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I added a new kind of undo record named CHANGE-RECORD, created by

(setf buffer-object).

This fixes a problem that was reported by Nikodemus Siivola where
fill-paragraph did not record any undo information, because it was
using (setf buffer-object) as opposed to insert or delete.
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1 parent 97965d9 commit 91990e61607d22882ef058c18debcc8e5f16b3bd Robert Strandh committed
Showing with 28 additions and 1 deletion.
  1. +28 −1 Drei/views.lisp
29 Drei/views.lisp
@@ -187,6 +187,16 @@ instance of `delete-record'."))
`delete-record' containing a mark is created and added to the
undo tree."))
+(defclass change-record (simple-undo-record)
+ ((objects :initarg :objects
+ :documentation "The sequence of objects that are to
+replace the records that are currently in the buffer at the
+offset whenever flip-undo-record is called on an instance of
+ (:documentation "Whenever objects are modified, a
+`change-record' containing a mark is created and added to the
+undo tree."))
(defclass compound-record (drei-undo-record)
((records :initform '()
:initarg :records
@@ -201,7 +211,11 @@ records."))
(defmethod print-object ((object insert-record) stream)
(with-slots (offset objects) object
- (format stream "[offset: ~a objects: ~a]" offset objects)))
+ (format stream "[offset: ~a inserted objects: ~a]" offset objects)))
+(defmethod print-object ((object change-record) stream)
+ (with-slots (offset objects) object
+ (format stream "[offset: ~a changed objects: ~a]" offset objects)))
(defmethod print-object ((object compound-record) stream)
(with-slots (records) object
@@ -227,6 +241,14 @@ records."))
:objects (buffer-sequence buffer offset (+ offset n)))
(undo-accumulate buffer))))
+(defmethod (setf buffer-object) :before (new-object (buffer undo-mixin) offset)
+ (unless (performing-undo buffer)
+ (push (make-instance 'change-record
+ :buffer buffer
+ :offset offset
+ :objects (buffer-sequence buffer offset (1+ offset)))
+ (undo-accumulate buffer))))
(defmacro with-undo ((get-buffers-exp) &body body)
"This macro executes the forms of `body', registering changes
made to the list of buffers retrieved by evaluating
@@ -273,6 +295,11 @@ all."
:objects (buffer-sequence buffer offset (+ offset length)))
(delete-buffer-range buffer offset length)))
+(defmethod flip-undo-record ((record change-record))
+ (with-slots (buffer offset objects) record
+ (loop for i from 0 below (length objects)
+ do (rotatef (aref objects i) (buffer-object buffer (+ i offset))))))
(defmethod flip-undo-record ((record compound-record))
(with-slots (records) record
(mapc #'flip-undo-record records)

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