From d703d5c3e37974142e5803da359cacb82043782a Mon Sep 17 00:00:00 2001
From: Alain Emilia Anna Zscheile <fogti+devel@ytrizja.de>
Date: Wed, 1 Jan 2025 22:53:13 +0100
Subject: [PATCH] feat(viewport,overlay): drag to select bbox

---
 crates/topola-egui/src/overlay.rs  | 18 ++++++++++++++++--
 crates/topola-egui/src/viewport.rs | 16 ++++++++++------
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/crates/topola-egui/src/overlay.rs b/crates/topola-egui/src/overlay.rs
index 51eea85..269392b 100644
--- a/crates/topola-egui/src/overlay.rs
+++ b/crates/topola-egui/src/overlay.rs
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: MIT
 
 use geo::Point;
-use rstar::AABB;
+use rstar::{Point as _, AABB};
 use spade::InsertionError;
 
 use topola::{
@@ -59,10 +59,24 @@ impl Overlay {
         self.reselect_bbox = Some(None);
     }
 
+    pub fn drag_start(&mut self, board: &Board<impl AccessMesadata>, at: Point) {
+        if let None | Some(None) = self.reselect_bbox {
+            // handle bounding box selection
+            self.reselect_bbox = Some(Some(at));
+        }
+    }
+
+    pub fn drag_stop(&mut self, board: &Board<impl AccessMesadata>, at: Point) {
+        if let Some(aabb) = self.get_bbox_reselect(at) {
+            // handle bounding box selection
+            self.selected_bbox = aabb;
+            self.reselect_bbox = None;
+        }
+    }
+
     pub fn click(&mut self, board: &Board<impl AccessMesadata>, at: Point) {
         if let Some(rsbb) = self.reselect_bbox.take() {
             // handle bounding box selection (takes precendence over other interactions)
-            use rstar::Point;
             self.reselect_bbox = match rsbb {
                 None => Some(Some(at)),
                 Some(pt) => {
diff --git a/crates/topola-egui/src/viewport.rs b/crates/topola-egui/src/viewport.rs
index d5d9daa..17b1e70 100644
--- a/crates/topola-egui/src/viewport.rs
+++ b/crates/topola-egui/src/viewport.rs
@@ -51,11 +51,13 @@ impl Viewport {
                     ui.ctx().request_repaint();
 
                     let (id, viewport_rect) = ui.allocate_space(ui.available_size());
-                    let response = ui.interact(viewport_rect, id, egui::Sense::click());
+                    let response = ui.interact(viewport_rect, id, egui::Sense::click_and_drag());
                     // NOTE: we use `interact_pos` instead of `latest_pos` to handle "pointer gone"
                     // events more graceful
                     let latest_pos = self.transform.inverse()
-                        * (ctx.input(|i| i.pointer.interact_pos().unwrap_or_default()));
+                        * (response.interact_pointer_pos().unwrap_or_else(|| {
+                            ctx.input(|i| i.pointer.interact_pos().unwrap_or_default())
+                        }));
 
                     let old_scaling = self.transform.scaling;
                     self.transform.scaling *= ctx.input(|i| i.zoom_delta());
@@ -70,6 +72,7 @@ impl Viewport {
                         let layers = &mut workspace.appearance_panel;
                         let overlay = &mut workspace.overlay;
                         let latest_point = point! {x: latest_pos.x as f64, y: -latest_pos.y as f64};
+                        let board = workspace.interactor.invoker().autorouter().board();
 
                         if response.clicked() {
                             if menu_bar.is_placing_via {
@@ -87,11 +90,12 @@ impl Viewport {
                                     maybe_net: Some(1234),
                                 }));
                             } else {
-                                overlay.click(
-                                    workspace.interactor.invoker().autorouter().board(),
-                                    latest_point,
-                                );
+                                overlay.click(board, latest_point);
                             }
+                        } else if response.drag_started() {
+                            overlay.drag_start(board, latest_point);
+                        } else if response.drag_stopped() {
+                            overlay.drag_stop(board, latest_point);
                         } else if let Some(cur_bbox) = overlay.get_bbox_reselect(latest_point) {
                             painter.paint_bbox_with_color(cur_bbox, egui::Color32::RED);
                         }