adding draw page methods, preparing double page mode

app/comic-book.js

@@ -5,9 +5,15 @@ let ProgressBar = require('./view/progress-bar')
 
 class ComicBook extends EventEmitter {
 
-  constructor (srcs = []) {
+  constructor (srcs = [], options) {
     super()
 
+    this.options = Object.assign({
+      // manga mode
+      rtl: false,
+      doublePage: false
+    }, options)
+
     // requested image srcs
     this.srcs = srcs
 
@@ -72,17 +78,32 @@ class ComicBook extends EventEmitter {
     this.progressBar.update(percentage)
   }
 
-  drawPage () {
-    let page = this.pages.get(this.currentPageIndex)
+  drawPage (pageIndex) {
+    if (typeof pageIndex !== 'number') pageIndex = this.currentPageIndex
+    let page = this.pages.get(pageIndex)
+
+    try {
       this.canvas.drawImage(page)
+      this.currentPageIndex = pageIndex
+    } catch (e) {
+      if (e.message !== 'Invalid image') throw e
+    }
   }
 
   drawNextPage () {
-    // TODO
+    let increment = this.options.doublePage ? 2 : 1
+    let index = this.currentPageIndex + increment
+    if (index >= this.pages.size) {
+      index = this.pages.size - 1
+    }
+    this.drawPage(index)
   }
 
-  drawPrevioousPage () {
-    // TODO
+  drawPreviousPage () {
+    let increment = this.options.doublePage ? 2 : 1
+    let index = this.currentPageIndex - increment
+    if (index < 0) index = 0
+    this.drawPage(index)
   }
 }
 

app/index.js

@@ -1,5 +1,5 @@
 let ComicBook = window.ComicBook = require('./comic-book')
-let comic = new ComicBook([
+let comic = window.comic = new ComicBook([
   'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_00.jpg',
   'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_01.jpg',
   'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_02.jpg',
@@ -13,8 +13,10 @@ let comic = new ComicBook([
   'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_10.jpg'
 ])
 
+comic.preload()
+comic.render()
+
 document.addEventListener('DOMContentLoaded', () => {
-  document.body.appendChild(comic.render().el)
-  comic.preload()
+  document.body.appendChild(comic.el)
 }, false)
 

app/view/canvas.js

@@ -13,8 +13,8 @@ class Canvas extends EventEmitter {
     this.options = Object.assign({
       // fitWidth, fitWindow, manua
       zoomMode: 'fitWidth',
-      // ltr, rtl
-      readDirection: 'ltr',
+      // manga mode
+      rtl: false,
       // should two pages be rendered at a time?
       doublePage: false
     }, options)
@@ -126,7 +126,7 @@ class Canvas extends EventEmitter {
     }
 
     // in manga double page mode reverse the page(s)
-    if (this.options.manga && this.options.doublePage && typeof page2 === 'object') {
+    if (this.options.rtl && this.options.doublePage && typeof page2 === 'object') {
       let tmpPage = page
       let tmpPage2 = page2
       page = tmpPage2

dist/comicbook.js

@@ -9,6 +9,8 @@ var _createClass = require('babel-runtime/helpers/create-class')['default'];
 
 var _classCallCheck = require('babel-runtime/helpers/class-call-check')['default'];
 
+var _Object$assign = require('babel-runtime/core-js/object/assign')['default'];
+
 var _Map = require('babel-runtime/core-js/map')['default'];
 
 var EventEmitter = require('events').EventEmitter;
@@ -19,22 +21,30 @@ var ProgressBar = require('./view/progress-bar');
 var ComicBook = (function (_EventEmitter) {
   _inherits(ComicBook, _EventEmitter);
 
-  function ComicBook() {
-    var srcs = arguments.length <= 0 || arguments[0] === undefined ? [] : arguments[0];
+  function ComicBook(srcs, options) {
+    if (srcs === undefined) srcs = [];
 
     _classCallCheck(this, ComicBook);
 
     _get(Object.getPrototypeOf(ComicBook.prototype), 'constructor', this).call(this);
 
+    this.options = _Object$assign({
+      // manga mode
+      rtl: false,
+      doublePage: false
+    }, options);
+
     // requested image srcs
     this.srcs = srcs;
 
