {
            let app = upgrade_weak!(app_weak);
            app.clear_graph();
            GPS_ERROR!("clear graph");
        });

        let app_weak = self.downgrade();
        self.connect_app_menu_action("open", move |_, _| {
            let app = upgrade_weak!(app_weak);
            GPSApp::get_file_from_dialog(&app, false, move |app, filename| {
                app.load_graph(&filename)
                    .unwrap_or_else(|_| GPS_ERROR!("Unable to open file {}", filename));
                Settings::add_recent_open_file(&filename);
            });
        });

        let app_weak = self.downgrade();
        self.connect_app_menu_action("save_as", move |_, _| {
            let app = upgrade_weak!(app_weak);
            GPSApp::get_file_from_dialog(&app, true, move |app, filename| {
                GPS_DEBUG!("Save file {}", filename);
                app.save_graph(&filename)
                    .unwrap_or_else(|_| GPS_ERROR!("Unable to save file to {}", filename));
            });
        });

        let app_weak = self.downgrade();
        self.connect_app_menu_action("preferences", move |_, _| {
            let app = upgrade_weak!(app_weak);
            GPSUI::preferences::display_settings(&app);
        });

        let app_weak = self.downgrade();
        self.connect_app_menu_action("delete", move |_, _| {
            let app = upgrade_weak!(app_weak);
            let graph_view = app.graphview.borrow();
            graph_view.delete_selected();
        });

        let app_weak = self.downgrade();
        self.connect_app_menu_action("about", move |_, _| {
            let app = upgrade_weak!(app_weak);
            GPSUI::about::display_about_dialog(&app);
        });

        let app_weak = self.downgrade();
        self.connect_button_action("button-play", move |_| {
            let app = upgrade_weak!(app_weak);
            let graph_view = app.graphview.borrow();
            let _ = app
                .player
                .borrow()
                .start_pipeline(&graph_view, GPS::PipelineState::Playing);
        });

        let app_weak = self.downgrade();
        self.connect_button_action("button-pause", move |_| {
            let app = upgrade_weak!(app_weak);
            let graph_view = app.graphview.borrow();
            let _ = app
                .player
                .borrow()
                .start_pipeline(&graph_view, GPS::PipelineState::Paused);
        });

        let app_weak = self.downgrade();
        self.connect_button_action("button-stop", move |_| {
            let app = upgrade_weak!(app_weak);
            let player = app.player.borrow();
            let _ = player.set_state(GPS::PipelineState::Stopped);
        });

        let app_weak = self.downgrade();
        self.connect_button_action("button-clear", move |_| {
            let app = upgrade_weak!(app_weak);
            app.clear_graph();
        });
        let app_weak = self.downgrade();
        self.graphview.borrow().connect_local(
            "node-added",
            false,
            glib::clone!(@weak application =>  @default-return None, move |values: &[Value]| {
                let app = upgrade_weak!(app_weak, None);
                let graph_id = values[1].get::<u32>().expect("graph id in args[1]");
                let node_id = values[2].get::<u32>().expect("node id in args[2]");
                GPS_INFO!("Node added node id={} in graph id={}", node_id, graph_id);
                if let Some(node) = app.graphview.borrow().node(node_id) {
                    let description = GPS::ElementInfo::element_description(&node.name()).ok();
                    node.set_tooltip_markup(description.as_deref());
                    for port in node.all_ports(GM::PortDirection::All) {
                        let caps = PropertyExt::property(&port,"_caps");
                        GPS_TRACE!("caps={} for port id {}", caps.clone().unwrap_or_else(|| "caps unknown".to_string()), port.id());
                        port.set_tooltip_markup(caps.as_deref());
                    }
                }

