| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| library trydart.htmlToText; |
| |
| import 'dart:math' show |
| max; |
| |
| import 'dart:html' show |
| Element, |
| Node, |
| NodeFilter, |
| ShadowRoot, |
| Text, |
| TreeWalker; |
| |
| import 'selection.dart' show |
| TrySelection; |
| |
| /// Returns true if [node] is a block element, that is, not inline. |
| bool isBlockElement(Node node) { |
| if (node is! Element) return false; |
| Element element = node; |
| |
| // TODO(ahe): Remove this line by changing code completion to avoid using a |
| // div element. |
| if (element.classes.contains('dart-code-completion')) return false; |
| |
| return element.getComputedStyle().display != 'inline'; |
| } |
| |
| /// Position [walker] at the last predecessor (that is, child of child of |
| /// child...) of [node]. The next call to walker.nextNode will return the first |
| /// node after [node]. |
| void skip(Node node, TreeWalker walker) { |
| if (walker.nextSibling() != null) { |
| walker.previousNode(); |
| return; |
| } |
| for (Node current = walker.nextNode(); |
| current != null; |
| current = walker.nextNode()) { |
| if (!node.contains(current)) { |
| walker.previousNode(); |
| return; |
| } |
| } |
| } |
| |
| /// Writes the text of [root] to [buffer]. Keeps track of [selection] and |
| /// returns the new anchorOffset from beginning of [buffer] or -1 if the |
| /// selection isn't in [root]. |
| int htmlToText(Node root, |
| StringBuffer buffer, |
| TrySelection selection, |
| {bool treatRootAsInline: false}) { |
| int selectionOffset = -1; |
| TreeWalker walker = new TreeWalker(root, NodeFilter.SHOW_ALL); |
| |
| for (Node node = root; node != null; node = walker.nextNode()) { |
| switch (node.nodeType) { |
| case Node.CDATA_SECTION_NODE: |
| case Node.TEXT_NODE: |
| if (selection.anchorNode == node) { |
| selectionOffset = selection.anchorOffset + buffer.length; |
| } |
| Text text = node; |
| buffer.write(text.data.replaceAll('\xA0', ' ')); |
| break; |
| |
| default: |
| if (!ShadowRoot.supported && |
| node is Element && |
| node.getAttribute('try-dart-shadow-root') != null) { |
| skip(node, walker); |
| } else if (node.nodeName == 'BR') { |
| buffer.write('\n'); |
| } else if (node != root && isBlockElement(node)) { |
| selectionOffset = |
| max(selectionOffset, htmlToText(node, buffer, selection)); |
| skip(node, walker); |
| } |
| break; |
| } |
| } |
| |
| if (!treatRootAsInline && isBlockElement(root)) { |
| buffer.write('\n'); |
| } |
| |
| return selectionOffset; |
| } |