branch: elpa/macrostep
commit 9cd674287e39447dbd4bb186a087dab7e38828fe
Author: joddie <[email protected]>
Commit: joddie <[email protected]>
Try to be smarter about maintaining buffer state
- save and restore buffer-read-only
- exit macrostep-mode correctly if the buffer is made writable again
- save and restore buffer-undo-list, and disable undo recording while
macrostep is active
- use `with-silent-modifications' to not mark buffer as modified.
Caveats: This is nicer for the user when inspecting an unmodified
buffer, but could be dangerous if we somehow manage leave the buffer
in an inconsistent state without warning. Is there a better way?
---
macrostep.el | 84 +++++++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 57 insertions(+), 27 deletions(-)
diff --git a/macrostep.el b/macrostep.el
index 6cae0ec..38f0bc1 100644
--- a/macrostep.el
+++ b/macrostep.el
@@ -190,6 +190,13 @@
"t if gensyms have been encountered during current level of macro
expansion.")
(make-variable-buffer-local 'macrostep-gensyms-this-level)
+(defvar macrostep-saved-undo-list nil
+ "Saved value of buffer-undo-list upon entering macrostep mode.")
+(make-variable-buffer-local 'macrostep-saved-undo-list)
+
+(defvar macrostep-saved-read-only nil
+ "Saved value of buffer-read-only upon entering macrostep mode.")
+(make-variable-buffer-local 'macrostep-saved-read-only)
;;; Faces
(defgroup macrostep nil
@@ -293,14 +300,34 @@ quit and return to normal editing.
nil " Macro-Stepper"
:keymap macrostep-keymap
:group macrostep
- (setq buffer-read-only macrostep-mode)
(if macrostep-mode
- (message
- (substitute-command-keys
- "\\<macrostep-keymap>Entering macro stepper mode. Use
\\[macrostep-expand] to expand, \\[macrostep-collapse] to collapse,
\\[macrostep-collapse-all] to exit."))
+ (progn
+ ;; Disable recording of undo information
+ (setq macrostep-saved-undo-list buffer-undo-list
+ buffer-undo-list t)
+ ;; Remember whether buffer was read-only
+ (setq macrostep-saved-read-only buffer-read-only
+ buffer-read-only t)
+ ;; Set up post-command hook to bail out on leaving read-only
+ (add-hook 'post-command-hook 'macrostep-command-hook nil t)
+ (message
+ (substitute-command-keys
+ "\\<macrostep-keymap>Entering macro stepper mode. Use
\\[macrostep-expand] to expand, \\[macrostep-collapse] to collapse,
\\[macrostep-collapse-all] to exit.")))
;; Exiting mode: collapse any remaining overlays
- (when macrostep-overlays (macrostep-collapse-all))))
+ (when macrostep-overlays (macrostep-collapse-all))
+ :; Restore undo info & read-only state
+ (setq buffer-undo-list macrostep-saved-undo-list
+ buffer-read-only macrostep-saved-read-only
+ macrostep-saved-undo-list nil)
+ ;; Remove our post-command hook
+ (remove-hook 'post-command-hook 'macrostep-command-hook t)))
+
+;; Post-command hook: bail out of macrostep-mode if the user types C-x
+;; C-q to make the buffer writable again.
+(defun macrostep-command-hook ()
+ (if (not buffer-read-only)
+ (macrostep-mode 0)))
;;; Interactive functions
@@ -342,21 +369,22 @@ buffer and expand the next macro form found, if any."
priority 1
macrostep-gensym-depth -1))
- (atomic-change-group
- (macrostep-replace-sexp-at-point expansion)
- (let ((new-ol
- (make-overlay (point)
- (scan-sexps (point) 1))))
- ;; move overlay over newline to make it prettier
- (when (equal (char-after (overlay-end new-ol)) ?\n)
- (move-overlay new-ol
- (overlay-start new-ol) (+ (overlay-end new-ol) 1)))
- (overlay-put new-ol 'face 'macrostep-expansion-highlight-face)
- (overlay-put new-ol 'evaporate t)
- (overlay-put new-ol 'priority priority)
- (overlay-put new-ol 'macrostep-original-text text)
- (overlay-put new-ol 'macrostep-gensym-depth macrostep-gensym-depth)
- (push new-ol macrostep-overlays))))))
+ (with-silent-modifications
+ (atomic-change-group
+ (macrostep-replace-sexp-at-point expansion)
+ (let ((new-ol
+ (make-overlay (point)
+ (scan-sexps (point) 1))))
+ ;; move overlay over newline to make it prettier
+ (when (equal (char-after (overlay-end new-ol)) ?\n)
+ (move-overlay new-ol
+ (overlay-start new-ol) (+ (overlay-end new-ol) 1)))
+ (overlay-put new-ol 'face 'macrostep-expansion-highlight-face)
+ (overlay-put new-ol 'evaporate t)
+ (overlay-put new-ol 'priority priority)
+ (overlay-put new-ol 'macrostep-original-text text)
+ (overlay-put new-ol 'macrostep-gensym-depth macrostep-gensym-depth)
+ (push new-ol macrostep-overlays)))))))
(defun macrostep-collapse ()
"Collapse the innermost macro expansion near point to its source text.
@@ -367,8 +395,9 @@ If no more macro expansions are visible after this, exit
(let ((overlay (macrostep-overlay-at-point)))
(when (not overlay) (error "No macro expansion at point"))
(let ((buffer-read-only nil))
- (atomic-change-group
- (macrostep-collapse-overlay overlay))))
+ (with-silent-modifications
+ (atomic-change-group
+ (macrostep-collapse-overlay overlay)))))
(if (not macrostep-overlays)
(macrostep-mode 0)))
@@ -376,11 +405,12 @@ If no more macro expansions are visible after this, exit
"Collapse all visible macro expansions and exit `macrostep-mode'."
(interactive)
(let ((buffer-read-only nil))
- (dolist (overlay macrostep-overlays)
- (let ((outermost (= (overlay-get overlay 'priority) 1)))
- ;; We only need restore the original text for the outermost
- ;; overlays
- (macrostep-collapse-overlay overlay (not outermost)))))
+ (with-silent-modifications
+ (dolist (overlay macrostep-overlays)
+ (let ((outermost (= (overlay-get overlay 'priority) 1)))
+ ;; We only need restore the original text for the outermost
+ ;; overlays
+ (macrostep-collapse-overlay overlay (not outermost))))))
(setq macrostep-overlays nil)
(macrostep-mode 0))
