Finalizing new RenderEngine

alchemy/src/window/window.rs

@@ -37,65 +37,18 @@ impl AppWindow {
     /// This method is called on the `show` event, and in rare cases can be useful to call
     /// directly.
     pub fn render(&mut self) {
-        /*
+        let children = match self.delegate.render() {
-        let mut new_root_node = create_root_node(None, &mut self.layout);
+            Ok(opt) => opt,
-
+            Err(e) => {
-        // For API reasons, we'll call the render for this Window, and then patch it into a new
+                eprintln!("Error rendering window! {}", e);
-        // root node for the tree diff/patch comparison. For this we only need to go one level
+                RSX::None
-        // deep, the recursion in the next step will handle the rest.
+            }
-        match self.delegate.render() {
+        };
-            Ok(opt) => match opt {
-                RSX::VirtualNode(mut child) => {
-                    if let RSX::VirtualNode(root) = &mut new_root_node {
-                        if child.tag == "Fragment" {
-                            root.children.append(&mut child.children);
-                        } else {
-                            root.children.push(RSX::VirtualNode(child));
-                        }
-                    }
-                },
-
-                // If it's an RSX::None, or a RSX::VirtualText, we do nothing, as... one
-                // requires nothing, and one isn't supported unless it's inside a <Text> tag.
-                _ => {}
-            },
 
+        match RENDER_ENGINE.diff_and_render_root(&self.render_key, children) {
+            Ok(_) => {}
             Err(e) => { eprintln!("Error rendering window! {}", e); }
         }
-
-        // Taking ownership of the tree makes parts of this so much easier, so let's swap
-        // them out for the moment. We're going to discard the old one anyway.
-        let mut old_root_node = RSX::None;
-        std::mem::swap(&mut old_root_node, &mut self.root_node);
-
-        self.root_node = match diff_and_patch_tree(old_root_node, new_root_node, &mut self.layout, 0) {
-            Ok(node) => node,
-            Err(e) => { eprintln!("Error: {}", e); RSX::None }
-        };
-
-        self.configure_and_apply_styles();
-        */
-    }
-
-    /// Walks the tree again, purely concerning itself with calculating layout and applying styles.
-    /// This in effect creates a two-pass layout system. In the future much of this may be made
-    /// async, so relying on underlying behavior in here is considered... suspect.
-    ///
-    /// This method is called on window resize and show events.
-    fn configure_and_apply_styles(&mut self) -> Result<(), Box<std::error::Error>> {
-        let window_size = Size {
-            width: Number::Defined(600.),
-            height: Number::Defined(600.)
-        };
-
-        /*if let RSX::VirtualNode(root_node) = &mut self.root_node {
-            if let Some(layout_node) = &root_node.layout_node {
-                self.layout.compute_layout(*layout_node, window_size)?;
-                walk_and_apply_styles(&root_node, &mut self.layout)?;
-            }
-        }*/
-
-        Ok(())
     }
 
     /// Renders and calls through to the native platform window show method.

lifecycle/src/reconciler/error.rs

@@ -0,0 +1,30 @@
+//! Implements a set of Error types that could happen during a diff/patch/reflow 
+//! run. These are mostly internal to the rendering engine itself, but could potentially 
+//! show up elsewhere.
+
+use std::fmt;
+use std::error::Error;
+
+pub enum RenderEngineError {
+    InvalidKeyError
+}
+
+impl fmt::Display for RenderEngineError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            RenderEngineError::InvalidKeyError => write!(f, "An invalid key was passed to the render engine.")
+        }
+    }
+}
+
+impl fmt::Debug for RenderEngineError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            RenderEngineError::InvalidKeyError => write!(f, "An invalid key was passed to the render engine: {{ file: {}, line: {} }}", file!(), line!())
+        }
+    }
+}
+
+impl Error for RenderEngineError {
+
+}

lifecycle/src/reconciler/mod.rs

@@ -16,6 +16,9 @@ use alchemy_styles::geometry::Size;
 use crate::traits::Component;
 use crate::rsx::{Props, RSX, VirtualNode};
 
+mod error;
+use error::RenderEngineError;
+
 // This is never actually created, it's just to satisfy the fact that View
 // is defined in the core crate, which we can't import here without creating a 
 // circular dependency.
@@ -77,12 +80,37 @@ impl RenderEngine {
     /// the new tree before discarding the old tree.
     ///
     /// This calls the necessary component lifecycles per-component.
-    pub fn diff_and_apply_root(&self, key: &Uuid, new_root: RSX) -> Result<(), Box<Error>> {
+    pub fn diff_and_render_root(&self, key: &Uuid, child: RSX) -> Result<(), Box<Error>> {
-        /*let trees = self.trees.lock().unwrap();
+        let mut new_root = RSX::node("root", || {
-        let (old_root, stretch) = trees.remove(key)?;
+            Arc::new(RwLock::new(StubView {}))
-        diff_and_patch_trees(old_root, new_root, &mut stretch, 0)?;
+        }, {
-        trees.insert(*key, (new_root, stretch));
+            let mut props = Props::default();
-        */
+            props.styles = "root".into();
+            props
+        });
+
+        // If it's an RSX::None, or a RSX::VirtualText, we do nothing, as... one
+        // requires nothing, and one isn't supported unless it's inside a <Text> tag. 
+        if let RSX::VirtualNode(mut child) = child {
+            if let RSX::VirtualNode(new_root_node) = &mut new_root {
+                if child.tag == "Fragment" {
+                    new_root_node.children.append(&mut child.children);
+                } else {
+                    new_root_node.children.push(RSX::VirtualNode(child));
+                }
+            }
+        }
+
+        let mut trees = self.trees.lock().unwrap();
+        let (old_root, mut stretch) = trees.remove(key).ok_or_else(|| RenderEngineError::InvalidKeyError {})?;
+        let patched_new_root = diff_and_patch_trees(old_root, new_root, &mut stretch, 0)?;
+
+        if let RSX::VirtualNode(node) = &patched_new_root {
+            walk_and_apply_styles(node, &mut stretch)?;
+        }
+
+        trees.insert(*key, (patched_new_root, stretch));
+        println!("RENDERED");
         Ok(())
     }
 }