The ornamental design for a case with buttons, as shown and described.
FIG. 1 is an isometric view of the case with buttons showing our new design.
FIG. 2 is an enlarged isometric view of the encircled portion shown in FIG. 1.
FIG. 3 is an enlarged left side view thereof.
FIG. 4 is an enlarged front view thereof.
FIG. 5 is an enlarged rear view thereof.
FIG. 6 is an enlarged top view thereof; and,
FIG. 7 is an enlarged bottom view thereof.
The broken lines immediately adjacent shaded surfaces represent boundaries of the claimed design. The dot-dash broken lines enclose portions of the claimed design shown on an enlarged scale. All other broken lines depict unclaimed environmental subject matter. All broken lines form no part of the claimed design.