refactor: combine open and save dialogs

examples/open-dialog/src/main.rs

@@ -5,7 +5,7 @@
 
 use apply::Apply;
 use cosmic::app::{Command, Core, Settings};
-use cosmic::dialog::{open_file, FileFilter};
+use cosmic::dialog::file_chooser::{self, FileFilter};
 use cosmic::iced_core::Length;
 use cosmic::{executor, iced, ApplicationExt, Element};
 use tokio::io::AsyncReadExt;
@@ -27,7 +27,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 pub enum Message {
     CloseError,
     DialogClosed,
-    DialogInit(open_file::Sender),
+    DialogInit(file_chooser::Sender),
     DialogOpened,
     Error(String),
     FileRead(Url, String),
@@ -38,7 +38,7 @@ pub enum Message {
 /// The [`App`] stores application-specific state.
 pub struct App {
     core: Core,
-    open_sender: Option<open_file::Sender>,
+    open_sender: Option<file_chooser::Sender>,
     file_contents: String,
     selected_file: Option<Url>,
     error_status: Option<String>,
@@ -90,15 +90,15 @@ impl cosmic::Application for App {
 
     fn subscription(&self) -> cosmic::iced_futures::Subscription<Self::Message> {
         // Creates a subscription for handling open dialogs.
-        open_file::subscription(|response| match response {
-            open_file::Message::Closed => Message::DialogClosed,
-            open_file::Message::Opened => Message::DialogOpened,
-            open_file::Message::Selected(files) => match files.uris().first() {
+        file_chooser::subscription(|response| match response {
+            file_chooser::Message::Closed => Message::DialogClosed,
+            file_chooser::Message::Opened => Message::DialogOpened,
+            file_chooser::Message::Selected(files) => match files.uris().first() {
                 Some(file) => Message::Selected(file.to_owned()),
                 None => Message::DialogClosed,
             },
-            open_file::Message::Init(sender) => Message::DialogInit(sender),
-            open_file::Message::Err(why) => {
+            file_chooser::Message::Init(sender) => Message::DialogInit(sender),
+            file_chooser::Message::Err(why) => {
                 let mut source: &dyn std::error::Error = &why;
                 let mut string = format!("open dialog subscription errored\n    cause: {source}");
 
@@ -180,7 +180,7 @@ impl cosmic::Application for App {
             // Creates a new open dialog.
             Message::OpenFile => {
                 if let Some(sender) = self.open_sender.as_mut() {
-                    if let Some(dialog) = open_file::builder() {
+                    if let Some(dialog) = file_chooser::open_file() {
                         eprintln!("opening new dialog");
 
                         return dialog

src/command/mod.rs

@@ -23,7 +23,7 @@ pub fn batch<M>(commands: impl IntoIterator<Item = Command<M>>) -> Command<M> {
     Command::batch(commands)
 }
 
-/// Yields a command which will run the future on thet runtime executor.
+/// Yields a command which will run the future on the runtime executor.
 pub fn future<M: Send + 'static>(future: impl Future<Output = M> + Send + 'static) -> Command<M> {
     Command::single(Action::Future(Box::pin(future)))
 }

