add image node

ui/src/nodes/image.rs

@@ -1,16 +1,27 @@
-use std::fmt::Debug;
-use femtovg::{ImageId, Paint, Path};
+use std::{fmt::Debug, mem, path::PathBuf};
+use femtovg::{Color, ErrorKind, ImageFlags, ImageId, Paint, Path};
 use crate::{events::handler::EventHandlerDatabase, SharedNode, WeakNode};
 use super::{Node, NodeChildren, Style};
 
 #[derive(Debug)]
-/// Simple image node.
-/// This is basically just a wrapper around Rectangle node with a fill of type Paint::image.
-/// Use that if you need more options.
+/// Status of the image - when rendering, image node attempts to load the image and sets this status accordingly.
+/// Changes this if you want to change the image. If the previous status was loaded, free the image.
+/// In case the loading fails, image load status changes to Error and the node doesn't render.
+pub enum ImageLoad {
+    LoadFile(PathBuf, ImageFlags),
+    // LoadArray(&[u8]),
+    LoadVec(Vec<u8>, ImageFlags),
+    Loaded(ImageId),
+    Error(ErrorKind)
+}
+
+#[derive(Debug)]
+/// Image node.
+/// Sadly doesn't implement `Default` because of the `ImageLoad` enum.
 pub struct Image {
     pub style: Style,
-    /// The image to be rendered. You are responsible for freeing the image data.
-    pub image: ImageId,
+    /// The image to be rendered.
+    pub image: ImageLoad,
     /// Image width - note that you also have to set the style accordingly for it to render correctly, this is more about scaling the image
     pub width: f32,
     /// Image height - note that you also have to set the style accordingly for it to render correctly, this is more about scaling the image
@@ -30,7 +41,33 @@ impl Node for Image {
         None
     }
 
-    fn render_pre_children(&self, context: &mut super::RenderContext, layout: taffy::prelude::Layout) {
+    fn render_pre_children(&mut self, context: &mut super::RenderContext, layout: taffy::prelude::Layout) {
+        match &self.image {
+            ImageLoad::LoadFile(_, _) => {
+                let image = mem::replace(&mut self.image, ImageLoad::Error(ErrorKind::UnknownError));
+                if let ImageLoad::LoadFile(path, flags) = image {
+                    match context.canvas.load_image_file(path, flags) {
+                        Ok(image) => {
+                            self.image = ImageLoad::Loaded(image);
+                        },
+                        Err(e) => {
+                            self.image = ImageLoad::Error(e);
+                        }
+                    }
+                }
+            },
+            ImageLoad::LoadVec(data, flags) => {
+                match context.canvas.load_image_mem(data, *flags) {
+                    Ok(image) => {
+                        self.image = ImageLoad::Loaded(image);
+                    },
+                    Err(e) => {
+                        self.image = ImageLoad::Error(e);
+                    }
+                }
+            },
+            _ => {}
+        }
         let mut path = Path::new();
         path.rounded_rect(
             0.,
@@ -39,10 +76,18 @@ impl Node for Image {
             layout.size.height,
             self.radius
         );
-        context.canvas.fill_path(
-            &path,
-            &Paint::image(self.image, 0., 0., self.width, self.height, 0., 1.)
-        );
+        match &self.image {
+            ImageLoad::Loaded(image) => {
+                context.canvas.fill_path(
+                    &path,
+                    &Paint::image(*image, 0., 0., self.width, self.height, 0., 1.)
+                );
+            },
+            ImageLoad::Error(_) => {
+                context.canvas.fill_path(&path, &Paint::color(Color::rgb(255, 0, 0)))
+            },
+            _ => unreachable!("We just loaded the image before, so it's either loaded or errored out.")
+        }
     }
 
     fn event_handlers(&self) -> Option<crate::events::handler::InnerEventHandlerDataset> {

ui/src/nodes/mod.rs

@@ -110,10 +110,10 @@ pub trait Node: Debug {
 
     /// Render the node, called before rendering it's children
     /// Canvas considers 0, 0 to be top left corner (for location after layouting happens)
-    fn render_pre_children(&self, _context: &mut RenderContext, _layout: Layout) {}
+    fn render_pre_children(&mut self, _context: &mut RenderContext, _layout: Layout) {}
     /// Render the node, called after rendering it's children
     /// Canvas considers 0, 0 to be top left corner (for location after layouting happens)
-    fn render_post_children(&self, _context: &mut RenderContext, _layout: Layout) {}
+    fn render_post_children(&mut self, _context: &mut RenderContext, _layout: Layout) {}
 
     /// Sets the parent node.
     /// May be called multiple times with the same value.
@@ -340,12 +340,12 @@ pub(crate) fn render_recursively(node: &SharedNode, context: &mut RenderContext)
         }
     }
     drop(read_node);
-    sself.read().unwrap().render_pre_children(context, layout);
+    sself.write().unwrap().render_pre_children(context, layout);
     if let Some(children) = sself.read().unwrap().children() {
         for child in children {
             render_recursively(child, context);
         }
     }
-    sself.read().unwrap().render_post_children(context, layout);
+    sself.write().unwrap().render_post_children(context, layout);
     context.canvas.restore();
 }

ui/src/nodes/primitives.rs

@@ -30,7 +30,7 @@ impl Node for Rectangle {
     fn children(&self) -> Option<&NodeChildren> {
         None
     }
-    fn render_pre_children(&self, context: &mut RenderContext, layout: Layout) {
+    fn render_pre_children(&mut self, context: &mut RenderContext, layout: Layout) {
         let mut path = Path::new();
         path.rounded_rect(
             0.,