Merge pull request #477 from kas-gui/work3

Better handling for close/suspend/exit

.github/workflows/test.yml

@@ -71,7 +71,7 @@ jobs:
         toolchain: [stable]
         include:
           - os: ubuntu-latest
-            toolchain: "1.80.1"
+            toolchain: "1.81.0"
             variant: MSRV
           - os: ubuntu-latest
             toolchain: beta

Cargo.toml

@@ -11,7 +11,7 @@ keywords = ["gui"]
 categories = ["gui"]
 repository = "https://github.com/kas-gui/kas"
 exclude = ["/examples"]
-rust-version = "1.80.1"
+rust-version = "1.81.0"
 
 [package.metadata.docs.rs]
 features = ["stable"]

README.md

@@ -5,7 +5,6 @@ KAS GUI
 [![Crates.io](https://img.shields.io/crates/v/kas.svg)](https://crates.io/crates/kas)
 [![kas-text](https://img.shields.io/badge/GitHub-kas--text-blueviolet)](https://github.com/kas-gui/kas-text/)
 [![Docs](https://docs.rs/kas/badge.svg)](https://docs.rs/kas)
-![Minimum rustc version](https://img.shields.io/badge/rustc-1.80+-lightgray.svg)
 
 KAS is a stateful, pure-Rust GUI toolkit supporting:
 

crates/kas-core/src/action.rs

@@ -75,7 +75,5 @@ bitflags! {
         const UPDATE = 1 << 17;
         /// The current window should be closed
         const CLOSE = 1 << 30;
-        /// Close all windows and exit
-        const EXIT = 1 << 31;
     }
 }

crates/kas-core/src/event/cx/cx_pub.rs

@@ -259,7 +259,7 @@ impl EventState {
     /// Terminate the GUI
     #[inline]
     pub fn exit(&mut self) {
-        self.action |= Action::EXIT;
+        self.pending_cmds.push_back((Id::ROOT, Command::Exit));
     }
 
     /// Notify that an [`Action`] should happen
@@ -849,21 +849,12 @@ impl<'a> EventCx<'a> {
     ///
     /// Navigation focus will return to whichever widget had focus before
     /// the popup was open.
-    pub fn close_window(&mut self, id: WindowId) {
-        if let Some(index) =
-            self.popups
-                .iter()
-                .enumerate()
-                .find_map(|(i, p)| if p.0 == id { Some(i) } else { None })
-        {
-            let (wid, popup, onf) = self.popups.remove(index);
-            self.popup_removed.push((popup.id, wid));
-            self.runner.close_window(wid);
-
-            if let Some(id) = onf {
-                self.set_nav_focus(id, FocusSource::Synthetic);
+    pub fn close_window(&mut self, mut id: WindowId) {
+        for (index, p) in self.popups.iter().enumerate() {
+            if p.0 == id {
+                id = self.close_popup(index);
+                break;
             }
-            return;
         }
 
         self.runner.close_window(id);

crates/kas-core/src/event/cx/mod.rs

@@ -183,6 +183,7 @@ type AccessLayer = (bool, HashMap<Key, Id>);
 // for each widget during drawing. Most fields contain only a few values, hence
 // `SmallVec` is used to keep contents in local memory.
 pub struct EventState {
+    pub(crate) window_id: WindowId,
     config: WindowConfig,
     platform: Platform,
     disabled: Vec<Id>,
@@ -362,6 +363,23 @@ impl EventState {
         grab
     }
 
+    // Remove popup at index and return its [`WindowId`]
+    //
+    // Panics if `index` is out of bounds.
+    //
+    // The caller must call `runner.close_window(window_id)`.
+    #[must_use]
+    fn close_popup(&mut self, index: usize) -> WindowId {
+        let (window_id, popup, onf) = self.popups.remove(index);
+        self.popup_removed.push((popup.id, window_id));
+
+        if let Some(id) = onf {
+            self.set_nav_focus(id, FocusSource::Synthetic);
+        }
+
+        window_id
+    }
+
     /// Clear all active events on `target`
     fn clear_events(&mut self, target: &Id) {
         if let Some(id) = self.sel_focus.as_ref() {
@@ -446,9 +464,15 @@ impl<'a> EventCx<'a> {
             widget.id()
         );
 
-        let opt_command = self.config.shortcuts().try_match(self.modifiers, &vkey);
+        let opt_cmd = self.config.shortcuts().try_match(self.modifiers, &vkey);
 
