Diverting your thoughts to something different from gambling is not a permanent solution but only a short term solution that you might not be capable of doing someday when the desperate to gamble increase more. What you should be capable of doing is to not gamble at all regardless of not doing anything else. Learn to say no to gambling and train your body to not allow it get to a stage that when ever you see gambling activities going on, you want to participate too. Prevention of addiction can be done by controlling how you gamble for people that are already into gambling. Controlling your gambling schedules will help reduce how long you gamble and how much that you are losing and this can help prevent gambling addiction too.
Directing your thoughts to healthier activities can help reduce this splash of chemicals in your brain that drive someone to gambling excessively. Now you you are saying learn not to gamble and train your mind not to gamble, how do you train that mind? One of practical ways is try doing other healthy activities, train your mind to focus on other healthy stuff, so you could get yourself busy and reduce your time and thought of gambling that is how you train your mind.
You said learn to train your mind with something else and control your gambling but how? For you to be able to control your gambling means you are doing something that is taking up your time so instead of showing up everyday, you show up on weekends and you play limited game because you've been actively working on something else better than gambling that is maybe a better form of investment for you.