                None
            }),
        );
        let app_weak = self.downgrade();
        self.graphview.borrow().connect_local(
            "port-added",
            false,
            glib::clone!(@weak application =>  @default-return None, move |values: &[Value]| {
                let app = upgrade_weak!(app_weak, None);
                let graph_id = values[1].get::<u32>().expect("graph id in args[1]");
                let node_id = values[2].get::<u32>().expect("node id in args[2]");
                let port_id = values[3].get::<u32>().expect("port id in args[3]");
                GPS_INFO!("Port added port id={} to node id={} in graph id={}", port_id, node_id, graph_id);
                if let Some(node) = app.graphview.borrow().node(node_id) {
                    if let Some(port) = node.port(port_id) {
                        let caps = PropertyExt::property(&port, "_caps");
                        GPS_TRACE!("caps={} for port id {}", caps.clone().unwrap_or_else(|| "caps unknown".to_string()), port.id());
                        port.set_tooltip_markup(caps.as_deref());
                    }
                }
                None
            }),
        );
        let app_weak = self.downgrade();
        self.graphview.borrow().connect_local(
            "graph-updated",
            false,
            glib::clone!(@weak application =>  @default-return None, move |values: &[Value]| {
                let app = upgrade_weak!(app_weak, None);
                let id = values[1].get::<u32>().expect("id in args[1]");
                GPS_TRACE!("Graph updated id={}", id);
                let _ = app
                    .save_graph(
                        Settings::default_graph_file_path()
                            .to_str()
                            .expect("Unable to convert to string"),
                    )
                    .map_err(|e| GPS_WARN!("Unable to save file {}", e));
                None
            }),
        );
        // When user clicks on port with right button
        let app_weak = self.downgrade();
        self.graphview
            .borrow()
            .connect_local(
                "graph-right-clicked",
                false,
                glib::clone!(@weak application =>  @default-return None, move |values: &[Value]| {
                    let app = upgrade_weak!(app_weak, None);
                    let point = values[1].get::<graphene::Point>().expect("point in args[2]");

                    let pop_menu = app.app_pop_menu_at_position(&*app.graphview.borrow(), point.to_vec2().x() as f64, point.to_vec2().y() as f64);
                    let menu: gio::MenuModel = app
                    .builder
                    .object("graph_menu")
                    .expect("Couldn't graph_menu");
                    pop_menu.set_menu_model(Some(&menu));

                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("graph.check",
                        move |_,_| {
                            let app = upgrade_weak!(app_weak);
                            let render_parse_launch = app.player.borrow().render_gst_launch(&app.graphview.borrow());
                            if app.player.borrow().create_pipeline(&render_parse_launch).is_ok() {
                                GPSUI::message::display_message_dialog(&render_parse_launch,gtk::MessageType::Info, |_| {});
                            } else {
                                GPSUI::message::display_error_dialog(false, &format!("Unable to render:\n\n{}", render_parse_launch));
                            }
                        }
                    );
                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("graph.pipeline_details",
                        move |_,_| {
                            let app = upgrade_weak!(app_weak);
                            GPSUI::properties::display_pipeline_details(&app);
                        }
                    );
                    pop_menu.show();
                    None
                }),
            );

        // When user clicks on port with right button
        let app_weak = self.downgrade();
        self.graphview.borrow().connect_local(
            "port-right-clicked",
            false,
            move |values: &[Value]| {
                let app = upgrade_weak!(app_weak, None);

                let port_id = values[1].get::<u32>().expect("port id args[1]");
                let node_id = values[2].get::<u32>().expect("node id args[2]");
                let point = values[3]
                    .get::<graphene::Point>()
                    .expect("point in args[3]");

                let pop_menu = app.app_pop_menu_at_position(
                    &*app.graphview.borrow(),
                    point.to_vec2().x() as f64,
                    point.to_vec2().y() as f64,
                );
                let menu: gio::MenuModel = app
                    .builder
                    .object("port_menu")
                    .expect("Couldn't get menu model for port");
                pop_menu.set_menu_model(Some(&menu));

                if app.graphview.borrow().can_remove_port(node_id, port_id) {
                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("port.delete", move |_, _| {
                        let app = upgrade_weak!(app_weak);
                        GPS_TRACE!("port.delete-link port {} node {}", port_id, node_id);
                        app.graphview.borrow().remove_port(node_id, port_id);
                    });
                } else {
                    app.disconnect_app_menu_action("port.delete");
                }

                let app_weak = app.downgrade();
                app.connect_app_menu_action("port.properties", move |_, _| {
                    let app = upgrade_weak!(app_weak);
                    GPS_TRACE!("port.properties port {} node {}", port_id, node_id);
                    let node = app.node(node_id);
                    let port = app.port(node_id, port_id);
                    GPSUI::properties::display_pad_properties(
                        &app,
                        &node.name(),
                        &port.name(),
                        node_id,
                        port_id,
                    );
                });
                pop_menu.show();
                None
            },
        );

