Add the active modifiers to the mouse event

This would solve the most important use case for #116. Only the Linux
version has been tested, but the Windows should work perfectly fine, and
I don't know anything about macOS programming but that version also
compiles so it should be fine.

src/event.rs

@@ -1,4 +1,4 @@
-use keyboard_types::KeyboardEvent;
+use keyboard_types::{KeyboardEvent, Modifiers};
 
 use crate::{Point, WindowInfo};
 
@@ -38,21 +38,42 @@ pub enum MouseEvent {
     CursorMoved {
         /// The logical coordinates of the mouse position
         position: Point,
+        /// The modifiers that were held down just before the event.
+        modifiers: Modifiers,
     },
 
     /// A mouse button was pressed.
-    ButtonPressed(MouseButton),
+    ButtonPressed {
+        /// The button that was pressed.
+        button: MouseButton,
+        /// The modifiers that were held down just before the event.
+        modifiers: Modifiers,
+    },
 
     /// A mouse button was released.
-    ButtonReleased(MouseButton),
+    ButtonReleased {
+        /// The button that was released.
+        button: MouseButton,
+        /// The modifiers that were held down just before the event.
+        modifiers: Modifiers,
+    },
 
     /// The mouse wheel was scrolled.
-    WheelScrolled(ScrollDelta),
+    WheelScrolled {
+        /// How much was scrolled, in factional lines.
+        delta: ScrollDelta,
+        /// The modifiers that were held down just before the event.
+        modifiers: Modifiers,
+    },
 
     /// The mouse cursor entered the window.
+    ///
+    /// May not be available on all platforms.
     CursorEntered,
 
     /// The mouse cursor left the window.
+    ///
+    /// May not be available on all platforms.
     CursorLeft,
 }
 

src/macos/view.rs

@@ -19,6 +19,7 @@ use crate::{
     WindowOpenOptions,
 };
 
+use super::keyboard::make_modifiers;
 use super::window::WindowState;
 
 /// Name of the field used to store the `WindowState` pointer.
@@ -42,6 +43,31 @@ macro_rules! add_simple_mouse_class_method {
     };
 }
 
+/// Similar to [add_simple_mouse_class_method!], but this creates its own event object for the
+/// press/release event and adds the active modifier keys to that event.
+macro_rules! add_mouse_button_class_method {
+    ($class:ident, $sel:ident, $event_ty:ident, $button:expr) => {
+        #[allow(non_snake_case)]
+        extern "C" fn $sel(this: &Object, _: Sel, event: id){
+            let state: &mut WindowState = unsafe {
+                WindowState::from_field(this)
+            };
+
+            let modifiers = unsafe { NSEvent::modifierFlags(event) };
+
+            state.trigger_event(Event::Mouse($event_ty {
+                button: $button,
+                modifiers: make_modifiers(modifiers),
+            }));
+        }
+
+        $class.add_method(
+            sel!($sel:),
+            $sel as extern "C" fn(&Object, Sel, id),
+        );
+    };
+}
+
 macro_rules! add_simple_keyboard_class_method {
     ($class:ident, $sel:ident) => {
         #[allow(non_snake_case)]
@@ -126,12 +152,12 @@ unsafe fn create_view_class() -> &'static Class {
         view_did_change_backing_properties as extern "C" fn(&Object, Sel, id),
     );
 
-    add_simple_mouse_class_method!(class, mouseDown, ButtonPressed(MouseButton::Left));
-    add_simple_mouse_class_method!(class, mouseUp, ButtonReleased(MouseButton::Left));
-    add_simple_mouse_class_method!(class, rightMouseDown, ButtonPressed(MouseButton::Right));
-    add_simple_mouse_class_method!(class, rightMouseUp, ButtonReleased(MouseButton::Right));
-    add_simple_mouse_class_method!(class, otherMouseDown, ButtonPressed(MouseButton::Middle));
-    add_simple_mouse_class_method!(class, otherMouseUp, ButtonReleased(MouseButton::Middle));
+    add_mouse_button_class_method!(class, mouseDown, ButtonPressed, MouseButton::Left);
+    add_mouse_button_class_method!(class, mouseUp, ButtonReleased, MouseButton::Left);
+    add_mouse_button_class_method!(class, rightMouseDown, ButtonPressed, MouseButton::Right);
+    add_mouse_button_class_method!(class, rightMouseUp, ButtonReleased, MouseButton::Right);
+    add_mouse_button_class_method!(class, otherMouseDown, ButtonPressed, MouseButton::Middle);
+    add_mouse_button_class_method!(class, otherMouseUp, ButtonReleased, MouseButton::Middle);
     add_simple_mouse_class_method!(class, mouseEntered, MouseEvent::CursorEntered);
     add_simple_mouse_class_method!(class, mouseExited, MouseEvent::CursorLeft);
 
