Merge pull request #7134 from yurydelendik/circ-stream-colorspace

Refactors to remove stream.js dependency on colorspace.js

src/core/colorspace.js

@@ -18,17 +18,16 @@
 (function (root, factory) {
   if (typeof define === 'function' && define.amd) {
     define('pdfjs/core/colorspace', ['exports', 'pdfjs/shared/util',
-      'pdfjs/core/primitives', 'pdfjs/core/function', 'pdfjs/core/stream'],
+      'pdfjs/core/primitives', 'pdfjs/core/function'],
       factory);
   } else if (typeof exports !== 'undefined') {
     factory(exports, require('../shared/util.js'), require('./primitives.js'),
-      require('./function.js'), require('./stream.js'));
+      require('./function.js'));
   } else {
     factory((root.pdfjsCoreColorSpace = {}), root.pdfjsSharedUtil,
-      root.pdfjsCorePrimitives, root.pdfjsCoreFunction, root.pdfjsCoreStream);
+      root.pdfjsCorePrimitives, root.pdfjsCoreFunction);
   }
-}(this, function (exports, sharedUtil, corePrimitives, coreFunction,
-                  coreStream) {
+}(this, function (exports, sharedUtil, corePrimitives, coreFunction) {
 
 var error = sharedUtil.error;
 var info = sharedUtil.info;
@@ -1299,7 +1298,4 @@ function _setCoreImage(coreImage_) {
 exports._setCoreImage = _setCoreImage;
 
 exports.ColorSpace = ColorSpace;
-
-// TODO refactor to remove dependency on colorspace.js
-coreStream._setCoreColorSpace(exports);
 }));

src/core/evaluator.js

@@ -72,6 +72,7 @@ var isRef = corePrimitives.isRef;
 var isStream = corePrimitives.isStream;
 var DecodeStream = coreStream.DecodeStream;
 var JpegStream = coreStream.JpegStream;
+var Stream = coreStream.Stream;
 var Lexer = coreParser.Lexer;
 var Parser = coreParser.Parser;
 var isEOF = coreParser.isEOF;
@@ -114,6 +115,51 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
     cMapOptions: { url: null, packed: false }
   };
 
+  function NativeImageDecoder(xref, resources, handler, forceDataSchema) {
+    this.xref = xref;
+    this.resources = resources;
+    this.handler = handler;
+    this.forceDataSchema = forceDataSchema;
+  }
+  NativeImageDecoder.prototype = {
+    canDecode: function (image) {
+      return image instanceof JpegStream &&
+             NativeImageDecoder.isDecodable(image, this.xref, this.resources);
+    },
+    decode: function (image) {
+      // For natively supported JPEGs send them to the main thread for decoding.
+      var dict = image.dict;
+      var colorSpace = dict.get('ColorSpace', 'CS');
+      colorSpace = ColorSpace.parse(colorSpace, this.xref, this.resources);
+      var numComps = colorSpace.numComps;
+      var decodePromise = this.handler.sendWithPromise('JpegDecode',
+        [image.getIR(this.forceDataSchema), numComps]);
+      return decodePromise.then(function (message) {
+        var data = message.data;
+        return new Stream(data, 0, data.length, image.dict);
+      });
+    }
+  };
+  /**
+   * Checks if the image can be decoded and displayed by the browser without any
+   * further processing such as color space conversions.
+   */
+  NativeImageDecoder.isSupported =
+      function NativeImageDecoder_isSupported(image, xref, res) {
+    var cs = ColorSpace.parse(image.dict.get('ColorSpace', 'CS'), xref, res);
+    return (cs.name === 'DeviceGray' || cs.name === 'DeviceRGB') &&
+           cs.isDefaultDecode(image.dict.get('Decode', 'D'));
+  };
+  /**
+   * Checks if the image can be decoded by the browser.
+   */
+  NativeImageDecoder.isDecodable =
+      function NativeImageDecoder_isDecodable(image, xref, res) {
+    var cs = ColorSpace.parse(image.dict.get('ColorSpace', 'CS'), xref, res);
+    return (cs.numComps === 1 || cs.numComps === 3) &&
+           cs.isDefaultDecode(image.dict.get('Decode', 'D'));
+  };
+
   function PartialEvaluator(pdfManager, xref, handler, pageIndex,
                             uniquePrefix, idCounters, fontCache, options) {
     this.pdfManager = pdfManager;
@@ -343,7 +389,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
       args = [objId, w, h];
 
       if (!softMask && !mask && image instanceof JpegStream &&
-          image.isNativelySupported(this.xref, resources)) {
+          NativeImageDecoder.isSupported(image, this.xref, resources)) {
         // These JPEGs don't need any more processing so we can just send it.
         operatorList.addOp(OPS.paintJpegXObject, args);
         this.handler.send('obj',
@@ -352,8 +398,16 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
         return;
       }
 
