新增epub书摘，高亮文字，适配平板

lib/pages/epub_reader/reader_webview.dart

@@ -1,3 +1,4 @@
+import 'dart:convert';
 import 'dart:io';
 import 'dart:ui' as ui;
 
@@ -59,6 +60,11 @@ class ReaderWebViewController {
     await _webViewState?._checkTapElementAt(x, y);
   }
 
+  /// 获取当前 iframe 中用户选中的文字（长按后调用）
+  Future<String?> getTextSelection() async {
+    return await _webViewState?._getTextSelection();
+  }
+
   Future<ui.Image?> takeScreenshot() async {
     return await _webViewState?._takeScreenshot();
   }
@@ -82,10 +88,121 @@ class ReaderWebViewController {
   Future<dynamic> runJavaScriptReturningResult(String js) async {
     return await _webViewState?._controller?.evaluateJavascript(source: js);
   }
+
+  /// 获取当前 iframe 中选区的详细信息（用于高亮持久化）
+  Future<Map<String, dynamic>?> getSelectionInfo() async {
+    final result = await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.getSelectionInfo()',
+    );
+    if (result == null) return null;
+    if (result is Map) return Map<String, dynamic>.from(result);
+    return null;
+  }
+
+  /// 应用单个高亮到当前 iframe
+  Future<bool> applyHighlight(Map<String, dynamic> info, String id, {String color = 'highlight', String text = ''}) async {
+    final infoJson = jsonEncode(info);
+    final textArg = text.replaceAll('\\', '\\\\').replaceAll("'", "\\'").replaceAll('\n', '\\n');
+    final result = await _webViewState?._controller?.evaluateJavascript(
+      source:
+          "window.__mooknoteHL && window.__mooknoteHL.applyHighlight($infoJson, \"$id\", \"$color\", '$textArg')",
+    );
+    return result == true;
+  }
+
+  /// 批量应用高亮（用于 spine 加载后恢复）
+  Future<int> applyHighlights(List<Map<String, dynamic>> highlights) async {
+    if (highlights.isEmpty) return 0;
+    final list = jsonEncode(highlights.map((h) {
+      // 优先使用嵌套的 info 对象（来自 restoreHighlightsForCurrentSpine）
+      final rawInfo = h['info'];
+      Map<String, dynamic> info;
+      if (rawInfo is Map) {
+        info = Map<String, dynamic>.from(rawInfo);
+      } else {
+        // 兼容扁平字段
+        info = {
+          'startXPath': h['start_x_path'] ?? h['startXPath'] ?? '',
+          'startOffset': h['start_offset'] ?? h['startOffset'] ?? 0,
+          'endXPath': h['end_x_path'] ?? h['endXPath'] ?? '',
+          'endOffset': h['end_offset'] ?? h['endOffset'] ?? 0,
+        };
+      }
+      return {
+        'info': info,
+        'id': (h['id'] ?? '').toString(),
+        'color': h['color'] == 'excerpt' ? 'excerpt' : 'highlight',
+        'text': h['text'] ?? h['content'] ?? '',
+      };
+    }).toList());
+    final result = await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.applyHighlights($list)',
+    );
+    if (result is int) return result;
+    if (result is num) return result.toInt();
+    return 0;
+  }
+
+  /// 移除指定 id 的高亮
+  Future<void> removeHighlight(String id) async {
+    await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.removeHighlight("$id")',
+    );
+  }
+
+  /// 移除当前文档中所有高亮标记
+  Future<void> clearAllHighlights() async {
+    await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.clearAllHighlights()',
+    );
+  }
+
+  /// 清除当前选区
+  Future<void> clearSelection() async {
+    await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.clearSelection()',
+    );
+  }
+
+  /// 编程式选中长按位置的文字（用于 Flutter 长按手势触发文本选择）
+  Future<void> selectWordAt(double x, double y) async {
+    await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.selectWordAt($x, $y)',
+    );
+  }
+
+  /// 拖动手柄时扩展选区
+  Future<void> extendSelection(double x, double y, bool isStart) async {
+    await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.extendSelection($x, $y, ${isStart ? 'true' : 'false'})',
+    );
+  }
+
+  /// 根据 XPath 获取元素所在的页码（用于跳转到高亮位置）
+  Future<int> getPageIndexForXPath(String xpath) async {
+    final result = await _webViewState?._controller?.evaluateJavascript(
+      source: 'window.__mooknoteHL && window.__mooknoteHL.getPageIndexForXPath("$xpath")',
+    );
+    if (result is int) return result;
+    if (result is num) return result.toInt();
+    return -1;
+  }
+
+  /// 根据文本内容获取所在页码（XPath 失败时的回退方案）
+  Future<int> getPageIndexForText(String text) async {
+    if (text.isEmpty) return -1;
+    final escaped = text.replaceAll('\\', '\\\\').replaceAll("'", "\\'").replaceAll('\n', '\\n');
+    final result = await _webViewState?._controller?.evaluateJavascript(