-        if let Some(cmd) = opt_command {
+        if Some(Command::Exit) == opt_cmd {
+            self.runner.exit();
+            return;
+        } else if Some(Command::Close) == opt_cmd {
+            self.handle_close();
+            return;
+        } else if let Some(cmd) = opt_cmd {
             let mut targets = vec![];
             let mut send = |_self: &mut Self, id: Id, cmd| -> bool {
                 if !targets.contains(&id) {
@@ -524,10 +548,10 @@ impl<'a> EventCx<'a> {
             }
             let event = Event::Command(Command::Activate, Some(code));
             self.send_event(widget, id, event);
-        } else if self.config.nav_focus && vkey == Key::Named(NamedKey::Tab) {
+        } else if self.config.nav_focus && opt_cmd == Some(Command::Tab) {
             let shift = self.modifiers.shift_key();
             self.next_nav_focus_impl(widget.re(), None, shift, FocusSource::Key);
-        } else if vkey == Key::Named(NamedKey::Escape) {
+        } else if opt_cmd == Some(Command::Escape) {
             if let Some(id) = self.popups.last().map(|(id, _, _)| *id) {
                 self.close_window(id);
             }
@@ -627,6 +651,15 @@ impl<'a> EventCx<'a> {
         }
     }
 
+    fn handle_close(&mut self) {
+        let mut id = self.window_id;
+        if !self.popups.is_empty() {
+            let index = self.popups.len() - 1;
+            id = self.close_popup(index);
+        }
+        self.runner.close_window(id);
+    }
+
     // Call Widget::_nav_next
     #[inline]
     fn nav_next(

crates/kas-core/src/event/cx/platform.rs

@@ -25,8 +25,9 @@ const FAKE_MOUSE_BUTTON: MouseButton = MouseButton::Other(0);
 impl EventState {
     /// Construct per-window event state
     #[inline]
-    pub(crate) fn new(config: WindowConfig, platform: Platform) -> Self {
+    pub(crate) fn new(window_id: WindowId, config: WindowConfig, platform: Platform) -> Self {
         EventState {
+            window_id,
             config,
             platform,
             disabled: vec![],
@@ -78,11 +79,10 @@ impl EventState {
     pub(crate) fn full_configure<A>(
         &mut self,
         sizer: &dyn ThemeSize,
-        wid: WindowId,
         win: &mut Window<A>,
         data: &A,
     ) {
-        let id = Id::ROOT.make_child(wid.get().cast());
+        let id = Id::ROOT.make_child(self.window_id.get().cast());
 
         log::debug!(target: "kas_core::event", "full_configure of Window{id}");
         self.action.remove(Action::RECONFIGURE);
@@ -248,8 +248,14 @@ impl EventState {
             }
 
             while let Some((id, cmd)) = cx.pending_cmds.pop_front() {
-                log::trace!(target: "kas_core::event", "sending pending command {cmd:?} to {id}");
-                cx.send_event(win.as_node(data), id, Event::Command(cmd, None));
+                if cmd == Command::Exit {
+                    cx.runner.exit();
+                } else if cmd == Command::Close {
+                    cx.handle_close();
+                } else {
+                    log::trace!(target: "kas_core::event", "sending pending command {cmd:?} to {id}");
+                    cx.send_event(win.as_node(data), id, Event::Command(cmd, None));
+                }
             }
 
             while let Some((id, msg)) = cx.send_queue.pop_front() {
@@ -282,6 +288,14 @@ impl EventState {
 
         std::mem::take(&mut self.action)
     }
+
+    /// Window has been closed: clean up state
+    pub(crate) fn suspended(&mut self, runner: &mut dyn RunnerT) {
+        while !self.popups.is_empty() {
+            let id = self.close_popup(self.popups.len() - 1);
+            runner.close_window(id);
+        }
+    }
 }
 
 /// Platform API

crates/kas-core/src/root.rs

@@ -401,21 +401,21 @@ impl<Data: 'static> Window<Data> {
     /// Each [`crate::Popup`] is assigned a [`WindowId`]; both are passed.
     pub(crate) fn add_popup(
         &mut self,
-        cx: &mut EventCx,
+        cx: &mut ConfigCx,
         data: &Data,
         id: WindowId,
         popup: kas::PopupDescriptor,
     ) {
         let index = self.popups.len();
         self.popups.push((id, popup, Offset::ZERO));
-        self.resize_popup(&mut cx.config_cx(), data, index);
+        self.resize_popup(cx, data, index);
         cx.action(Id::ROOT, Action::REDRAW);
     }
 
     /// Trigger closure of a pop-up
     ///
     /// If the given `id` refers to a pop-up, it should be closed.
-    pub(crate) fn remove_popup(&mut self, cx: &mut EventCx, id: WindowId) {
+    pub(crate) fn remove_popup(&mut self, cx: &mut ConfigCx, id: WindowId) {
         for i in 0..self.popups.len() {
             if id == self.popups[i].0 {
                 self.popups.remove(i);

crates/kas-core/src/runner/event_loop.rs

@@ -108,7 +108,7 @@ where
             for window in self.windows.values_mut() {
                 match window.resume(&mut self.state, el) {
                     Ok(winit_id) => {
-                        self.id_map.insert(winit_id, window.window_id);
+                        self.id_map.insert(winit_id, window.window_id());
                     }
                     Err(e) => {
                         log::error!("Unable to create window: {}", e);
@@ -152,15 +152,15 @@ where
 
     fn suspended(&mut self, _: &ActiveEventLoop) {
         if !self.suspended {
-            for window in self.windows.values_mut() {
-                window.suspend();
-            }
+            self.windows
+                .retain(|_, window| window.suspend(&mut self.state));
+            self.state.suspended();
             self.suspended = true;
         }
     }
 
