Refactor persistence to combine document handling and workspace layout (#4031)

* Unify editor state persistence

* Review

* Fix

* Remove redundant DocumentDetails

* LoadDocumentContent indirection

editor/src/messages/portfolio/persistent_state/mod.rs

@@ -0,0 +1,7 @@
+mod persistent_state_message;
+mod persistent_state_message_handler;
+
+#[doc(inline)]
+pub use persistent_state_message::{PersistentStateMessage, PersistentStateMessageDiscriminant};
+#[doc(inline)]
+pub use persistent_state_message_handler::{PersistentStateMessageContext, PersistentStateMessageHandler};

editor/src/messages/portfolio/persistent_state/persistent_state_message.rs

@@ -0,0 +1,30 @@
+use crate::messages::frontend::utility_types::PersistedState;
+use crate::messages::prelude::*;
+
+#[impl_message(Message, PortfolioMessage, PersistentState)]
+#[derive(PartialEq, Clone, Debug, serde::Serialize, serde::Deserialize)]
+pub enum PersistentStateMessage {
+	ReadState,
+	WriteState,
+	LoadState {
+		state: PersistedState,
+	},
+	ReadDocument {
+		#[serde(rename = "documentId")]
+		document_id: DocumentId,
+	},
+	WriteDocument {
+		#[serde(rename = "documentId")]
+		document_id: DocumentId,
+		document: String,
+	},
+	DeleteDocument {
+		#[serde(rename = "documentId")]
+		document_id: DocumentId,
+	},
+	LoadDocument {
+		#[serde(rename = "documentId")]
+		document_id: DocumentId,
+		document: String,
+	},
+}

editor/src/messages/portfolio/persistent_state/persistent_state_message_handler.rs

@@ -0,0 +1,54 @@
+use crate::messages::frontend::utility_types::PersistedState;
+use crate::messages::portfolio::utility_types::WorkspacePanelLayout;
+use crate::messages::prelude::*;
+
+#[derive(Default, Debug, Clone, ExtractField)]
+pub struct PersistentStateMessageHandler {
+	loaded: bool,
+}
+
+#[derive(ExtractField)]
+pub struct PersistentStateMessageContext {
+	pub persisted_state: PersistedState,
+}
+
+#[message_handler_data]
+impl MessageHandler<PersistentStateMessage, PersistentStateMessageContext> for PersistentStateMessageHandler {
+	fn process_message(&mut self, message: PersistentStateMessage, responses: &mut VecDeque<Message>, context: PersistentStateMessageContext) {
+		let PersistentStateMessageContext { persisted_state: state } = context;
+
+		match message {
+			PersistentStateMessage::ReadState => {
+				responses.add(FrontendMessage::TriggerPersistenceReadState);
+			}
+			PersistentStateMessage::WriteState => {
+				if !self.loaded && (state.documents.is_empty() && (state.workspace_layout == Some(WorkspacePanelLayout::default()) || state.workspace_layout.is_none())) {
+					return;
+				}
+				self.loaded = true;
+				responses.add(FrontendMessage::TriggerPersistenceWriteState { state });
+			}
+			PersistentStateMessage::LoadState { state } => {
+				self.loaded = true;
+				responses.add(PortfolioMessage::LoadPersistedState { state });
+			}
+			PersistentStateMessage::ReadDocument { document_id } => {
+				responses.add(FrontendMessage::TriggerPersistenceReadDocument { document_id });
+			}
+			PersistentStateMessage::WriteDocument { document_id, document } => {
+				responses.add(FrontendMessage::TriggerPersistenceWriteDocument { document_id, document });
+			}
+			PersistentStateMessage::DeleteDocument { document_id } => {
+				responses.add(FrontendMessage::TriggerPersistenceDeleteDocument { document_id });
+			}
+			PersistentStateMessage::LoadDocument { document_id, document } => {
+				responses.add(PortfolioMessage::LoadDocumentContent {
+					document_id,
+					document_serialized_content: document,
+				});
+			}
+		}
+	}
+
+	advertise_actions!(PersistentStateMessageDiscriminant;);
+}