+      source: "window.__mooknoteHL && window.__mooknoteHL.getPageIndexForText('$escaped')",
+    );
+    if (result is int) return result;
+    if (result is num) return result.toInt();
+    return -1;
+  }
 }
 
 final InAppWebViewSettings defaultSettings = InAppWebViewSettings(
-  disableContextMenu: true,
+  disableContextMenu: false,
   disableLongPressContextMenuOnLinks: true,
   selectionGranularity: SelectionGranularity.CHARACTER,
   transparentBackground: true,
@@ -98,7 +215,7 @@ final InAppWebViewSettings defaultSettings = InAppWebViewSettings(
   disableHorizontalScroll: true,
   disableVerticalScroll: true,
   supportZoom: false,
-  useHybridComposition: false,
+  useHybridComposition: true,
   resourceCustomSchemes: [EpubWebViewHandler.virtualScheme],
   verticalScrollBarEnabled: false,
   horizontalScrollBarEnabled: false,
@@ -116,6 +233,7 @@ class ReaderWebViewCallbacks {
   final Function(String innerHtml, Rect rect, String baseUrl) onFootnoteTap;
   final Function(String url) onLinkTap;
   final bool Function(String url) shouldHandleLinkTap;
+  final Function(String selectedText, Rect rect, int spineIndex, double scrollRatio, Offset? startHandle, Offset? endHandle, Map<String, dynamic>? selectionInfo)? onTextSelection;
 
   const ReaderWebViewCallbacks({
     required this.onInitialized,
@@ -127,6 +245,7 @@ class ReaderWebViewCallbacks {
     required this.onFootnoteTap,
     required this.onLinkTap,
     required this.shouldHandleLinkTap,
+    this.onTextSelection,
   });
 }
 
@@ -184,6 +303,16 @@ class _ReaderWebViewState extends State<ReaderWebView> {
     widget.controller._attachState(this);
   }
 
+  @override
+  void dispose() {
+    widget.controller._attachState(null);
+    _bridge.detach();
+    _headlessWebView?.dispose();
+    _headlessWebView = null;
+    _controller = null;
+    super.dispose();
+  }
+
   @override
   void didUpdateWidget(covariant ReaderWebView oldWidget) {
     super.didUpdateWidget(oldWidget);
@@ -246,6 +375,21 @@ class _ReaderWebViewState extends State<ReaderWebView> {
   Future<void> _checkTapElementAt(double x, double y) =>
       _api.checkTapElementAt(x, y);
 
+  /// 获取当前 iframe 中用户选中的文字
+  Future<String?> _getTextSelection() async {
+    if (_controller == null) return null;
+    final result = await _controller!.evaluateJavascript(source: '''
+(function(){
+  var f = document.getElementById('frame-curr');
+  if (!f || !f.contentWindow) return '';
+  var sel = f.contentWindow.getSelection();
+  return sel ? sel.toString() : '';
+})()
+''');
+    if (result == null) return null;
+    return result.toString();
+  }
+
   InAppWebViewInitialData _generateInitialData(double width, double height) {
     return InAppWebViewInitialData(
       data: generateSkeletonHtml(
@@ -302,6 +446,642 @@ class _ReaderWebViewState extends State<ReaderWebView> {
   }
 
   void _onLoadStop(InAppWebViewController controller, WebUri? url) {
+    // 注入高亮辅助函数库 + CSS + 文本选中检测（一次性注入，定时重新应用到新 contentDocument）
+    controller.evaluateJavascript(source: r'''
+      (function(){
+        if (window.__mooknoteHL) {
+          console.log('[MN] already injected, re-running setup');
+          setupSelectionListener();
+          return;
+        }
+        console.log('[MN] injecting highlight + selection JS');
+
+        function getFrameDoc() {
+          var f = document.getElementById('frame-curr');
+          return f && f.contentDocument ? f.contentDocument : null;
+        }
+
+        function getFrameWin() {
+          var f = document.getElementById('frame-curr');
+          return f && f.contentWindow ? f.contentWindow : null;
+        }
+
+        function getXPath(node, root) {
+          if (node.nodeType === 3) {
+            var parent = node.parentNode;
+            var textIndex = 0;
+            for (var i = 0; i < parent.childNodes.length; i++) {
+              if (parent.childNodes[i] === node) break;
+              if (parent.childNodes[i].nodeType === 3) textIndex++;
+            }
+            return getXPath(parent, root) + '/text()[' + (textIndex + 1) + ']';
+          }
+          if (node.nodeType !== 1) return '';
+          if (node === root) return '';
+          var parts = [];
+          var current = node;
+          while (current && current.nodeType === 1 && current !== root) {
+            var parent = current.parentNode;
+            if (!parent) break;
+            var index = 1;
