Dialogs

For the open and save dialog, we'll use the same functions as in the previous chapter:

use std::path::PathBuf;

use gtk::{FileChooserAction, FileChooserDialog, FileFilter};
use gtk_sys::{GTK_RESPONSE_ACCEPT, GTK_RESPONSE_CANCEL};

const RESPONSE_ACCEPT: i32 = GTK_RESPONSE_ACCEPT as i32;
const RESPONSE_CANCEL: i32 = GTK_RESPONSE_CANCEL as i32;

fn show_open_dialog(parent: &Window) -> Option<PathBuf> {
    let mut file = None;
    let dialog = FileChooserDialog::new(Some("Select an MP3 audio file"), 
    Some(parent), FileChooserAction::Open);

    let mp3_filter = FileFilter::new();
    mp3_filter.add_mime_type("audio/mp3");
    mp3_filter.set_name("MP3 audio file");
    dialog.add_filter(&mp3_filter);

    let m3u_filter = FileFilter::new();
    m3u_filter.add_mime_type("audio/x-mpegurl");
    m3u_filter.set_name("M3U playlist file");
    dialog.add_filter(&m3u_filter);

    dialog.add_button("Cancel", RESPONSE_CANCEL);
    dialog.add_button("Accept", RESPONSE_ACCEPT);
    let result = dialog.run();
    if result == RESPONSE_ACCEPT {
        file = dialog.get_filename();
    }
    dialog.destroy();
    file
}

fn show_save_dialog(parent: &Window) -> Option<PathBuf> {
    let mut file = None;
    let dialog = FileChooserDialog::new(Some("Choose a destination M3U playlist 
    file"), Some(parent), FileChooserAction::Save);
    let filter = FileFilter::new();
    filter.add_mime_type("audio/x-mpegurl");
    filter.set_name("M3U playlist file");
    dialog.set_do_overwrite_confirmation(true);
    dialog.add_filter(&filter);
    dialog.add_button("Cancel", RESPONSE_CANCEL);
    dialog.add_button("Save", RESPONSE_ACCEPT);
    let result = dialog.run();
    if result == RESPONSE_ACCEPT {
        file = dialog.get_filename();
    }
    dialog.destroy();
    file
}

But this time, we'll put the code for the open action in a method on the App widget:

use gtk::{ButtonsType, DialogFlags, MessageDialog, MessageType};

impl App {
    fn open(&self) {
        let file = show_open_dialog(&self.window);
        if let Some(file) = file {
            let ext = file.extension().map(|ext| 
             ext.to_str().unwrap().to_string());
            if let Some(ext) = ext {
                match ext.as_str() {
                    "mp3" => (),
                    "m3u" => (),
                    extension => {
                        let dialog = 
                        MessageDialog::new(Some(&self.window),  
                        DialogFlags::empty(), MessageType::Error,
                        ButtonsType::Ok, &format!("Cannot open file 
                         with extension . {}", extension));
                        dialog.run();
                        dialog.destroy();
                    },
                }
            }
        }
    }
}

We can then call these functions in the update() method:

fn update(&mut self, event: Msg) {
    match event {
        Open => self.open(),
        PlayPause =>  (),
        Quit => gtk::main_quit(),
        Save => show_save_dialog(&self.window),
        Stop => (),
    }
}

Let's manage some of the other actions.