From 2ccb1a98cad08bba6e2bb63f21b44377ec49ceb4 Mon Sep 17 00:00:00 2001
From: Gui Meira <guimeira@guimeira.com>
Date: Wed, 25 Jun 2014 19:17:59 -0300
Subject: [PATCH] Added the wheelSensitivity initialisation option

---
 documentation/md/core/init.md                         | 3 +++
 src/core.js                                           | 4 +++-
 src/extensions/renderer.canvas.define-and-init-etc.js | 1 +
 src/extensions/renderer.canvas.load-and-listeners.js  | 1 +
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/documentation/md/core/init.md b/documentation/md/core/init.md
index 4268e900b..eadc480d6 100644
--- a/documentation/md/core/init.md
+++ b/documentation/md/core/init.md
@@ -114,6 +114,7 @@ cytoscape({
   hideEdgesOnViewport: false,
   hideLabelsOnViewport: false,
   textureOnViewport: false,
+  wheelSensitivity: 1,
   renderer: { /* ... */ },
   style: undefined /* ... */,
   styleEnabled: isHeadless ? false : true,
@@ -148,6 +149,8 @@ cytoscape({
 
 **`textureOnViewport`** : When set to `true`, the renderer uses a texture (if supported) during panning and zooming instead of drawing the elements, making large graphs more responsive.
 
+**`wheelSensitivity`** : Changes the scroll wheel sensitivity when zooming. A value between 0 and 1 reduces the sensitivity (zooms slower), a value greater than 1 does the oposite.
+
 **`renderer`** : A plain object containing options for the renderer to be used.  The `options.renderer.name` field specifies which renderer is used.  You need not specify anything for the `renderer` option, unless you want to specify one of the rendering options below:
 
 * **`renderer.name`** : The name of the renderer to use.  By default, the `'canvas'` renderer is used.  If you [build and register](#extensions) your own renderer, then you can specify its name here.
diff --git a/src/core.js b/src/core.js
index 53493edee..784d6f255 100644
--- a/src/core.js
+++ b/src/core.js
@@ -118,7 +118,8 @@
     cy.initRenderer( $$.util.extend({
       hideEdgesOnViewport: options.hideEdgesOnViewport,
       hideLabelsOnViewport: options.hideLabelsOnViewport,
-      textureOnViewport: options.textureOnViewport
+      textureOnViewport: options.textureOnViewport,
+      wheelSensitivity: $$.is.number(options.wheelSensitivity) && options.wheelSensitivity > 0 ? options.wheelSensitivity : 1
     }, options.renderer) );
 
     // trigger the passed function for the `initrender` event
@@ -292,6 +293,7 @@
       json.hideEdgesOnViewport = cy._private.options.hideEdgesOnViewport;
       json.hideLabelsOnViewport = cy._private.options.hideLabelsOnViewport;
       json.textureOnViewport = cy._private.options.textureOnViewport;
+      json.wheelSensitivity = cy._private.options.wheelSensitivity;
       
       return json;
     }
diff --git a/src/extensions/renderer.canvas.define-and-init-etc.js b/src/extensions/renderer.canvas.define-and-init-etc.js
index 3c6476260..60aa61c5d 100644
--- a/src/extensions/renderer.canvas.define-and-init-etc.js
+++ b/src/extensions/renderer.canvas.define-and-init-etc.js
@@ -97,6 +97,7 @@
     this.hideEdgesOnViewport = options.hideEdgesOnViewport;
     this.hideLabelsOnViewport = options.hideLabelsOnViewport;
     this.textureOnViewport = options.textureOnViewport;
+    this.wheelSensitivity = options.wheelSensitivity;
 
     this.load();
   }
diff --git a/src/extensions/renderer.canvas.load-and-listeners.js b/src/extensions/renderer.canvas.load-and-listeners.js
index 240417a3f..4e05ad007 100644
--- a/src/extensions/renderer.canvas.load-and-listeners.js
+++ b/src/extensions/renderer.canvas.load-and-listeners.js
@@ -866,6 +866,7 @@
         }, 150);
       
         var diff = e.wheelDeltaY / 1000 || e.wheelDelta / 1000 || e.detail / -32 || -e.deltaY / 500;
+        diff = diff * r.wheelSensitivity;
 
         cy.zoom({
           level: cy.zoom() * Math.pow(10, diff),