+            var siblings = parent.childNodes;
+            for (var i = 0; i < siblings.length; i++) {
+              var s = siblings[i];
+              if (s.nodeType === 1 && s.tagName === current.tagName) {
+                if (s === current) break;
+                index++;
+              }
+            }
+            parts.unshift(current.tagName.toLowerCase() + '[' + index + ']');
+            current = parent;
+          }
+          return '/' + parts.join('/');
+        }
+
+        function getNodeByXPath(doc, xpath) {
+          if (!doc.evaluate) return null;
+          try {
+            var result = doc.evaluate(xpath, doc, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
+            return result.singleNodeValue;
+          } catch (e) {
+            return null;
+          }
+        }
+
+        /// 计算节点在分栏排版中的页码
+        function calcPageIndex(doc, node) {
+          if (!node) return -1;
+          var el = node.nodeType === 3 ? node.parentNode : node;
+          var f = document.getElementById('frame-curr');
+          if (!f) return -1;
+          var iframeWidth = f.clientWidth;
+          var iframeHeight = f.clientHeight;
+          // 获取元素相对于 iframe 内容的偏移
+          var rect = el.getBoundingClientRect();
+          var scrollLeft = doc.documentElement.scrollLeft || doc.body.scrollLeft || 0;
+          var scrollTop = doc.documentElement.scrollTop || doc.body.scrollTop || 0;
+          // 水平分栏
+          var pageX = iframeWidth > 0 ? Math.floor((rect.left + scrollLeft) / iframeWidth) : 0;
+          // 垂直分栏
+          var pageY = iframeHeight > 0 ? Math.floor((rect.top + scrollTop) / iframeHeight) : 0;
+          // 判断是水平还是垂直分栏：看 scrollWidth 是否大于 clientWidth
+          var hasHorizontalPagination = doc.documentElement.scrollWidth > doc.documentElement.clientWidth + 10;
+          return hasHorizontalPagination ? pageX : pageY;
+        }
+
+        /// 文本搜索回退：遍历所有文本节点，拼接后搜索目标文本，定位并高亮
+        function applyHighlightByTextSearch(doc, text, id, color) {
+          if (!text || text.length === 0) return false;
+          try {
+            var walker = doc.createTreeWalker(doc.body, NodeFilter.SHOW_TEXT, {
+              acceptNode: function(node) {
+                if (node.textContent.trim().length > 0) return NodeFilter.FILTER_ACCEPT;
+                return NodeFilter.FILTER_SKIP;
+              }
+            }, null);
+            var nodes = [];
+            var n;
+            while (n = walker.nextNode()) nodes.push(n);
+            if (nodes.length === 0) return false;
+
+            var fullText = '';
+            var ranges = [];
+            for (var i = 0; i < nodes.length; i++) {
+              var c = nodes[i].textContent;
+              ranges.push({ node: nodes[i], start: fullText.length, len: c.length });
+              fullText += c;
+            }
+
+            var idx = fullText.indexOf(text);
+            if (idx === -1) return false;
+            var endIdx = idx + text.length;
+
+            var startInfo = null, endInfo = null;
+            for (var i = 0; i < ranges.length; i++) {
+              var r = ranges[i];
+              if (!startInfo && idx >= r.start && idx < r.start + r.len) {
+                startInfo = { node: r.node, offset: idx - r.start };
+              }
+              if (endIdx > r.start && endIdx <= r.start + r.len) {
+                endInfo = { node: r.node, offset: endIdx - r.start };
+                break;
+              }
+            }
+            if (!startInfo || !endInfo) return false;
+
+            var range = doc.createRange();
+            range.setStart(startInfo.node, startInfo.offset);
+            range.setEnd(endInfo.node, endInfo.offset);
+
+            return wrapRangeMultiNode(doc, range, id, color);
+          } catch (e) {
+            console.log('[MN] applyHighlightByTextSearch error: ' + e);
+            return false;
+          }
+        }
+
+        /// 多节点包裹：遍历 range 内所有文本节点，逐个包裹在 <mooknote-mark> 中
+        /// 保留段落结构，不用 extractContents
+        function wrapRangeMultiNode(doc, range, id, color) {
+          var bg = color === 'excerpt' ? 'rgba(33, 150, 243, 0.35)' : 'rgba(255, 235, 59, 0.5)';
+          var markType = color === 'excerpt' ? 'excerpt' : 'highlight';
+
+          var ancestor = range.commonAncestorContainer;
+          var walkerRoot = ancestor.nodeType === 3 ? ancestor.parentNode : ancestor;