+      // Creates native image decoder only if a JPEG image or mask is present.
+      var nativeImageDecoder = null;
+      if (image instanceof JpegStream || mask instanceof JpegStream ||
+          softMask instanceof JpegStream) {
+        nativeImageDecoder = new NativeImageDecoder(self.xref, resources,
+          self.handler, self.options.forceDataSchema);
+      }
+
       PDFImage.buildImage(self.handler, self.xref, resources, image, inline,
-                          this.options.forceDataSchema).
+                          nativeImageDecoder).
         then(function(imageObj) {
           var imgData = imageObj.createImageData(/* forceRGBA = */ false);
           self.handler.send('obj', [objId, self.pageIndex, 'Image', imgData],

src/core/image.js

@@ -42,29 +42,17 @@ var Name = corePrimitives.Name;
 var isStream = corePrimitives.isStream;
 var ColorSpace = coreColorSpace.ColorSpace;
 var DecodeStream = coreStream.DecodeStream;
-var Stream = coreStream.Stream;
 var JpegStream = coreStream.JpegStream;
 var JpxImage = coreJpx.JpxImage;
 
 var PDFImage = (function PDFImageClosure() {
   /**
-   * Decode the image in the main thread if it supported. Resovles the promise
+   * Decodes the image using native decoder if possible. Resolves the promise
    * when the image data is ready.
    */
-  function handleImageData(handler, xref, res, image, forceDataSchema) {
-    if (image instanceof JpegStream && image.isNativelyDecodable(xref, res)) {
-      // For natively supported jpegs send them to the main thread for decoding.
-      var dict = image.dict;
-      var colorSpace = dict.get('ColorSpace', 'CS');
-      colorSpace = ColorSpace.parse(colorSpace, xref, res);
-      var numComps = colorSpace.numComps;
-      var decodePromise = handler.sendWithPromise('JpegDecode',
-                                                  [image.getIR(forceDataSchema),
-                                                   numComps]);
-      return decodePromise.then(function (message) {
-        var data = message.data;
-        return new Stream(data, 0, data.length, image.dict);
-      });
+  function handleImageData(image, nativeDecoder) {
+    if (nativeDecoder && nativeDecoder.canDecode(image)) {
+      return nativeDecoder.decode(image);
     } else {
       return Promise.resolve(image);
     }
@@ -186,9 +174,8 @@ var PDFImage = (function PDFImageClosure() {
    */
   PDFImage.buildImage = function PDFImage_buildImage(handler, xref,
                                                      res, image, inline,
-                                                     forceDataSchema) {
-    var imagePromise = handleImageData(handler, xref, res, image,
-                                       forceDataSchema);
+                                                     nativeDecoder) {
+    var imagePromise = handleImageData(image, nativeDecoder);
     var smaskPromise;
     var maskPromise;
 
@@ -196,15 +183,13 @@ var PDFImage = (function PDFImageClosure() {
     var mask = image.dict.get('Mask');
 
     if (smask) {
-      smaskPromise = handleImageData(handler, xref, res, smask,
-                                     forceDataSchema);
+      smaskPromise = handleImageData(smask, nativeDecoder);
       maskPromise = Promise.resolve(null);
     } else {
       smaskPromise = Promise.resolve(null);
       if (mask) {
         if (isStream(mask)) {
-          maskPromise = handleImageData(handler, xref, res, mask,
-                                        forceDataSchema);
+          maskPromise = handleImageData(mask, nativeDecoder);
         } else if (isArray(mask)) {
           maskPromise = Promise.resolve(mask);
         } else {

src/core/stream.js

@@ -43,9 +43,6 @@ var Jbig2Image = coreJbig2.Jbig2Image;
 var JpegImage = coreJpg.JpegImage;
 var JpxImage = coreJpx.JpxImage;
 
-var coreColorSpace; // see _setCoreColorSpace below
-var ColorSpace; // = coreColorSpace.ColorSpace;
-
 var Stream = (function StreamClosure() {
   function Stream(arrayBuffer, start, length, dict) {
     this.bytes = (arrayBuffer instanceof Uint8Array ?
@@ -962,25 +959,6 @@ var JpegStream = (function JpegStreamClosure() {
   JpegStream.prototype.getIR = function JpegStream_getIR(forceDataSchema) {
     return createObjectURL(this.bytes, 'image/jpeg', forceDataSchema);
   };
-  /**
-   * Checks if the image can be decoded and displayed by the browser without any
-   * further processing such as color space conversions.
-   */
-  JpegStream.prototype.isNativelySupported =
-      function JpegStream_isNativelySupported(xref, res) {
-    var cs = ColorSpace.parse(this.dict.get('ColorSpace', 'CS'), xref, res);
-    return (cs.name === 'DeviceGray' || cs.name === 'DeviceRGB') &&
-           cs.isDefaultDecode(this.dict.get('Decode', 'D'));
-  };
-  /**
-   * Checks if the image can be decoded by the browser.
-   */
-  JpegStream.prototype.isNativelyDecodable =
-      function JpegStream_isNativelyDecodable(xref, res) {
-    var cs = ColorSpace.parse(this.dict.get('ColorSpace', 'CS'), xref, res);
-    return (cs.numComps === 1 || cs.numComps === 3) &&
-           cs.isDefaultDecode(this.dict.get('Decode', 'D'));
-  };
 
   return JpegStream;
 })();
@@ -2500,13 +2478,6 @@ var NullStream = (function NullStreamClosure() {
   return NullStream;
 })();
 
-// TODO refactor to remove dependency on colorspace.js
-function _setCoreColorSpace(coreColorSpace_) {
-  coreColorSpace = coreColorSpace_;
-  ColorSpace = coreColorSpace_.ColorSpace;
-}
-exports._setCoreColorSpace = _setCoreColorSpace;
-
 exports.Ascii85Stream = Ascii85Stream;
 exports.AsciiHexStream = AsciiHexStream;
 exports.CCITTFaxStream = CCITTFaxStream;