Change ModifiersState to a bitflags struct (#1306)

* Change ModifiersState to a bitflags struct

* Make examples work

* Add modifier state methods

* all things considered, only erroring out in one file throughout all of these changes is kinda impressive

* Make expansion plans more clear

* Move changelog entry

* Try to fix macos build

* Revert modifiers println in cursor_grab

* Make serde serialization less bug-prone

CHANGELOG.md

@@ -15,6 +15,7 @@
   - `RedrawRequested` is now issued only after `MainEventsCleared`.
   - `RedrawEventsCleared` is issued after each set of `RedrawRequested` events.
 - Implement synthetic window focus key events on Windows.
+- **Breaking**: Change `ModifiersState` to a `bitflags` struct.
 
 # 0.20.0 Alpha 5 (2019-12-09)
 

Cargo.toml

@@ -25,6 +25,7 @@ libc = "0.2.64"
 log = "0.4"
 serde = { version = "1", optional = true, features = ["serde_derive"] }
 raw-window-handle = "0.3"
+bitflags = "1"
 
 [dev-dependencies]
 image = "0.21"
@@ -48,9 +49,6 @@ version = "0.1.3"
 default_features = false
 features = ["display_link"]
 
-[target.'cfg(any(target_os = "ios", target_os = "windows"))'.dependencies]
-bitflags = "1"
-
 [target.'cfg(target_os = "windows")'.dependencies.winapi]
 version = "0.3.6"
 features = [

examples/cursor_grab.rs

@@ -30,8 +30,8 @@ fn main() {
                     use winit::event::VirtualKeyCode::*;
                     match key {
                         Escape => *control_flow = ControlFlow::Exit,
-                        G => window.set_cursor_grab(!modifiers.shift).unwrap(),
+                        G => window.set_cursor_grab(!modifiers.shift()).unwrap(),
-                        H => window.set_cursor_visible(modifiers.shift),
+                        H => window.set_cursor_visible(modifiers.shift()),
                         _ => (),
                     }
                 }

examples/multithreaded.rs

@@ -60,7 +60,7 @@ fn main() {
                         ..
                     } => {
                         window.set_title(&format!("{:?}", key));
-                        let state = !modifiers.shift;
+                        let state = !modifiers.shift();
                         use VirtualKeyCode::*;
                         match key {
                             A => window.set_always_on_top(state),
@@ -81,7 +81,7 @@ fn main() {
                                     video_modes.iter().nth(video_mode_id).unwrap()
                                 );
                             }
-                            F => window.set_fullscreen(match (state, modifiers.alt) {
+                            F => window.set_fullscreen(match (state, modifiers.alt()) {
                                 (true, false) => {
                                     Some(Fullscreen::Borderless(window.current_monitor()))
                                 }

src/event.rs

@@ -675,21 +675,99 @@ pub enum VirtualKeyCode {
     Cut,
 }
 
-/// Represents the current state of the keyboard modifiers
+impl ModifiersState {
-///
+    /// Returns `true` if the shift key is pressed.
-/// Each field of this struct represents a modifier and is `true` if this modifier is active.
+    pub fn shift(&self) -> bool {
-#[derive(Default, Debug, Hash, PartialEq, Eq, Clone, Copy)]
+        self.intersects(Self::SHIFT)
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+    }
-#[cfg_attr(feature = "serde", serde(default))]
+    /// Returns `true` if the control key is pressed.
-pub struct ModifiersState {
+    pub fn ctrl(&self) -> bool {
-    /// The "shift" key
+        self.intersects(Self::CTRL)
-    pub shift: bool,
+    }
-    /// The "control" key
+    /// Returns `true` if the alt key is pressed.
-    pub ctrl: bool,
+    pub fn alt(&self) -> bool {
-    /// The "alt" key
+        self.intersects(Self::ALT)
-    pub alt: bool,
+    }
-    /// The "logo" key
+    /// Returns `true` if the logo key is pressed.
-    ///
+    pub fn logo(&self) -> bool {
-    /// This is the "windows" key on PC and "command" key on Mac.
+        self.intersects(Self::LOGO)
-    pub logo: bool,
+    }
+}
+
+bitflags! {
+    /// Represents the current state of the keyboard modifiers
+    ///
+    /// Each flag represents a modifier and is set if this modifier is active.
+    #[derive(Default)]
+    pub struct ModifiersState: u32 {
+        // left and right modifiers are currently commented out, but we should be able to support
+        // them in a future release
+        /// The "shift" key.
+        const SHIFT = 0b100 << 0;
+        // const LSHIFT = 0b010 << 0;
+        // const RSHIFT = 0b001 << 0;
+        /// The "control" key.
+        const CTRL = 0b100 << 3;
+        // const LCTRL = 0b010 << 3;
+        // const RCTRL = 0b001 << 3;
+        /// The "alt" key.
+        const ALT = 0b100 << 6;
+        // const LALT = 0b010 << 6;
+        // const RALT = 0b001 << 6;
+        /// This is the "windows" key on PC and "command" key on Mac.
+        const LOGO = 0b100 << 9;
+        // const LLOGO = 0b010 << 9;
+        // const RLOGO = 0b001 << 9;
+    }
+}
+
+#[cfg(feature = "serde")]
+mod modifiers_serde {
+    use super::ModifiersState;
+    use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+    #[derive(Default, Serialize, Deserialize)]
+    #[serde(default)]
+    #[serde(rename = "ModifiersState")]
+    pub struct ModifiersStateSerialize {
+        pub shift: bool,
+        pub ctrl: bool,
+        pub alt: bool,
+        pub logo: bool,
+    }
+
+    impl Serialize for ModifiersState {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            let s = ModifiersStateSerialize {
+                shift: self.shift(),
+                ctrl: self.ctrl(),
+                alt: self.alt(),
+                logo: self.logo(),
+            };
+            s.serialize(serializer)
+        }
+    }
+
+    impl<'de> Deserialize<'de> for ModifiersState {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            let ModifiersStateSerialize {
+                shift,
+                ctrl,
+                alt,
+                logo,
+            } = ModifiersStateSerialize::deserialize(deserializer)?;
+            let mut m = ModifiersState::empty();
+            m.set(ModifiersState::SHIFT, shift);
+            m.set(ModifiersState::CTRL, ctrl);
+            m.set(ModifiersState::ALT, alt);
+            m.set(ModifiersState::LOGO, logo);
+            Ok(m)
+        }
+    }
 }

