DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (b6d82b1a6b02)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "CanvasRenderingContextHelper.h"
#include "ImageBitmapRenderingContext.h"
#include "ImageEncoder.h"
#include "mozilla/dom/CanvasRenderingContext2D.h"
#include "mozilla/Telemetry.h"
#include "mozilla/UniquePtr.h"
#include "MozFramebuffer.h"
#include "nsContentUtils.h"
#include "nsDOMJSUtils.h"
#include "nsIScriptContext.h"
#include "nsJSUtils.h"
#include "WebGL1Context.h"
#include "WebGL2Context.h"

namespace mozilla {
namespace dom {

void CanvasRenderingContextHelper::ToBlob(
    JSContext* aCx, nsIGlobalObject* aGlobal, BlobCallback& aCallback,
    const nsAString& aType, JS::Handle<JS::Value> aParams, bool aUsePlaceholder,
    ErrorResult& aRv) {
  // Encoder callback when encoding is complete.
  class EncodeCallback : public EncodeCompleteCallback {
   public:
    EncodeCallback(nsIGlobalObject* aGlobal, BlobCallback* aCallback)
        : mGlobal(aGlobal), mBlobCallback(aCallback) {}

    // This is called on main thread.
    MOZ_CAN_RUN_SCRIPT
    nsresult ReceiveBlob(already_AddRefed<Blob> aBlob) override {
      RefPtr<Blob> blob = aBlob;

      RefPtr<Blob> newBlob = Blob::Create(mGlobal, blob->Impl());

      RefPtr<BlobCallback> callback(mBlobCallback.forget());
      ErrorResult rv;
      callback->Call(newBlob, rv);

      mGlobal = nullptr;
      MOZ_ASSERT(!mBlobCallback);

      return rv.StealNSResult();
    }

    nsCOMPtr<nsIGlobalObject> mGlobal;
    RefPtr<BlobCallback> mBlobCallback;
  };

  RefPtr<EncodeCompleteCallback> callback =
      new EncodeCallback(aGlobal, &aCallback);

  ToBlob(aCx, aGlobal, callback, aType, aParams, aUsePlaceholder, aRv);
}

void CanvasRenderingContextHelper::ToBlob(
    JSContext* aCx, nsIGlobalObject* aGlobal, EncodeCompleteCallback* aCallback,
    const nsAString& aType, JS::Handle<JS::Value> aParams, bool aUsePlaceholder,
    ErrorResult& aRv) {
  nsAutoString type;
  nsContentUtils::ASCIIToLower(aType, type);

  nsAutoString params;
  bool usingCustomParseOptions;
  aRv = ParseParams(aCx, type, aParams, params, &usingCustomParseOptions);
  if (aRv.Failed()) {
    return;
  }

  if (mCurrentContext) {
    // We disallow canvases of width or height zero, and set them to 1, so
    // we will have a discrepancy with the sizes of the canvas and the context.
    // That discrepancy is OK, the rest are not.
    nsIntSize elementSize = GetWidthHeight();
    if ((elementSize.width != mCurrentContext->GetWidth() &&
         (elementSize.width != 0 || mCurrentContext->GetWidth() != 1)) ||
        (elementSize.height != mCurrentContext->GetHeight() &&
         (elementSize.height != 0 || mCurrentContext->GetHeight() != 1))) {
      aRv.Throw(NS_ERROR_FAILURE);
      return;
    }
  }

  UniquePtr<uint8_t[]> imageBuffer;
  int32_t format = 0;
  if (mCurrentContext) {
    imageBuffer = mCurrentContext->GetImageBuffer(&format);
  }

  RefPtr<EncodeCompleteCallback> callback = aCallback;

  aRv = ImageEncoder::ExtractDataAsync(
      type, params, usingCustomParseOptions, std::move(imageBuffer), format,
      GetWidthHeight(), aUsePlaceholder, callback);
}

already_AddRefed<nsICanvasRenderingContextInternal>
CanvasRenderingContextHelper::CreateContext(CanvasContextType aContextType) {
  return CreateContextHelper(aContextType, layers::LayersBackend::LAYERS_NONE);
}

already_AddRefed<nsICanvasRenderingContextInternal>
CanvasRenderingContextHelper::CreateContextHelper(
    CanvasContextType aContextType, layers::LayersBackend aCompositorBackend) {
  MOZ_ASSERT(aContextType != CanvasContextType::NoContext);
  RefPtr<nsICanvasRenderingContextInternal> ret;

  switch (aContextType) {
    case CanvasContextType::NoContext:
      break;

    case CanvasContextType::Canvas2D:
      Telemetry::Accumulate(Telemetry::CANVAS_2D_USED, 1);
      ret = new CanvasRenderingContext2D(aCompositorBackend);
      break;

    case CanvasContextType::WebGL1:
      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);

      ret = WebGL1Context::Create();
      if (!ret) return nullptr;

      break;