-    fn exiting(&mut self, _: &ActiveEventLoop) {
-        self.state.on_exit();
+    fn exiting(&mut self, el: &ActiveEventLoop) {
+        self.suspended(el);
     }
 }
 
@@ -171,7 +171,7 @@ where
     pub(super) fn new(mut windows: Vec<Box<Window<A, G, T>>>, state: State<A, G, T>) -> Self {
         Loop {
             suspended: true,
-            windows: windows.drain(..).map(|w| (w.window_id, w)).collect(),
+            windows: windows.drain(..).map(|w| (w.window_id(), w)).collect(),
             popups: Default::default(),
             id_map: Default::default(),
             state,
@@ -180,6 +180,7 @@ where
     }
 
     fn flush_pending(&mut self, el: &ActiveEventLoop) {
+        let mut close_all = false;
         while let Some(pending) = self.state.shared.pending.pop_front() {
             match pending {
                 Pending::AddPopup(parent_id, id, popup) => {
@@ -211,11 +212,11 @@ where
                         win_id = id;
                     }
                     if let Some(window) = self.windows.get_mut(&win_id) {
-                        window.send_close(&mut self.state, target);
+                        window.send_close(target);
                     }
                 }
                 Pending::Action(action) => {
-                    if action.contains(Action::CLOSE | Action::EXIT) {
+                    if action.contains(Action::CLOSE) {
                         self.windows.clear();
                         self.id_map.clear();
                         el.set_control_flow(ControlFlow::Poll);
@@ -225,32 +226,30 @@ where
                         }
                     }
                 }
+                Pending::Exit => close_all = true,
             }
         }
 
-        let mut close_all = false;
         self.resumes.clear();
         self.windows.retain(|window_id, window| {
             let (action, resume) = window.flush_pending(&mut self.state);
             if let Some(instant) = resume {
                 self.resumes.push((instant, *window_id));
             }
-            if action.contains(Action::EXIT) {
-                close_all = true;
-                true
-            } else if action.contains(Action::CLOSE) {
+
+            if close_all || action.contains(Action::CLOSE) {
+                window.suspend(&mut self.state);
+
+                // Call flush_pending again since suspend may queue messages.
+                // We don't care about the returned Action or resume times since
+                // the window is being destroyed.
+                let _ = window.flush_pending(&mut self.state);
+
                 self.id_map.retain(|_, v| v != window_id);
                 false
             } else {
                 true
             }
         });
-
-        if close_all {
-            for (_, mut window) in self.windows.drain() {
-                window.suspend();
-            }
-            self.id_map.clear();
-        }
     }
 }

crates/kas-core/src/runner/mod.rs

@@ -39,17 +39,32 @@ pub extern crate raw_window_handle;
 /// across windows). This trait must be implemented by the latter.
 ///
 /// When no top-level data is required, use `()` which implements this trait.
+///
+/// TODO: should we pass some type of interface to the runner to these methods?
+/// We could pass a `&mut dyn RunnerT` easily, but that trait is not public.
 pub trait AppData: 'static {
     /// Handle messages
     ///
     /// This is the last message handler: it is called when, after traversing
     /// the widget tree (see [kas::event] module doc), a message is left on the
     /// stack. Unhandled messages will result in warnings in the log.
     fn handle_messages(&mut self, messages: &mut MessageStack);
+
+    /// Application is being suspended
+    ///
+    /// The application should ensure any important state is saved.
+    ///
+    /// This method is called when the application has been suspended or is
+    /// about to exit (on Android/iOS/Web platforms, the application may resume
+    /// after this method is called; on other platforms this probably indicates
+    /// imminent closure). Widget state may still exist, but is not live
+    /// (widgets will not process events or messages).
+    fn suspended(&mut self) {}
 }
 
 impl AppData for () {
     fn handle_messages(&mut self, _: &mut MessageStack) {}
+    fn suspended(&mut self) {}
 }
 
 #[crate::autoimpl(Debug)]
@@ -61,6 +76,7 @@ enum Pending<A: AppData, G: GraphicsBuilder, T: kas::theme::Theme<G::Shared>> {
     AddWindow(WindowId, Box<Window<A, G, T>>),
     CloseWindow(WindowId),
     Action(kas::Action),
+    Exit,
 }
 
 #[cfg(winit)]