[api-minor] Adds additional parameter so background color of canvas can be set

src/display/api.js

@@ -717,6 +717,11 @@ var PDFDocumentProxy = (function PDFDocumentProxyClosure() {
  * @property {Object} canvasFactory - (optional) The factory that will be used
  *                    when creating canvases. The default value is
  *                    {DOMCanvasFactory}.
+ * @property {Object} background - (optional) Background to use for the canvas.
+ *                    Can use any valid canvas.fillStyle: A DOMString parsed as
+ *                    CSS <color> value, a CanvasGradient object (a linear or
+ *                    radial gradient) or a CanvasPattern object (a repetitive
+ *                    image). The default value is 'rgb(255,255,255)'.
  */
 
 /**
@@ -2128,7 +2133,12 @@ var InternalRenderTask = (function InternalRenderTaskClosure() {
                                     this.objs, this.canvasFactory,
                                     params.imageLayer);
 
-      this.gfx.beginDrawing(params.transform, params.viewport, transparency);
+      this.gfx.beginDrawing({
+        transform: params.transform,
+        viewport: params.viewport,
+        transparency,
+        background: params.background,
+      });
       this.operatorListIdx = 0;
       this.graphicsReady = true;
       if (this.graphicsReadyCallback) {

src/display/canvas.js

@@ -705,8 +705,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
   CanvasGraphics.prototype = {
 
-    beginDrawing: function CanvasGraphics_beginDrawing(transform, viewport,
-                                                       transparency) {
+    beginDrawing({ transform, viewport, transparency,
+                   background = null, }) {
       // For pdfs that use blend modes we have to clear the canvas else certain
       // blend modes can look wrong since we'd be blending with a white
       // backdrop. The problem with a transparent backdrop though is we then
@@ -716,7 +716,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       var height = this.ctx.canvas.height;
 
       this.ctx.save();
-      this.ctx.fillStyle = 'rgb(255, 255, 255)';
+      this.ctx.fillStyle = background || 'rgb(255, 255, 255)';
       this.ctx.fillRect(0, 0, width, height);
       this.ctx.restore();
 

test/pdfs/.gitignore

@@ -280,3 +280,4 @@
 !issue7878.pdf
 !font_ascent_descent.pdf
 !issue8097_reduced.pdf
+!transparent.pdf

test/unit/api_spec.js

@@ -13,6 +13,9 @@
  * limitations under the License.
  */
 
+import {
+  buildGetDocumentParams, NodeFileReaderFactory, TEST_PDFS_PATH
+} from './test_utils';
 import {
   createPromiseCapability, FontType, InvalidPDFException, isNodeJS,
   MissingPDFException, PasswordException, PasswordResponses, StreamType,
@@ -24,29 +27,8 @@ import {
 import {
   getDocument, PDFDocumentProxy, PDFPageProxy
 } from '../../src/display/api';
-import { NodeFileReaderFactory } from './test_utils';
 import { PDFJS } from '../../src/display/global';
 
-const TEST_PDFS_PATH = {
-  dom: '../pdfs/',
-  node: './test/pdfs/',
-};
-
-function buildGetDocumentParams(filename, options) {
-  let params = Object.create(null);
-  if (isNodeJS()) {
-    params.data = NodeFileReaderFactory.fetch({
-      path: TEST_PDFS_PATH.node + filename,
-    });
-  } else {
-    params.url = new URL(TEST_PDFS_PATH.dom + filename, window.location).href;
-  }
-  for (let option in options) {
-    params[option] = options[option];
-  }
-  return params;
-}
-
 describe('api', function() {
   let basicApiFileName = 'basicapi.pdf';
   let basicApiFileLength = 105779; // bytes

