Use file dialogs to open/save files

src/main.rs

@@ -14,15 +14,18 @@
 //  You should have received a copy of the GNU Affero General Public License
 //  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-use log::warn;
+use log::{info, warn};
 
 use druid::im::{vector, Vector};
 use druid::kurbo::BezPath;
 use druid::widget::prelude::*;
-use druid::{AppLauncher, Color, Data, Event, LocalizedString, WindowDesc};
+use druid::{AppLauncher, Color, Data, Event, LocalizedString, WindowDesc, AppDelegate, Target, Env, DelegateCtx, FileDialogOptions, FileSpec, Command};
+use druid::commands;
 
 use stiletto::{CanvasElement, VersionedCanvas, Canvas, DocumentSnapshot};
 
+struct Delegate;
+
 #[derive(Clone, Data)]
 struct CanvasData {
     current_element: Option<CanvasElement>,
@@ -89,7 +92,7 @@ impl Widget<CanvasData> for CanvasWidget {
                         data.elements.update(move |canvas: &Canvas| -> Canvas {
                             let mut new_canvas = canvas.clone();
                             new_canvas.push_back(current_element);
-                            return new_canvas;
+                            new_canvas
                         });
 
                     }
@@ -173,38 +176,38 @@ fn build_ui() -> impl Widget<CanvasData> {
         )
         .with_child(Button::new("Redo").on_click(|_ctx: &mut EventCtx, data: &mut CanvasData, _env: &Env| data.perform_redo()));
 
+    let stlt = FileSpec::new("Stiletto notebook", &["stlt"]);
+    let save_dialog_options = FileDialogOptions::new()
+        .allowed_types(vec![stlt])
+        .default_type(stlt);
+    let open_dialog_options = save_dialog_options.clone();
+
     let save_buttons = Flex::row()
         .cross_axis_alignment(CrossAxisAlignment::Center)
         .with_child(
             Button::new("Open")
-                .on_click(|_ctx, data: &mut CanvasData, _env| {
+                .on_click(move |ctx, _, _| {
-                    use std::fs::File;
+                    ctx.submit_command(
-
+                        Command::new(
-                    if let Ok(f) = File::open("test.stlt") {
+                            druid::commands::SHOW_OPEN_PANEL,
-                        let res_snapshot: Result<DocumentSnapshot, serde_json::Error> = serde_json::from_reader(f);
+                            open_dialog_options.clone(),
-                        if let Ok(document_snapshot) = res_snapshot {
+                        ),
-                            data.set_from_snapshot(document_snapshot);
+                        None,
-                        } else {
+                    )
-                            warn!("didn't work: {:?}", res_snapshot.err());
-                        }
-                    }
                 }))
         .with_child(
             Button::new("Save")
-                .on_click(|_ctx, data: &mut CanvasData, _env| {
+                .on_click(move |ctx, _, _| {
-                    use std::fs::File;
+                    ctx.submit_command(
-
+                        Command::new(
-                    let res_file = File::create("test.stlt");
+                            druid::commands::SHOW_SAVE_PANEL,
-                    if let Ok(f) = res_file {
+                            save_dialog_options.clone(),
-                        let write_res = serde_json::to_writer_pretty(f, &data.get_document_snapshot());
+                        ),
-                        if write_res.is_err() {
+                        None,
-                            warn!("Error while saving: {:?}", write_res.err());
+                    )
-                        }
-                    } else {
-                        warn!("Cannot create file: {:?}", res_file.err());
-                    }
                 }));
 
+
     let toolbar = Flex::row()
         .cross_axis_alignment(CrossAxisAlignment::Center)
         .with_spacer(30.0)
@@ -231,6 +234,48 @@ pub fn main() {
     };
     AppLauncher::with_window(window)
         .use_simple_logger()
+        .delegate(Delegate)
         .launch(canvas_data)
         .expect("launch failed");
 }
+
+impl AppDelegate<CanvasData> for Delegate {
+    fn command(
+        &mut self,
+        _ctx: &mut DelegateCtx,
+        _target: Target,
+        cmd: &Command,
+        data: &mut CanvasData,
+        _env: &Env,
+    ) -> bool {
+        use std::fs::File;
+
+        if let Some(Some(file_info)) = cmd.get(commands::SAVE_FILE) {
+            let res_file = File::create(file_info.path());
+            if let Ok(f) = res_file {
+                let write_res = serde_json::to_writer_pretty(f, &data.get_document_snapshot());
+                if write_res.is_err() {
+                    warn!("Error while saving: {:?}", write_res.err());
+                } else {
+                    info!("Written to file: {}", file_info.path().display());
+                }
+            } else {
+                warn!("Cannot create file: {:?}", res_file.err());
+            }
+            return true;
+        }
+        if let Some(file_info) = cmd.get(commands::OPEN_FILE) {
+            if let Ok(f) = File::open(file_info.path()) {
+                let res_snapshot: Result<DocumentSnapshot, serde_json::Error> = serde_json::from_reader(f);
+                if let Ok(document_snapshot) = res_snapshot {
+                    data.set_from_snapshot(document_snapshot);
+                    info!("Loaded file {}", file_info.path().display());
+                } else {
+                    warn!("didn't work: {:?}", res_snapshot.err());
+                }
+            }
+            return true;
+        }
+        false
+    }
+}