新增阅读器功能，待优化

assets/foliate-js/src/text-walker.js

@@ -0,0 +1,49 @@
+const walkRange = (range, walker) => {
+    const nodes = []
+    for (let node = walker.currentNode; node; node = walker.nextNode()) {
+        const compare = range.comparePoint(node, 0)
+        if (compare === 0) nodes.push(node)
+        else if (compare > 0) break
+    }
+    return nodes
+}
+
+const walkDocument = (_, walker) => {
+    const nodes = []
+    for (let node = walker.nextNode(); node; node = walker.nextNode())
+        nodes.push(node)
+    return nodes
+}
+
+const filter = NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_TEXT
+    | NodeFilter.SHOW_CDATA_SECTION
+
+const acceptNode = node => {
+    if (node.nodeType === 1) {
+        const name = node.tagName.toLowerCase()
+        if (name === 'script' || name === 'style') return NodeFilter.FILTER_REJECT
+        
+        // Skip translation elements to preserve CFI calculations
+        if (node.classList && node.classList.contains('translated-text')) {
+            return NodeFilter.FILTER_REJECT
+        }
+        
+        return NodeFilter.FILTER_SKIP
+    }
+    return NodeFilter.FILTER_ACCEPT
+}
+
+export const textWalker = function* (x, func) {
+    const root = x.commonAncestorContainer ?? x.body ?? x
+    const walker = document.createTreeWalker(root, filter, { acceptNode })
+    const walk = x.commonAncestorContainer ? walkRange : walkDocument
+    const nodes = walk(x, walker)
+    const strs = nodes.map(node => node.nodeValue)
+    const makeRange = (startIndex, startOffset, endIndex, endOffset) => {
+        const range = document.createRange()
+        range.setStart(nodes[startIndex], startOffset)
+        range.setEnd(nodes[endIndex], endOffset)
+        return range
+    }
+    for (const match of func(strs, makeRange)) yield match
+}