+          var walker = doc.createTreeWalker(walkerRoot, NodeFilter.SHOW_TEXT, null);
+
+          var nodesToWrap = [];
+          var n;
+          while (n = walker.nextNode()) {
+            if (range.intersectsNode(n)) {
+              var s = 0, e = n.length;
+              if (n === range.startContainer) s = range.startOffset;
+              if (n === range.endContainer) e = range.endOffset;
+              if (n === range.startContainer && n === range.endContainer) { s = range.startOffset; e = range.endOffset; }
+              if (s < e) nodesToWrap.push({ node: n, start: s, end: e });
+            }
+          }
+
+          if (nodesToWrap.length === 0) {
+            var mark = doc.createElement('mooknote-mark');
+            mark.setAttribute('data-hl-id', id);
+            mark.setAttribute('data-hl-type', markType);
+            mark.style.backgroundColor = bg;
+            mark.style.color = 'inherit';
+            mark.style.borderRadius = '2px';
+            try {
+              range.surroundContents(mark);
+              return true;
+            } catch (e) {
+              return false;
+            }
+          }
+
+          // 倒序包裹（防止 splitText 影响后面的节点索引）
+          for (var i = nodesToWrap.length - 1; i >= 0; i--) {
+            var item = nodesToWrap[i];
+            var tn = item.node;
+            var start = item.start;
+            var end = item.end;
+
+            var wrapNode = tn;
+            if (start > 0) wrapNode = tn.splitText(start);
+            if (end - start < wrapNode.length) wrapNode.splitText(end - start);
+
+            var mk = doc.createElement('mooknote-mark');
+            mk.setAttribute('data-hl-id', id);
+            mk.setAttribute('data-hl-type', markType);
+            mk.style.backgroundColor = bg;
+            mk.style.color = 'inherit';
+            mk.style.borderRadius = '2px';
+
+            wrapNode.parentNode.insertBefore(mk, wrapNode);
+            mk.appendChild(wrapNode);
+          }
+          return true;
+        }
+
+        window.__mooknoteHL = {
+          getSelectionInfo: function() {
+            var win = getFrameWin();
+            if (!win) return null;
+            var sel = win.getSelection();
+            if (!sel || sel.isCollapsed || sel.rangeCount === 0) return null;
+            var range = sel.getRangeAt(0);
+            var doc = getFrameDoc();
+            if (!doc) return null;
+            return {
+              text: sel.toString(),
+              startXPath: getXPath(range.startContainer, doc),
+              startOffset: range.startOffset,
+              endXPath: getXPath(range.endContainer, doc),
+              endOffset: range.endOffset
+            };
+          },
+
+          applyHighlight: function(info, id, color, text) {
+            var doc = getFrameDoc();
+            if (!doc || !info) {
+              return false;
+            }
+
+            var startNode = getNodeByXPath(doc, info.startXPath);
+            var endNode = getNodeByXPath(doc, info.endXPath);
+
+            if (!startNode || !endNode) {
+              if (text && text.length > 0) {
+                return applyHighlightByTextSearch(doc, text, id, color);
+              }
+              return false;
+            }
+
+            try {
+              var so = Math.min(info.startOffset, startNode.length || 0);
+              var eo = Math.min(info.endOffset, endNode.length || 0);
+
+              var range = doc.createRange();
+              range.setStart(startNode, so);
+              range.setEnd(endNode, eo);
+
+              return wrapRangeMultiNode(doc, range, id, color);
+            } catch (e) {
+              if (text) return applyHighlightByTextSearch(doc, text, id, color);
+              return false;
+            }
+          },
+
+          applyHighlights: function(list) {
+            if (!list || list.length === 0) return 0;
+            // 按文档位置倒序排序（从末尾往前应用），避免前面的高亮分裂文本节点影响后面的 XPath
+            // 用数字排序而非字符串排序（/p[10] 应排在 /p[2] 之后）
+            function docOrder(item) {
+              var xp = (item && item.info && item.info.startXPath) || '';
+              // 提取所有 [N] 中的数字，组成数组用于比较
+              var nums = [];
+              var re = /\[(\d+)\]/g;
+              var m;
+              while ((m = re.exec(xp)) !== null) nums.push(parseInt(m[1], 10));
+              return nums;
+            }
