Better node selection logic

scripts/force-directed-graph/src/lib.rs

@@ -18,8 +18,8 @@ impl Default for Body {
             position: Vec2::ZERO,
             velocity: Vec2::ZERO,
             acceleration: Vec2::ZERO,
-            drag: 0.8,
-            mass: 40.0,
+            drag: 0.85,
+            mass: 25.0,
             fixed: false,
         }
     }
@@ -338,7 +338,35 @@ impl ForceGraph {
             let offset = Vec2::from_angle(child as f32) * 10.0;
             let child = &mut self.nodes[child];
             child.info.hidden = false;
+            child.body.fixed = false;
             child.body.position = position + offset;
+            child.body.velocity = Vec2::ZERO;
+        }
+    }
+
+    pub fn hide(&mut self, node: usize) {
+        let node = &mut self.nodes[node];
+        node.info.hidden = true;
+
+        let children = node.info.unhide.to_owned();
+        for child in children {
+            self.hide(child);
+        }
+    }
+
+    pub fn on_select(&mut self, id: usize) {
+        let node = &mut self.nodes[id];
+
+        if !node.body.fixed {
+            node.body.fixed = true;
+            self.unhide(id);
+        } else {
+            node.body.fixed = false;
+
+            let children = node.info.unhide.to_owned();
+            for child in children {
+                self.hide(child);
+            }
         }
     }
 
@@ -446,7 +474,7 @@ impl PanelImpl for ForceDirectedGraphPanel {
                 .iter()
                 .position(|node| !node.info.hidden && node.body.position.distance(at) < 6.0);
             if let Some(node) = node {
-                self.graph.unhide(node);
+                self.graph.on_select(node);
             }
         }
     }