src/dialog/file_chooser/mod.rs

@@ -0,0 +1,216 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+//! Dialogs for opening and save files.
+
+pub mod open;
+pub mod save;
+
+pub use ashpd::desktop::file_chooser::{Choice, FileFilter, SelectedFiles};
+use iced::futures::{channel, SinkExt, StreamExt};
+use iced::{Command, Subscription};
+use std::sync::atomic::{AtomicBool, Ordering};
+use thiserror::Error;
+
+/// Prevents duplicate file chooser dialog requests.
+static OPENED: AtomicBool = AtomicBool::new(false);
+
+/// Whether a file chooser dialog is currently active.
+fn dialog_active() -> bool {
+    OPENED.load(Ordering::Relaxed)
+}
+
+/// Sets the existence of a file chooser dialog.
+fn dialog_active_set(value: bool) {
+    OPENED.store(value, Ordering::SeqCst);
+}
+
+/// Creates an [`open::Dialog`] if no other file chooser exists.
+pub fn open_file() -> Option<open::Dialog> {
+    if dialog_active() {
+        None
+    } else {
+        Some(open::Dialog::new())
+    }
+}
+
+/// Creates a [`save::Dialog`] if no other file chooser exists.
+pub fn save_file() -> Option<save::Dialog> {
+    if dialog_active() {
+        None
+    } else {
+        Some(save::Dialog::new())
+    }
+}
+
+/// Creates a subscription for file chooser events.
+pub fn subscription<M: Send + 'static>(handle: fn(Message) -> M) -> Subscription<M> {
+    let type_id = std::any::TypeId::of::<Handler<M>>();
+
+    iced::subscription::channel(type_id, 1, move |output| async move {
+        let mut state = Handler {
+            active: None,
+            handle,
+            output,
+        };
+
+        loop {
+            let (sender, mut receiver) = channel::mpsc::channel(1);
+
+            state.emit(Message::Init(Sender(sender))).await;
+
+            while let Some(request) = receiver.next().await {
+                match request {
+                    Request::Close => state.close().await,
+
+                    Request::Open(dialog) => {
+                        state.open(dialog).await;
+                        dialog_active_set(false);
+                    }
+
+                    Request::Save(dialog) => {
+                        state.save(dialog).await;
+                        dialog_active_set(false);
+                    }
+
+                    Request::Response => state.response().await,
+                }
+            }
+        }
+    })
+}
+
+/// Errors that my occur when interacting with the file chooser subscription
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("dialog close failed")]
+    Close(#[source] ashpd::Error),
+    #[error("dialog open failed")]
+    Open(#[source] ashpd::Error),
+    #[error("dialog response failed")]
+    Response(#[source] ashpd::Error),
+}
+
+/// Requests for the file chooser subscription
+enum Request {
+    Close,
+    Open(open::Dialog),
+    Save(save::Dialog),
+    Response,
+}
+
+/// Messages from the file chooser subscription.
+pub enum Message {
+    Closed,
+    Err(Error),
+    Init(Sender),
+    Opened,
+    Selected(SelectedFiles),
+}
+
+/// Sends requests to the file chooser subscription.
+#[derive(Clone, Debug)]
+pub struct Sender(channel::mpsc::Sender<Request>);
+
+impl Sender {
+    /// Creates a [`Command`] that closes a file chooser dialog.
+    pub fn close(&mut self) -> Command<()> {
+        let mut sender = self.0.clone();
+
+        crate::command::future(async move {
+            let _res = sender.send(Request::Close).await;
+            ()
+        })
+    }
+
+    /// Creates a [`Command`] that opens the file chooser.
+    pub fn open(&mut self, dialog: open::Dialog) -> Command<()> {
+        dialog_active_set(true);
+        let mut sender = self.0.clone();
+
+        crate::command::future(async move {
+            let _res = sender.send(Request::Open(dialog)).await;
+            ()
+        })
+    }
+
+    /// Creates a [`Command`] that requests the response from a file chooser dialog.
+    pub fn response(&mut self) -> Command<()> {
+        let mut sender = self.0.clone();
+
+        crate::command::future(async move {
+            let _res = sender.send(Request::Response).await;
+            ()
+        })
+    }
+
+    /// Creates a [`Command`] that opens a new save file dialog.
+    pub fn save(&mut self, dialog: save::Dialog) -> Command<()> {
+        dialog_active_set(true);
+        let mut sender = self.0.clone();
+
+        crate::command::future(async move {
+            let _res = sender.send(Request::Save(dialog)).await;
+            ()
+        })
+    }
+}
+
+struct Handler<M> {
+    active: Option<ashpd::desktop::Request<SelectedFiles>>,
+    handle: fn(Message) -> M,
+    output: channel::mpsc::Sender<M>,
+}
+
+impl<M> Handler<M> {
+    /// Emits close request if there is an active dialog request.
+    async fn close(&mut self) {
+        if let Some(request) = self.active.take() {
+            if let Err(why) = request.close().await {
+                self.emit(Message::Err(Error::Close(why))).await;
+            }
+        }
+    }
+
+    async fn emit(&mut self, response: Message) {
+        let _res = self.output.send((self.handle)(response)).await;
+    }
+
+    /// Creates a new dialog, and closes any prior active dialogs.
+    async fn open(&mut self, dialog: open::Dialog) {
+        let response = match open::create(dialog).await {
+            Ok(request) => {
+                self.active = Some(request);
+                Message::Opened
+            }
+            Err(why) => Message::Err(Error::Open(why)),
+        };
+
+        self.emit(response).await;
+    }
+
+    /// Collects selected files from the active dialog.
+    async fn response(&mut self) {
+        if let Some(request) = self.active.as_ref() {
+            let response = match request.response() {
+                Ok(selected) => Message::Selected(selected),
+                Err(why) => Message::Err(Error::Response(why)),
+            };
+
+            self.emit(response).await;
+        }
+    }
+
+    /// Creates a new dialog, and closes any prior active dialogs.
+    async fn save(&mut self, dialog: save::Dialog) {
+        let response = match save::create(dialog).await {
+            Ok(request) => {
+                self.active = Some(request);
+                Message::Opened
+            }
+            Err(why) => Message::Err(Error::Open(why)),
+        };
+
+        self.emit(response).await;
+    }
+}

