netwerk/base/nsMediaFragmentURIParser.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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 #if !defined(nsMediaFragmentURIParser_h__)
   7 #  define nsMediaFragmentURIParser_h__
   8
   9 #  include "mozilla/Maybe.h"
  10 #  include "nsStringFwd.h"
  11 #  include "nsRect.h"
  12
  13 class nsIURI;
  14
  15 // Class to handle parsing of a W3C media fragment URI as per
  16 // spec at: http://www.w3.org/TR/media-frags/
  17 // Only the temporaral URI portion of the spec is implemented.
  18 // To use:
  19 // a) Construct an instance with the URI containing the fragment
  20 // b) Check for the validity of the values you are interested in
  21 //    using e.g. HasStartTime().
  22 // c) If the values are valid, obtain them using e.g. GetStartTime().
  23
  24 namespace mozilla {
  25 namespace net {
  26
  27 enum ClipUnit {
  28   eClipUnit_Pixel,
  29   eClipUnit_Percent,
  30 };
  31
  32 class nsMediaFragmentURIParser {
  33  public:
  34   // Create a parser with the provided URI.
  35   explicit nsMediaFragmentURIParser(nsIURI* aURI);
  36
  37   // Create a parser with the provided URI reference portion.
  38   explicit nsMediaFragmentURIParser(nsCString& aRef);
  39
  40   // True if a valid temporal media fragment indicated a start time.
  41   bool HasStartTime() const { return mStart.isSome(); }
  42
  43   // If a valid temporal media fragment indicated a start time, returns
  44   // it in units of seconds. If not, defaults to 0.
  45   double GetStartTime() const { return *mStart; }
  46
  47   // True if a valid temporal media fragment indicated an end time.
  48   bool HasEndTime() const { return mEnd.isSome(); }
  49
  50   // If a valid temporal media fragment indicated an end time, returns
  51   // it in units of seconds. If not, defaults to -1.
  52   double GetEndTime() const { return *mEnd; }
  53
  54   // True if a valid spatial media fragment indicated a clipping region.
  55   bool HasClip() const { return mClip.isSome(); }
  56
  57   // If a valid spatial media fragment indicated a clipping region,
  58   // returns the region. If not, returns an empty region. The unit
  59   // used depends on the value returned by GetClipUnit().
  60   nsIntRect GetClip() const { return *mClip; }
  61
  62   // If a valid spatial media fragment indicated a clipping region,
  63   // returns the unit used.
  64   ClipUnit GetClipUnit() const { return mClipUnit; }
  65
  66  private:
  67   // Parse the URI ref provided, looking for media fragments. This is
  68   // the top-level parser the invokes the others below.
  69   void Parse(nsACString& aRef);
  70
  71   // The following methods parse the fragment as per the media
  72   // fragments specification. 'aString' contains the remaining
  73   // fragment data to be parsed. The method returns true
  74   // if the parse was successful and leaves the remaining unparsed
  75   // data in 'aString'. If the parse fails then false is returned
  76   // and 'aString' is left as it was when called.
  77   bool ParseNPT(nsDependentSubstring aString);
  78   bool ParseNPTTime(nsDependentSubstring& aString, double& aTime);
  79   bool ParseNPTSec(nsDependentSubstring& aString, double& aSec);
  80   bool ParseNPTFraction(nsDependentSubstring& aString, double& aFraction);
  81   bool ParseNPTMMSS(nsDependentSubstring& aString, double& aTime);
  82   bool ParseNPTHHMMSS(nsDependentSubstring& aString, double& aTime);
  83   bool ParseNPTHH(nsDependentSubstring& aString, uint32_t& aHour);
  84   bool ParseNPTMM(nsDependentSubstring& aString, uint32_t& aMinute);
  85   bool ParseNPTSS(nsDependentSubstring& aString, uint32_t& aSecond);
  86   bool ParseXYWH(nsDependentSubstring aString);
  87   bool ParseMozResolution(nsDependentSubstring aString);
  88
  89   // Media fragment information.
  90   Maybe<double> mStart;
  91   Maybe<double> mEnd;
  92   Maybe<nsIntRect> mClip;
  93   ClipUnit mClipUnit;
  94 };
  95
  96 }  // namespace net
  97 }  // namespace mozilla
  98
  99 #endif