Creating GUI on a click event only after a command has been issued?

I'm writing a plugin (my first) that will allow users to rotate a block with a series of commands and GUIs

Here's the idea that I have so far:

Command: /rotate
Return: [in chat] Right-click on a block you would like to rotate

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I have that command set with that feedback prompt being returned in chat
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User input: Selects block
Return: 9x9 InventoryGUI with three options for axes (X, Y Z)

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I have the GUI layout created... and that's about it. I don't know how to get a player to actually select a block. Also, I don't have all of the clickEvents written
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What I want to happen is that if a player wants to rotate a block, they would type in chat /rotate
They would get a return message in chat saying 'Right click on a block you would like to rotate'
After this event a player would right-click on a block and a GUI would pull up saying "Select an axis" with three options. I have the inventoryGUI layout completed, but that's about it. I was wondering how I might go about handling this. I know it's possible because plugins like LockettePro have something similar.

Here is a link to the source code: http://pastebin.com/XsxHn47s

Thanks in advance for any help.

 

You know, you can only rotate some of the blocks on the y axis (piston, stairs, hopper, etc.), not blocks like grass, stone etc.
And even fewer on the x/z axis (upside down stair/halfslab/piston, etc.). This sounds like a really complicated first plugin if you want to consider that all. I would highly recommend you to start with something simpler and work your way up.

 

When a player types /rotate, add them to an arraylist
PlayerInteractEvent:

• Check if the player is in the arraylist and if they are right clicking a block
• open the GUI
• remove them from the arraylist
• Add them to a hashmap with the block coordinates

InventoryCloseEvent:

• If the player is in the hashmap, remove them

Also, remember not to store the player object in the arraylist or the hashmap, store their UUID instead.