     // loaded image objects
     this.pages = new _Map();
 
-    this.currentPageIndex = 0;
     this.preloadBuffer = 4;
 
+    // TODO move this logic into the router
+    this.currentPageIndex = 0;
+
     this.canvas = new Canvas();
     this.loadIndicator = new LoadIndicator();
     this.progressBar = new ProgressBar();
@@ -96,9 +106,34 @@ var ComicBook = (function (_EventEmitter) {
     }
   }, {
     key: 'drawPage',
-    value: function drawPage() {
-      var page = this.pages.get(this.currentPageIndex);
+    value: function drawPage(pageIndex) {
+      if (typeof pageIndex !== 'number') pageIndex = this.currentPageIndex;
+      var page = this.pages.get(pageIndex);
+
+      try {
         this.canvas.drawImage(page);
+        this.currentPageIndex = pageIndex;
+      } catch (e) {
+        if (e.message !== 'Invalid image') throw e;
+      }
+    }
+  }, {
+    key: 'drawNextPage',
+    value: function drawNextPage() {
+      var increment = this.options.doublePage ? 2 : 1;
+      var index = this.currentPageIndex + increment;
+      if (index >= this.pages.size) {
+        index = this.pages.size - 1;
+      }
+      this.drawPage(index);
+    }
+  }, {
+    key: 'drawPreviousPage',
+    value: function drawPreviousPage() {
+      var increment = this.options.doublePage ? 2 : 1;
+      var index = this.currentPageIndex - increment;
+      if (index < 0) index = 0;
+      this.drawPage(index);
     }
   }]);
 
@@ -107,15 +142,17 @@ var ComicBook = (function (_EventEmitter) {
 
 module.exports = ComicBook;
 
-},{"./view/canvas":3,"./view/load-indicator":4,"./view/progress-bar":5,"babel-runtime/core-js/map":7,"babel-runtime/helpers/class-call-check":12,"babel-runtime/helpers/create-class":13,"babel-runtime/helpers/get":14,"babel-runtime/helpers/inherits":15,"events":53}],2:[function(require,module,exports){
+},{"./view/canvas":3,"./view/load-indicator":4,"./view/progress-bar":5,"babel-runtime/core-js/map":7,"babel-runtime/core-js/object/assign":8,"babel-runtime/helpers/class-call-check":12,"babel-runtime/helpers/create-class":13,"babel-runtime/helpers/get":14,"babel-runtime/helpers/inherits":15,"events":53}],2:[function(require,module,exports){
 'use strict';
 
 var ComicBook = window.ComicBook = require('./comic-book');
-var comic = new ComicBook(['https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_00.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_01.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_02.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_03.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_04.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_05.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_06.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_07.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_08.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_09.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_10.jpg']);
+var comic = window.comic = new ComicBook(['https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_00.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_01.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_02.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_03.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_04.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_05.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_06.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_07.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_08.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_09.jpg', 'https://raw.githubusercontent.com/balaclark/HTML5-Comic-Book-Reader/master/examples/goldenboy/goldenboy_10.jpg']);
+
+comic.preload();
+comic.render();
 
 document.addEventListener('DOMContentLoaded', function () {
-  document.body.appendChild(comic.render().el);
-  comic.preload();
+  document.body.appendChild(comic.el);
 }, false);
 
 },{"./comic-book":1}],3:[function(require,module,exports){
@@ -149,8 +186,8 @@ var Canvas = (function (_EventEmitter) {
     this.options = _Object$assign({
       // fitWidth, fitWindow, manua
       zoomMode: 'fitWidth',
-      // ltr, rtl
-      readDirection: 'ltr',
+      // manga mode
+      rtl: false,
       // should two pages be rendered at a time?
       doublePage: false
     }, options);
@@ -261,7 +298,7 @@ var Canvas = (function (_EventEmitter) {
       }
 
       // in manga double page mode reverse the page(s)
-      if (this.options.manga && this.options.doublePage && typeof page2 === 'object') {
+      if (this.options.rtl && this.options.doublePage && typeof page2 === 'object') {
         var tmpPage = page;
         var tmpPage2 = page2;
         page = tmpPage2;

test/comic-book.test.js

@@ -95,8 +95,176 @@ describe('ComicBook', () => {
         done()
       })
     })
+
+    it('should restart the preload from whatever page is requested')
   })
 