+            function compareNums(a, b) {
+              for (var i = 0; i < Math.max(a.length, b.length); i++) {
+                var av = a[i] || 0;
+                var bv = b[i] || 0;
+                if (av !== bv) return av - bv;
+              }
+              return 0;
+            }
+            var sorted = list.slice().sort(function(a, b) {
+              return compareNums(docOrder(b), docOrder(a)); // 倒序
+            });
+            var applied = 0;
+            for (var i = 0; i < sorted.length; i++) {
+              if (this.applyHighlight(sorted[i].info, sorted[i].id, sorted[i].color, sorted[i].text)) applied++;
+            }
+            return applied;
+          },
+
+          removeHighlight: function(id) {
+            var doc = getFrameDoc();
+            if (!doc) return;
+            var mark = doc.querySelector('[data-hl-id="' + id + '"]');
+            if (mark && mark.tagName === 'MOOKNOTE-MARK') {
+              var parent = mark.parentNode;
+              while (mark.firstChild) parent.insertBefore(mark.firstChild, mark);
+              parent.removeChild(mark);
+              parent.normalize();
+            }
+          },
+
+          clearAllHighlights: function() {
+            var doc = getFrameDoc();
+            if (!doc) return;
+            var marks = doc.querySelectorAll('mooknote-mark[data-hl-id]');
+            for (var i = 0; i < marks.length; i++) {
+              var mark = marks[i];
+              var parent = mark.parentNode;
+              while (mark.firstChild) parent.insertBefore(mark.firstChild, mark);
+              parent.removeChild(mark);
+            }
+            // normalize 合并相邻文本节点
+            if (doc.body) doc.body.normalize();
+          },
+
+          clearSelection: function() {
+            var win = getFrameWin();
+            if (!win) return;
+            var sel = win.getSelection();
+            if (sel) sel.removeAllRanges();
+          },
+
+          /// 根据 XPath 获取元素所在页码（用于跳转到高亮位置）
+          getPageIndexForXPath: function(xpath) {
+            var doc = getFrameDoc();
+            if (!doc || !xpath) return -1;
+            var node = getNodeByXPath(doc, xpath);
+            if (!node) return -1;
+            return calcPageIndex(doc, node);
+          },
+
+          /// 根据文本内容获取所在页码（XPath 失败时的回退）
+          getPageIndexForText: function(text) {
+            var doc = getFrameDoc();
+            if (!doc || !text) return -1;
+            // 遍历所有文本节点，找到包含目标文本的节点
+            var walker = doc.createTreeWalker(doc.body, NodeFilter.SHOW_TEXT, null, null);
+            var n;
+            while (n = walker.nextNode()) {
+              if (n.textContent.indexOf(text) !== -1) {
+                return calcPageIndex(doc, n);
+              }
+            }
+            // 去掉空白再试
+            var cleanText = text.replace(/\s+/g, '');
+            walker = doc.createTreeWalker(doc.body, NodeFilter.SHOW_TEXT, null, null);
+            while (n = walker.nextNode()) {
+              if (n.textContent.replace(/\s+/g, '').indexOf(cleanText) !== -1) {
+                return calcPageIndex(doc, n);
+              }
+            }
+            return -1;
+          },
+
+          /// 编程式选中最接近 (x,y) 的文字（单词/句子），并触发 onTextSelection 回调
+          selectWordAt: function(x, y) {
+            var f = document.getElementById('frame-curr');
+            if (!f || !f.contentDocument || !f.contentWindow) {
+              console.log('[MN] selectWordAt: no frame');
+              return false;
+            }
+            var doc = f.contentDocument;
+            var win = f.contentWindow;
+            var iframeRect = f.getBoundingClientRect();
+            var localX = x - iframeRect.left;
+            var localY = y - iframeRect.top;
+
+            // 用 caretRangeFromPoint 找到该位置的文本节点
+            var range = null;
+            if (doc.caretRangeFromPoint) {
+              range = doc.caretRangeFromPoint(localX, localY);
+            } else if (doc.caretPositionFromPoint) {
+              var pos = doc.caretPositionFromPoint(localX, localY);
+              if (pos) {
+                range = doc.createRange();
+                range.setStart(pos.offsetNode, pos.offset);
+                range.setEnd(pos.offsetNode, pos.offset);
+              }
+            }
+            if (!range || !range.startContainer || range.startContainer.nodeType !== 3) {
