check update

lib/utils/update.dart

@@ -0,0 +1,63 @@
+import 'package:fluent_ui/fluent_ui.dart';
+import 'package:pixes/appdata.dart';
+import 'package:pixes/foundation/app.dart';
+import 'package:pixes/network/app_dio.dart';
+import 'package:pixes/utils/translation.dart';
+import 'package:url_launcher/url_launcher_string.dart';
+
+Future<String> getLatestVersion() async {
+  var dio = AppDio();
+  var res = await dio
+      .get("https://api.github.com/repos/wgh136/pixes/releases/latest");
+  return (res.data["tag_name"] as String).replaceFirst("v", "");
+}
+
+/// Compare two versions.
+/// Return `true` if `a` is greater than `b`.
+bool compareVersion(String a, String b) {
+  var aList = a.split(".").map(int.parse).toList();
+  var bList = b.split(".").map(int.parse).toList();
+  for (var i = 0; i < aList.length; i++) {
+    if (aList[i] > bList[i]) {
+      return true;
+    } else if (aList[i] < bList[i]) {
+      return false;
+    }
+  }
+  return false;
+}
+
+Future<void> checkUpdate() async {
+  if (appdata.account == null) return;
+  try {
+    var latestVersion = await getLatestVersion();
+    if (compareVersion(latestVersion, App.version)) {
+      showDialog(
+          context: App.rootNavigatorKey.currentContext!,
+          builder: (context) => ContentDialog(
+                title: Text("New version available".tl),
+                content: Text(
+                  "A new version of Pixes is available. Do you want to update now?"
+                      .tl,
+                ),
+                actions: [
+                  Button(
+                    child: Text("Cancel".tl),
+                    onPressed: () {
+                      Navigator.of(context).pop();
+                    },
+                  ),
+                  FilledButton(
+                      child: Text("Update".tl),
+                      onPressed: () {
+                        Navigator.of(context).pop();
+                        launchUrlString(
+                            "https://github.com/wgh136/pixes/releases/latest");
+                      })
+                ],
+              ));
+    }
+  } catch (e) {
+    // ignore
+  }
+}