@@ -308,8 +334,12 @@ extern "C" fn mouse_moved(this: &Object, _sel: Sel, event: id) {
 
         msg_send![this, convertPoint:point fromView:nil]
     };
+    let modifiers = unsafe { NSEvent::modifierFlags(event) };
 
     let position = Point { x: point.x, y: point.y };
 
-    state.trigger_event(Event::Mouse(MouseEvent::CursorMoved { position }));
+    state.trigger_event(Event::Mouse(MouseEvent::CursorMoved {
+        position,
+        modifiers: make_modifiers(modifiers),
+    }));
 }

src/win/keyboard.rs

@@ -29,14 +29,14 @@ use winapi::shared::ntdef::SHORT;
 use winapi::shared::windef::HWND;
 use winapi::um::winuser::{
     GetKeyState, GetKeyboardLayout, MapVirtualKeyExW, PeekMessageW, ToUnicodeEx, MAPVK_VK_TO_CHAR,
-    MAPVK_VSC_TO_VK_EX, PM_NOREMOVE, VK_ACCEPT, VK_ADD, VK_APPS, VK_ATTN, VK_BACK, VK_BROWSER_BACK,
-    VK_BROWSER_FAVORITES, VK_BROWSER_FORWARD, VK_BROWSER_HOME, VK_BROWSER_REFRESH,
-    VK_BROWSER_SEARCH, VK_BROWSER_STOP, VK_CANCEL, VK_CAPITAL, VK_CLEAR, VK_CONTROL, VK_CONVERT,
-    VK_CRSEL, VK_DECIMAL, VK_DELETE, VK_DIVIDE, VK_DOWN, VK_END, VK_EREOF, VK_ESCAPE, VK_EXECUTE,
-    VK_EXSEL, VK_F1, VK_F10, VK_F11, VK_F12, VK_F2, VK_F3, VK_F4, VK_F5, VK_F6, VK_F7, VK_F8,
-    VK_F9, VK_FINAL, VK_HELP, VK_HOME, VK_INSERT, VK_JUNJA, VK_KANA, VK_KANJI, VK_LAUNCH_APP1,
-    VK_LAUNCH_APP2, VK_LAUNCH_MAIL, VK_LAUNCH_MEDIA_SELECT, VK_LCONTROL, VK_LEFT, VK_LMENU,
-    VK_LSHIFT, VK_LWIN, VK_MEDIA_NEXT_TRACK, VK_MEDIA_PLAY_PAUSE, VK_MEDIA_PREV_TRACK,
+    MAPVK_VSC_TO_VK_EX, MK_CONTROL, MK_SHIFT, PM_NOREMOVE, VK_ACCEPT, VK_ADD, VK_APPS, VK_ATTN,
+    VK_BACK, VK_BROWSER_BACK, VK_BROWSER_FAVORITES, VK_BROWSER_FORWARD, VK_BROWSER_HOME,
+    VK_BROWSER_REFRESH, VK_BROWSER_SEARCH, VK_BROWSER_STOP, VK_CANCEL, VK_CAPITAL, VK_CLEAR,
+    VK_CONTROL, VK_CONVERT, VK_CRSEL, VK_DECIMAL, VK_DELETE, VK_DIVIDE, VK_DOWN, VK_END, VK_EREOF,
+    VK_ESCAPE, VK_EXECUTE, VK_EXSEL, VK_F1, VK_F10, VK_F11, VK_F12, VK_F2, VK_F3, VK_F4, VK_F5,
+    VK_F6, VK_F7, VK_F8, VK_F9, VK_FINAL, VK_HELP, VK_HOME, VK_INSERT, VK_JUNJA, VK_KANA, VK_KANJI,
+    VK_LAUNCH_APP1, VK_LAUNCH_APP2, VK_LAUNCH_MAIL, VK_LAUNCH_MEDIA_SELECT, VK_LCONTROL, VK_LEFT,
+    VK_LMENU, VK_LSHIFT, VK_LWIN, VK_MEDIA_NEXT_TRACK, VK_MEDIA_PLAY_PAUSE, VK_MEDIA_PREV_TRACK,
     VK_MEDIA_STOP, VK_MENU, VK_MODECHANGE, VK_MULTIPLY, VK_NEXT, VK_NONCONVERT, VK_NUMLOCK,
     VK_NUMPAD0, VK_NUMPAD1, VK_NUMPAD2, VK_NUMPAD3, VK_NUMPAD4, VK_NUMPAD5, VK_NUMPAD6, VK_NUMPAD7,
     VK_NUMPAD8, VK_NUMPAD9, VK_OEM_ATTN, VK_OEM_CLEAR, VK_PAUSE, VK_PLAY, VK_PRINT, VK_PRIOR,
@@ -562,6 +562,30 @@ impl KeyboardState {
         }
     }
 
