Does PIC16F84A has TIMER0 interrupt? How to use with button?

I wanna connect my 8LEDs in the PORTB of the PIC then a button in any PORTA pins. I'll use the button to change the pattern of the blinking. How to do this in timer interrupt? Is it possible for the TMR0 to check the status of the button, if it was pressed then change the pattern? Say, I have four patterns.