components/autofill/content/renderer/form_autofill

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This source file includes following definitions.
IsOptionElement
IsScriptElement
IsNoScriptElement
HasTagName
IsAutofillableElement
SatisfiesRequireAutocomplete
CombineAndCollapseWhitespace
FindChildTextInner
FindChildText
InferLabelFromPrevious
InferLabelFromListItem
InferLabelFromTableColumn
InferLabelFromTableRow
InferLabelFromDivTable
InferLabelFromDefinitionList
InferLabelForElement
GetOptionStringsFromElement
ForEachMatchingFormField
FillFormField
PreviewFormField
RetrievalMethodToString
IsWebNodeVisibleImpl
IsMonthInput
IsTextInput
IsSelectElement
IsTextAreaElement
IsCheckableElement
IsAutofillableInputElement
GetFormIdentifier
IsWebNodeVisible
ClickElement
ExtractAutofillableElements
WebFormControlElementToFormField
WebFormElementToFormData
FindFormAndFieldForFormControlElement
FillForm
FillFormIncludingNonFocusableElements
FillFormForAllElements
PreviewForm
ClearPreviewedFormWithElement
FormWithElementIsAutofilled
IsWebpageEmpty
IsWebElementEmpty
GetScaledBoundingBox
// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/autofill/content/renderer/form_autofill_util.h"

#include <map>

#include "base/command_line.h"
#include "base/logging.h"
#include "base/memory/scoped_vector.h"
#include "base/metrics/field_trial.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "components/autofill/core/common/autofill_data_validation.h"
#include "components/autofill/core/common/autofill_switches.h"
#include "components/autofill/core/common/form_data.h"
#include "components/autofill/core/common/form_field_data.h"
#include "components/autofill/core/common/web_element_descriptor.h"
#include "third_party/WebKit/public/platform/WebString.h"
#include "third_party/WebKit/public/platform/WebVector.h"
#include "third_party/WebKit/public/web/WebDocument.h"
#include "third_party/WebKit/public/web/WebElement.h"
#include "third_party/WebKit/public/web/WebElementCollection.h"
#include "third_party/WebKit/public/web/WebExceptionCode.h"
#include "third_party/WebKit/public/web/WebFormControlElement.h"
#include "third_party/WebKit/public/web/WebFormElement.h"
#include "third_party/WebKit/public/web/WebFrame.h"
#include "third_party/WebKit/public/web/WebInputElement.h"
#include "third_party/WebKit/public/web/WebLabelElement.h"
#include "third_party/WebKit/public/web/WebNode.h"
#include "third_party/WebKit/public/web/WebNodeList.h"
#include "third_party/WebKit/public/web/WebOptionElement.h"
#include "third_party/WebKit/public/web/WebSelectElement.h"
#include "third_party/WebKit/public/web/WebTextAreaElement.h"

using blink::WebDocument;
using blink::WebElement;
using blink::WebElementCollection;
using blink::WebExceptionCode;
using blink::WebFormControlElement;
using blink::WebFormElement;
using blink::WebFrame;
using blink::WebInputElement;
using blink::WebLabelElement;
using blink::WebNode;
using blink::WebNodeList;
using blink::WebOptionElement;
using blink::WebSelectElement;
using blink::WebTextAreaElement;
using blink::WebString;
using blink::WebVector;

namespace autofill {
namespace {

// A bit field mask for FillForm functions to not fill some fields.
enum FieldFilterMask {
  FILTER_NONE                       = 0,
  FILTER_DISABLED_ELEMENTS          = 1 << 0,
  FILTER_READONLY_ELEMENTS          = 1 << 1,
  FILTER_NON_FOCUSABLE_ELEMENTS     = 1 << 2,
  FILTER_ALL_NON_EDITIABLE_ELEMENTS = FILTER_DISABLED_ELEMENTS |
                                      FILTER_READONLY_ELEMENTS |
                                      FILTER_NON_FOCUSABLE_ELEMENTS,
};

bool IsOptionElement(const WebElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kOption, ("option"));
  return element.hasTagName(kOption);
}

bool IsScriptElement(const WebElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kScript, ("script"));
  return element.hasTagName(kScript);
}

bool IsNoScriptElement(const WebElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kNoScript, ("noscript"));
  return element.hasTagName(kNoScript);
}

bool HasTagName(const WebNode& node, const blink::WebString& tag) {
  return node.isElementNode() && node.toConst<WebElement>().hasHTMLTagName(tag);
}

bool IsAutofillableElement(const WebFormControlElement& element) {
  const WebInputElement* input_element = toWebInputElement(&element);
  return IsAutofillableInputElement(input_element) ||
         IsSelectElement(element) ||
         IsTextAreaElement(element);
}

// Check whether the given field satisfies the REQUIRE_AUTOCOMPLETE requirement.
bool SatisfiesRequireAutocomplete(const WebInputElement& input_element) {
  return input_element.autoComplete();
}

