snip%

A direct instance of snip% is uninteresting. Useful snips are defined by instantiating derived subclasses, but this class defines the basic fucntionality.

In deriving a new snip class, these methods must be overridden to create a useful snip:

• get-extent
• draw
• resize if the snip can be resized by the user
• partial-offset if the snip can contain more than one item
• split if the snip can contain more than one item
• size-cache-invalid if the snip caches the result to get-extent
• get-text (not required)
• find-scroll-step, get-num-scroll-steps, and get-scroll-step-offset if the snip can contain more than one scroll position

If a snip can contain more than one item, then the snip's count must be maintained as well.

To define a class of snips that can be saved or cut-and-pasted:

• Create an instance of snip-class%, implementing the read method.
• For each instance of the snip class, set the snip's classs object with set-snipclass.
• Override the copy method.
• Override the write method.

• (make-object snip%) -> snip% object

  Creates a plain snip of length 1.

  
  

• adjust-cursor
• blink-caret
• copy
• do-edit-operation
• draw
• find-scroll-step
• get-admin
• get-count
• get-extent
• get-flags
• get-num-scroll-steps
• get-scroll-step-offset
• get-snipclass
• get-style
• get-text
• is-owned?
• match?
• merge-with
• next
• on-char
• on-event
• own-caret
• partial-offset
• previous
• release-from-owner
• resize
• set-admin
• set-count
• set-flags
• set-snipclass
• set-style
• size-cache-invalid
• split
• write