lib/Ext/Component.js
function(animation) {
        if(this.activeAnimation) {
            this.activeAnimation.on({
                animationend: function(){
                    this.show(animation);
                },
                scope: this,
                single: true
            });
            return this;
        }

        var hidden = this.getHidden();
        if (hidden || hidden === null) {
            if (animation === true) {
                animation = 'fadeIn';
            }
            else if (animation === undefined || (animation && animation.isComponent)) {
                animation = this.getShowAnimation();
            }

            if (animation) {
                this.beforeShowAnimation();
                this.onBefore({
                    hiddenchange: 'animateFn',
                    scope: this,
                    single: true,
                    args: [animation]
                });
            }

            this.setHidden(false);
        }

        return this;
    }
function(animation) {
        if(this.activeAnimation) {
            this.activeAnimation.on({
                animationend: function(){
                    this.show(animation);
                },
                scope: this,
                single: true
            });
            return this;
        }

        var hidden = this.getHidden();
        if (hidden || hidden === null) {
            if (animation === true) {
                animation = 'fadeIn';
            }
            else if (animation === undefined || (animation && animation.isComponent)) {
                animation = this.getShowAnimation();
            }

            if (animation) {
                this.beforeShowAnimation();
                this.onBefore({
                    hiddenchange: 'animateFn',
                    scope: this,
                    single: true,
                    args: [animation]
                });
            }

            this.setHidden(false);
        }

        return this;
    }
Shows this component optionally using an animation.
@param {Object/Boolean} [animation] You can specify an animation here or a bool to use the {@link #showAnimation} config.
@return {Ext.Component}
@chainable