+              console.log('[MN] selectWordAt: no text node at (' + x + ',' + y + ')');
+              return false;
+            }
+
+            var node = range.startContainer;
+            var offset = range.startOffset;
+            var text = node.textContent;
+
+            // 向前找到词/句边界（支持中文和英文）
+            var start = offset;
+            while (start > 0) {
+              var ch = text[start - 1];
+              // 遇到空格、标点、换行就停
+              if (/[\s。，！？；：、""''（）【】《》\n\r]/.test(ch)) break;
+              start--;
+            }
+            // 向后找到词/句边界
+            var end = offset;
+            while (end < text.length) {
+              var ch = text[end];
+              if (/[\s。，！？；：、""''（）【】《》\n\r]/.test(ch)) break;
+              end++;
+            }
+
+            // 如果只选中了一个字，尝试扩展到整个句子（按句号分割）
+            if (end - start <= 1) {
+              start = 0;
+              end = text.length;
+            }
+
+            var selRange = doc.createRange();
+            selRange.setStart(node, start);
+            selRange.setEnd(node, end);
+
+            // 应用选区
+            var sel = win.getSelection();
+            sel.removeAllRanges();
+            sel.addRange(selRange);
+
+            var selectedText = sel.toString();
+            console.log('[MN] selectWordAt: selected "' + selectedText.substring(0, 30) + '"');
+
+            var selRect = selRange.getBoundingClientRect();
+            var rect = [iframeRect.left + selRect.left, iframeRect.top + selRect.top, selRect.width, selRect.height];
+
+            var handles = getHandlePositions(f, selRange, iframeRect);
+            var info = {
+              startXPath: getXPath(selRange.startContainer, doc),
+              startOffset: selRange.startOffset,
+              endXPath: getXPath(selRange.endContainer, doc),
+              endOffset: selRange.endOffset
+            };
+
+            // 触发 onTextSelection 回调
+            window.flutter_inappwebview.callHandler('onTextSelection',
+              selectedText,
+              rect,
+              0,
+              0,
+              handles.start,
+              handles.end,
+              info
+            );
+            return true;
+          },
+
+          /// 拖动手柄时扩展选区：将起点或终点移动到 (x, y) 处的文字位置
+          extendSelection: function(x, y, isStart) {
+            var f = document.getElementById('frame-curr');
+            if (!f || !f.contentDocument || !f.contentWindow) return false;
+            var doc = f.contentDocument;
+            var win = f.contentWindow;
+            var iframeRect = f.getBoundingClientRect();
+            var localX = x - iframeRect.left;
+            var localY = y - iframeRect.top;
+
+            var pos = null;
+            if (doc.caretRangeFromPoint) {
+              var r = doc.caretRangeFromPoint(localX, localY);
+              if (r) pos = { node: r.startContainer, offset: r.startOffset };
+            } else if (doc.caretPositionFromPoint) {
+              var p = doc.caretPositionFromPoint(localX, localY);
+              if (p) pos = { node: p.offsetNode, offset: p.offset };
+            }
+            if (!pos) return false;
+
+            var sel = win.getSelection();
+            if (!sel || sel.rangeCount === 0) return false;
+            var currentRange = sel.getRangeAt(0);
+
+            var newRange = doc.createRange();
+            if (isStart) {
+              // 拖动起点手柄：新起点 = pos，终点 = 原终点
+              newRange.setStart(pos.node, pos.offset);
+              newRange.setEnd(currentRange.endContainer, currentRange.endOffset);
+            } else {
+              // 拖动终点手柄：起点 = 原起点，新终点 = pos
+              newRange.setStart(currentRange.startContainer, currentRange.startOffset);
+              newRange.setEnd(pos.node, pos.offset);
+            }
+
+            // 确保起点在终点之前
+            if (newRange.collapsed || currentRange.startContainer === newRange.endContainer && newRange.startOffset > newRange.endOffset) {
+              // 反向了，交换
+              if (isStart) {
+                newRange.setStart(currentRange.endContainer, currentRange.endOffset);
+                newRange.setEnd(pos.node, pos.offset);
+              } else {
+                newRange.setStart(pos.node, pos.offset);
+                newRange.setEnd(currentRange.startContainer, currentRange.startOffset);
+              }
+            }
+
+            sel.removeAllRanges();
+            sel.addRange(newRange);
