Update UI when deleting last point of shape with Path tool (#979)

* Added new DocumentResponse variant

* Update Operation::DeleteSelectedManipulatorPoints to update Layer Tree by delegating deletion to Operation::DeleteLayer. Also emits Operation::DeletedSelectedManipulatorPoints to let editor clear Properties panel

* Update process_message() to deal with new DocumentResponse::DeletedSelectedManipulatorPoints match case. When this DocumentResponse is emitted, it clears the Properties panel.

* Added Display trait implementation for DocumentResponse::DeletedSelectedManipulatorPoints. Updated imports in document_message_handler.rs to get the correct types for messages emitted from DocumentResponse::DeletedSelectedManipulatorPoints match case in process_message().

* Removed useless import. Capitalized comments for style consistency.

* Updated messages emitted to clear Properties panel by emitting LayoutMessage::SendLayout's instead, which update the backend widget state

* Revert inclusion of unused imports

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

document-legacy/src/document.rs

@@ -1098,10 +1098,16 @@ impl Document {
 
 						// Delete the layer if there are no longer any manipulator groups
 						if (shape.manipulator_groups().len() - 1) == 0 {
-							self.delete(&layer_path)?;
+							// Delegate deletion to DeleteLayer to update Layer Tree in frontend
-							responses.push(DocumentChanged);
+							match self.handle_operation(Operation::DeleteLayer { path: layer_path.clone() }, font_cache) {
-							responses.push(DocumentResponse::DeletedLayer { path: layer_path });
+								Ok(Some(delete_responses)) => {
-							return Ok(Some(responses));
+									responses.extend(delete_responses);
+									responses.push(DocumentResponse::DeletedSelectedManipulatorPoints);
+									return Ok(Some(responses));
+								}
+								Err(e) => error!("DocumentError: {:?}", e),
+								Ok(_) => {}
+							}
 						}
 
 						// If we still have manipulator groups, update the layer and thumbnails

document-legacy/src/response.rs

@@ -21,6 +21,7 @@ pub enum DocumentResponse {
 	LayerChanged {
 		path: Vec<LayerId>,
 	},
+	DeletedSelectedManipulatorPoints,
 }
 
 impl fmt::Display for DocumentResponse {
@@ -31,6 +32,7 @@ impl fmt::Display for DocumentResponse {
 			DocumentResponse::CreatedLayer { .. } => write!(f, "CreatedLayer"),
 			DocumentResponse::LayerChanged { .. } => write!(f, "LayerChanged"),
 			DocumentResponse::DeletedLayer { .. } => write!(f, "DeleteLayer"),
+			DocumentResponse::DeletedSelectedManipulatorPoints { .. } => write!(f, "DeletedSelectedManipulatorPoints"),
 		}
 	}
 }

editor/src/messages/portfolio/document/document_message_handler.rs

@@ -143,6 +143,23 @@ impl MessageHandler<DocumentMessage, (u64, &InputPreprocessorMessageHandler, &Pe
 								);
 							}
 							DocumentResponse::DocumentChanged => responses.push_back(RenderDocument.into()),
+							DocumentResponse::DeletedSelectedManipulatorPoints => {
+								// Clear Properties panel after deleting all points by updating backend widget state.
+								responses.push_back(
+									LayoutMessage::SendLayout {
+										layout: Layout::WidgetLayout(WidgetLayout::new(vec![])),
+										layout_target: LayoutTarget::PropertiesOptions,
+									}
+									.into(),
+								);
+								responses.push_back(
+									LayoutMessage::SendLayout {
+										layout: Layout::WidgetLayout(WidgetLayout::new(vec![])),
+										layout_target: LayoutTarget::PropertiesSections,
+									}
+									.into(),
+								);
+							}
 						};
 						responses.push_back(BroadcastEvent::DocumentIsDirty.into());
 					}