+  describe('draw', () => {
+
+    describe('drawPage()', () => {
+
+      it('should draw a given page', () => {
+        let comic = new ComicBook(srcs)
+
+        comic.canvas.drawImage = spy()
+
+        comic.drawPage(1)
+
+        assert.equal(comic.canvas.drawImage.callCount, 1)
+        assert(comic.canvas.drawImage.calls[0].calledWith(comic.pages.get(1)))
+      })
+
+      it('should default to drawing the current page', () => {
+        let comic = new ComicBook(srcs)
+
+        comic.canvas.drawImage = spy()
+        comic.currentPageIndex = 2
+
+        comic.drawPage()
+
+        assert.equal(comic.canvas.drawImage.callCount, 1)
+        assert(comic.canvas.drawImage.calls[0].calledWith(comic.pages.get(2)))
+      })
+
+      it('should update the current page index after drawing', () => {
+        let comic = new ComicBook(srcs)
+
+        comic.canvas.drawImage = () => {}
+        comic.currentPageIndex = 1
+
+        comic.drawPage(2)
+
+        assert.equal(comic.currentPageIndex, 2)
+      })
+
+      it('should ignore "Invalid image" exceptions and not draw the page when they occur', () => {
+        let comic = new ComicBook(srcs)
+
+        comic.currentPageIndex = 1
+
+        assert.doesNotThrow(comic.drawPage.bind(comic, 666))
+        assert.equal(comic.currentPageIndex, 1)
+      })
+
+      it('should throw all other exceptions and not draw the page when they occur', () => {
+        let comic = new ComicBook(srcs)
+
+        comic.canvas.drawImage = () => { throw new Error('Some other exception') }
+
+        assert.throws(comic.drawPage.bind(comic))
+      })
+
+      it('should draw two pages in double page mode')
+    })
+
+    describe('drawNextPage()', () => {
+
+      it('should draw the next page', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 1
+
+        comic.on('preload:finish', () => {
+          comic.drawNextPage()
+          assert(comic.drawPage.calls[0].calledWith(2))
+          done()
+        })
+
+        comic.preload()
+      })
+
+      it('should draw the next page in double page mode', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 1
+        comic.options.doublePage = true
+
+        comic.on('preload:finish', () => {
+          comic.drawNextPage()
+          assert(comic.drawPage.calls[0].calledWith(3))
+          done()
+        })
+
+        comic.preload()
+      })
+
+      it('should handle the final page of double page mode being a single page', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 3
+        comic.options.doublePage = true
+
+        comic.on('preload:finish', () => {
+          comic.drawNextPage()
+          assert(comic.drawPage.calls[0].calledWith(4))
+          done()
+        })
+
+        comic.preload()
+      })
+    })
+
+    describe('drawPreviousPage()', () => {
+
+      it('should draw the previous page', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 2
+
+        comic.on('preload:finish', () => {
+          comic.drawPreviousPage()
+          assert(comic.drawPage.calls[0].calledWith(1))
+          done()
+        })
+
+        comic.preload()
+      })
+
+      it('should draw the previous page in double page mode', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 3
+        comic.options.doublePage = true
+
+        comic.on('preload:finish', () => {
+          comic.drawPreviousPage()
+          assert(comic.drawPage.calls[0].calledWith(1))
+          done()
+        })
+
+        comic.preload()
+      })
+
+      it('should handle navigating back to an uneven first page in double page mode', done => {
+        let comic = new ComicBook(srcs)
+
+        comic.drawPage = spy()
+        comic.currentPageIndex = 1
+        comic.options.doublePage = true
+
+        comic.on('preload:finish', () => {
+          comic.drawPreviousPage()
+          assert(comic.drawPage.calls[0].calledWith(0))
+          done()
+        })
+
+        comic.preload()
+      })
+
+      it('should reverse image order in double page manga mode')
+    })
+  })
+
+  describe('routing', () => {
+
     it('should scroll to the top of the page on page turn')
 
+    it('should render a page when the route changes')
+  })
+
 })