        // When user clicks on node with right button
        let app_weak = self.downgrade();
        self.graphview
            .borrow()
            .connect_local(
                "node-right-clicked",
                false,
                glib::clone!(@weak application =>  @default-return None, move |values: &[Value]| {
                    let app = upgrade_weak!(app_weak, None);

                    let node_id = values[1].get::<u32>().expect("node id args[1]");
                    let point = values[2].get::<graphene::Point>().expect("point in args[2]");

                    let pop_menu = app.app_pop_menu_at_position(&*app.graphview.borrow(), point.to_vec2().x() as f64, point.to_vec2().y() as f64);
                    let menu: gio::MenuModel = app
                        .builder
                        .object("node_menu")
                        .expect("Couldn't get menu model for node");
                    pop_menu.set_menu_model(Some(&menu));

                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("node.add-to-favorite",
                        move |_,_| {
                            let app = upgrade_weak!(app_weak);
                            GPS_DEBUG!("node.add-to-favorite {}", node_id);
                            if let Some(node) = app.graphview.borrow().node(node_id) {
                                GPSUI::elements::add_to_favorite_list(&app, node.name());
                            };
                        }
                    );

                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("node.delete",
                        move |_,_| {
                            let app = upgrade_weak!(app_weak);
                            GPS_DEBUG!("node.delete {}", node_id);
                            app.graphview.borrow_mut().remove_node(node_id);
                        }
                    );
                    let node = app.node(node_id);
                    if let Some(input) = GPS::ElementInfo::element_supports_new_pad_request(&node.name(),  GM::PortDirection::Input) {
                        let app_weak = app.downgrade();
                        app.connect_app_menu_action("node.request-pad-input",
                            move |_,_| {
                                let app = upgrade_weak!(app_weak);
                                GPS_DEBUG!("node.request-pad-input {}", node_id);
                                app.create_port_with_caps(node_id, GM::PortDirection::Input, GM::PortPresence::Sometimes, input.caps().to_string())
                            }
                        );
                    } else {
                        app.disconnect_app_menu_action("node.request-pad-input");
                    }
                    let node = app.node(node_id);
                    if let Some(output) = GPS::ElementInfo::element_supports_new_pad_request(&node.name(),  GM::PortDirection::Output) {
                        let app_weak = app.downgrade();
                        app.connect_app_menu_action("node.request-pad-output",
                            move |_,_| {
                                let app = upgrade_weak!(app_weak);
                                GPS_DEBUG!("node.request-pad-output {}", node_id);
                                app.create_port_with_caps(node_id, GM::PortDirection::Output, GM::PortPresence::Sometimes, output.caps().to_string());
                            }
                        );
                    } else {
                        app.disconnect_app_menu_action("node.request-pad-output");
                    }

                    let app_weak = app.downgrade();
                    app.connect_app_menu_action("node.properties",
                        move |_,_| {
                            let app = upgrade_weak!(app_weak);
                            GPS_DEBUG!("node.properties {}", node_id);
                            let node = app.graphview.borrow().node(node_id).unwrap();
                            GPSUI::properties::display_plugin_properties(&app, &node.name(), node_id);
                        }
                    );

                    pop_menu.show();
                    None
                }),
            );

        // Setup the favorite list
        GPSUI::elements::setup_favorite_list(self);
        // Setup the favorite list
        GPSUI::elements::setup_elements_list(self);

        let _ = self
            .load_graph(
                Settings::default_graph_file_path()
                    .to_str()
                    .expect("Unable to convert to string"),
            )
            .map_err(|_e| {
                GPS_WARN!("Unable to load default graph");
            });
    }

    // Downgrade to a weak reference
    pub fn downgrade(&self) -> GPSAppWeak {
        GPSAppWeak(Rc::downgrade(&self.0))
    }

