fix: 完善本地与网络图片渲染

apps/desktop/src/main.ts

@@ -8,7 +8,7 @@ import {
   session,
   type IpcMainInvokeEvent
 } from "electron";
-import { access, writeFile } from "node:fs/promises";
+import { access, readFile, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath, pathToFileURL } from "node:url";
 import {
@@ -19,6 +19,7 @@ import {
   DESKTOP_GET_THEME_CSS,
   DESKTOP_GENERATE_PDF,
   DESKTOP_LIST_THEMES,
+  DESKTOP_OPEN_MARKDOWN,
   DESKTOP_RENDER_MARKDOWN,
   DESKTOP_SAVE_PDF
 } from "./channels.js";
@@ -229,7 +230,31 @@ async function createApplication(
     event.senderFrame !== null &&
     new URL(event.senderFrame.url).origin ===
       new URL(applicationUrl).origin;
+  let documentRoot: string | undefined;
 
+  ipcMain.handle(DESKTOP_OPEN_MARKDOWN, async (event) => {
+    if (!validateSender(event)) {
+      throw new Error("拒绝未授权的桌面文件请求");
+    }
+    const selection = await dialog.showOpenDialog(window, {
+      title: "打开 Markdown",
+      properties: ["openFile"],
+      filters: [
+        { name: "Markdown 文件", extensions: ["md", "markdown"] },
+        { name: "文本文件", extensions: ["txt"] }
+      ]
+    });
+    const filePath = selection.filePaths[0];
+    if (selection.canceled || !filePath) {
+      return undefined;
+    }
+    const content = await readFile(filePath, "utf8");
+    documentRoot = path.dirname(filePath);
+    return {
+      markdown: content,
+      fileName: path.basename(filePath)
+    };
+  });
   ipcMain.handle(
     DESKTOP_RENDER_MARKDOWN,
     async (event, unsafeRequest: unknown) => {
@@ -237,7 +262,8 @@ async function createApplication(
         throw new Error("拒绝未授权的桌面渲染请求");
       }
       return applicationService.render(
-        parseMarkdownRenderRequest(unsafeRequest)
+        parseMarkdownRenderRequest(unsafeRequest),
+        documentRoot ? { localRoot: documentRoot } : {}
       );
     }
   );
@@ -317,6 +343,7 @@ async function createApplication(
 
   window.once("ready-to-show", () => window.show());
   window.on("closed", () => {
+    ipcMain.removeHandler(DESKTOP_OPEN_MARKDOWN);
     ipcMain.removeHandler(DESKTOP_RENDER_MARKDOWN);
     ipcMain.removeHandler(DESKTOP_LIST_THEMES);
     ipcMain.removeHandler(DESKTOP_GET_THEME_CSS);