I'm trying to get certain parts of my custom inventory to display a tooltip when I hover over them with the mouse.  I want to be able to display the name, and then some info, just like if you hover over an item.  I have no idea how to do this, so any help will be appreciated.

Try to be more specific please,

Do you want to have an object in your gui that will display a tooltip when hovered over?

All code is already in the game, search for something as renderToolTip in GuiScreen or GuiContainer.

You can use Item's:

public void addInformation(ItemStack par1ItemStack, EntityPlayer par2EntityPlayer, List par3List, boolean par4)

To place text (or tooltips) you need to "add" a String to the list field.

I want a object in my gui (not an item) that will display a tooltip when hovered over.  I also want you to be able to click and drag those objects.  I am trying to make a gui like Ars Magica 2's Inscription table.

Check whether the mouse is hovering over your item, then display a special GUI.

Look at Item#addInformation for resources and help.

Also, how do you draw an icon from a ResourceLocation in you gui.

I know how to draw an Icon, but I need to get one from a ResourceLocation.

There is a method in the GUI class to draw an Icon.  I just need to convert a ResourceLocation (the location of the image) into an Icon (the image).  I could use an placeholder Item to register the icons in registerICons() (and then store them for latter use), but it seems that there should be a better way.

You can use the TextureStitchEvent.Pre event to register a new icon independent of a block / an item.

 

To do it, register to that event. You also need a field somewhere to hold the icon instance (e.g.

public static IIcon sun

).

Check if the texture type of the map (the map is a field in the event) represents the type of the icon. Check if it's 0 for blocks or 1 for items. Icon texture files registered as item icons belong next to the "actual" item icon files, same for blocks.

Use map.registerIcon like you would register an icon in a block/item, like

sun = event.map.registerIcon("enderstuffp:sun");

.

 

After that, you can reference the field anywhere you see fit.

 

No need for ResourceLocations here.