Add a view inspector

examples/counter/src/main.rs

@@ -1,4 +1,6 @@
 use floem::{
+    event::{Event, EventListener},
+    keyboard::{Key, NamedKey},
     peniko::Color,
     reactive::create_signal,
     unit::UnitExt,
@@ -8,7 +10,7 @@ use floem::{
 
 fn app_view() -> impl View {
     let (counter, set_counter) = create_signal(0);
-    stack((
+    let view = stack((
         label(move || format!("Value: {}", counter.get())).style(|s| s.padding(10.0)),
         stack((
             text("Increment")
@@ -72,6 +74,16 @@ fn app_view() -> impl View {
             .flex_col()
             .items_center()
             .justify_center()
+    });
+
+    let id = view.id();
+    view.on_event(EventListener::KeyUp, move |e| {
+        if let Event::KeyUp(e) = e {
+            if e.key.logical_key == Key::Named(NamedKey::F11) {
+                id.inspect();
+            }
+        }
+        true
     })
 }
 

examples/widget-gallery/src/main.rs

@@ -31,7 +31,7 @@ fn app_view() -> impl View {
     let (tabs, _set_tabs) = create_signal(tabs);
 
     let (active_tab, set_active_tab) = create_signal(0);
-    stack({
+    let view = stack({
         (
             container({
                 scroll({
@@ -144,7 +144,17 @@ fn app_view() -> impl View {
         )
     })
     .style(|s| s.size(100.pct(), 100.pct()))
-    .window_title(|| "Widget Gallery".to_owned())
+    .window_title(|| "Widget Gallery".to_owned());
+
+    let id = view.id();
+    view.on_event(EventListener::KeyUp, move |e| {
+        if let Event::KeyUp(e) = e {
+            if e.key.logical_key == Key::Named(NamedKey::F11) {
+                id.inspect();
+            }
+        }
+        true
+    })
 }
 
 fn main() {

renderer/src/lib.rs

@@ -20,7 +20,7 @@ pub struct Img<'a> {
 }
 
 pub trait Renderer {
-    fn begin(&mut self);
+    fn begin(&mut self, capture: bool);
 
     fn transform(&mut self, transform: Affine);
 
@@ -49,5 +49,5 @@ pub trait Renderer {
 
     fn draw_img(&mut self, img: Img<'_>, rect: Rect);
 
-    fn finish(&mut self);
+    fn finish(&mut self) -> Option<DynamicImage>;
 }

src/app.rs

@@ -1,5 +1,6 @@
 use std::{cell::RefCell, sync::Arc};
 
+use floem_reactive::WriteSignal;
 use once_cell::sync::Lazy;
 use parking_lot::Mutex;
 use winit::{
@@ -8,7 +9,10 @@ use winit::{
     window::WindowId,
 };
 
-use crate::{action::Timer, app_handle::ApplicationHandle, view::View, window::WindowConfig};
+use crate::{
+    action::Timer, app_handle::ApplicationHandle, inspector::Capture, view::View,
+    window::WindowConfig,
+};
 
 type AppEventCallback = dyn Fn(AppEvent);
 
@@ -42,6 +46,10 @@ pub(crate) enum AppUpdateEvent {
     CloseWindow {
         window_id: WindowId,
     },
+    CaptureWindow {
+        window_id: WindowId,
+        capture: WriteSignal<Option<Capture>>,
+    },
     RequestTimer {
         timer: Timer,
     },

src/app_handle.rs

@@ -12,6 +12,7 @@ use crate::{
     action::{Timer, TimerToken},
     app::{AppUpdateEvent, UserEvent, APP_UPDATE_EVENTS},
     ext_event::EXT_EVENT_HANDLER,
+    inspector::Capture,
     view::View,
     window::WindowConfig,
     window_handle::WindowHandle,
@@ -64,6 +65,9 @@ impl ApplicationHandle {
                 AppUpdateEvent::RequestTimer { timer } => {
                     self.request_timer(timer, event_loop);
                 }
+                AppUpdateEvent::CaptureWindow { window_id, capture } => {
+                    capture.set(self.capture_window(window_id));
+                }
                 #[cfg(target_os = "linux")]
                 AppUpdateEvent::MenuAction {
                     window_id,
@@ -234,6 +238,12 @@ impl ApplicationHandle {
         }
     }
 
+    fn capture_window(&mut self, window_id: WindowId) -> Option<Capture> {
+        self.window_handles
+            .get_mut(&window_id)
+            .map(|handle| handle.capture())
+    }
+
     pub(crate) fn idle(&mut self) {
         while let Some(trigger) = { EXT_EVENT_HANDLER.queue.lock().pop_front() } {
             trigger.notify();

src/context.rs

@@ -261,6 +261,9 @@ pub struct AppState {
     pub(crate) keyboard_navigation: bool,
     pub(crate) window_menu: HashMap<usize, Box<dyn Fn()>>,
     pub(crate) context_menu: HashMap<usize, Box<dyn Fn()>>,
+
+    /// This is set if we're currently capturing the window for the inspector.
+    pub(crate) capture: Option<()>,
 }
 
 impl Default for AppState {
@@ -298,6 +301,7 @@ impl AppState {
             grid_bps: GridBreakpoints::default(),
             window_menu: HashMap::new(),
             context_menu: HashMap::new(),
+            capture: None,
         }
     }
 

src/event.rs

@@ -9,7 +9,7 @@ use crate::{
     pointer::{PointerInputEvent, PointerMoveEvent, PointerWheelEvent},
 };
 
-#[derive(Hash, PartialEq, Eq)]
+#[derive(Debug, Hash, PartialEq, Eq)]
 pub enum EventListener {
     KeyDown,
     KeyUp,

src/id.rs

@@ -214,6 +214,10 @@ impl Id {
         self.add_update_message(UpdateMessage::PopoutMenu { id: *self, menu });
     }
 
+    pub fn inspect(&self) {
+        self.add_update_message(UpdateMessage::Inspect);
+    }
+
     fn add_update_message(&self, msg: UpdateMessage) {
         CENTRAL_UPDATE_MESSAGES.with(|msgs| {
             msgs.borrow_mut().push((*self, msg));