implement slider ball turn gray effect

Author: zilongshanren

extensions/ccui/base-classes/UIWidget.js

@@ -1692,6 +1692,14 @@ ccui.Widget = ccui.ProtectedNode.extend(/** @lends ccui.Widget# */{
         cc.arrayRemoveObject(this._nodes, node);
     },
 
+    _getNormalGLProgram: function () {
+        return cc.shaderCache.programForKey(cc.SHADER_SPRITE_POSITION_TEXTURECOLOR);
+    },
+
+    _getGrayGLProgram: function () {
+        return cc.shaderCache.programForKey(cc.SHADER_SPRITE_POSITION_TEXTURECOLOR_GRAY);
+    },
+
     /**
      * Removes node by tag
      * @deprecated since v3.0, please use removeChildByTag instead.

extensions/ccui/uiwidgets/UISlider.js

@@ -648,6 +648,7 @@ ccui.Slider = ccui.Widget.extend(/** @lends ccui.Slider# */{
         this._slidBallDisabledRenderer.setVisible(false);
 
         this._slidBallNormalRenderer.setScale(this._sliderBallNormalTextureScaleX, this._sliderBallNormalTextureScaleY);
+        this._slidBallNormalRenderer._renderCmd._shaderProgram = this._getNormalGLProgram();
     },
 
     _onPressStateChangedToPressed: function () {
@@ -658,12 +659,16 @@ ccui.Slider = ccui.Widget.extend(/** @lends ccui.Slider# */{
             this._slidBallPressedRenderer.setVisible(true);
             this._slidBallDisabledRenderer.setVisible(false);
         }
+        this._slidBallNormalRenderer._renderCmd._shaderProgram = this._getNormalGLProgram();
     },
 
     _onPressStateChangedToDisabled: function () {
         if (this._slidBallDisabledTextureFile) {
             this._slidBallNormalRenderer.setVisible(false);
             this._slidBallDisabledRenderer.setVisible(true);
+        } else {
+            this._slidBallNormalRenderer.setVisible(true);
+            this._slidBallNormalRenderer._renderCmd._shaderProgram = this._getGrayGLProgram();
         }
         this._slidBallNormalRenderer.setScale(this._sliderBallNormalTextureScaleX, this._sliderBallNormalTextureScaleY);
         this._slidBallPressedRenderer.setVisible(false);