Add Ui.input_mut & InputState.ignore_key (#1212)

egui/src/data/input.rs

@@ -264,6 +264,42 @@ pub struct Modifiers {
 }
 
 impl Modifiers {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn alt(self, value: bool) -> Self {
+        Self { alt: value, ..self }
+    }
+
+    pub fn ctrl(self, value: bool) -> Self {
+        Self {
+            ctrl: value,
+            ..self
+        }
+    }
+
+    pub fn shift(self, value: bool) -> Self {
+        Self {
+            shift: value,
+            ..self
+        }
+    }
+
+    pub fn mac_cmd(self, value: bool) -> Self {
+        Self {
+            mac_cmd: value,
+            ..self
+        }
+    }
+
+    pub fn command(self, value: bool) -> Self {
+        Self {
+            command: value,
+            ..self
+        }
+    }
+
     #[inline(always)]
     pub fn is_none(&self) -> bool {
         self == &Self::default()

egui/src/input_state.rs

@@ -192,6 +192,24 @@ impl InputState {
         self.pointer.wants_repaint() || self.scroll_delta != Vec2::ZERO || !self.events.is_empty()
     }
 
+    /// Ignore a key if it was pressed or released this frame. Useful for hotkeys.
+    /// Matches on both key press and key release, consuming them and removing them from `self.events`.
+    /// Returns true if the key was pressed this frame (even if the key release was consumed).
+    pub fn consume_key(&mut self, modifiers: Modifiers, key: Key) -> bool {
+        self.events.retain(|event| {
+            !matches!(
+                event,
+                Event::Key {
+                    key: ev_key,
+                    modifiers: ev_mods,
+                    ..
+                } if *ev_key == key && *ev_mods == modifiers
+            )
+        });
+
+        self.keys_down.remove(&key)
+    }
+
     /// Was the given key pressed this frame?
     pub fn key_pressed(&self, desired_key: Key) -> bool {
         self.num_presses(desired_key) > 0

egui/src/ui.rs

@@ -338,6 +338,21 @@ impl Ui {
         self.ctx().input()
     }
 
+    /// The [`InputState`] of the [`Context`] associated with this [`Ui`].
+    /// Equivalent to `.ctx().input_mut()`.
+    ///
+    /// Note that this locks the [`Context`], so be careful with if-let bindings
+    /// like for [`Self::input()`].
+    /// ```
+    /// # egui::__run_test_ui(|ui| {
+    /// ui.input_mut().consume_key(egui::Modifiers::default(), egui::Key::Enter);
+    /// # });
+    /// ```
+    #[inline]
+    pub fn input_mut(&self) -> RwLockWriteGuard<'_, InputState> {
+        self.ctx().input_mut()
+    }
+
     /// The [`Memory`] of the [`Context`] associated with this ui.
     /// Equivalent to `.ctx().memory()`.
     #[inline]