Mouse Wheel zooming

Related #217

app/Application.js

@@ -128,6 +128,22 @@ Ext.define('Rambox.Application', {
 			]
 		});
 
+		// Mouse Wheel zooming
+		document.addEventListener('mousewheel', function(e) {
+			if( e.ctrlKey ) {
+				var delta = Math.max(-1, Math.min(1, (e.wheelDelta || -e.detail)));
+
+				var tabPanel = Ext.cq1('app-main');
+				if ( tabPanel.items.indexOf(tabPanel.getActiveTab()) === 0 ) return false;
+
+				if ( delta === 1 ) { // Zoom In
+					tabPanel.getActiveTab().zoomIn();
+				} else { // Zoom Out
+					tabPanel.getActiveTab().zoomOut();
+				}
+			}
+		});
+
 		if ( process.platform !== 'win32' ) {
 			this.checkUpdate(true);
 		}