Add auto-panning to the Artboard tool (#1652)

* Move panning functionality to auto_panning.rs

* Add auto-panning to Artboard tool

* Hide debug messages containing AnimationFrame

editor/src/messages/tool/common_functionality/auto_panning.rs

@@ -0,0 +1,79 @@
+use crate::consts::{DRAG_BEYOND_VIEWPORT_MAX_OVEREXTENSION_PIXELS, DRAG_BEYOND_VIEWPORT_SPEED_FACTOR};
+use crate::messages::prelude::*;
+use crate::messages::tool::tool_messages::tool_prelude::*;
+
+#[derive(Clone, Debug, Default)]
+pub struct AutoPanning {
+	subscribed_to_animation_frame: bool,
+}
+
+impl AutoPanning {
+	pub fn start(&mut self, messages: &[Message], responses: &mut VecDeque<Message>) {
+		if !self.subscribed_to_animation_frame {
+			self.subscribed_to_animation_frame = true;
+
+			for message in messages {
+				responses.add(BroadcastMessage::SubscribeEvent {
+					on: BroadcastEvent::AnimationFrame,
+					send: Box::new(message.clone()),
+				});
+			}
+		}
+	}
+
+	pub fn stop(&mut self, messages: &[Message], responses: &mut VecDeque<Message>) {
+		if self.subscribed_to_animation_frame {
+			self.subscribed_to_animation_frame = false;
+
+			for message in messages {
+				responses.add(BroadcastMessage::UnsubscribeEvent {
+					on: BroadcastEvent::AnimationFrame,
+					message: Box::new(message.clone()),
+				});
+			}
+		}
+	}
+
+	pub fn setup_by_mouse_position(&mut self, mouse_position: DVec2, viewport_size: DVec2, messages: &[Message], responses: &mut VecDeque<Message>) {
+		let is_pointer_outside_edge = mouse_position.x < 0. || mouse_position.x > viewport_size.x || mouse_position.y < 0. || mouse_position.y > viewport_size.y;
+
+		match is_pointer_outside_edge {
+			true => self.start(messages, responses),
+			false => self.stop(messages, responses),
+		}
+	}
+
+	/// Shifts the viewport when the mouse reaches the edge of the viewport.
+	///
+	/// If the mouse was beyond any edge, it returns the amount shifted. Otherwise it returns None.
+	/// The shift is proportional to the distance between edge and mouse. It is also guaranteed to be integral.
+	pub fn shift_viewport(mouse_position: DVec2, viewport_size: DVec2, responses: &mut VecDeque<Message>) -> Option<DVec2> {
+		let mouse_position = mouse_position.clamp(
+			DVec2::ZERO - DVec2::splat(DRAG_BEYOND_VIEWPORT_MAX_OVEREXTENSION_PIXELS),
+			viewport_size + DVec2::splat(DRAG_BEYOND_VIEWPORT_MAX_OVEREXTENSION_PIXELS),
+		);
+		let mouse_position_percent = mouse_position / viewport_size;
+
+		let mut shift_percent = DVec2::ZERO;
+
+		if mouse_position_percent.x < 0. {
+			shift_percent.x = -mouse_position_percent.x;
+		} else if mouse_position_percent.x > 1. {
+			shift_percent.x = 1. - mouse_position_percent.x;
+		}
+
+		if mouse_position_percent.y < 0. {
+			shift_percent.y = -mouse_position_percent.y;
+		} else if mouse_position_percent.y > 1. {
+			shift_percent.y = 1. - mouse_position_percent.y;
+		}
+
+		if shift_percent.x == 0. && shift_percent.y == 0. {
+			return None;
+		}
+
+		let delta = (shift_percent * DRAG_BEYOND_VIEWPORT_SPEED_FACTOR * viewport_size).round();
+		responses.add(NavigationMessage::TranslateCanvas { delta });
+		Some(delta)
+	}
+}

editor/src/messages/tool/common_functionality/mod.rs

@@ -1,3 +1,4 @@
+pub mod auto_panning;
 pub mod color_selector;
 pub mod graph_modification_utils;
 pub mod pivot;