// Appends |suffix| to |prefix| so that any intermediary whitespace is collapsed
// to a single space.  If |force_whitespace| is true, then the resulting string
// is guaranteed to have a space between |prefix| and |suffix|.  Otherwise, the
// result includes a space only if |prefix| has trailing whitespace or |suffix|
// has leading whitespace.
// A few examples:
//  * CombineAndCollapseWhitespace("foo", "bar", false)       -> "foobar"
//  * CombineAndCollapseWhitespace("foo", "bar", true)        -> "foo bar"
//  * CombineAndCollapseWhitespace("foo ", "bar", false)      -> "foo bar"
//  * CombineAndCollapseWhitespace("foo", " bar", false)      -> "foo bar"
//  * CombineAndCollapseWhitespace("foo", " bar", true)       -> "foo bar"
//  * CombineAndCollapseWhitespace("foo   ", "   bar", false) -> "foo bar"
//  * CombineAndCollapseWhitespace(" foo", "bar ", false)     -> " foobar "
//  * CombineAndCollapseWhitespace(" foo", "bar ", true)      -> " foo bar "
const base::string16 CombineAndCollapseWhitespace(
    const base::string16& prefix,
    const base::string16& suffix,
    bool force_whitespace) {
  base::string16 prefix_trimmed;
  base::TrimPositions prefix_trailing_whitespace =
      base::TrimWhitespace(prefix, base::TRIM_TRAILING, &prefix_trimmed);

  // Recursively compute the children's text.
  base::string16 suffix_trimmed;
  base::TrimPositions suffix_leading_whitespace =
      base::TrimWhitespace(suffix, base::TRIM_LEADING, &suffix_trimmed);

  if (prefix_trailing_whitespace || suffix_leading_whitespace ||
      force_whitespace) {
    return prefix_trimmed + base::ASCIIToUTF16(" ") + suffix_trimmed;
  } else {
    return prefix_trimmed + suffix_trimmed;
  }
}

// This is a helper function for the FindChildText() function (see below).
// Search depth is limited with the |depth| parameter.
base::string16 FindChildTextInner(const WebNode& node, int depth) {
  if (depth <= 0 || node.isNull())
    return base::string16();

  // Skip over comments.
  if (node.nodeType() == WebNode::CommentNode)
    return FindChildTextInner(node.nextSibling(), depth - 1);

  if (node.nodeType() != WebNode::ElementNode &&
      node.nodeType() != WebNode::TextNode)
    return base::string16();

  // Ignore elements known not to contain inferable labels.
  if (node.isElementNode()) {
    const WebElement element = node.toConst<WebElement>();
    if (IsOptionElement(element) ||
        IsScriptElement(element) ||
        IsNoScriptElement(element) ||
        (element.isFormControlElement() &&
         IsAutofillableElement(element.toConst<WebFormControlElement>()))) {
      return base::string16();
    }
  }

  // Extract the text exactly at this node.
  base::string16 node_text = node.nodeValue();

  // Recursively compute the children's text.
  // Preserve inter-element whitespace separation.
  base::string16 child_text = FindChildTextInner(node.firstChild(), depth - 1);
  bool add_space = node.nodeType() == WebNode::TextNode && node_text.empty();
  node_text = CombineAndCollapseWhitespace(node_text, child_text, add_space);

  // Recursively compute the siblings' text.
  // Again, preserve inter-element whitespace separation.
  base::string16 sibling_text =
      FindChildTextInner(node.nextSibling(), depth - 1);
  add_space = node.nodeType() == WebNode::TextNode && node_text.empty();
  node_text = CombineAndCollapseWhitespace(node_text, sibling_text, add_space);

  return node_text;
}

// Returns the aggregated values of the descendants of |element| that are
// non-empty text nodes.  This is a faster alternative to |innerText()| for
// performance critical operations.  It does a full depth-first search so can be
// used when the structure is not directly known.  However, unlike with
// |innerText()|, the search depth and breadth are limited to a fixed threshold.
// Whitespace is trimmed from text accumulated at descendant nodes.
base::string16 FindChildText(const WebNode& node) {
  if (node.isTextNode())
    return node.nodeValue();

  WebNode child = node.firstChild();

  const int kChildSearchDepth = 10;
  base::string16 node_text = FindChildTextInner(child, kChildSearchDepth);
  base::TrimWhitespace(node_text, base::TRIM_ALL, &node_text);
  return node_text;
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// a previous sibling of |element|,
// e.g. Some Text <input ...>
// or   Some <span>Text</span> <input ...>
// or   <p>Some Text</p><input ...>
// or   <label>Some Text</label> <input ...>
// or   Some Text <img><input ...>
// or   <b>Some Text</b><br/> <input ...>.
base::string16 InferLabelFromPrevious(const WebFormControlElement& element) {
  base::string16 inferred_label;
  WebNode previous = element;
  while (true) {
    previous = previous.previousSibling();
    if (previous.isNull())
      break;

    // Skip over comments.
    WebNode::NodeType node_type = previous.nodeType();
    if (node_type == WebNode::CommentNode)
      continue;

    // Otherwise, only consider normal HTML elements and their contents.
    if (node_type != WebNode::TextNode &&
        node_type != WebNode::ElementNode)
      break;

    // A label might be split across multiple "lightweight" nodes.
    // Coalesce any text contained in multiple consecutive
    //  (a) plain text nodes or
    //  (b) inline HTML elements that are essentially equivalent to text nodes.
    CR_DEFINE_STATIC_LOCAL(WebString, kBold, ("b"));
    CR_DEFINE_STATIC_LOCAL(WebString, kStrong, ("strong"));
    CR_DEFINE_STATIC_LOCAL(WebString, kSpan, ("span"));
    CR_DEFINE_STATIC_LOCAL(WebString, kFont, ("font"));
    if (previous.isTextNode() ||
        HasTagName(previous, kBold) || HasTagName(previous, kStrong) ||
        HasTagName(previous, kSpan) || HasTagName(previous, kFont)) {
      base::string16 value = FindChildText(previous);
      // A text node's value will be empty if it is for a line break.
      bool add_space = previous.isTextNode() && value.empty();
      inferred_label =
          CombineAndCollapseWhitespace(value, inferred_label, add_space);
      continue;
    }

