Make dialogs on windows non-sychronous.

CHANGELOG.md

@@ -114,6 +114,7 @@ You can find its changes [documented below](#060---2020-06-01).
 - Fix `widget::Either` using the wrong paint insets ([#1299] by [@andrewhickman])
 - Various fixes to cross-platform menus ([#1306] by [@raphlinus])
 - Improve Windows 7 DXGI compatibility ([#1311] by [@raphlinus])
+- Don't drop events while showing file dialogs ([#1302], [#1328] by [@jneem])
 
 ### Visual
 
@@ -511,10 +512,12 @@ Last release without a changelog :(
 [#1295]: https://github.com/linebender/druid/pull/1280
 [#1298]: https://github.com/linebender/druid/pull/1298
 [#1299]: https://github.com/linebender/druid/pull/1299
+[#1302]: https://github.com/linebender/druid/pull/1302
 [#1306]: https://github.com/linebender/druid/pull/1306
 [#1311]: https://github.com/linebender/druid/pull/1311
 [#1320]: https://github.com/linebender/druid/pull/1320
 [#1326]: https://github.com/linebender/druid/pull/1326
+[#1328]: https://github.com/linebender/druid/pull/1328
 [#1346]: https://github.com/linebender/druid/pull/1346
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.6.0...master

druid-shell/examples/shello.rs

@@ -18,8 +18,8 @@ use druid_shell::kurbo::{Line, Size};
 use druid_shell::piet::{Color, RenderContext};
 
 use druid_shell::{
-    Application, Cursor, FileDialogOptions, FileSpec, HotKey, KeyEvent, Menu, MouseEvent, Region,
-    SysMods, TimerToken, WinHandler, WindowBuilder, WindowHandle,
+    Application, Cursor, FileDialogOptions, FileDialogToken, FileInfo, FileSpec, HotKey, KeyEvent,
+    Menu, MouseEvent, Region, SysMods, TimerToken, WinHandler, WindowBuilder, WindowHandle,
 };
 
 const BG_COLOR: Color = Color::rgb8(0x27, 0x28, 0x22);
@@ -56,13 +56,16 @@ impl WinHandler for HelloState {
                     FileSpec::TEXT,
                     FileSpec::JPG,
                 ]);
-                let filename = self.handle.open_file_sync(options);
-                println!("result: {:?}", filename);
+                self.handle.open_file(options);
             }
             _ => println!("unexpected id {}", id),
         }
     }
 
+    fn open_file(&mut self, _token: FileDialogToken, file_info: Option<FileInfo>) {
+        println!("open file result: {:?}", file_info);
+    }
+
     fn key_down(&mut self, event: KeyEvent) -> bool {
         println!("keydown: {:?}", event);
         false

druid-shell/src/platform/gtk/window.rs

@@ -366,8 +366,6 @@ impl WindowBuilder {
                     // Note that we're borrowing the surface while calling the handler. This is ok,
                     // because we don't return control to the system or re-borrow the surface from
                     // any code that the client can call.
-                    // (TODO: the above comment isn't true yet because of save_as_sync and
-                    // open_sync, but it will be true soon)
                     state.with_handler_and_dont_check_the_other_borrows(|handler| {
                         let surface_context = cairo::Context::new(surface);
 
@@ -753,6 +751,10 @@ impl WindowState {
                     .map(|s| FileInfo { path: s.into() });
                     self.with_handler(|h| h.save_as(token, file_info));
                 }
+                e => {
+                    // The other deferred ops shouldn't appear, because we don't defer them in GTK.
+                    log::error!("unexpected deferred op {:?}", e);
+                }
             }
         }
     }
@@ -986,16 +988,6 @@ impl WindowHandle {
         }
     }
 
