Only trigger proximity detector when object enters the range, not when he moves within range

Question

I'm making a text-based radar for Minecraft. If a player comes within 20 blocks of you, it will say in chat. As of now, it spams the chat. How can I get it to only write to chat about that player ONCE? Even if you don't play the game, it should be easy to understand. ``` if (Camb.radar) { for (Entity e: (List < Entity > ) mc.theWorld.loadedEntityList) { if (e instanceof EntityPlayer) { EntityPlayer player = (EntityPlayer) e; if (player == mc.thePlayer || mc.thePlayer.getDistanceToEntity(e) > 20.0) continue; mc.thePlayer.addChatMessage("\2479[CAMB] \247e" + player.getEntityName() + " has entered your 20 block radius!"); //Write to chat, only want this line done once for every player } } } ```

Accepted Answer

You'll need to keep track of when the player leaves the range and set a flag, so you'll know when they're transitioning from "out of range" to "in range". Might also want to add a timer so that you can only alert once every N seconds.

Only trigger proximity detector when object enters the range, not when he moves within range

Solution

Problem