Info Catalog elisp: Button Types elisp: Buttons elisp: Manipulating Buttons

elisp: Making Buttons

 
 37.19.3 Making Buttons
 ----------------------
 
 Buttons are associated with a region of text, using an overlay or text
 properties to hold button-specific information, all of which are
 initialized from the button’s type (which defaults to the built-in
 button type ‘button’).  Like all Emacs text, the appearance of the
 button is governed by the ‘face’ property; by default (via the ‘face’
 property inherited from the ‘button’ button-type) this is a simple
 underline, like a typical web-page link.
 
    For convenience, there are two sorts of button-creation functions,
 those that add button properties to an existing region of a buffer,
 called ‘make-...button’, and those that also insert the button text,
 called ‘insert-...button’.
 
    The button-creation functions all take the ‘&rest’ argument
 PROPERTIES, which should be a sequence of PROPERTY VALUE pairs,
 specifying properties to add to the button; see Button
 Properties.  In addition, the keyword argument ‘:type’ may be used to
 specify a button-type from which to inherit other properties; see 
 Button Types.  Any properties not explicitly specified during creation
 will be inherited from the button’s type (if the type defines such a
 property).
 
 Overlays::) to hold the button properties:
 
  -- Function: make-button beg end &rest properties
      This makes a button from BEG to END in the current buffer, and
      returns it.
 
  -- Function: insert-button label &rest properties
      This insert a button with the label LABEL at point, and returns it.
 
    The following functions are similar, but using text properties (
 Text Properties) to hold the button properties.  Such buttons do not
 add markers to the buffer, so editing in the buffer does not slow down
 if there is an extremely large numbers of buttons.  However, if there is
 an existing face text property on the text (e.g., a face assigned by
 Font Lock mode), the button face may not be visible.  Both of these
 functions return the starting position of the new button.
 
  -- Function: make-text-button beg end &rest properties
      This makes a button from BEG to END in the current buffer, using
      text properties.
 
  -- Function: insert-text-button label &rest properties
      This inserts a button with the label LABEL at point, using text
      properties.
 

Info Catalog elisp: Button Types elisp: Buttons elisp: Manipulating Buttons