How to manipulate the text to have half gradient or half pattern?

[Ofnuts]

To make anything apply on to the text shape, several methods:

• Set the Alpha lock on the text layer and then apply paint (Brush, Gradient, bucket-fill). Easier solution but this makes the text layer a plain layer (so you cannot edit the text further without redoing everything from scratch)
  

Or:

• Create a group with two layers:  
  

• A top layer for the color, set to Multiply mode
  
• A bottom layer for the text
  
• Create the text in white
  
• Apply the painting to the top layer
  
• You can paint different parts of the top layer differently if you use selections, if you need to do something really fancy you can replace the top layer by another group (set that group to Multiply)
  

   

Using separate layers makes it easy to change your mind or tweak things, for instance below I only replaced the layer with squares by one with triangles

   

Or even classier IMHO with smaller triangles for the feet: