add zooming

1 files changed, 17 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index 534d634..bbd54b8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -289,6 +289,23 @@ impl canvas::Program<Message, Renderer> for Graph {
         if let canvas::Event::Mouse(mouse::Event::ButtonReleased(_)) = event {
             state.interaction = Interaction::Pointer;
         }
+
+        if let canvas::Event::Mouse(mouse::Event::WheelScrolled { delta }) = event {
+            match delta {
+                mouse::ScrollDelta::Lines { y, .. } => {
+                    if y > 0.0 {
+                        state.scale /= 1.1;
+                    } else {
+                        state.scale *= 1.1;
+                    }
+                    state.scale = state.scale.max(0.000001);
+                    println!("SCALE: {}", state.scale);
+                    return (event::Status::Captured, Some(Message::UpdateScreen))
+                },
+                _ => {
+                }
+            }
+        }
         (event::Status::Ignored, None)
     }