    // If we have identified a partial label and have reached a non-lightweight
    // element, consider the label to be complete.
    base::string16 trimmed_label;
    base::TrimWhitespace(inferred_label, base::TRIM_ALL, &trimmed_label);
    if (!trimmed_label.empty())
      break;

    // <img> and <br> tags often appear between the input element and its
    // label text, so skip over them.
    CR_DEFINE_STATIC_LOCAL(WebString, kImage, ("img"));
    CR_DEFINE_STATIC_LOCAL(WebString, kBreak, ("br"));
    if (HasTagName(previous, kImage) || HasTagName(previous, kBreak))
      continue;

    // We only expect <p> and <label> tags to contain the full label text.
    CR_DEFINE_STATIC_LOCAL(WebString, kPage, ("p"));
    CR_DEFINE_STATIC_LOCAL(WebString, kLabel, ("label"));
    if (HasTagName(previous, kPage) || HasTagName(previous, kLabel))
      inferred_label = FindChildText(previous);

    break;
  }

  base::TrimWhitespace(inferred_label, base::TRIM_ALL, &inferred_label);
  return inferred_label;
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// enclosing list item,
// e.g. <li>Some Text<input ...><input ...><input ...></tr>
base::string16 InferLabelFromListItem(const WebFormControlElement& element) {
  WebNode parent = element.parentNode();
  CR_DEFINE_STATIC_LOCAL(WebString, kListItem, ("li"));
  while (!parent.isNull() && parent.isElementNode() &&
         !parent.to<WebElement>().hasTagName(kListItem)) {
    parent = parent.parentNode();
  }

  if (!parent.isNull() && HasTagName(parent, kListItem))
    return FindChildText(parent);

  return base::string16();
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// surrounding table structure,
// e.g. <tr><td>Some Text</td><td><input ...></td></tr>
// or   <tr><th>Some Text</th><td><input ...></td></tr>
// or   <tr><td><b>Some Text</b></td><td><b><input ...></b></td></tr>
// or   <tr><th><b>Some Text</b></th><td><b><input ...></b></td></tr>
base::string16 InferLabelFromTableColumn(const WebFormControlElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kTableCell, ("td"));
  WebNode parent = element.parentNode();
  while (!parent.isNull() && parent.isElementNode() &&
         !parent.to<WebElement>().hasTagName(kTableCell)) {
    parent = parent.parentNode();
  }

  if (parent.isNull())
    return base::string16();

  // Check all previous siblings, skipping non-element nodes, until we find a
  // non-empty text block.
  base::string16 inferred_label;
  WebNode previous = parent.previousSibling();
  CR_DEFINE_STATIC_LOCAL(WebString, kTableHeader, ("th"));
  while (inferred_label.empty() && !previous.isNull()) {
    if (HasTagName(previous, kTableCell) || HasTagName(previous, kTableHeader))
      inferred_label = FindChildText(previous);

    previous = previous.previousSibling();
  }

  return inferred_label;
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// surrounding table structure,
// e.g. <tr><td>Some Text</td></tr><tr><td><input ...></td></tr>
base::string16 InferLabelFromTableRow(const WebFormControlElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kTableRow, ("tr"));
  WebNode parent = element.parentNode();
  while (!parent.isNull() && parent.isElementNode() &&
         !parent.to<WebElement>().hasTagName(kTableRow)) {
    parent = parent.parentNode();
  }

  if (parent.isNull())
    return base::string16();

  // Check all previous siblings, skipping non-element nodes, until we find a
  // non-empty text block.
  base::string16 inferred_label;
  WebNode previous = parent.previousSibling();
  while (inferred_label.empty() && !previous.isNull()) {
    if (HasTagName(previous, kTableRow))
      inferred_label = FindChildText(previous);

    previous = previous.previousSibling();
  }

  return inferred_label;
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// a surrounding div table,
// e.g. <div>Some Text<span><input ...></span></div>
// e.g. <div>Some Text</div><div><input ...></div>
base::string16 InferLabelFromDivTable(const WebFormControlElement& element) {
  WebNode node = element.parentNode();
  bool looking_for_parent = true;

  // Search the sibling and parent <div>s until we find a candidate label.
  base::string16 inferred_label;
  CR_DEFINE_STATIC_LOCAL(WebString, kDiv, ("div"));
  CR_DEFINE_STATIC_LOCAL(WebString, kTable, ("table"));
  CR_DEFINE_STATIC_LOCAL(WebString, kFieldSet, ("fieldset"));
  while (inferred_label.empty() && !node.isNull()) {
    if (HasTagName(node, kDiv)) {
      looking_for_parent = false;
      inferred_label = FindChildText(node);
    } else if (looking_for_parent &&
               (HasTagName(node, kTable) || HasTagName(node, kFieldSet))) {
      // If the element is in a table or fieldset, its label most likely is too.
      break;
    }

    if (node.previousSibling().isNull()) {
      // If there are no more siblings, continue walking up the tree.
      looking_for_parent = true;
    }

    if (looking_for_parent)
      node = node.parentNode();
    else
      node = node.previousSibling();
  }

  return inferred_label;
}

// Helper for |InferLabelForElement()| that infers a label, if possible, from
// a surrounding definition list,
// e.g. <dl><dt>Some Text</dt><dd><input ...></dd></dl>
// e.g. <dl><dt><b>Some Text</b></dt><dd><b><input ...></b></dd></dl>
base::string16 InferLabelFromDefinitionList(
    const WebFormControlElement& element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kDefinitionData, ("dd"));
  WebNode parent = element.parentNode();
  while (!parent.isNull() && parent.isElementNode() &&
         !parent.to<WebElement>().hasTagName(kDefinitionData))
    parent = parent.parentNode();

  if (parent.isNull() || !HasTagName(parent, kDefinitionData))
    return base::string16();

