Refactor texture image filtering

- Support only `Linear` or `Nearest`
- Simplify `Layer` groups
- Move `FilterMethod` to `Image` and `image::Viewer`

widget/src/image.rs

@@ -13,7 +13,7 @@ use crate::core::{
 
 use std::hash::Hash;
 
-pub use image::{FilterMethod, Handle, TextureFilter};
+pub use image::{FilterMethod, Handle};
 
 /// Creates a new [`Viewer`] with the given image `Handle`.
 pub fn viewer<Handle>(handle: Handle) -> Viewer<Handle> {
@@ -37,6 +37,7 @@ pub struct Image<Handle> {
     width: Length,
     height: Length,
     content_fit: ContentFit,
+    filter_method: FilterMethod,
 }
 
 impl<Handle> Image<Handle> {
@@ -47,6 +48,7 @@ impl<Handle> Image<Handle> {
             width: Length::Shrink,
             height: Length::Shrink,
             content_fit: ContentFit::Contain,
+            filter_method: FilterMethod::default(),
         }
     }
 
@@ -65,11 +67,15 @@ impl<Handle> Image<Handle> {
     /// Sets the [`ContentFit`] of the [`Image`].
     ///
     /// Defaults to [`ContentFit::Contain`]
-    pub fn content_fit(self, content_fit: ContentFit) -> Self {
-        Self {
-            content_fit,
-            ..self
-        }
+    pub fn content_fit(mut self, content_fit: ContentFit) -> Self {
+        self.content_fit = content_fit;
+        self
+    }
+
+    /// Sets the [`FilterMethod`] of the [`Image`].
+    pub fn filter_method(mut self, filter_method: FilterMethod) -> Self {
+        self.filter_method = filter_method;
+        self
     }
 }
 
@@ -119,6 +125,7 @@ pub fn draw<Renderer, Handle>(
     layout: Layout<'_>,
     handle: &Handle,
     content_fit: ContentFit,
+    filter_method: FilterMethod,
 ) where
     Renderer: image::Renderer<Handle = Handle>,
     Handle: Clone + Hash,
@@ -141,7 +148,7 @@ pub fn draw<Renderer, Handle>(
             ..bounds
         };
 
-        renderer.draw(handle.clone(), drawing_bounds + offset);
+        renderer.draw(handle.clone(), filter_method, drawing_bounds + offset);
     };
 
     if adjusted_fit.width > bounds.width || adjusted_fit.height > bounds.height
@@ -191,7 +198,13 @@ where
         _cursor: mouse::Cursor,
         _viewport: &Rectangle,
     ) {
-        draw(renderer, layout, &self.handle, self.content_fit);
+        draw(
+            renderer,
+            layout,
+            &self.handle,
+            self.content_fit,
+            self.filter_method,
+        );
     }
 }
 

widget/src/image/viewer.rs

@@ -22,19 +22,21 @@ pub struct Viewer<Handle> {
     max_scale: f32,
     scale_step: f32,
     handle: Handle,
+    filter_method: image::FilterMethod,
 }
 
 impl<Handle> Viewer<Handle> {
     /// Creates a new [`Viewer`] with the given [`State`].
     pub fn new(handle: Handle) -> Self {
         Viewer {
+            handle,
             padding: 0.0,
             width: Length::Shrink,
             height: Length::Shrink,
             min_scale: 0.25,
             max_scale: 10.0,
             scale_step: 0.10,
-            handle,
+            filter_method: image::FilterMethod::default(),
         }
     }
 
@@ -329,6 +331,7 @@ where
                 image::Renderer::draw(
                     renderer,
                     self.handle.clone(),
+                    self.filter_method,
                     Rectangle {
                         x: bounds.x,
                         y: bounds.y,