src/lib.rs

@@ -119,7 +119,6 @@ extern crate log;
 #[macro_use]
 extern crate serde;
 #[macro_use]
-#[cfg(any(target_os = "ios", target_os = "windows"))]
 extern crate bitflags;
 #[cfg(any(target_os = "macos", target_os = "ios"))]
 #[macro_use]

src/platform_impl/linux/wayland/keyboard.rs

@@ -404,12 +404,12 @@ fn keysym_to_vkey(keysym: u32) -> Option<VirtualKeyCode> {
 
 impl ModifiersState {
     pub(crate) fn from_wayland(mods: keyboard::ModifiersState) -> ModifiersState {
-        ModifiersState {
+        let mut m = ModifiersState::empty();
-            shift: mods.shift,
+        m.set(ModifiersState::SHIFT, mods.shift);
-            ctrl: mods.ctrl,
+        m.set(ModifiersState::CTRL, mods.ctrl);
-            alt: mods.alt,
+        m.set(ModifiersState::ALT, mods.alt);
-            logo: mods.logo,
+        m.set(ModifiersState::LOGO, mods.logo);
-        }
+        m
     }
 }
 

src/platform_impl/linux/x11/util/input.rs

@@ -17,12 +17,12 @@ impl ModifiersState {
     }
 
     pub(crate) fn from_x11_mask(mask: c_uint) -> Self {
-        ModifiersState {
+        let mut m = ModifiersState::empty();
-            alt: mask & ffi::Mod1Mask != 0,
+        m.set(ModifiersState::SHIFT, mask & ffi::Mod1Mask != 0);
-            shift: mask & ffi::ShiftMask != 0,
+        m.set(ModifiersState::CTRL, mask & ffi::ShiftMask != 0);
-            ctrl: mask & ffi::ControlMask != 0,
+        m.set(ModifiersState::ALT, mask & ffi::ControlMask != 0);
-            logo: mask & ffi::Mod4Mask != 0,
+        m.set(ModifiersState::LOGO, mask & ffi::Mod4Mask != 0);
-        }
+        m
     }
 }
 

src/platform_impl/linux/x11/util/modifiers.rs

@@ -116,10 +116,10 @@ impl ModifierKeyState {
         let mut new_state = *state;
 
         match except {
-            Some(Modifier::Alt) => new_state.alt = self.state.alt,
+            Some(Modifier::Alt) => new_state.set(ModifiersState::ALT, self.state.alt()),
-            Some(Modifier::Ctrl) => new_state.ctrl = self.state.ctrl,
+            Some(Modifier::Ctrl) => new_state.set(ModifiersState::CTRL, self.state.ctrl()),
-            Some(Modifier::Shift) => new_state.shift = self.state.shift,
+            Some(Modifier::Shift) => new_state.set(ModifiersState::SHIFT, self.state.shift()),
-            Some(Modifier::Logo) => new_state.logo = self.state.logo,
+            Some(Modifier::Logo) => new_state.set(ModifiersState::LOGO, self.state.logo()),
             None => (),
         }
 