  // Skip by any intervening text nodes.
  WebNode previous = parent.previousSibling();
  while (!previous.isNull() && previous.isTextNode())
    previous = previous.previousSibling();

  CR_DEFINE_STATIC_LOCAL(WebString, kDefinitionTag, ("dt"));
  if (previous.isNull() || !HasTagName(previous, kDefinitionTag))
    return base::string16();

  return FindChildText(previous);
}

// Infers corresponding label for |element| from surrounding context in the DOM,
// e.g. the contents of the preceding <p> tag or text element.
base::string16 InferLabelForElement(const WebFormControlElement& element) {
  base::string16 inferred_label = InferLabelFromPrevious(element);
  if (!inferred_label.empty())
    return inferred_label;

  // If we didn't find a label, check for list item case.
  inferred_label = InferLabelFromListItem(element);
  if (!inferred_label.empty())
    return inferred_label;

  // If we didn't find a label, check for table cell case.
  inferred_label = InferLabelFromTableColumn(element);
  if (!inferred_label.empty())
    return inferred_label;

  // If we didn't find a label, check for table row case.
  inferred_label = InferLabelFromTableRow(element);
  if (!inferred_label.empty())
    return inferred_label;

  // If we didn't find a label, check for definition list case.
  inferred_label = InferLabelFromDefinitionList(element);
  if (!inferred_label.empty())
    return inferred_label;

  // If we didn't find a label, check for div table case.
  return InferLabelFromDivTable(element);
}

// Fills |option_strings| with the values of the <option> elements present in
// |select_element|.
void GetOptionStringsFromElement(const WebSelectElement& select_element,
                                 std::vector<base::string16>* option_values,
                                 std::vector<base::string16>* option_contents) {
  DCHECK(!select_element.isNull());

  option_values->clear();
  option_contents->clear();
  WebVector<WebElement> list_items = select_element.listItems();
  option_values->reserve(list_items.size());
  option_contents->reserve(list_items.size());
  for (size_t i = 0; i < list_items.size(); ++i) {
    if (IsOptionElement(list_items[i])) {
      const WebOptionElement option = list_items[i].toConst<WebOptionElement>();
      option_values->push_back(option.value());
      option_contents->push_back(option.text());
    }
  }
}

// The callback type used by |ForEachMatchingFormField()|.
typedef void (*Callback)(const FormFieldData&,
                         bool, /* is_initiating_element */
                         blink::WebFormControlElement*);

// For each autofillable field in |data| that matches a field in the |form|,
// the |callback| is invoked with the corresponding |form| field data.
void ForEachMatchingFormField(const WebFormElement& form_element,
                              const WebElement& initiating_element,
                              const FormData& data,
                              FieldFilterMask filters,
                              bool force_override,
                              Callback callback) {
  std::vector<WebFormControlElement> control_elements;
  ExtractAutofillableElements(form_element, REQUIRE_AUTOCOMPLETE,
                              &control_elements);

  if (control_elements.size() != data.fields.size()) {
    // This case should be reachable only for pathological websites and tests,
    // which add or remove form fields while the user is interacting with the
    // Autofill popup.
    return;
  }

  // It's possible that the site has injected fields into the form after the
  // page has loaded, so we can't assert that the size of the cached control
  // elements is equal to the size of the fields in |form|.  Fortunately, the
  // one case in the wild where this happens, paypal.com signup form, the fields
  // are appended to the end of the form and are not visible.
  for (size_t i = 0; i < control_elements.size(); ++i) {
    WebFormControlElement* element = &control_elements[i];

    if (base::string16(element->nameForAutofill()) != data.fields[i].name) {
      // This case should be reachable only for pathological websites, which
      // rename form fields while the user is interacting with the Autofill
      // popup.  I (isherman) am not aware of any such websites, and so am
      // optimistically including a NOTREACHED().  If you ever trip this check,
      // please file a bug against me.
      NOTREACHED();
      continue;
    }

    bool is_initiating_element = (*element == initiating_element);

    // Only autofill empty fields and the field that initiated the filling,
    // i.e. the field the user is currently editing and interacting with.
    const WebInputElement* input_element = toWebInputElement(element);
    if (!force_override && !is_initiating_element &&
        ((IsAutofillableInputElement(input_element) ||
          IsTextAreaElement(*element)) &&
         !element->value().isEmpty()))
      continue;

    if (((filters & FILTER_DISABLED_ELEMENTS) && !element->isEnabled()) ||
        ((filters & FILTER_READONLY_ELEMENTS) && element->isReadOnly()) ||
        ((filters & FILTER_NON_FOCUSABLE_ELEMENTS) && !element->isFocusable()))
      continue;

    callback(data.fields[i], is_initiating_element, element);
  }
}

// Sets the |field|'s value to the value in |data|.
// Also sets the "autofilled" attribute, causing the background to be yellow.
void FillFormField(const FormFieldData& data,
                   bool is_initiating_node,
                   blink::WebFormControlElement* field) {
  // Nothing to fill.
  if (data.value.empty())
    return;

  field->setAutofilled(true);