+
+            var text = sel.toString();
+            var selRect = newRange.getBoundingClientRect();
+            var rect = [iframeRect.left + selRect.left, iframeRect.top + selRect.top, selRect.width, selRect.height];
+            var handles = getHandlePositions(f, newRange, iframeRect);
+            var info = {
+              startXPath: getXPath(newRange.startContainer, doc),
+              startOffset: newRange.startOffset,
+              endXPath: getXPath(newRange.endContainer, doc),
+              endOffset: newRange.endOffset
+            };
+
+            window.flutter_inappwebview.callHandler('onTextSelection',
+              text,
+              rect,
+              0,
+              0,
+              handles.start,
+              handles.end,
+              info
+            );
+            return true;
+          }
+        };
+
+        // ─── 文本选中检测 ────────────────────────────────────
+        var lastText = '';
+        var debounceTimer = null;
+
+        function checkSelection() {
+          var f = document.getElementById('frame-curr');
+          if (!f || !f.contentWindow || !f.contentDocument) {
+            console.log('[MN] checkSelection: no frame');
+            return;
+          }
+          var win = f.contentWindow;
+          var doc = f.contentDocument;
+          var sel = win.getSelection();
+          if (!sel) {
+            console.log('[MN] checkSelection: no getSelection');
+            return;
+          }
+          if (sel.isCollapsed || sel.rangeCount === 0) {
+            lastText = '';
+            return;
+          }
+          var text = sel.toString();
+          if (!text || text === lastText) return;
+          lastText = text;
+          console.log('[MN] selection detected: ' + text.substring(0, 30));
+
+          var range = sel.getRangeAt(0);
+          var selRect = range.getBoundingClientRect();
+          var iframeRect = f.getBoundingClientRect();
+          var left = iframeRect.left + selRect.left;
+          var top = iframeRect.top + selRect.top;
+
+          var scrollRatio = 0;
+          if (doc.documentElement) {
+            var sh = doc.documentElement.scrollHeight - doc.documentElement.clientHeight;
+            if (sh > 0) scrollRatio = doc.documentElement.scrollTop / sh;
+          }
+
+          var handles = getHandlePositions(f, range, iframeRect);
+          var info = getSelectionInfoInternal();
+
+          window.flutter_inappwebview.callHandler('onTextSelection',
+            text,
+            [left, top, selRect.width, selRect.height],
+            0,
+            scrollRatio,
+            handles.start,
+            handles.end,
+            info
+          );
+        }
+
+        /// 获取选区 DOM 信息（XPath + offset），用于高亮持久化
+        function getSelectionInfoInternal() {
+          var win = getFrameWin();
+          if (!win) return null;
+          var sel = win.getSelection();
+          if (!sel || sel.isCollapsed || sel.rangeCount === 0) return null;
+          var range = sel.getRangeAt(0);
+          var doc = getFrameDoc();
+          if (!doc) return null;
+          return {
+            startXPath: getXPath(range.startContainer, doc),
+            startOffset: range.startOffset,
+            endXPath: getXPath(range.endContainer, doc),
+            endOffset: range.endOffset
+          };
+        }
+
+        /// 获取选区起点和终点的屏幕坐标
+        function getHandlePositions(f, range, iframeRect) {
+          var rects = range.getClientRects();
+          if (rects.length === 0) {
+            var r = range.getBoundingClientRect();
+            rects = [r];
+          }
+          var firstRect = rects[0];
+          var lastRect = rects[rects.length - 1];
+          // 起点手柄：第一行的左下角（手柄线覆盖文字行，圆点在上方）
+          var startX = iframeRect.left + firstRect.left;
+          var startY = iframeRect.top + firstRect.bottom;
+          // 终点手柄：最后一行的右上角（手柄线覆盖文字行，圆点在下方）
+          var endX = iframeRect.left + lastRect.right;
+          var endY = iframeRect.top + lastRect.top;
+          return { start: [startX, startY], end: [endX, endY] };
+        }
+
+        // 每次 iframe 内容变化后重新注入 CSS + 事件监听
+        function setupSelectionListener() {
+          var f = document.getElementById('frame-curr');
+          if (!f || !f.contentDocument) return;
+          var doc = f.contentDocument;
+
+          // 1. 重新注入 user-select CSS（loadFrame 会替换 contentDocument，CSS 会丢失）