    // Called when the application shuts down. We drop our app struct here
    fn drop(self) {}

    pub fn add_new_element(&self, element_name: &str) {
        let graphview = self.graphview.borrow();
        let (inputs, outputs) = GPS::PadInfo::pads(element_name, false);
        let node =
            graphview.create_node(element_name, GPS::ElementInfo::element_type(element_name));
        let node_id = node.id();
        if GPS::ElementInfo::element_is_uri_src_handler(element_name) {
            GPSApp::get_file_from_dialog(self, false, move |app, filename| {
                GPS_DEBUG!("Open file {}", filename);
                let graphview = app.graphview.borrow();
                let mut properties: HashMap<String, String> = HashMap::new();
                properties.insert(String::from("location"), filename);
                if let Some(node) = graphview.node(node_id) {
                    node.update_properties(&properties);
                }
            });
        }
        graphview.add_node(node);
        for input in inputs {
            self.create_port_with_caps(
                node_id,
                GM::PortDirection::Input,
                GM::PortPresence::Always,
                input.caps().to_string(),
            );
        }
        for output in outputs {
            self.create_port_with_caps(
                node_id,
                GM::PortDirection::Output,
                GM::PortPresence::Always,
                output.caps().to_string(),
            );
        }
    }

    fn node(&self, node_id: u32) -> GM::Node {
        let node = self
            .graphview
            .borrow()
            .node(node_id)
            .unwrap_or_else(|| panic!("Unable to retrieve node with id {}", node_id));
        node
    }

    fn port(&self, node_id: u32, port_id: u32) -> GM::Port {
        let node = self.node(node_id);
        node.port(port_id)
            .unwrap_or_else(|| panic!("Unable to retrieve port with id {}", port_id))
    }

    pub fn update_element_properties(&self, node_id: u32, properties: &HashMap<String, String>) {
        let node = self.node(node_id);
        node.update_properties(properties);
    }

    pub fn update_pad_properties(
        &self,
        node_id: u32,
        port_id: u32,
        properties: &HashMap<String, String>,
    ) {
        let port = self.port(node_id, port_id);
        port.update_properties(properties);
    }

    pub fn element_property(&self, node_id: u32, property_name: &str) -> Option<String> {
        let node = self.node(node_id);
        PropertyExt::property(&node, property_name)
    }

    pub fn pad_properties(&self, node_id: u32, port_id: u32) -> HashMap<String, String> {
        let port = self.port(node_id, port_id);
        let mut properties: HashMap<String, String> = HashMap::new();
        for (name, value) in port.properties().iter() {
            if !port.hidden_property(name) {
                properties.insert(name.to_string(), value.to_string());
            }
        }
        properties
    }

    fn create_port_with_caps(
        &self,
        node_id: u32,
        direction: GM::PortDirection,
        presence: GM::PortPresence,
        caps: String,
    ) {
        let node = self.node(node_id);
        let ports = node.all_ports(direction);
        let port_name = match direction {
            GM::PortDirection::Input => String::from("sink_"),
            GM::PortDirection::Output => String::from("src_"),
            _ => String::from("?"),
        };
        let graphview = self.graphview.borrow();
        let port_name = format!("{}{}", port_name, ports.len());
        let port = graphview.create_port(&port_name, direction, presence);
        let properties: HashMap<String, String> = HashMap::from([("_caps".to_string(), caps)]);
        port.update_properties(&properties);
        if let Some(mut node) = graphview.node(node_id) {
            graphview.add_port_to_node(&mut node, port);
        }
    }

    fn clear_graph(&self) {
        let graph_view = self.graphview.borrow();
        graph_view.clear();
    }

    fn save_graph(&self, filename: &str) -> anyhow::Result<()> {
        let graph_view = self.graphview.borrow();
        let mut file = File::create(filename)?;
        let buffer = graph_view.render_xml()?;
        file.write_all(&buffer)?;

        Ok(())
    }

    fn load_graph(&self, filename: &str) -> anyhow::Result<()> {
        let graph_view = self.graphview.borrow();
        let mut file = File::open(filename)?;
        let mut buffer = Vec::new();
        file.read_to_end(&mut buffer).expect("buffer overflow");
        graph_view.load_from_xml(buffer)?;
        Ok(())
    }
}