+    /// The same as [Self::get_modifiers()], but it reads the Ctrl and Shift state from a mouse
+    /// event's wParam parameter. Saves two calls to [GetKeyState()].
+    pub(crate) fn get_modifiers_from_mouse_wparam(&self, wparam: WPARAM) -> Modifiers {
+        unsafe {
+            let mut modifiers = Modifiers::empty();
+            for &(vk, modifier, mask) in MODIFIER_MAP {
+                let modifier_active = match modifier {
+                    Modifiers::CONTROL => wparam & MK_CONTROL != 0,
+                    Modifiers::SHIFT => wparam & MK_SHIFT != 0,
+                    _ => GetKeyState(vk) & mask != 0,
+                };
+
+                if modifier_active {
+                    modifiers |= modifier;
+                }
+            }
+            if self.has_altgr && GetKeyState(VK_RMENU) & 0x80 != 0 {
+                modifiers |= Modifiers::ALT_GRAPH;
+                modifiers &= !(Modifiers::CONTROL | Modifiers::ALT);
+            }
+            modifiers
+        }
+    }
+
     /// Load a keyboard layout.
     ///
     /// We need to retain a map of virtual key codes in various modifier

src/win/window.rs

@@ -138,27 +138,28 @@ unsafe extern "system" fn wnd_proc(
                 let y = ((lparam >> 16) & 0xFFFF) as i16 as i32;
 
                 let physical_pos = PhyPoint { x, y };
-
                 let logical_pos = physical_pos.to_logical(&window_state.window_info);
+                let event = Event::Mouse(MouseEvent::CursorMoved {
+                    position: logical_pos,
+                    modifiers: window_state.keyboard_state.get_modifiers_from_mouse_wparam(wparam),
+                });
+
+                window_state.handler.on_event(&mut window, event);
 
-                window_state.handler.on_event(
-                    &mut window,
-                    Event::Mouse(MouseEvent::CursorMoved { position: logical_pos }),
-                );
                 return 0;
             }
             WM_MOUSEWHEEL => {
                 let value = (wparam >> 16) as i16;
                 let value = value as i32;
                 let value = value as f32 / WHEEL_DELTA as f32;
 
-                window_state.handler.on_event(
-                    &mut window,
-                    Event::Mouse(MouseEvent::WheelScrolled(ScrollDelta::Lines {
-                        x: 0.0,
-                        y: value,
-                    })),
-                );
+                let event = Event::Mouse(MouseEvent::WheelScrolled {
+                    delta: ScrollDelta::Lines { x: 0.0, y: value },
+                    modifiers: window_state.keyboard_state.get_modifiers_from_mouse_wparam(wparam),
+                });
+
+                window_state.handler.on_event(&mut window, event);
+
                 return 0;
             }
             WM_LBUTTONDOWN | WM_LBUTTONUP | WM_MBUTTONDOWN | WM_MBUTTONUP | WM_RBUTTONDOWN
@@ -183,7 +184,12 @@ unsafe extern "system" fn wnd_proc(
                             // Capture the mouse cursor on button down
                             mouse_button_counter = mouse_button_counter.saturating_add(1);
                             SetCapture(hwnd);
-                            MouseEvent::ButtonPressed(button)
+                            MouseEvent::ButtonPressed {
+                                button,
+                                modifiers: window_state
+                                    .keyboard_state
+                                    .get_modifiers_from_mouse_wparam(wparam),
+                            }
                         }
                         WM_LBUTTONUP | WM_MBUTTONUP | WM_RBUTTONUP | WM_XBUTTONUP => {
                             // Release the mouse cursor capture when all buttons are released
@@ -192,7 +198,12 @@ unsafe extern "system" fn wnd_proc(
                                 ReleaseCapture();
                             }
 
