dom/svg/SVGMotionSMILPathUtils.cpp

   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 "SVGMotionSMILPathUtils.h"
   8
   9 #include "nsCharSeparatedTokenizer.h"
  10 #include "nsContentUtils.h"  // for NS_ENSURE_FINITE2
  11 #include "SVGContentUtils.h"
  12 #include "SVGLength.h"
  13
  14 using namespace mozilla::gfx;
  15
  16 namespace mozilla {
  17
  18 //----------------------------------------------------------------------
  19 // PathGenerator methods
  20
  21 // For the dummy 'from' value used in pure by-animation & to-animation
  22 void SVGMotionSMILPathUtils::PathGenerator::MoveToOrigin() {
  23   MOZ_ASSERT(!mHaveReceivedCommands,
  24              "Not expecting requests for mid-path MoveTo commands");
  25   mHaveReceivedCommands = true;
  26   mPathBuilder->MoveTo(Point(0, 0));
  27 }
  28
  29 // For 'from' and the first entry in 'values'.
  30 bool SVGMotionSMILPathUtils::PathGenerator::MoveToAbsolute(
  31     const nsAString& aCoordPairStr) {
  32   MOZ_ASSERT(!mHaveReceivedCommands,
  33              "Not expecting requests for mid-path MoveTo commands");
  34   mHaveReceivedCommands = true;
  35
  36   float xVal, yVal;
  37   if (!ParseCoordinatePair(aCoordPairStr, xVal, yVal)) {
  38     return false;
  39   }
  40   mPathBuilder->MoveTo(Point(xVal, yVal));
  41   return true;
  42 }
  43
  44 // For 'to' and every entry in 'values' except the first.
  45 bool SVGMotionSMILPathUtils::PathGenerator::LineToAbsolute(
  46     const nsAString& aCoordPairStr, double& aSegmentDistance) {
  47   mHaveReceivedCommands = true;
  48
  49   float xVal, yVal;
  50   if (!ParseCoordinatePair(aCoordPairStr, xVal, yVal)) {
  51     return false;
  52   }
  53   Point initialPoint = mPathBuilder->CurrentPoint();
  54
  55   mPathBuilder->LineTo(Point(xVal, yVal));
  56   aSegmentDistance = NS_hypot(initialPoint.x - xVal, initialPoint.y - yVal);
  57   return true;
  58 }
  59
  60 // For 'by'.
  61 bool SVGMotionSMILPathUtils::PathGenerator::LineToRelative(
  62     const nsAString& aCoordPairStr, double& aSegmentDistance) {
  63   mHaveReceivedCommands = true;
  64
  65   float xVal, yVal;
  66   if (!ParseCoordinatePair(aCoordPairStr, xVal, yVal)) {
  67     return false;
  68   }
  69   mPathBuilder->LineTo(mPathBuilder->CurrentPoint() + Point(xVal, yVal));
  70   aSegmentDistance = NS_hypot(xVal, yVal);
  71   return true;
  72 }
  73
  74 already_AddRefed<Path>
  75 SVGMotionSMILPathUtils::PathGenerator::GetResultingPath() {
  76   return mPathBuilder->Finish();
  77 }
  78
  79 //----------------------------------------------------------------------
  80 // Helper / protected methods
  81
  82 bool SVGMotionSMILPathUtils::PathGenerator::ParseCoordinatePair(
  83     const nsAString& aCoordPairStr, float& aXVal, float& aYVal) {
  84   nsCharSeparatedTokenizerTemplate<nsContentUtils::IsHTMLWhitespace,
  85                                    nsTokenizerFlags::SeparatorOptional>
  86       tokenizer(aCoordPairStr, ',');
  87
  88   SVGLength x, y;
  89
  90   if (!tokenizer.hasMoreTokens() ||
  91       !x.SetValueFromString(tokenizer.nextToken())) {
  92     return false;
  93   }
  94
  95   if (!tokenizer.hasMoreTokens() ||
  96       !y.SetValueFromString(tokenizer.nextToken())) {
  97     return false;
  98   }
  99
 100   if (tokenizer.separatorAfterCurrentToken() ||  // Trailing comma.
 101       tokenizer.hasMoreTokens()) {               // More text remains
 102     return false;
 103   }
 104
 105   float xRes = x.GetValueInPixels(mSVGElement, SVGContentUtils::X);
 106   float yRes = y.GetValueInPixels(mSVGElement, SVGContentUtils::Y);
 107
 108   NS_ENSURE_FINITE2(xRes, yRes, false);
 109
 110   aXVal = xRes;
 111   aYVal = yRes;
 112   return true;
 113 }
 114
 115 //----------------------------------------------------------------------
 116 // MotionValueParser methods
 117 bool SVGMotionSMILPathUtils::MotionValueParser::Parse(
 118     const nsAString& aValueStr) {
 119   bool success;
 120   if (!mPathGenerator->HaveReceivedCommands()) {
 121     // Interpret first value in "values" attribute as the path's initial MoveTo
 122     success = mPathGenerator->MoveToAbsolute(aValueStr);
 123     if (success) {
 124       success = !!mPointDistances->AppendElement(0.0, fallible);
 125     }
 126   } else {
 127     double dist;
 128     success = mPathGenerator->LineToAbsolute(aValueStr, dist);
 129     if (success) {
 130       mDistanceSoFar += dist;
 131       success = !!mPointDistances->AppendElement(mDistanceSoFar, fallible);
 132     }
 133   }
 134   return success;
 135 }
 136
 137 }  // namespace mozilla