@@ -170,18 +170,18 @@ impl ModifierKeyState {
 
 fn get_modifier(state: &ModifiersState, modifier: Modifier) -> bool {
     match modifier {
-        Modifier::Alt => state.alt,
+        Modifier::Alt => state.alt(),
-        Modifier::Ctrl => state.ctrl,
+        Modifier::Ctrl => state.ctrl(),
-        Modifier::Shift => state.shift,
+        Modifier::Shift => state.shift(),
-        Modifier::Logo => state.logo,
+        Modifier::Logo => state.logo(),
     }
 }
 
 fn set_modifier(state: &mut ModifiersState, modifier: Modifier, value: bool) {
     match modifier {
-        Modifier::Alt => state.alt = value,
+        Modifier::Alt => state.set(ModifiersState::ALT, value),
-        Modifier::Ctrl => state.ctrl = value,
+        Modifier::Ctrl => state.set(ModifiersState::CTRL, value),
-        Modifier::Shift => state.shift = value,
+        Modifier::Shift => state.set(ModifiersState::SHIFT, value),
-        Modifier::Logo => state.logo = value,
+        Modifier::Logo => state.set(ModifiersState::LOGO, value),
     }
 }

src/platform_impl/macos/app_state.rs

@@ -14,7 +14,7 @@ use std::{
 use cocoa::{appkit::NSApp, base::nil, foundation::NSString};
 
 use crate::{
-    event::{Event, StartCause, WindowEvent},
+    event::{Event, StartCause},
     event_loop::{ControlFlow, EventLoopWindowTarget as RootWindowTarget},
     platform_impl::platform::{observer::EventLoopWaker, util::Never},
     window::WindowId,

src/platform_impl/macos/event.rs

@@ -224,12 +224,24 @@ pub fn check_function_keys(string: &str) -> Option<VirtualKeyCode> {
 
 pub fn event_mods(event: id) -> ModifiersState {
     let flags = unsafe { NSEvent::modifierFlags(event) };
-    ModifiersState {
+    let mut m = ModifiersState::empty();
-        shift: flags.contains(NSEventModifierFlags::NSShiftKeyMask),
+    m.set(
-        ctrl: flags.contains(NSEventModifierFlags::NSControlKeyMask),
+        ModifiersState::SHIFT,
-        alt: flags.contains(NSEventModifierFlags::NSAlternateKeyMask),
+        flags.contains(NSEventModifierFlags::NSShiftKeyMask),
-        logo: flags.contains(NSEventModifierFlags::NSCommandKeyMask),
+    );
-    }
+    m.set(
+        ModifiersState::CTRL,
+        flags.contains(NSEventModifierFlags::NSControlKeyMask),
+    );
+    m.set(
+        ModifiersState::ALT,
+        flags.contains(NSEventModifierFlags::NSAlternateKeyMask),
+    );
+    m.set(
+        ModifiersState::LOGO,
+        flags.contains(NSEventModifierFlags::NSCommandKeyMask),
+    );
+    m
 }
 
 pub fn get_scancode(event: cocoa::base::id) -> c_ushort {

src/platform_impl/macos/view.rs

@@ -646,36 +646,36 @@ extern "C" fn flags_changed(this: &Object, _sel: Sel, event: id) {
         if let Some(window_event) = modifier_event(
             event,
             NSEventModifierFlags::NSShiftKeyMask,
-            state.modifiers.shift,
+            state.modifiers.shift(),
         ) {
-            state.modifiers.shift = !state.modifiers.shift;
+            state.modifiers.toggle(ModifiersState::SHIFT);
             events.push_back(window_event);
         }
 
         if let Some(window_event) = modifier_event(
             event,
             NSEventModifierFlags::NSControlKeyMask,
-            state.modifiers.ctrl,
+            state.modifiers.ctrl(),
         ) {
-            state.modifiers.ctrl = !state.modifiers.ctrl;
+            state.modifiers.toggle(ModifiersState::CTRL);
             events.push_back(window_event);
         }
 
         if let Some(window_event) = modifier_event(
             event,
             NSEventModifierFlags::NSCommandKeyMask,
-            state.modifiers.logo,
+            state.modifiers.logo(),
         ) {
-            state.modifiers.logo = !state.modifiers.logo;
+            state.modifiers.toggle(ModifiersState::LOGO);
             events.push_back(window_event);
         }
 
         if let Some(window_event) = modifier_event(
             event,
             NSEventModifierFlags::NSAlternateKeyMask,
-            state.modifiers.alt,
+            state.modifiers.alt(),
         ) {
-            state.modifiers.alt = !state.modifiers.alt;
+            state.modifiers.toggle(ModifiersState::ALT);
             events.push_back(window_event);
         }
 

