Show & hide graph buttons

Please help me for :-

• If I will click button named as Case 1 & Case 2 then only the graph names as Case 1 and Case 2 should be present and third one should be hidden or removed. In short which ever button is clicked only those graphs should be present.

• The color of the clicked button should get changed to its lighter/darker counterpart or some other color.

• If button case 1 and case 3 is clicked then the graph should be arranged automatically so that there should be no space between the two graphs, accordingly if only case 2 & case 3 buttons are clicked then both the graph should be moved to left.

• Is it possible to give a common legend for all the three graph centered at the bottom. if then please tell me how.

Below is the link for sample file