  WebInputElement* input_element = toWebInputElement(field);
  if (IsCheckableElement(input_element)) {
    input_element->setChecked(data.is_checked, true);
  } else {
    base::string16 value = data.value;
    if (IsTextInput(input_element) || IsMonthInput(input_element)) {
      // If the maxlength attribute contains a negative value, maxLength()
      // returns the default maxlength value.
      value = value.substr(0, input_element->maxLength());
    }
    field->setValue(value, true);
  }

  if (is_initiating_node &&
      ((IsTextInput(input_element) || IsMonthInput(input_element)) ||
       IsTextAreaElement(*field))) {
    int length = field->value().length();
    field->setSelectionRange(length, length);
    // Clear the current IME composition (the underline), if there is one.
    field->document().frame()->unmarkText();
  }
}

// Sets the |field|'s "suggested" (non JS visible) value to the value in |data|.
// Also sets the "autofilled" attribute, causing the background to be yellow.
void PreviewFormField(const FormFieldData& data,
                      bool is_initiating_node,
                      blink::WebFormControlElement* field) {
  // Nothing to preview.
  if (data.value.empty())
    return;

  // Preview input, textarea and select fields. For input fields, excludes
  // checkboxes and radio buttons, as there is no provision for
  // setSuggestedCheckedValue in WebInputElement.
  WebInputElement* input_element = toWebInputElement(field);
  if (IsTextInput(input_element) || IsMonthInput(input_element)) {
    // If the maxlength attribute contains a negative value, maxLength()
    // returns the default maxlength value.
    input_element->setSuggestedValue(
      data.value.substr(0, input_element->maxLength()));
    input_element->setAutofilled(true);
  } else if (IsTextAreaElement(*field) || IsSelectElement(*field)) {
    field->setSuggestedValue(data.value);
    field->setAutofilled(true);
  }

  if (is_initiating_node &&
      (IsTextInput(input_element) || IsTextAreaElement(*field))) {
    // Select the part of the text that the user didn't type.
    int start = field->value().length();
    int end = field->suggestedValue().length();
    field->setSelectionRange(start, end);
  }
}

std::string RetrievalMethodToString(
    const WebElementDescriptor::RetrievalMethod& method) {
  switch (method) {
    case WebElementDescriptor::CSS_SELECTOR:
      return "CSS_SELECTOR";
    case WebElementDescriptor::ID:
      return "ID";
    case WebElementDescriptor::NONE:
      return "NONE";
  }
  NOTREACHED();
  return "UNKNOWN";
}

// Recursively checks whether |node| or any of its children have a non-empty
// bounding box. The recursion depth is bounded by |depth|.
bool IsWebNodeVisibleImpl(const blink::WebNode& node, const int depth) {
  if (depth < 0)
    return false;
  if (node.hasNonEmptyBoundingBox())
    return true;

  // The childNodes method is not a const method. Therefore it cannot be called
  // on a const reference. Therefore we need a const cast.
  const blink::WebNodeList& children =
      const_cast<blink::WebNode&>(node).childNodes();
  size_t length = children.length();
  for (size_t i = 0; i < length; ++i) {
    const blink::WebNode& item = children.item(i);
    if (IsWebNodeVisibleImpl(item, depth - 1))
      return true;
  }
  return false;
}

}  // namespace

const size_t kMaxParseableFields = 200;

bool IsMonthInput(const WebInputElement* element) {
  CR_DEFINE_STATIC_LOCAL(WebString, kMonth, ("month"));
  return element && element->formControlType() == kMonth;
}

// All text fields, including password fields, should be extracted.
bool IsTextInput(const WebInputElement* element) {
  return element && element->isTextField();
}

bool IsSelectElement(const WebFormControlElement& element) {
  // Static for improved performance.
  CR_DEFINE_STATIC_LOCAL(WebString, kSelectOne, ("select-one"));
  return element.formControlType() == kSelectOne;
}

bool IsTextAreaElement(const WebFormControlElement& element) {
  // Static for improved performance.
  CR_DEFINE_STATIC_LOCAL(WebString, kTextArea, ("textarea"));
  return element.formControlType() == kTextArea;
}

bool IsCheckableElement(const WebInputElement* element) {
  if (!element)
    return false;

  return element->isCheckbox() || element->isRadioButton();
}

bool IsAutofillableInputElement(const WebInputElement* element) {
  return IsTextInput(element) ||
         IsMonthInput(element) ||
         IsCheckableElement(element);
}

const base::string16 GetFormIdentifier(const WebFormElement& form) {
  base::string16 identifier = form.name();
  CR_DEFINE_STATIC_LOCAL(WebString, kId, ("id"));
  if (identifier.empty())
    identifier = form.getAttribute(kId);

  return identifier;
}

bool IsWebNodeVisible(const blink::WebNode& node) {
  // In the bug http://crbug.com/237216 the form's bounding box is empty
  // however the form has non empty children. Thus we need to look at the
  // form's children.
  int kNodeSearchDepth = 2;
  return IsWebNodeVisibleImpl(node, kNodeSearchDepth);
}

bool ClickElement(const WebDocument& document,
                  const WebElementDescriptor& element_descriptor) {
  WebString web_descriptor = WebString::fromUTF8(element_descriptor.descriptor);
  blink::WebElement element;

  switch (element_descriptor.retrieval_method) {
    case WebElementDescriptor::CSS_SELECTOR: {
      WebExceptionCode ec = 0;
      element = document.querySelector(web_descriptor, ec);
      if (ec)
        DVLOG(1) << "Query selector failed. Error code: " << ec << ".";
      break;
    }
    case WebElementDescriptor::ID:
      element = document.getElementById(web_descriptor);
      break;
    case WebElementDescriptor::NONE:
      return true;
  }

