From 3af64d3f451d1023934f2040b7f3a1e30cf99a2b Mon Sep 17 00:00:00 2001
From: jdescottes <julian.descottes@gmail.com>
Date: Fri, 15 Nov 2013 00:32:18 +0100
Subject: [PATCH] feature : zoom level : code review

+ added explanatory comment for CanvasUtils.disableImageSmoothing
+ detect browser for chosing wheel/mousewheel event in DrawingController
+ create ABSTRACT_FUNCTION constant to be reused forabstract methods
---
 js/Constants.js                    |  4 +++-
 js/controller/DrawingController.js |  8 ++++++--
 js/rendering/AbstractRenderer.js   | 22 +++++++++++-----------
 js/utils/CanvasUtils.js            |  7 +++++++
 4 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/js/Constants.js b/js/Constants.js
index 294d347f..1b7f8569 100644
--- a/js/Constants.js
+++ b/js/Constants.js
@@ -50,5 +50,7 @@ var Constants = {
 
   LEFT_BUTTON : 'left_button_1',
   RIGHT_BUTTON : 'right_button_2',
-  MOUSEMOVE_THROTTLING : 10
+  MOUSEMOVE_THROTTLING : 10,
+
+  ABSTRACT_FUNCTION : function () {throw 'abstract method should be implemented';}
 };
\ No newline at end of file
diff --git a/js/controller/DrawingController.js b/js/controller/DrawingController.js
index 417e0b44..f4eb5ba4 100644
--- a/js/controller/DrawingController.js
+++ b/js/controller/DrawingController.js
@@ -81,8 +81,12 @@
     var body = $('body');
     this.container.mousedown($.proxy(this.onMousedown_, this));
     this.container.mousemove($.proxy(this.onMousemove_, this));
-    this.container.on('mousewheel', $.proxy(this.onMousewheel_, this));
-    this.container.on('wheel', $.proxy(this.onMousewheel_, this));
+
+    if (pskl.utils.UserAgent.isChrome) {
+      this.container.on('mousewheel', $.proxy(this.onMousewheel_, this));
+    } else {
+      this.container.on('wheel', $.proxy(this.onMousewheel_, this));
+    }
 
     body.mouseup($.proxy(this.onMouseup_, this));
 
diff --git a/js/rendering/AbstractRenderer.js b/js/rendering/AbstractRenderer.js
index a3539402..6254ee39 100644
--- a/js/rendering/AbstractRenderer.js
+++ b/js/rendering/AbstractRenderer.js
@@ -3,20 +3,20 @@
 
   ns.AbstractRenderer = function () {};
 
-  ns.AbstractRenderer.prototype.clear =          function ()       {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.clear = Constants.ABSTRACT_FUNCTION;
 
-  ns.AbstractRenderer.prototype.getCoordinates = function (x, y)   {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.getCoordinates = Constants.ABSTRACT_FUNCTION;
 
-  ns.AbstractRenderer.prototype.setGridEnabled = function (b)      {throw 'abstract method should be implemented';};
-  ns.AbstractRenderer.prototype.isGridEnabled =  function ()       {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.setGridEnabled = Constants.ABSTRACT_FUNCTION;
+  ns.AbstractRenderer.prototype.isGridEnabled =  Constants.ABSTRACT_FUNCTION;
 
-  ns.AbstractRenderer.prototype.setZoom =        function (zoom)   {throw 'abstract method should be implemented';};
-  ns.AbstractRenderer.prototype.getZoom =        function ()       {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.setZoom = Constants.ABSTRACT_FUNCTION;
+  ns.AbstractRenderer.prototype.getZoom = Constants.ABSTRACT_FUNCTION;
 
-  ns.AbstractRenderer.prototype.moveOffset =     function (x, y)   {throw 'abstract method should be implemented';};
-  ns.AbstractRenderer.prototype.setOffset =      function (x, y)   {throw 'abstract method should be implemented';};
-  ns.AbstractRenderer.prototype.getOffset =      function ()       {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.moveOffset = Constants.ABSTRACT_FUNCTION;
+  ns.AbstractRenderer.prototype.setOffset = Constants.ABSTRACT_FUNCTION;
+  ns.AbstractRenderer.prototype.getOffset = Constants.ABSTRACT_FUNCTION;
 
-  ns.AbstractRenderer.prototype.setDisplaySize = function (w, h)   {throw 'abstract method should be implemented';};
-  ns.AbstractRenderer.prototype.getDisplaySize = function ()       {throw 'abstract method should be implemented';};
+  ns.AbstractRenderer.prototype.setDisplaySize = Constants.ABSTRACT_FUNCTION;
+  ns.AbstractRenderer.prototype.getDisplaySize = Constants.ABSTRACT_FUNCTION;
 })();
\ No newline at end of file
diff --git a/js/utils/CanvasUtils.js b/js/utils/CanvasUtils.js
index 19cca6b3..be3e041d 100644
--- a/js/utils/CanvasUtils.js
+++ b/js/utils/CanvasUtils.js
@@ -19,6 +19,13 @@
       return canvas;
     },
 
+    /**
+     * By default, all scaling operations on a Canvas 2D Context are performed using antialiasing.
+     * Resizing a 32x32 image to 320x320 will lead to a blurry output.
+     * On Chrome, FF and IE>=11, this can be disabled by setting a property on the Canvas 2D Context.
+     * In this case the browser will use a nearest-neighbor scaling.
+     * @param  {Canvas} canvas
+     */
     disableImageSmoothing : function (canvas) {
       var context = canvas.getContext('2d');
       context.imageSmoothingEnabled = false;