-    pub fn save_as_sync(&mut self, _options: FileDialogOptions) -> Option<FileInfo> {
-        log::error!("save as sync no longer supported on GTK");
-        None
-    }
-
-    pub fn open_file_sync(&mut self, _options: FileDialogOptions) -> Option<FileInfo> {
-        log::error!("open file sync no longer supported on GTK");
-        None
-    }
-
     /// Get a handle that can be used to schedule an idle task.
     pub fn get_idle_handle(&self) -> Option<IdleHandle> {
         self.state.upgrade().map(|s| IdleHandle {

druid-shell/src/platform/mac/window.rs

@@ -934,20 +934,10 @@ impl WindowHandle {
         }
     }
 
-    pub fn open_file_sync(&mut self, _options: FileDialogOptions) -> Option<FileInfo> {
-        log::warn!("open_file_sync should no longer be called on mac!");
-        None
-    }
-
     pub fn open_file(&mut self, options: FileDialogOptions) -> Option<FileDialogToken> {
         self.open_save_impl(FileDialogType::Open, options)
     }
 
-    pub fn save_as_sync(&mut self, _options: FileDialogOptions) -> Option<FileInfo> {
-        log::warn!("save_as_sync should no longer be called on mac!");
-        None
-    }
-
     pub fn save_as(&mut self, options: FileDialogOptions) -> Option<FileDialogToken> {
         self.open_save_impl(FileDialogType::Save, options)
     }

druid-shell/src/platform/web/window.rs

@@ -564,25 +564,13 @@ impl WindowHandle {
         None
     }
 
-    pub fn open_file_sync(&mut self, options: FileDialogOptions) -> Option<FileInfo> {
-        log::warn!("open_file_sync is currently unimplemented for web.");
-        self.file_dialog(FileDialogType::Open, options)
-            .ok()
-            .map(|s| FileInfo { path: s.into() })
-    }
-
     pub fn open_file(&mut self, _options: FileDialogOptions) -> Option<FileDialogToken> {
+        log::warn!("open_file is currently unimplemented for web.");
         None
     }
 
-    pub fn save_as_sync(&mut self, options: FileDialogOptions) -> Option<FileInfo> {
-        log::warn!("save_as_sync is currently unimplemented for web.");
-        self.file_dialog(FileDialogType::Save, options)
-            .ok()
-            .map(|s| FileInfo { path: s.into() })
-    }
-
     pub fn save_as(&mut self, _options: FileDialogOptions) -> Option<FileDialogToken> {
+        log::warn!("save_as is currently unimplemented for web.");
         None
     }
 

druid-shell/src/platform/windows/application.rs

@@ -28,8 +28,8 @@ use winapi::um::errhandlingapi::GetLastError;
 use winapi::um::shellscalingapi::PROCESS_PER_MONITOR_DPI_AWARE;
 use winapi::um::winuser::{
     DispatchMessageW, GetAncestor, GetMessageW, LoadIconW, PeekMessageW, PostMessageW,
-    PostQuitMessage, RegisterClassW, SendMessageW, TranslateAcceleratorW, TranslateMessage,
-    GA_ROOT, IDI_APPLICATION, MSG, PM_NOREMOVE, WM_TIMER, WNDCLASSW,
+    PostQuitMessage, RegisterClassW, TranslateAcceleratorW, TranslateMessage, GA_ROOT,
+    IDI_APPLICATION, MSG, PM_NOREMOVE, WM_TIMER, WNDCLASSW,
 };
 
 use crate::application::AppHandler;
@@ -38,7 +38,7 @@ use super::accels;
 use super::clipboard::Clipboard;
 use super::error::Error;
 use super::util::{self, ToWide, CLASS_NAME, OPTIONAL_FUNCTIONS};
-use super::window::{self, DS_HANDLE_DEFERRED, DS_REQUEST_DESTROY};
+use super::window::{self, DS_REQUEST_DESTROY};
 
 #[derive(Clone)]
 pub(crate) struct Application {
@@ -112,11 +112,6 @@ impl Application {
             // NOTE: Code here will not run when we aren't in charge of the message loop. That
             // will include when moving or resizing the window, and when showing modal dialogs.
             loop {
-                if let Ok(state) = self.state.try_borrow() {
-                    for hwnd in &state.windows {
-                        SendMessageW(*hwnd, DS_HANDLE_DEFERRED, 0, 0);
-                    }
-                }
                 let mut msg = mem::MaybeUninit::uninit();
 
                 // Timer messages have a low priority and tend to get delayed. Peeking for them