test: add simple plugin example

Author: tu6ge

crates/core/examples/plugin.rs

@@ -0,0 +1,142 @@
+use ferrum_flow::*;
+use gpui::{
+    AnyElement, AppContext as _, Application, Element as _, ParentElement as _, Styled,
+    WindowOptions, div, px, rgb, white,
+};
+use serde_json::json;
+
+/// A beginner-friendly custom plugin example.
+///
+/// Run with:
+/// `cargo run -p ferrum-flow --example plugin`
+fn main() {
+    Application::new().run(|cx| {
+        let mut graph = Graph::new();
+
+        graph
+            .create_node("default")
+            .position(120.0, 120.0)
+            .input()
+            .output()
+            .data(json!({ "label": "Base Node" }))
+            .build();
+
+        cx.open_window(WindowOptions::default(), |window, cx| {
+            cx.new(|ctx| {
+                FlowCanvas::builder(graph, ctx, window)
+                    .default_plugins()
+                    .plugin(StarterPlugin::new())
+                    .plugin(ToastPlugin::new())
+                    .build()
+            })
+        })
+        .unwrap();
+    });
+}
+
+/// A tiny plugin that demonstrates:
+/// 1) plugin state
+/// 2) input handling
+/// 3) custom overlay rendering
+/// 4) mutating graph data through `PluginContext`
+struct StarterPlugin {
+    next_index: usize,
+    clicks: usize,
+    show_hud: bool,
+}
+
+impl StarterPlugin {
+    fn new() -> Self {
+        Self {
+            next_index: 1,
+            clicks: 0,
+            show_hud: true,
+        }
+    }
+
+    fn add_demo_node(&mut self, ctx: &mut PluginContext) {
+        let i = self.next_index;
+        self.next_index += 1;
+
+        let x = 120.0 + ((i % 6) as f32) * 180.0;
+        let y = 280.0 + ((i / 6) as f32) * 140.0;
+
+        ctx.create_node("default")
+            .position(x, y)
+            .input()
+            .output()
+            .data(json!({ "label": format!("Plugin Node {i}") }))
+            .build();
+
+        ctx.emit(FlowEvent::custom(ToastMessage::success(format!(
+            "Created node #{i} from StarterPlugin"
+        ))));
+    }
+}
+
+impl Plugin for StarterPlugin {
+    fn name(&self) -> &'static str {
+        "starter_plugin"
+    }
+
+    fn setup(&mut self, _ctx: &mut InitPluginContext) {
+        // Put one initial node index behind the first generated node label.
+        self.next_index = 1;
+    }
+
+    fn on_event(&mut self, event: &FlowEvent, ctx: &mut PluginContext) -> EventResult {
+        if let FlowEvent::Input(InputEvent::KeyDown(ev)) = event {
+            if ev.keystroke.key == "n" {
+                self.add_demo_node(ctx);
+                return EventResult::Stop;
+            }
+            if ev.keystroke.key == "h" {
+                self.show_hud = !self.show_hud;
+                ctx.notify();
+                return EventResult::Stop;
+            }
+        }
+
+        if let FlowEvent::Input(InputEvent::MouseDown(_)) = event {
+            self.clicks += 1;
+            ctx.notify();
+        }
+
+        EventResult::Continue
+    }
+
+    fn render(&mut self, _ctx: &mut RenderContext) -> Option<AnyElement> {
+        if !self.show_hud {
+            return None;
+        }
+
+        Some(
+            div()
+                .absolute()
+                .left(px(12.0))
+                .top(px(12.0))
+                .px_3()
+                .py_2()
+                .rounded(px(8.0))
+                .bg(rgb(0x001F2937))
+                .text_color(white())
+                .child(div().text_sm().child("StarterPlugin (custom example)"))
+                .child(
+                    div()
+                        .text_sm()
+                        .child(format!("Mouse clicks: {}", self.clicks)),
+                )
+                .child(div().text_sm().child("Press N: create node"))
+                .child(div().text_sm().child("Press H: hide/show this panel"))
+                .into_any(),
+        )
+    }
+
+    fn priority(&self) -> i32 {
+        120
+    }
+
+    fn render_layer(&self) -> RenderLayer {
+        RenderLayer::Overlay
+    }
+}