Add time since pointerdown to input event handling (#4443)

desktop/src/input.rs

@@ -6,6 +6,7 @@ use crate::ui::{MULTICLICK_ALLOWED_TRAVEL, MULTICLICK_TIMEOUT, PINCH_ZOOM_SPEED,
 use crate::wrapper::messages::{DesktopWrapperMessage, InputMessage, ModifierKeys, MouseKeys, PointerState, ScrollDelta};
 
 pub(crate) struct InputState {
+	start: Instant,
 	viewport_info: Option<ViewportInfo>,
 	pointer_lock_position: Option<PhysicalPosition<f64>>,
 	modifier_keys: ModifierKeys,
@@ -29,6 +30,7 @@ impl InputAction {
 impl InputState {
 	pub(crate) fn new() -> Self {
 		Self {
+			start: Instant::now(),
 			viewport_info: None,
 			pointer_lock_position: None,
 			modifier_keys: ModifierKeys::empty(),
@@ -193,6 +195,7 @@ impl InputState {
 		PointerState {
 			editor_position: (self.pointer_position.x / self.scale(), self.pointer_position.y / self.scale()).into(),
 			mouse_keys: self.pointer_keys,
+			time: Some(self.start.elapsed().as_secs_f64() * 1000.),
 			..Default::default()
 		}
 	}

editor/src/messages/input_mapper/utility_types/pointer.rs

@@ -56,6 +56,7 @@ pub struct PointerState {
 	pub position: ViewportPosition,
 	pub mouse_keys: MouseKeys,
 	pub scroll_delta: ScrollDelta,
+	pub time: Option<f64>,
 	pub pressure: Option<f64>,
 	pub tilt: Option<DVec2>,
 	pub twist: Option<f64>,
@@ -77,6 +78,7 @@ pub struct EditorPointerState {
 	pub editor_position: EditorPosition,
 	pub mouse_keys: MouseKeys,
 	pub scroll_delta: ScrollDelta,
+	pub time: Option<f64>,
 	pub pressure: Option<f64>,
 	pub tilt: Option<DVec2>,
 	pub twist: Option<f64>,
@@ -101,6 +103,7 @@ impl EditorPointerState {
 			position: (viewport.logical(self.editor_position) - viewport.offset()).into(),
 			mouse_keys: self.mouse_keys,
 			scroll_delta: self.scroll_delta,
+			time: self.time,
 			pressure: self.pressure,
 			tilt: self.tilt,
 			twist: self.twist,

editor/src/messages/input_preprocessor/input_preprocessor_message_handler.rs

@@ -16,6 +16,7 @@ pub struct InputPreprocessorMessageHandler {
 	pub time: u64,
 	pub keyboard: KeyStates,
 	pub mouse: PointerState,
+	pointer_down_time: f64,
 }
 
 #[message_handler_data]
@@ -144,6 +145,13 @@ impl InputPreprocessorMessageHandler {
 			}
 		}
 
+		let raw_time = new_state.time.unwrap_or(self.time as f64);
+		if self.mouse.mouse_keys == MouseKeys::empty() {
+			self.pointer_down_time = raw_time;
+		}
+		let interacting = (self.mouse.mouse_keys | new_state.mouse_keys) != MouseKeys::empty();
+		new_state.time = interacting.then_some(raw_time - self.pointer_down_time);
+
 		self.mouse = new_state;
 	}