Merge pull request #13908 from brendandahl/xfa-find

[api-minor] XFA - Support text search in XFA documents.

src/display/api.js

@@ -62,6 +62,7 @@ import { MessageHandler } from "../shared/message_handler.js";
 import { Metadata } from "./metadata.js";
 import { OptionalContentConfig } from "./optional_content_config.js";
 import { PDFDataTransportStream } from "./transport_stream.js";
+import { XfaText } from "./xfa_text.js";
 
 const DEFAULT_RANGE_CHUNK_SIZE = 65536; // 2^16 = 65536
 const RENDERING_CANCELLED_TIMEOUT = 100; // ms
@@ -1531,6 +1532,13 @@ class PDFPageProxy {
    *   {@link TextContent} object that represents the page's text content.
    */
   getTextContent(params = {}) {
+    if (this._transport._htmlForXfa) {
+      // TODO: We need to revisit this once the XFA foreground patch lands and
+      // only do this for non-foreground XFA.
+      return this.getXfa().then(xfa => {
+        return XfaText.textContent(xfa);
+      });
+    }
     const readableStream = this.streamTextContent(params);
 
     return new Promise(function (resolve, reject) {

src/display/xfa_layer.js

@@ -13,6 +13,8 @@
  * limitations under the License.
  */
 
+import { XfaText } from "./xfa_text.js";
+
 class XfaLayer {
   static setupStorage(html, id, element, storage, intent) {
     const storedData = storage.getValue(id, { value: null });
@@ -127,6 +129,9 @@ class XfaLayer {
     // Set defaults.
     rootDiv.setAttribute("class", "xfaLayer xfaFont");
 
+    // Text nodes used for the text highlighter.
+    const textDivs = [];
+
     while (stack.length > 0) {
       const [parent, i, html] = stack[stack.length - 1];
       if (i + 1 === parent.children.length) {
@@ -141,7 +146,9 @@ class XfaLayer {
 
       const { name } = child;
       if (name === "#text") {
-        html.appendChild(document.createTextNode(child.value));
+        const node = document.createTextNode(child.value);
+        textDivs.push(node);
+        html.appendChild(node);
         continue;
       }
 
@@ -160,7 +167,11 @@ class XfaLayer {
       if (child.children && child.children.length > 0) {
         stack.push([child, -1, childHtml]);
       } else if (child.value) {
-        childHtml.appendChild(document.createTextNode(child.value));
+        const node = document.createTextNode(child.value);
+        if (XfaText.shouldBuildText(name)) {
+          textDivs.push(node);
+        }
+        childHtml.appendChild(node);
       }
     }
 
@@ -185,6 +196,10 @@ class XfaLayer {
     )) {
       el.setAttribute("readOnly", true);
     }
+
+    return {
+      textDivs,
+    };
   }
 
   /**

src/display/xfa_text.js

@@ -0,0 +1,79 @@
+/* Copyright 2021 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class XfaText {
+  /**
+   * Walk an XFA tree and create an array of text nodes that is compatible
+   * with a regular PDFs TextContent. Currently, only TextItem.str is supported,
+   * all other fields and styles haven't been implemented.
+   *
+   * @param {Object} xfa - An XFA fake DOM object.
+   *
+   * @returns {TextContent}
+   */
+  static textContent(xfa) {
+    const items = [];
+    const output = {
+      items,
+      styles: Object.create(null),
+    };
+    function walk(node) {
+      if (!node) {
+        return;
+      }
+      let str = null;
+      const name = node.name;
+      if (name === "#text") {
+        str = node.value;
+      } else if (!XfaText.shouldBuildText(name)) {
+        return;
+      } else if (node?.attributes?.textContent) {
+        str = node.attributes.textContent;
+      } else if (node.value) {
+        str = node.value;
+      }
+      if (str !== null) {
+        items.push({
+          str,
+        });
+      }
+      if (!node.children) {
+        return;
+      }
+      for (const child of node.children) {
+        walk(child);
+      }
+    }
+    walk(xfa);
+    return output;
+  }
+
+  /**
+   * @param {string} name - DOM node name. (lower case)
+   *
+   * @returns {boolean} true if the DOM node should have a corresponding text
+   * node.
+   */
+  static shouldBuildText(name) {
+    return !(
+      name === "textarea" ||
+      name === "input" ||
+      name === "option" ||
+      name === "select"
+    );
+  }
+}
+
+export { XfaText };