replace SelectableText with SelectionArea

Signed-off-by: dom <githubaccount56556@proton.me>

lib/utils/extension/selectable_region_ext.dart

@@ -0,0 +1,32 @@
+import 'package:PiliPlus/utils/extension/iterable_ext.dart';
+import 'package:PiliPlus/utils/page_utils.dart';
+import 'package:flutter/material.dart';
+
+extension SelectableRegionStateExt on SelectableRegionState {
+  void addLaunchMenuIfNeeded(
+    List<ContextMenuButtonItem> buttonItems, {
+    required int index,
+  }) {
+    try {
+      if (selectionEndpoints.first != selectionEndpoints[1]) {
+        buttonItems.insertOrAdd(
+          index,
+          ContextMenuButtonItem(
+            label: '打开',
+            onPressed: () {
+              final text = (this as dynamic).selectable
+                  ?.getSelectedContent()
+                  ?.plainText
+                  .trim();
+              hideToolbar();
+              clearSelection();
+              if (text != null && text.isNotEmpty) {
+                PageUtils.launchURL(text);
+              }
+            },
+          ),
+        );
+      }
+    } catch (_) {}
+  }
+}