+          var s = doc.getElementById('_ts_css');
+          if (!s) {
+            s = doc.createElement('style');
+            s.id = '_ts_css';
+            doc.head.appendChild(s);
+            s.textContent = 'html,body,p,span,div,a,h1,h2,h3,h4,h5,h6,li,td,th,blockquote,figcaption{-webkit-user-select:text!important;-moz-user-select:text!important;user-select:text!important;-webkit-touch-callout:default!important}';
+            console.log('[MN] CSS injected into new contentDocument');
+          }
+
+          // 2. 附加事件监听器
+          if (doc.__mnSelListener) return;
+          doc.__mnSelListener = true;
+          console.log('[MN] attaching selection listeners');
+
+          doc.addEventListener('selectionchange', function() {
+            if (debounceTimer) clearTimeout(debounceTimer);
+            debounceTimer = setTimeout(checkSelection, 250);
+          });
+
+          doc.addEventListener('touchend', function() {
+            if (debounceTimer) clearTimeout(debounceTimer);
+            debounceTimer = setTimeout(checkSelection, 350);
+          }, true);
+          doc.addEventListener('mouseup', function() {
+            if (debounceTimer) clearTimeout(debounceTimer);
+            debounceTimer = setTimeout(checkSelection, 350);
+          }, true);
+        }
+
+        // 定时重新注入 CSS + 重新附加监听器（iframe 内容会在翻页/切换章节时变化）
+        setInterval(setupSelectionListener, 500);
+        setupSelectionListener();
+        console.log('[MN] injection complete');
+      })();
+    ''');
+
     widget.callbacks.onInitialized();
   }
 
@@ -329,6 +1109,9 @@ class _ReaderWebViewState extends State<ReaderWebView> {
                         shouldOverrideUrlLoading: _shouldOverrideUrlLoading,
                         onWebViewCreated: _onWebViewCreated,
                         onLoadStop: _onLoadStop,
+                        onConsoleMessage: (controller, consoleMessage) {
+                          debugPrint('[EPUB-JS] ${consoleMessage.message}');
+                        },
                       )
                     : Container(color: _currentTheme.surfaceColor),
               ),
@@ -497,6 +1280,65 @@ class _ReaderWebViewState extends State<ReaderWebView> {
         }
       },
     );
+
+    // ─── 文本选择（划线功能） ────────────────
+    controller.addJavaScriptHandler(
+      handlerName: 'onTextSelection',
+      callback: (args) async {
+        debugPrint('[MN] onTextSelection handler called, args: ${args.length}');
+        if (args.isEmpty) return;
+        final selectedText = args[0] as String? ?? '';
+        final rectList = args[1] as List?;
+        final spineIndex = (args[2] as num?)?.toInt() ?? 0;
+        final scrollRatio = (args[3] as num?)?.toDouble() ?? 0.0;
+        Offset? startHandle;
+        Offset? endHandle;
+        Map<String, dynamic>? selectionInfo;
+        if (args.length >= 6) {
+          final startList = args[4] as List?;
+          final endList = args[5] as List?;
+          if (startList != null && startList.length >= 2) {
+            startHandle = Offset(
+              (startList[0] as num).toDouble(),
+              (startList[1] as num).toDouble(),
+            );
+          }
+          if (endList != null && endList.length >= 2) {
+            endHandle = Offset(
+              (endList[0] as num).toDouble(),
+              (endList[1] as num).toDouble(),
+            );
+          }
+        }
+        if (args.length >= 7) {
+          final rawInfo = args[6];
+          if (rawInfo is Map) {
+            selectionInfo = Map<String, dynamic>.from(rawInfo);
+          }
+        }
+        debugPrint('[MN] selectedText="$selectedText" info=$selectionInfo');
+        Rect? rect;
+        if (rectList != null && rectList.length >= 4) {
+          rect = Rect.fromLTWH(
+            (rectList[0] as num).toDouble(),
+            (rectList[1] as num).toDouble(),
+            (rectList[2] as num).toDouble(),
+            (rectList[3] as num).toDouble(),
+          );
+        }
+        if (selectedText.isNotEmpty && rect != null) {
+          widget.callbacks.onTextSelection?.call(
+            selectedText,
+            rect,
+            spineIndex,
+            scrollRatio,
+            startHandle,
+            endHandle,
+            selectionInfo,
+          );
+        }
+      },
+    );
   }
 
   Future<ui.Image?> _takeScreenshot() async {