  if (element.isNull()) {
    DVLOG(1) << "Could not find "
             << element_descriptor.descriptor
             << " by "
             << RetrievalMethodToString(element_descriptor.retrieval_method)
             << ".";
    return false;
  }

  element.simulateClick();
  return true;
}

// Fills |autofillable_elements| with all the auto-fillable form control
// elements in |form_element|.
void ExtractAutofillableElements(
    const WebFormElement& form_element,
    RequirementsMask requirements,
    std::vector<WebFormControlElement>* autofillable_elements) {
  WebVector<WebFormControlElement> control_elements;
  form_element.getFormControlElements(control_elements);

  autofillable_elements->clear();
  for (size_t i = 0; i < control_elements.size(); ++i) {
    WebFormControlElement element = control_elements[i];
    if (!IsAutofillableElement(element))
      continue;

    if (requirements & REQUIRE_AUTOCOMPLETE) {
      // TODO(isherman): WebKit currently doesn't handle the autocomplete
      // attribute for select or textarea elements, but it probably should.
      WebInputElement* input_element = toWebInputElement(&control_elements[i]);
      if (IsAutofillableInputElement(input_element) &&
          !SatisfiesRequireAutocomplete(*input_element))
        continue;
    }

    autofillable_elements->push_back(element);
  }
}

void WebFormControlElementToFormField(const WebFormControlElement& element,
                                      ExtractMask extract_mask,
                                      FormFieldData* field) {
  DCHECK(field);
  DCHECK(!element.isNull());
  CR_DEFINE_STATIC_LOCAL(WebString, kAutocomplete, ("autocomplete"));

  // The label is not officially part of a WebFormControlElement; however, the
  // labels for all form control elements are scraped from the DOM and set in
  // WebFormElementToFormData.
  field->name = element.nameForAutofill();
  field->form_control_type = base::UTF16ToUTF8(element.formControlType());
  field->autocomplete_attribute =
      base::UTF16ToUTF8(element.getAttribute(kAutocomplete));
  if (field->autocomplete_attribute.size() > kMaxDataLength) {
    // Discard overly long attribute values to avoid DOS-ing the browser
    // process.  However, send over a default string to indicate that the
    // attribute was present.
    field->autocomplete_attribute = "x-max-data-length-exceeded";
  }

  if (!IsAutofillableElement(element))
    return;

  const WebInputElement* input_element = toWebInputElement(&element);
  if (IsAutofillableInputElement(input_element) ||
      IsTextAreaElement(element)) {
    field->is_autofilled = element.isAutofilled();
    field->is_focusable = element.isFocusable();
    field->should_autocomplete = element.autoComplete();
    field->text_direction = element.directionForFormData() ==
        "rtl" ? base::i18n::RIGHT_TO_LEFT : base::i18n::LEFT_TO_RIGHT;
  }

  if (IsAutofillableInputElement(input_element)) {
    if (IsTextInput(input_element))
      field->max_length = input_element->maxLength();

    field->is_checkable = IsCheckableElement(input_element);
    field->is_checked = input_element->isChecked();
  } else if (IsTextAreaElement(element)) {
    // Nothing more to do in this case.
  } else if (extract_mask & EXTRACT_OPTIONS) {
    // Set option strings on the field if available.
    DCHECK(IsSelectElement(element));
    const WebSelectElement select_element = element.toConst<WebSelectElement>();
    GetOptionStringsFromElement(select_element,
                                &field->option_values,
                                &field->option_contents);
  }

  if (!(extract_mask & EXTRACT_VALUE))
    return;

  base::string16 value = element.value();

  if (IsSelectElement(element)) {
    const WebSelectElement select_element = element.toConst<WebSelectElement>();
    // Convert the |select_element| value to text if requested.
    if (extract_mask & EXTRACT_OPTION_TEXT) {
      WebVector<WebElement> list_items = select_element.listItems();
      for (size_t i = 0; i < list_items.size(); ++i) {
        if (IsOptionElement(list_items[i])) {
          const WebOptionElement option_element =
              list_items[i].toConst<WebOptionElement>();
          if (option_element.value() == value) {
            value = option_element.text();
            break;
          }
        }
      }
    }
  }

  // Constrain the maximum data length to prevent a malicious site from DOS'ing
  // the browser: http://crbug.com/49332
  if (value.size() > kMaxDataLength)
    value = value.substr(0, kMaxDataLength);

  field->value = value;
}

bool WebFormElementToFormData(
    const blink::WebFormElement& form_element,
    const blink::WebFormControlElement& form_control_element,
    RequirementsMask requirements,
    ExtractMask extract_mask,
    FormData* form,
    FormFieldData* field) {
  CR_DEFINE_STATIC_LOCAL(WebString, kLabel, ("label"));
  CR_DEFINE_STATIC_LOCAL(WebString, kFor, ("for"));
  CR_DEFINE_STATIC_LOCAL(WebString, kHidden, ("hidden"));

  const WebFrame* frame = form_element.document().frame();
  if (!frame)
    return false;

  if (requirements & REQUIRE_AUTOCOMPLETE && !form_element.autoComplete())
    return false;

  form->name = GetFormIdentifier(form_element);
  form->method = form_element.method();
  form->origin = frame->document().url();
  form->action = frame->document().completeURL(form_element.action());
  form->user_submitted = form_element.wasUserSubmitted();

  // If the completed URL is not valid, just use the action we get from
  // WebKit.
  if (!form->action.is_valid())
    form->action = GURL(form_element.action());

  // A map from a FormFieldData's name to the FormFieldData itself.
  std::map<base::string16, FormFieldData*> name_map;

