starting canvas module

app/view/canvas.js

@@ -0,0 +1,28 @@
+let EventEmitter = require('events').EventEmitter
+
+class Canvas extends EventEmitter {
+
+  constructor (options) {
+    super()
+
+    this.options = Object.assign({
+      // fitWidth, fitWindow, manua
+      zoomMode: 'fitWidth',
+      // ltr, rtl
+      readDirection: 'ltr'
+    }, options)
+
+    this.canvas = document.createElement('canvas')
+    this.context = this.canvas.getContext('2d')
+  }
+
+  draw (image, doublePage, image2) {
+    if (!(image instanceof window.Image) || (doublePage && !(image2 instanceof window.Image))) {
+      throw new Error('Invalid image')
+    }
+
+    this.emit('draw')
+  }
+}
+
+module.exports = Canvas