Add basic music player script message handling

scripts/music-player/Cargo.toml

@@ -9,4 +9,5 @@ crate-type = ["cdylib"]
 [dependencies]
 canary_script = { path = "../../crates/script" }
 canary-music-player-protocol = { path = "../../crates/music-player-protocol" }
+serde_json = "1"
 wee_alloc = "^0.4"

scripts/music-player/src/lib.rs

@@ -1,7 +1,10 @@
 #[global_allocator]
 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
-use canary_script::{BindPanel, CursorEventKind, Color, TextLayout, Font, Message, Panel, PanelImpl, Vec2};
+use canary_script::{
+    draw::DrawContext, BindPanel, Color, CursorEventKind, Font, Message, Panel, PanelImpl,
+    TextLayout, Vec2,
+};
 
 canary_script::export_abi!(MusicPlayerPanel);
 
@@ -10,14 +13,17 @@ const DISPLAY_FONT: &str = "Liberation Sans";
 pub struct MusicPlayerPanel {
     panel: Panel,
     display_font: Font,
+    label: Label,
 }
 
 impl BindPanel for MusicPlayerPanel {
     fn bind(panel: Panel, message: Message) -> Box<dyn PanelImpl> {
         let display_font = Font::new(DISPLAY_FONT);
+        let label = Label::new(display_font, "Hello, world!".into(), 1.2);
         let panel = Self {
             panel,
             display_font,
+            label,
         };
         Box::new(panel)
     }
@@ -27,14 +33,61 @@ impl PanelImpl for MusicPlayerPanel {
     fn update(&mut self, dt: f32) {}
 
     fn draw(&mut self) {
-        let layout = TextLayout::new(&self.display_font, "Hello world!");
-        let offset = Vec2 { x: 100.0, y: 100.0 };
-        let scale = 14.0;
+        let ctx = DrawContext::new(self.panel);
+
+        let offset = Vec2 { x: 5.0, y: 12.0 };
+        let size = 8.0;
         let color = Color::WHITE;
-        self.panel.draw_text_layout(&layout, offset, scale, color);
+        self.label.draw(&ctx, offset, size, color);
     }
 
     fn on_cursor_event(&mut self, kind: CursorEventKind, at: Vec2) {}
 
-    fn on_message(&mut self, message: Message) {}
+    fn on_message(&mut self, msg: Message) {
+        use canary_music_player_protocol::InMsg;
+        let msg = msg.to_vec();
+        let msg = serde_json::from_slice::<InMsg>(&msg);
+        self.label.set_text(format!("{:#?}", msg));
+    }
+}
+
+pub struct Label {
+    font: Font,
+    text: String,
+    line_height: f32,
+    layout: Option<Vec<TextLayout>>,
+}
+
+impl Label {
+    pub fn new(font: Font, text: String, line_height: f32) -> Self {
+        Self {
+            font,
+            text,
+            line_height,
+            layout: None,
+        }
+    }
+
+    pub fn draw(&mut self, ctx: &DrawContext, offset: Vec2, size: f32, color: Color) {
+        let layout = self.layout.get_or_insert_with(|| {
+            self.text
+                .lines()
+                .map(|line| TextLayout::new(&self.font, line))
+                .collect()
+        });
+
+        for (line, layout) in layout.iter().enumerate() {
+            let offset = Vec2 {
+                x: offset.x,
+                y: self.line_height * size * line as f32 + offset.y,
+            };
+
+            ctx.draw_text_layout(layout, offset.into(), size, color);
+        }
+    }
+
+    pub fn set_text(&mut self, text: String) {
+        self.text = text;
+        self.layout = None;
+    }
 }