-                            MouseEvent::ButtonReleased(button)
+                            MouseEvent::ButtonReleased {
+                                button,
+                                modifiers: window_state
+                                    .keyboard_state
+                                    .get_modifiers_from_mouse_wparam(wparam),
+                            }
                         }
                         _ => {
                             unreachable!()

src/x11/keyboard.rs

@@ -362,7 +362,7 @@ fn hardware_keycode_to_code(hw_keycode: u16) -> Code {
 
 // Extracts the keyboard modifiers from, e.g., the `state` field of
 // `xcb::xproto::ButtonPressEvent`
-fn key_mods(mods: u16) -> Modifiers {
+pub(super) fn key_mods(mods: u16) -> Modifiers {
     let mut ret = Modifiers::default();
     let mut key_masks = [
         (xproto::MOD_MASK_SHIFT, Modifiers::SHIFT),

src/x11/window.rs

@@ -16,7 +16,7 @@ use crate::{
     WindowHandler, WindowInfo, WindowOpenOptions, WindowScalePolicy,
 };
 
-use super::keyboard::{convert_key_press_event, convert_key_release_event};
+use super::keyboard::{convert_key_press_event, convert_key_release_event, key_mods};
 
 #[cfg(feature = "opengl")]
 use crate::{
@@ -580,7 +580,10 @@ impl Window {
 
                     handler.on_event(
                         &mut crate::Window::new(self),
-                        Event::Mouse(MouseEvent::CursorMoved { position: logical_pos }),
+                        Event::Mouse(MouseEvent::CursorMoved {
+                            position: logical_pos,
+                            modifiers: key_mods(event.state()),
+                        }),
                     );
                 }
             }
@@ -593,26 +596,29 @@ impl Window {
                     4 => {
                         handler.on_event(
                             &mut crate::Window::new(self),
-                            Event::Mouse(MouseEvent::WheelScrolled(ScrollDelta::Lines {
-                                x: 0.0,
-                                y: 1.0,
-                            })),
+                            Event::Mouse(MouseEvent::WheelScrolled {
+                                delta: ScrollDelta::Lines { x: 0.0, y: 1.0 },
+                                modifiers: key_mods(event.state()),
+                            }),
                         );
                     }
                     5 => {
                         handler.on_event(
                             &mut crate::Window::new(self),
-                            Event::Mouse(MouseEvent::WheelScrolled(ScrollDelta::Lines {
-                                x: 0.0,
-                                y: -1.0,
-                            })),
+                            Event::Mouse(MouseEvent::WheelScrolled {
+                                delta: ScrollDelta::Lines { x: 0.0, y: -1.0 },
+                                modifiers: key_mods(event.state()),
+                            }),
                         );
                     }
                     detail => {
                         let button_id = mouse_id(detail);
                         handler.on_event(
                             &mut crate::Window::new(self),
-                            Event::Mouse(MouseEvent::ButtonPressed(button_id)),
+                            Event::Mouse(MouseEvent::ButtonPressed {
+                                button: button_id,
+                                modifiers: key_mods(event.state()),
+                            }),
                         );
                     }
                 }
@@ -626,7 +632,10 @@ impl Window {
                     let button_id = mouse_id(detail);
                     handler.on_event(
                         &mut crate::Window::new(self),
-                        Event::Mouse(MouseEvent::ButtonReleased(button_id)),
+                        Event::Mouse(MouseEvent::ButtonReleased {
+                            button: button_id,
+                            modifiers: key_mods(event.state()),
+                        }),
                     );
                 }
             }