Rename function to have chordpro- prefix

Make chord regexp save the actual chord without the brackets
Add function for deleting chord without killing it
Add functionality to use dropdown lists to pick chord to insert/replace
from chords already in the document.
Remap middle buttons to do more useful things

README.md

@@ -31,6 +31,10 @@ extension for such files):
 
 Now when you visit a .pro file you should automatically get chordpro-mode.
 
+Some of the functions use dropdown-list.el, which can be installed
+with package-list-packages in modern emacs. If you don't have this
+installed they'll just do nothing.
+
 ## Use ##
 
 ### Keyboard ###
@@ -40,6 +44,8 @@ All of the keyboard commands use the Ctrl-c prefix.
 * Ctrl-c i : Insert a chord at the point. You'll be prompted for the
   chord name in the minibuffer. The brackets will automatically be
   inserted, space trimmed, and the chord capitalized.
+* Ctrl-c l : Insert a chord at the point, chosen from a dropdown list
+  of chords already in the document.
 * Ctrl-c w : Kills the current chord. The current chord is one
   containing the point - because of the way emacs works this means
   that this command doesn't do what you want if the cursor is on the
@@ -48,6 +54,8 @@ All of the keyboard commands use the Ctrl-c prefix.
 * Ctrl-c z : Kills the next chord. Finds the next chord after the
   point and kills it. This one works if you are on the opening
   [, or if you are between chords.
+* Ctrl-c r : Replace the current chord with one chosen from a dropdown
+  list of chords already in the document.
 * Ctrl-c c : Copy the current chord
 * Ctrl-c x : Copy the next chord
 * Ctrl-c h : Insert a chordpro comment
@@ -63,7 +71,10 @@ experiments. All of them have corresponding keyboard commands (whether
 specific to this mode or standard emacs commands).
 
 * Ctrl-mouse-1 : Kills current chord
-* Ctrl-mouse-2 : Yanks last kill (this is prone to change, as you can typically do this with a normal mouse-2)
+* Ctrl-mouse-2 : Insert a chord at the point, chosen from a dropdown list
+  of chords already in the document. Note that unfortunately as currently
+  implemented the mouse click can only bring up the menu - you still need
+  to use the keyboard to perform the selection.
 * Ctrl-mouse-3 : Kills next chord
 * Shift-mouse-1 : Copies current chord
 * Shift-mouse-2 : Insert chord

chordpro-mode.el

@@ -1,4 +1,5 @@
 (require 'derived)
+(require 'dropdown-list nil t)
 
 (defvar chordpro-font-lock-defaults
   '((("\\(\\[[^]]*\\]\\)" . font-lock-string-face)
@@ -23,16 +24,18 @@ Special commands:
 (define-key chordpro-mode-map "\C-ch" 'chordpro-insert-chorus)
 (define-key chordpro-mode-map "\C-ct" 'chordpro-insert-title)
 (define-key chordpro-mode-map "\C-cs" 'chordpro-insert-subtitle)
+(define-key chordpro-mode-map "\C-cl" 'chordpro-choose-insert-chord)
+(define-key chordpro-mode-map "\C-cr" 'chordpro-choose-replace-current-chord)
 (define-key chordpro-mode-map [C-down-mouse-1] 'mouse-set-point)
 (define-key chordpro-mode-map [C-mouse-1] 'chordpro-kill-current-chord)
 (define-key chordpro-mode-map [C-down-mouse-2] 'mouse-set-point)
-(define-key chordpro-mode-map [C-mouse-2] 'yank)
+(define-key chordpro-mode-map [C-mouse-2] 'chordpro-mouse-choose-insert-chord)
 (define-key chordpro-mode-map [C-down-mouse-3] 'mouse-set-point)
 (define-key chordpro-mode-map [C-mouse-3] 'chordpro-kill-next-chord)
 (define-key chordpro-mode-map [S-down-mouse-1] 'mouse-set-point)
 (define-key chordpro-mode-map [S-mouse-1] 'chordpro-copy-current-chord)
 (define-key chordpro-mode-map [S-down-mouse-2] 'mouse-set-point)
-(define-key chordpro-mode-map [S-mouse-2] 'mouse-insert-chord)
+(define-key chordpro-mode-map [S-mouse-2] 'chordpro-mouse-insert-chord)
 (define-key chordpro-mode-map [S-down-mouse-3] 'mouse-set-point)
 (define-key chordpro-mode-map [S-mouse-3] 'chordpro-copy-next-chord)
 
@@ -41,17 +44,60 @@ Special commands:
   (interactive "*MChord:")
   (insert "[" (chordpro-normalize-chord chord) "]"))
 
-(defun mouse-insert-chord (event chord)
+(defun chordpro-mouse-insert-chord (event chord)
   "Prompt for and insert chord at point, performing some normalization."
   (interactive "@e\nMChord:")
   (insert "[" (chordpro-normalize-chord chord) "]"))
 
+(defun chordpro-choose-insert-chord ()
+  "Insert a chord chosen from a dropdown menu that contains all chords
+already in the document."
+  (interactive)
+  (when (featurep 'dropdown-list)
+    (let* ((choices (chordpro-buffer-chord-list))
+           (selection (dropdown-list choices)))
+      (when selection
+        (chordpro-insert-chord (nth selection choices))))))
+
+(defun chordpro-mouse-choose-insert-chord (event)
+  "Insert a chord chosen from a dropdown menu that contains all chords
+already in the document."
+  (interactive "@e")
+    (when (featurep 'dropdown-list)
+    (let* ((choices (chordpro-buffer-chord-list))
+           (selection (dropdown-list choices)))
+      (when selection
+        (chordpro-insert-chord (nth selection choices))))))
+
+;;;This could be done more efficiently, but for most usages
+;;;it shouldn't be a problem to just scan the whole document each time
+(defun chordpro-buffer-chord-list ()
+  "Return a list of the chords currently used in the document."
+  (interactive)
+  (let ((chords nil))
+    (save-excursion
+      (save-match-data
+        (goto-char (point-min))
+        (while (re-search-forward chordpro-chord-regexp nil t)
+          (add-to-list 'chords (match-string 1)))))
+    (sort chords 'string<)))
+
+(defun chordpro-choose-replace-current-chord ()
+  "Replace the current chord with one chosen from a dropdown list"
+  (interactive)
+  (when (featurep 'dropdown-list)
+    (let* ((choices (chordpro-buffer-chord-list))
+           (selection (dropdown-list choices)))
+      (when selection
+        (chordpro-delete-current-chord)
+        (chordpro-insert-chord (nth selection choices))))))
+
 (defun chordpro-normalize-chord (chord)
   "Trim whitespace, capitalize first letter of chord."
   (capitalize (replace-regexp-in-string "\\s " "" chord)))
 
 (defvar chordpro-chord-regexp
-  "\\[[^][]*\\]"
+  "\\[\\([^][]*\\)\\]"
   "Regexp for matching a chord without regard for the point.")
 
 (defun chordpro-kill-next-chord ()
@@ -76,6 +122,11 @@ Special commands:
   (interactive)
   (operate-on-current-chord 'kill-region))
 
+(defun chordpro-delete-current-chord ()
+  "Delete the chord surrounding the point, if there is one."
+  (interactive)
+  (operate-on-current-chord 'delete-region))
+
 (defun chordpro-copy-current-chord ()
   "Copy the chord surrounding the point, if there is one."
   (interactive)