Desktop: Add native file dialogs (#2939)

* Add native open file dialog

* Add native save file dialog

* Fix integer underflow in defer message handler

* Update nix flake

* Cleanup

---------

Co-authored-by: Dennis Kobert <dennis@kobert.dev>

frontend/src/messages.ts

@@ -791,6 +791,16 @@ export class TriggerImport extends JsMessage {}
 
 export class TriggerPaste extends JsMessage {}
 
+export class TriggerSaveDocument extends JsMessage {
+	readonly documentId!: bigint;
+
+	readonly name!: string;
+
+	readonly path!: string | undefined;
+
+	readonly document!: string;
+}
+
 export class TriggerDownloadImage extends JsMessage {
 	readonly svg!: string;
 
@@ -1647,6 +1657,7 @@ export const messageMakers: Record<string, MessageMaker> = {
 	DisplayRemoveEditableTextbox,
 	SendUIMetadata,
 	TriggerAboutGraphiteLocalizedCommitDate,
+	TriggerSaveDocument,
 	TriggerDownloadImage,
 	TriggerDownloadTextFile,
 	TriggerFetchAndOpenDocument,

frontend/src/state-providers/portfolio.ts

@@ -6,6 +6,7 @@ import { type Editor } from "@graphite/editor";
 import {
 	type FrontendDocumentDetails,
 	TriggerFetchAndOpenDocument,
+	TriggerSaveDocument,
 	TriggerDownloadImage,
 	TriggerDownloadTextFile,
 	TriggerImport,
@@ -84,6 +85,9 @@ export function createPortfolioState(editor: Editor) {
 		const imageData = await extractPixelData(new Blob([data.content.data], { type: data.type }));
 		editor.handle.pasteImage(data.filename, new Uint8Array(imageData.data), imageData.width, imageData.height);
 	});
+	editor.subscriptions.subscribeJsMessage(TriggerSaveDocument, (triggerSaveDocument) => {
+		downloadFileText(triggerSaveDocument.name, triggerSaveDocument.document);
+	});
 	editor.subscriptions.subscribeJsMessage(TriggerDownloadTextFile, (triggerFileDownload) => {
 		downloadFileText(triggerFileDownload.name, triggerFileDownload.document);
 	});