how to use

[HeisenBerg?]

this is maybe a dumb question due to my limited knowledge of rust, can you give me some help about use this one

/// We derive Deserialize/Serialize so we can persist app state on shutdown.
#[derive(serde::Deserialize, serde::Serialize)]
#[serde(default)] // if we add new fields, give them default values when deserializing old state
use egui_file::FileDialog;
use std::path::PathBuf;

pub struct TemplateApp {
    // Example stuff:
    label: String,

    #[serde(skip)] // This how you opt-out of serialization of a field
    value: f32,
    opened_file: Option<PathBuf>,
    open_file_dialog: Option<FileDialog>,   

}

impl Default for TemplateApp {
    fn default() -> Self {
        Self {
            // Example stuff:
            label: "Hello World!".to_owned(),
            value: 2.7,
            opened_file: '',
            open_file_dialog: '',   
        }
    }
}

impl TemplateApp {
    /// Called once before the first frame.
    pub fn new(cc: &eframe::CreationContext<'_>) -> Self {
        // This is also where you can customize the look and feel of egui using
        // `cc.egui_ctx.set_visuals` and `cc.egui_ctx.set_fonts`.

        // Load previous app state (if any).
        // Note that you must enable the `persistence` feature for this to work.
        if let Some(storage) = cc.storage {
            return eframe::get_value(storage, eframe::APP_KEY).unwrap_or_default();
        }

        Default::default()
    }
}

impl eframe::App for TemplateApp {
    /// Called by the frame work to save state before shutdown.
    fn save(&mut self, storage: &mut dyn eframe::Storage) {
        eframe::set_value(storage, eframe::APP_KEY, self);
    }

    /// Called each time the UI needs repainting, which may be many times per second.
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        // Put your widgets into a `SidePanel`, `TopPanel`, `CentralPanel`, `Window` or `Area`.
        // For inspiration and more examples, go to https://emilk.github.io/egui
 
        egui::TopBottomPanel::top("top_panel").show(ctx, |ui| {
            // The top panel is often a good place for a menu bar:

            egui::menu::bar(ui, |ui| {
                #[cfg(not(target_arch = "wasm32"))] // no File->Quit on web pages!
                {
                    ui.menu_button("File", |ui| {
                        if ui.button("Quit").clicked() {
                            _frame.close();
                        }
                    });
                    ui.add_space(16.0);
                }

                egui::widgets::global_dark_light_mode_buttons(ui);
            });
        });

        egui::CentralPanel::default().show(ctx, |ui| {
            
            // The central panel the region left after adding TopPanel's and SidePanel's
            ui.heading("eframe template");

            ui.horizontal(|ui| {
                ui.label("Write something: ");
                ui.text_edit_singleline(&mut self.label);
            });

            ui.add(egui::Slider::new(&mut self.value, 0.0..=10.0).text("value"));
            if ui.button("Increment").clicked() {
                self.value += 1.0;
            }

            ui.separator();
            if (ui.button("Open")).clicked() {
                let mut dialog = FileDialog::open_file(self.opened_file.clone());
                dialog.open();
                self.open_file_dialog = Some(dialog);
              }
        
              if let Some(dialog) = &mut self.open_file_dialog {
                if dialog.show(ctx).selected() {
                  if let Some(file) = dialog.path() {
                    self.opened_file = Some(file);
                  }
                }
              }
              if (ui.button("Open")).clicked() {
                let mut dialog = FileDialog::open_file(self.opened_file.clone());
                dialog.open();
                self.open_file_dialog = Some(dialog);
              }
        
              if let Some(dialog) = &mut self.open_file_dialog {
                if dialog.show(ctx).selected() {
                  if let Some(file) = dialog.path() {
                    self.opened_file = Some(file);
                  }
                }
              }

            ui.add(egui::github_link_file!(
                "https://github.com/emilk/eframe_template/blob/master/",
                "Source code."
            ));

            ui.with_layout(egui::Layout::bottom_up(egui::Align::LEFT), |ui| {
                powered_by_egui_and_eframe(ui);
                egui::warn_if_debug_build(ui);
            });
        });
    }
}

fn powered_by_egui_and_eframe(ui: &mut egui::Ui) {
    ui.horizontal(|ui| {
        ui.spacing_mut().item_spacing.x = 0.0;
        ui.label("Powered by ");
        ui.hyperlink_to("egui", "https://github.com/emilk/egui");
        ui.label(" and ");
        ui.hyperlink_to(
            "eframe",
            "https://github.com/emilk/egui/tree/master/crates/eframe",
        );
        ui.label(".");
    });
}

[Barugon]

You need something like this in update:

  if let Some(dialog) = &mut self.open_file_dialog {
    if !dialog.show(ctx).visible() {
      if dialog.selected() {
        if let Some(path) = dialog.path() {
          // Do something with the file path.
          ...
        }
      }
      self.open_file_dialog = None;
    }
  }

Examples

https://github.com/Barugon/cota/blob/3327fba8f673fab8286c9ace0e971126abd91792/src/app.rs#L387
https://github.com/Barugon/fp_app/blob/2bfcd5de4344105a40193b9cc7179066721c89b4/src/app.rs#L425