    case CanvasContextType::WebGL2:
      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_USED, 1);

      ret = WebGL2Context::Create();
      if (!ret) return nullptr;

      break;

    case CanvasContextType::ImageBitmap:
      ret = new ImageBitmapRenderingContext();

      break;
  }
  MOZ_ASSERT(ret);

  return ret.forget();
}

already_AddRefed<nsISupports> CanvasRenderingContextHelper::GetContext(
    JSContext* aCx, const nsAString& aContextId,
    JS::Handle<JS::Value> aContextOptions, ErrorResult& aRv) {
  CanvasContextType contextType;
  if (!CanvasUtils::GetCanvasContextType(aContextId, &contextType))
    return nullptr;

  if (!mCurrentContext) {
    // This canvas doesn't have a context yet.
    RefPtr<nsICanvasRenderingContextInternal> context;
    context = CreateContext(contextType);
    if (!context) {
      return nullptr;
    }

    // Ensure that the context participates in CC.  Note that returning a
    // CC participant from QI doesn't addref.
    nsXPCOMCycleCollectionParticipant* cp = nullptr;
    CallQueryInterface(context, &cp);
    if (!cp) {
      aRv.Throw(NS_ERROR_FAILURE);
      return nullptr;
    }

    mCurrentContext = context.forget();
    mCurrentContextType = contextType;

    nsresult rv = UpdateContext(aCx, aContextOptions, aRv);
    if (NS_FAILED(rv)) {
      // See bug 645792 and bug 1215072.
      // We want to throw only if dictionary initialization fails,
      // so only in case aRv has been set to some error value.
      if (contextType == CanvasContextType::WebGL1)
        Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_SUCCESS, 0);
      else if (contextType == CanvasContextType::WebGL2)
        Telemetry::Accumulate(Telemetry::CANVAS_WEBGL2_SUCCESS, 0);
      return nullptr;
    }
    if (contextType == CanvasContextType::WebGL1)
      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_SUCCESS, 1);
    else if (contextType == CanvasContextType::WebGL2)
      Telemetry::Accumulate(Telemetry::CANVAS_WEBGL2_SUCCESS, 1);
  } else {
    // We already have a context of some type.
    if (contextType != mCurrentContextType) return nullptr;
  }

  nsCOMPtr<nsICanvasRenderingContextInternal> context = mCurrentContext;
  return context.forget();
}

nsresult CanvasRenderingContextHelper::UpdateContext(
    JSContext* aCx, JS::Handle<JS::Value> aNewContextOptions,
    ErrorResult& aRvForDictionaryInit) {
  if (!mCurrentContext) return NS_OK;

  nsIntSize sz = GetWidthHeight();

  nsCOMPtr<nsICanvasRenderingContextInternal> currentContext = mCurrentContext;

  currentContext->SetOpaqueValueFromOpaqueAttr(GetOpaqueAttr());

  nsresult rv = currentContext->SetContextOptions(aCx, aNewContextOptions,
                                                  aRvForDictionaryInit);
  if (NS_FAILED(rv)) {
    mCurrentContext = nullptr;
    return rv;
  }

  rv = currentContext->SetDimensions(sz.width, sz.height);
  if (NS_FAILED(rv)) {
    mCurrentContext = nullptr;
  }

  return rv;
}

nsresult CanvasRenderingContextHelper::ParseParams(
    JSContext* aCx, const nsAString& aType, const JS::Value& aEncoderOptions,
    nsAString& outParams, bool* const outUsingCustomParseOptions) {
  // Quality parameter is only valid for the image/jpeg MIME type
  if (aType.EqualsLiteral("image/jpeg")) {
    if (aEncoderOptions.isNumber()) {
      double quality = aEncoderOptions.toNumber();
      // Quality must be between 0.0 and 1.0, inclusive
      if (quality >= 0.0 && quality <= 1.0) {
        outParams.AppendLiteral("quality=");
        outParams.AppendInt(NS_lround(quality * 100.0));
      }
    }
  }

  // If we haven't parsed the aParams check for proprietary options.
  // The proprietary option -moz-parse-options will take a image lib encoder
  // parse options string as is and pass it to the encoder.
  *outUsingCustomParseOptions = false;
  if (outParams.Length() == 0 && aEncoderOptions.isString()) {
    NS_NAMED_LITERAL_STRING(mozParseOptions, "-moz-parse-options:");
    nsAutoJSString paramString;
    if (!paramString.init(aCx, aEncoderOptions.toString())) {
      return NS_ERROR_FAILURE;
    }
    if (StringBeginsWith(paramString, mozParseOptions)) {
      nsDependentSubstring parseOptions =
          Substring(paramString, mozParseOptions.Length(),
                    paramString.Length() - mozParseOptions.Length());
      outParams.Append(parseOptions);
      *outUsingCustomParseOptions = true;
    }
  }

  return NS_OK;
}

}  // namespace dom
}  // namespace mozilla