src/dialog/file_chooser/open.rs

@@ -0,0 +1,90 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+//! Request to open files and/or directories.
+//!
+//! Check out the [open-dialog](https://github.com/pop-os/libcosmic/tree/master/examples/open-dialog)
+//! example in our repository.
+
+use derive_setters::Setters;
+use iced::Command;
+
+/// A builder for an open file dialog, passed as a request by a [`Sender`]
+#[derive(Setters)]
+#[must_use]
+pub struct Dialog {
+    /// The label for the dialog's window title.
+    title: String,
+
+    /// The label for the accept button. Mnemonic underlines are allowed.
+    #[setters(strip_option)]
+    accept_label: Option<String>,
+
+    /// Whether to select for folders instead of files. Default is to select files.
+    include_directories: bool,
+
+    /// Modal dialogs require user input before continuing the program.
+    modal: bool,
+
+    /// Whether to allow selection of multiple files. Default is no.
+    multiple_files: bool,
+
+    /// Adds a list of choices.
+    choices: Vec<super::Choice>,
+
+    /// Specifies the default file filter.
+    #[setters(into)]
+    current_filter: Option<super::FileFilter>,
+
+    /// A collection of file filters.
+    filters: Vec<super::FileFilter>,
+}
+
+impl Dialog {
+    pub(super) const fn new() -> Self {
+        Self {
+            title: String::new(),
+            accept_label: None,
+            include_directories: false,
+            modal: true,
+            multiple_files: false,
+            current_filter: None,
+            choices: Vec::new(),
+            filters: Vec::new(),
+        }
+    }
+
+    /// Creates a [`Command`] which opens the dialog.
+    pub fn create(self, sender: &mut super::Sender) -> Command<()> {
+        sender.open(self)
+    }
+
+    /// Adds a choice.
+    pub fn choice(mut self, choice: impl Into<super::Choice>) -> Self {
+        self.choices.push(choice.into());
+        self
+    }
+
+    /// Adds a files filter.
+    pub fn filter(mut self, filter: impl Into<super::FileFilter>) -> Self {
+        self.filters.push(filter.into());
+        self
+    }
+}
+
+/// Creates a new file dialog, and begins to await its responses.
+pub(super) async fn create(
+    dialog: Dialog,
+) -> ashpd::Result<ashpd::desktop::Request<super::SelectedFiles>> {
+    ashpd::desktop::file_chooser::OpenFileRequest::default()
+        .title(Some(dialog.title.as_str()))
+        .accept_label(dialog.accept_label.as_deref())
+        .directory(dialog.include_directories)
+        .modal(dialog.modal)
+        .multiple(dialog.multiple_files)
+        .choices(dialog.choices)
+        .filters(dialog.filters)
+        .current_filter(dialog.current_filter)
+        .send()
+        .await
+}