  // The extracted FormFields.  We use pointers so we can store them in
  // |name_map|.
  ScopedVector<FormFieldData> form_fields;

  WebVector<WebFormControlElement> control_elements;
  form_element.getFormControlElements(control_elements);

  // A vector of bools that indicate whether each field in the form meets the
  // requirements and thus will be in the resulting |form|.
  std::vector<bool> fields_extracted(control_elements.size(), false);

  for (size_t i = 0; i < control_elements.size(); ++i) {
    const WebFormControlElement& control_element = control_elements[i];

    if (!IsAutofillableElement(control_element))
      continue;

    const WebInputElement* input_element = toWebInputElement(&control_element);
    if (requirements & REQUIRE_AUTOCOMPLETE &&
        IsAutofillableInputElement(input_element) &&
        !SatisfiesRequireAutocomplete(*input_element))
      continue;

    // Create a new FormFieldData, fill it out and map it to the field's name.
    FormFieldData* form_field = new FormFieldData;
    WebFormControlElementToFormField(control_element, extract_mask, form_field);
    form_fields.push_back(form_field);
    // TODO(jhawkins): A label element is mapped to a form control element's id.
    // field->name() will contain the id only if the name does not exist.  Add
    // an id() method to WebFormControlElement and use that here.
    name_map[form_field->name] = form_field;
    fields_extracted[i] = true;
  }

  // If we failed to extract any fields, give up.  Also, to avoid overly
  // expensive computation, we impose a maximum number of allowable fields.
  if (form_fields.empty() || form_fields.size() > kMaxParseableFields)
    return false;

  // Loop through the label elements inside the form element.  For each label
  // element, get the corresponding form control element, use the form control
  // element's name as a key into the <name, FormFieldData> map to find the
  // previously created FormFieldData and set the FormFieldData's label to the
  // label.firstChild().nodeValue() of the label element.
  WebElementCollection labels = form_element.getElementsByTagName(kLabel);
  DCHECK(!labels.isNull());
  for (WebElement item = labels.firstItem(); !item.isNull();
       item = labels.nextItem()) {
    WebLabelElement label = item.to<WebLabelElement>();
    WebFormControlElement field_element =
        label.correspondingControl().to<WebFormControlElement>();

    base::string16 element_name;
    if (field_element.isNull()) {
      // Sometimes site authors will incorrectly specify the corresponding
      // field element's name rather than its id, so we compensate here.
      element_name = label.getAttribute(kFor);
    } else if (
        !field_element.isFormControlElement() ||
        field_element.formControlType() == kHidden) {
      continue;
    } else {
      element_name = field_element.nameForAutofill();
    }

    std::map<base::string16, FormFieldData*>::iterator iter =
        name_map.find(element_name);
    if (iter != name_map.end()) {
      base::string16 label_text = FindChildText(label);

      // Concatenate labels because some sites might have multiple label
      // candidates.
      if (!iter->second->label.empty() && !label_text.empty())
        iter->second->label += base::ASCIIToUTF16(" ");
      iter->second->label += label_text;
    }
  }

  // Loop through the form control elements, extracting the label text from
  // the DOM.  We use the |fields_extracted| vector to make sure we assign the
  // extracted label to the correct field, as it's possible |form_fields| will
  // not contain all of the elements in |control_elements|.
  for (size_t i = 0, field_idx = 0;
       i < control_elements.size() && field_idx < form_fields.size(); ++i) {
    // This field didn't meet the requirements, so don't try to find a label
    // for it.
    if (!fields_extracted[i])
      continue;

    const WebFormControlElement& control_element = control_elements[i];
    if (form_fields[field_idx]->label.empty())
      form_fields[field_idx]->label = InferLabelForElement(control_element);

    if (field && form_control_element == control_element)
      *field = *form_fields[field_idx];

    ++field_idx;
  }

  // Copy the created FormFields into the resulting FormData object.
  for (ScopedVector<FormFieldData>::const_iterator iter = form_fields.begin();
       iter != form_fields.end(); ++iter) {
    form->fields.push_back(**iter);
  }

  return true;
}

bool FindFormAndFieldForFormControlElement(const WebFormControlElement& element,
                                           FormData* form,
                                           FormFieldData* field,
                                           RequirementsMask requirements) {
  if (!IsAutofillableElement(element))
    return false;

  const WebFormElement form_element = element.form();
  if (form_element.isNull())
    return false;

  ExtractMask extract_mask =
      static_cast<ExtractMask>(EXTRACT_VALUE | EXTRACT_OPTIONS);
  return WebFormElementToFormData(form_element,
                                  element,
                                  requirements,
                                  extract_mask,
                                  form,
                                  field);
}

void FillForm(const FormData& form, const WebFormControlElement& element) {
  WebFormElement form_element = element.form();
  if (form_element.isNull())
    return;

  ForEachMatchingFormField(form_element,
                           element,
                           form,
                           FILTER_ALL_NON_EDITIABLE_ELEMENTS,
                           false, /* dont force override */
                           &FillFormField);
}

void FillFormIncludingNonFocusableElements(const FormData& form_data,
                                           const WebFormElement& form_element) {
  if (form_element.isNull())
    return;

  FieldFilterMask filter_mask = static_cast<FieldFilterMask>(
      FILTER_DISABLED_ELEMENTS | FILTER_READONLY_ELEMENTS);
  ForEachMatchingFormField(form_element,
                           WebInputElement(),
                           form_data,
                           filter_mask,
                           true, /* force override */
                           &FillFormField);
}

void FillFormForAllElements(const FormData& form_data,
                            const WebFormElement& form_element) {
  if (form_element.isNull())
    return;

