tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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ViewportMetaData.cpp (3699B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "ViewportMetaData.h"
      8 
      9 #include "nsCRT.h"
     10 #include "nsContentUtils.h"
     11 
     12 using namespace mozilla;
     13 using namespace mozilla::dom;
     14 
     15 /*
     16 * Helper function for ViewportMetaData::ProcessViewportInfo.
     17 *
     18 * Handles a single key=value pair. If it corresponds to a valid viewport
     19 * attribute, add it to the document header data. No validation is done on the
     20 * value itself (this is done at display time).
     21 */
     22 static void ProcessViewportToken(ViewportMetaData& aData,
     23                                 const nsAString& token) {
     24  /* Iterators. */
     25  nsAString::const_iterator tip, tail, end;
     26  token.BeginReading(tip);
     27  tail = tip;
     28  token.EndReading(end);
     29 
     30  /* Move tip to the '='. */
     31  while ((tip != end) && (*tip != '=')) {
     32    ++tip;
     33  }
     34 
     35  /* If we didn't find an '=', punt. */
     36  if (tip == end) {
     37    return;
     38  }
     39 
     40  /* Extract the key and value. */
     41  const nsAString& key = nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(
     42      Substring(tail, tip), true);
     43  const nsAString& value = nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(
     44      Substring(++tip, end), true);
     45 
     46  /* Check for known keys. If we find a match, insert the appropriate
     47   * information into the document header. */
     48  RefPtr<nsAtom> key_atom = NS_Atomize(key);
     49  if (key_atom == nsGkAtoms::height) {
     50    aData.mHeight.Assign(value);
     51  } else if (key_atom == nsGkAtoms::width) {
     52    aData.mWidth.Assign(value);
     53  } else if (key_atom == nsGkAtoms::initial_scale) {
     54    aData.mInitialScale.Assign(value);
     55  } else if (key_atom == nsGkAtoms::minimum_scale) {
     56    aData.mMinimumScale.Assign(value);
     57  } else if (key_atom == nsGkAtoms::maximum_scale) {
     58    aData.mMaximumScale.Assign(value);
     59  } else if (key_atom == nsGkAtoms::user_scalable) {
     60    aData.mUserScalable.Assign(value);
     61  } else if (key_atom == nsGkAtoms::viewport_fit) {
     62    aData.mViewportFit.Assign(value);
     63  } else if (key_atom == nsGkAtoms::interactive_widget) {
     64    aData.mInteractiveWidgetMode.Assign(value);
     65  }
     66 }
     67 
     68 #define IS_SEPARATOR(c)                                             \
     69  (((c) == '=') || ((c) == ',') || ((c) == ';') || ((c) == '\t') || \
     70   ((c) == '\n') || ((c) == '\r'))
     71 
     72 ViewportMetaData::ViewportMetaData(const nsAString& aViewportInfo) {
     73  /* Iterators. */
     74  nsAString::const_iterator tip, tail, end;
     75  aViewportInfo.BeginReading(tip);
     76  tail = tip;
     77  aViewportInfo.EndReading(end);
     78 
     79  /* Read the tip to the first non-separator character. */
     80  while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip))) {
     81    ++tip;
     82  }
     83 
     84  /* Read through and find tokens separated by separators. */
     85  while (tip != end) {
     86    /* Synchronize tip and tail. */
     87    tail = tip;
     88 
     89    /* Advance tip past non-separator characters. */
     90    while ((tip != end) && !IS_SEPARATOR(*tip)) {
     91      ++tip;
     92    }
     93 
     94    /* Allow white spaces that surround the '=' character */
     95    if ((tip != end) && (*tip == '=')) {
     96      ++tip;
     97 
     98      while ((tip != end) && nsCRT::IsAsciiSpace(*tip)) {
     99        ++tip;
    100      }
    101 
    102      while ((tip != end) &&
    103             !(IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip))) {
    104        ++tip;
    105      }
    106    }
    107 
    108    /* Our token consists of the characters between tail and tip. */
    109    ProcessViewportToken(*this, Substring(tail, tip));
    110 
    111    /* Skip separators. */
    112    while ((tip != end) && (IS_SEPARATOR(*tip) || nsCRT::IsAsciiSpace(*tip))) {
    113      ++tip;
    114    }
    115  }
    116 }
    117 
    118 #undef IS_SEPARATOR