test/unit/custom_spec.js

@@ -0,0 +1,110 @@
+/* Copyright 2017 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { buildGetDocumentParams } from './test_utils';
+import { DOMCanvasFactory } from '../../src/display/dom_utils';
+import { getDocument } from '../../src/display/api';
+import { isNodeJS } from '../../src/shared/util';
+import { PDFJS } from '../../src/display/global';
+
+function getTopLeftPixel(canvasContext) {
+  let imgData = canvasContext.getImageData(0, 0, 1, 1);
+  return {
+    r: imgData.data[0],
+    g: imgData.data[1],
+    b: imgData.data[2],
+    a: imgData.data[3],
+  };
+}
+
+describe('custom canvas rendering', function() {
+  let transparentGetDocumentParams = buildGetDocumentParams('transparent.pdf');
+
+  let CanvasFactory;
+  let loadingTask;
+  let page;
+
+  beforeAll(function(done) {
+    if (isNodeJS()) {
+      PDFJS.pdfjsNext = true;
+      // NOTE: To support running the canvas-related tests in Node.js,
+      // a `NodeCanvasFactory` would need to be added (in test_utils.js).
+    } else {
+      CanvasFactory = new DOMCanvasFactory();
+    }
+    loadingTask = getDocument(transparentGetDocumentParams);
+    loadingTask.promise.then(function(doc) {
+      return doc.getPage(1);
+    }).then(function(data) {
+      page = data;
+      done();
+    }).catch(function (reason) {
+      done.fail(reason);
+    });
+  });
+
+  afterAll(function(done) {
+    CanvasFactory = null;
+    page = null;
+    loadingTask.destroy().then(done);
+  });
+
+  it('renders to canvas with a default white background', function(done) {
+    if (isNodeJS()) {
+      pending('TODO: Support Canvas testing in Node.js.');
+    }
+    var viewport = page.getViewport(1);
+    var canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
+
+    page.render({
+      canvasContext: canvasAndCtx.context,
+      viewport,
+    }).then(function() {
+      var { r, g, b, a } = getTopLeftPixel(canvasAndCtx.context);
+      CanvasFactory.destroy(canvasAndCtx);
+      expect(r).toEqual(255);
+      expect(g).toEqual(255);
+      expect(b).toEqual(255);
+      expect(a).toEqual(255);
+      done();
+    }).catch(function (reason) {
+      done(reason);
+    });
+  });
+
+  it('renders to canvas with a custom background', function(done) {
+    if (isNodeJS()) {
+      pending('TODO: Support Canvas testing in Node.js.');
+    }
+    var viewport = page.getViewport(1);
+    var canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
+
+    page.render({
+      canvasContext: canvasAndCtx.context,
+      viewport,
+      background: 'rgba(255,0,0,1.0)'
+    }).then(function() {
+      var { r, g, b, a } = getTopLeftPixel(canvasAndCtx.context);
+      CanvasFactory.destroy(canvasAndCtx);
+      expect(r).toEqual(255);
+      expect(g).toEqual(0);
+      expect(b).toEqual(0);
+      expect(a).toEqual(255);
+      done();
+    }).catch(function (reason) {
+      done(reason);
+    });
+  });
+});

test/unit/jasmine-boot.js

@@ -52,7 +52,8 @@ function initializePDFJS(callback) {
     'pdfjs-test/unit/network_spec', 'pdfjs-test/unit/parser_spec',
     'pdfjs-test/unit/primitives_spec', 'pdfjs-test/unit/stream_spec',
     'pdfjs-test/unit/type1_parser_spec', 'pdfjs-test/unit/ui_utils_spec',
-    'pdfjs-test/unit/unicode_spec', 'pdfjs-test/unit/util_spec'
+    'pdfjs-test/unit/unicode_spec', 'pdfjs-test/unit/util_spec',
+    'pdfjs-test/unit/custom_spec'
   ].map(function (moduleName) {
     return SystemJS.import(moduleName);
   })).then(function (modules) {

test/unit/test_utils.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { CMapCompressionType } from '../../src/shared/util';
+import { CMapCompressionType, isNodeJS } from '../../src/shared/util';
 
 class NodeFileReaderFactory {
   static fetch(params) {
@@ -23,6 +23,26 @@ class NodeFileReaderFactory {
   }
 }
 
+const TEST_PDFS_PATH = {
+  dom: '../pdfs/',
+  node: './test/pdfs/',
+};
+
+function buildGetDocumentParams(filename, options) {
+  let params = Object.create(null);
+  if (isNodeJS()) {
+    params.data = NodeFileReaderFactory.fetch({
+      path: TEST_PDFS_PATH.node + filename,
+    });
+  } else {
+    params.url = new URL(TEST_PDFS_PATH.dom + filename, window.location).href;
+  }
+  for (let option in options) {
+    params[option] = options[option];
+  }
+  return params;
+}
+
 class NodeCMapReaderFactory {
   constructor({ baseUrl = null, isCompressed = false, }) {
     this.baseUrl = baseUrl;
@@ -57,4 +77,6 @@ class NodeCMapReaderFactory {
 export {
   NodeFileReaderFactory,
   NodeCMapReaderFactory,
+  buildGetDocumentParams,
+  TEST_PDFS_PATH,
 };