  ForEachMatchingFormField(form_element,
                           WebInputElement(),
                           form_data,
                           FILTER_NONE,
                           true, /* force override */
                           &FillFormField);
}

void PreviewForm(const FormData& form, const WebFormControlElement& element) {
  WebFormElement form_element = element.form();
  if (form_element.isNull())
    return;

  ForEachMatchingFormField(form_element,
                           element,
                           form,
                           FILTER_ALL_NON_EDITIABLE_ELEMENTS,
                           false, /* dont force override */
                           &PreviewFormField);
}

bool ClearPreviewedFormWithElement(const WebFormControlElement& element,
                                   bool was_autofilled) {
  WebFormElement form_element = element.form();
  if (form_element.isNull())
    return false;

  std::vector<WebFormControlElement> control_elements;
  ExtractAutofillableElements(form_element, REQUIRE_AUTOCOMPLETE,
                              &control_elements);
  for (size_t i = 0; i < control_elements.size(); ++i) {
    // There might be unrelated elements in this form which have already been
    // auto-filled.  For example, the user might have already filled the address
    // part of a form and now be dealing with the credit card section.  We only
    // want to reset the auto-filled status for fields that were previewed.
    WebFormControlElement control_element = control_elements[i];

    // Only text input, textarea and select elements can be previewed.
    WebInputElement* input_element = toWebInputElement(&control_element);
    if (!IsTextInput(input_element) &&
        !IsMonthInput(input_element) &&
        !IsTextAreaElement(control_element) &&
        !IsSelectElement(control_element))
      continue;

    // If the element is not auto-filled, we did not preview it,
    // so there is nothing to reset.
    if(!control_element.isAutofilled())
      continue;

    if ((IsTextInput(input_element) ||
         IsMonthInput(input_element) ||
         IsTextAreaElement(control_element) ||
         IsSelectElement(control_element)) &&
        control_element.suggestedValue().isEmpty())
      continue;

    // Clear the suggested value. For the initiating node, also restore the
    // original value.
    if (IsTextInput(input_element) || IsMonthInput(input_element) ||
        IsTextAreaElement(control_element)) {
      control_element.setSuggestedValue(WebString());
      bool is_initiating_node = (element == control_element);
      if (is_initiating_node) {
        control_element.setAutofilled(was_autofilled);
        // Clearing the suggested value in the focused node (above) can cause
        // selection to be lost. We force selection range to restore the text
        // cursor.
        int length = control_element.value().length();
        control_element.setSelectionRange(length, length);
      } else {
        control_element.setAutofilled(false);
      }
    } else if (IsSelectElement(control_element)) {
      control_element.setSuggestedValue(WebString());
      control_element.setAutofilled(false);
    }
  }

  return true;
}

bool FormWithElementIsAutofilled(const WebInputElement& element) {
  WebFormElement form_element = element.form();
  if (form_element.isNull())
    return false;

  std::vector<WebFormControlElement> control_elements;
  ExtractAutofillableElements(form_element, REQUIRE_AUTOCOMPLETE,
                              &control_elements);
  for (size_t i = 0; i < control_elements.size(); ++i) {
    WebInputElement* input_element = toWebInputElement(&control_elements[i]);
    if (!IsAutofillableInputElement(input_element))
      continue;

    if (input_element->isAutofilled())
      return true;
  }

  return false;
}

bool IsWebpageEmpty(const blink::WebFrame* frame) {
  blink::WebDocument document = frame->document();

  return IsWebElementEmpty(document.head()) &&
         IsWebElementEmpty(document.body());
}

bool IsWebElementEmpty(const blink::WebElement& element) {
  // This array contains all tags which can be present in an empty page.
  const char* const kAllowedValue[] = {
    "script",
    "meta",
    "title",
  };
  const size_t kAllowedValueLength = arraysize(kAllowedValue);

  if (element.isNull())
    return true;
  // The childNodes method is not a const method. Therefore it cannot be called
  // on a const reference. Therefore we need a const cast.
  const blink::WebNodeList& children =
      const_cast<blink::WebElement&>(element).childNodes();
  for (size_t i = 0; i < children.length(); ++i) {
    const blink::WebNode& item = children.item(i);

    if (item.isTextNode() &&
        !base::ContainsOnlyChars(item.nodeValue().utf8(),
                                 base::kWhitespaceASCII))
      return false;

    // We ignore all other items with names which begin with
    // the character # because they are not html tags.
    if (item.nodeName().utf8()[0] == '#')
      continue;

    bool tag_is_allowed = false;
    // Test if the item name is in the kAllowedValue array
    for (size_t allowed_value_index = 0;
         allowed_value_index < kAllowedValueLength; ++allowed_value_index) {
      if (HasTagName(item,
                     WebString::fromUTF8(kAllowedValue[allowed_value_index]))) {
        tag_is_allowed = true;
        break;
      }
    }
    if (!tag_is_allowed)
      return false;
  }
  return true;
}

gfx::RectF GetScaledBoundingBox(float scale, WebFormControlElement* element) {
  gfx::Rect bounding_box(element->boundsInViewportSpace());
  return gfx::RectF(bounding_box.x() * scale,
                    bounding_box.y() * scale,
                    bounding_box.width() * scale,
                    bounding_box.height() * scale);
}

}  // namespace autofill
/* [<][>][^][v][top][bottom][index][help] */
root/components/autofill/content/renderer/form_autofill_util.cc

DEFINITIONS
