Layer opacity (#312)

Closes #187

* Add layer opacity input

* Improve Rust code cleanliness

core/document/src/document.rs

@@ -412,15 +412,22 @@ impl Document {
 			}
 			Operation::SetLayerBlendMode { path, blend_mode } => {
 				self.mark_as_dirty(path)?;
-				self.layer_mut(&path).unwrap().blend_mode = *blend_mode;
+				self.layer_mut(path)?.blend_mode = *blend_mode;
+
+				let path = path.as_slice()[..path.len() - 1].to_vec();
+
+				Some(vec![DocumentResponse::DocumentChanged, DocumentResponse::FolderChanged { path }])
+			}
+			Operation::SetLayerOpacity { path, opacity } => {
+				self.mark_as_dirty(path)?;
+				self.layer_mut(path)?.opacity = *opacity;
 
 				let path = path.as_slice()[..path.len() - 1].to_vec();
 
 				Some(vec![DocumentResponse::DocumentChanged, DocumentResponse::FolderChanged { path }])
 			}
 			Operation::FillLayer { path, color } => {
-				let layer = self.layer_mut(path).unwrap();
-				layer.style.set_fill(layers::style::Fill::new(*color));
+				self.layer_mut(path)?.style.set_fill(layers::style::Fill::new(*color));
 				self.mark_as_dirty(path)?;
 				Some(vec![DocumentResponse::DocumentChanged])
 			}

core/document/src/layers/mod.rs

@@ -175,6 +175,7 @@ pub struct Layer {
 	pub thumbnail_cache: String,
 	pub cache_dirty: bool,
 	pub blend_mode: BlendMode,
+	pub opacity: f64,
 }
 
 impl Layer {
@@ -189,6 +190,7 @@ impl Layer {
 			thumbnail_cache: String::new(),
 			cache_dirty: true,
 			blend_mode: BlendMode::Normal,
+			opacity: 1.,
 		}
 	}
 
@@ -203,8 +205,9 @@ impl Layer {
 			self.cache.clear();
 			let _ = write!(
 				self.cache,
-				r#"<g style="mix-blend-mode: {}">{}</g>"#,
+				r#"<g style="mix-blend-mode: {}; opacity: {}">{}</g>"#,
 				self.blend_mode.to_svg_style_name(),
+				self.opacity,
 				self.thumbnail_cache.as_str()
 			);
 

core/document/src/operation.rs

@@ -77,6 +77,10 @@ pub enum Operation {
 		path: Vec<LayerId>,
 		blend_mode: BlendMode,
 	},
+	SetLayerOpacity {
+		path: Vec<LayerId>,
+		opacity: f64,
+	},
 	FillLayer {
 		path: Vec<LayerId>,
 		color: Color,

core/editor/src/document/document_file.rs

@@ -40,6 +40,7 @@ fn layer_data<'a>(layer_data: &'a mut HashMap<Vec<LayerId>, LayerData>, path: &[
 
 pub fn layer_panel_entry(layer_data: &mut LayerData, layer: &mut Layer, path: Vec<LayerId>) -> LayerPanelEntry {
 	let blend_mode = layer.blend_mode;
+	let opacity = layer.opacity;
 	let layer_type: LayerType = (&layer.data).into();
 	let name = layer.name.clone().unwrap_or_else(|| format!("Unnamed {}", layer_type));
 	let arr = layer.current_bounding_box().unwrap_or([DVec2::ZERO, DVec2::ZERO]);
@@ -66,6 +67,7 @@ pub fn layer_panel_entry(layer_data: &mut LayerData, layer: &mut Layer, path: Ve
 		name,
 		visible: layer.visible,
 		blend_mode,
+		opacity,
 		layer_type,
 		layer_data: *layer_data,
 		path,

core/editor/src/document/document_message_handler.rs

@@ -27,6 +27,7 @@ pub enum DocumentMessage {
 	DuplicateSelectedLayers,
 	CopySelectedLayers,
 	SetBlendModeForSelectedLayers(BlendMode),
+	SetOpacityForSelectedLayers(f64),
 	PasteLayers { path: Vec<LayerId>, insert_index: isize },
 	AddFolder(Vec<LayerId>),
 	RenameLayer(Vec<LayerId>, String),
@@ -61,7 +62,7 @@ pub enum DocumentMessage {
 	AlignSelectedLayers(AlignAxis, AlignAggregate),
 	DragLayer(Vec<LayerId>, DVec2),
 	MoveSelectedLayersTo { path: Vec<LayerId>, insert_index: isize },
-	ReorderSelectedLayers(i32), // relatve_position,
+	ReorderSelectedLayers(i32), // relative_position,
 	SetLayerTranslation(Vec<LayerId>, Option<f64>, Option<f64>),
 }
 
@@ -361,8 +362,16 @@ impl MessageHandler<DocumentMessage, &InputPreprocessor> for DocumentMessageHand
 			SetBlendModeForSelectedLayers(blend_mode) => {
 				let active_document = self.active_document();
 
-				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path)) {
-					responses.push_back(DocumentOperation::SetLayerBlendMode { path: path.clone(), blend_mode }.into());
+				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path.clone())) {
+					responses.push_back(DocumentOperation::SetLayerBlendMode { path, blend_mode }.into());
+				}
+			}
+			SetOpacityForSelectedLayers(opacity) => {
+				let opacity = opacity.clamp(0., 1.);
+				let active_document = self.active_document();
+
+				for path in active_document.layer_data.iter().filter_map(|(path, data)| data.selected.then(|| path.clone())) {
+					responses.push_back(DocumentOperation::SetLayerOpacity { path, opacity }.into());
 				}
 			}
 			ToggleLayerVisibility(path) => {

core/editor/src/frontend/layer_panel.rs

@@ -11,6 +11,7 @@ pub struct LayerPanelEntry {
 	pub name: String,
 	pub visible: bool,
 	pub blend_mode: BlendMode,
+	pub opacity: f64,
 	pub layer_type: LayerType,
 	pub layer_data: LayerData,
 	pub path: Vec<LayerId>,