src/platform_impl/web/stdweb/event.rs

@@ -15,12 +15,12 @@ pub fn mouse_button(event: &impl IMouseEvent) -> MouseButton {
 }
 
 pub fn mouse_modifiers(event: &impl IMouseEvent) -> ModifiersState {
-    ModifiersState {
+    let mut m = ModifiersState::empty();
-        shift: event.shift_key(),
+    m.set(ModifiersState::SHIFT, event.shift_key());
-        ctrl: event.ctrl_key(),
+    m.set(ModifiersState::CTRL, event.ctrl_key());
-        alt: event.alt_key(),
+    m.set(ModifiersState::ALT, event.alt_key());
-        logo: event.meta_key(),
+    m.set(ModifiersState::LOGO, event.meta_key());
-    }
+    m
 }
 
 pub fn mouse_position(event: &impl IMouseEvent) -> LogicalPosition {
@@ -213,12 +213,12 @@ pub fn virtual_key_code(event: &impl IKeyboardEvent) -> Option<VirtualKeyCode> {
 }
 
 pub fn keyboard_modifiers(event: &impl IKeyboardEvent) -> ModifiersState {
-    ModifiersState {
+    let mut m = ModifiersState::empty();
-        shift: event.shift_key(),
+    m.set(ModifiersState::SHIFT, event.shift_key());
-        ctrl: event.ctrl_key(),
+    m.set(ModifiersState::CTRL, event.ctrl_key());
-        alt: event.alt_key(),
+    m.set(ModifiersState::ALT, event.alt_key());
-        logo: event.meta_key(),
+    m.set(ModifiersState::LOGO, event.meta_key());
-    }
+    m
 }
 
 pub fn codepoint(event: &impl IKeyboardEvent) -> char {

src/platform_impl/web/web_sys/event.rs

@@ -14,12 +14,12 @@ pub fn mouse_button(event: &MouseEvent) -> MouseButton {
 }
 
 pub fn mouse_modifiers(event: &MouseEvent) -> ModifiersState {
-    ModifiersState {
+    let mut m = ModifiersState::empty();
-        shift: event.shift_key(),
+    m.set(ModifiersState::SHIFT, event.shift_key());
-        ctrl: event.ctrl_key(),
+    m.set(ModifiersState::CTRL, event.ctrl_key());
-        alt: event.alt_key(),
+    m.set(ModifiersState::ALT, event.alt_key());
-        logo: event.meta_key(),
+    m.set(ModifiersState::LOGO, event.meta_key());
-    }
+    m
 }
 
 pub fn mouse_position(event: &MouseEvent) -> LogicalPosition {
@@ -211,12 +211,12 @@ pub fn virtual_key_code(event: &KeyboardEvent) -> Option<VirtualKeyCode> {
 }
 
 pub fn keyboard_modifiers(event: &KeyboardEvent) -> ModifiersState {
-    ModifiersState {
+    let mut m = ModifiersState::empty();
-        shift: event.shift_key(),
+    m.set(ModifiersState::SHIFT, event.shift_key());
-        ctrl: event.ctrl_key(),
+    m.set(ModifiersState::CTRL, event.ctrl_key());
-        alt: event.alt_key(),
+    m.set(ModifiersState::ALT, event.alt_key());
-        logo: event.meta_key(),
+    m.set(ModifiersState::LOGO, event.meta_key());
-    }
+    m
 }
 
 pub fn codepoint(event: &KeyboardEvent) -> char {

src/platform_impl/windows/event.rs

@@ -17,13 +17,22 @@ fn key_pressed(vkey: c_int) -> bool {
 }
 
 pub fn get_key_mods() -> ModifiersState {
-    let mut mods = ModifiersState::default();
     let filter_out_altgr = layout_uses_altgr() && key_pressed(winuser::VK_RMENU);
 
-    mods.shift = key_pressed(winuser::VK_SHIFT);
+    let mut mods = ModifiersState::empty();
-    mods.ctrl = key_pressed(winuser::VK_CONTROL) && !filter_out_altgr;
+    mods.set(ModifiersState::SHIFT, key_pressed(winuser::VK_SHIFT));
-    mods.alt = key_pressed(winuser::VK_MENU) && !filter_out_altgr;
+    mods.set(
-    mods.logo = key_pressed(winuser::VK_LWIN) || key_pressed(winuser::VK_RWIN);
+        ModifiersState::CTRL,
+        key_pressed(winuser::VK_CONTROL) && !filter_out_altgr,
+    );
+    mods.set(
+        ModifiersState::ALT,
+        key_pressed(winuser::VK_MENU) && !filter_out_altgr,
+    );
+    mods.set(
+        ModifiersState::LOGO,
+        key_pressed(winuser::VK_LWIN) || key_pressed(winuser::VK_RWIN),
+    );
     mods
 }