Fix #17 errors when not enough room is available.

Also gives more control over whether and where to show prefix keys. When
the buffer is vertical showing in first line seems to make more sense.

diff --git a/which-key.el b/which-key.el
index 58a674f546fbc69041cc124b6003c100bd40720f..f86248f1f0b3bb6ee92b59027d4dc63ba388b62e 100644 (file)
--- a/which-key.el
+++ b/which-key.el
@@ -57,6 +57,10 @@ if it becomes problematic.")
 and have `which-key-special-key-face' applied to them.")
 (defvar which-key-buffer-name "*which-key*"
   "Name of which-key buffer.")
+(defvar which-key-show-prefix 'left
+  "Whether to and where to display the current prfix sequence.
+Possible choices are left (the default), top and nil. Nil turns
+the feature off.")
 (defvar which-key-popup-type 'minibuffer
   "Supported types are minibuffer, side-window and frame.")
 (defvar which-key-side-window-location 'right
@@ -205,10 +209,11 @@ Finally, show the buffer."
 dimensions, (height . width) of the buffer text to be displayed
 in the popup.  Return nil if no window is shown, or if there is no
 need to start the closing timer."
-  (cl-case which-key-popup-type
-    (minibuffer (which-key/show-buffer-minibuffer act-popup-dim))
-    (side-window (which-key/show-buffer-side-window act-popup-dim))
-    (frame (which-key/show-buffer-frame act-popup-dim))))
+  (when (and (> (car act-popup-dim) 0) (> (cdr act-popup-dim) 0))
+    (cl-case which-key-popup-type
+      (minibuffer (which-key/show-buffer-minibuffer act-popup-dim))
+      (side-window (which-key/show-buffer-side-window act-popup-dim))
+      (frame (which-key/show-buffer-frame act-popup-dim)))))
 
 (defun which-key/show-buffer-minibuffer (act-popup-dim)
   nil)
@@ -369,7 +374,7 @@ N-COLUMNS is the number of text columns to use and MAX-LINES is
 the maximum number of lines availabel in the target buffer."
   (let* ((n-keys (length keys))
          (n-lines (min (ceiling (/ (float n-keys) n-columns)) max-lines))
-         (line-padding (s-repeat prefix-len " "))
+         (line-padding (when (eq which-key-show-prefix 'left) (s-repeat prefix-len " ")))
          lines)
     (dotimes (i n-lines)
       (setq lines
@@ -382,37 +387,50 @@ the maximum number of lines availabel in the target buffer."
   "Insert FORMATTED-STRINGS into which-key buffer, breaking after BUFFER-WIDTH."
   (let* ((prefix-w-face (which-key/propertize-key prefix-keys))
          (prefix-len (+ 2 (length (substring-no-properties prefix-w-face))))
+         (prefix-string (when which-key-show-prefix
+                          (if (eq which-key-show-prefix 'left)
+                              (concat prefix-w-face "  ")
+                            (concat prefix-w-face "-\n"))))
          (n-keys (length formatted-keys))
          (max-dims (which-key/popup-max-dimensions sel-win-width))
          (max-height (when (car max-dims) (car max-dims)))
-         (max-width (when (cdr max-dims) (cdr max-dims)))
-         ;; the 3 leaves room for the ... possibly on the first page
-         (n-columns (/ (- max-width prefix-len 3) column-width)) ;; integer division
+         (max-width (if (cdr max-dims)
+                      (if (eq which-key-show-prefix 'left)
+                          (- (cdr max-dims) prefix-len)
+                        (cdr max-dims)) 0))
+         ;; the 3 leaves room for the ... possibly on the first page (remove for now)
+         (n-columns (/ max-width column-width)) ;; integer division
          (act-width (* n-columns column-width))
          ;; (avl-lines/page (which-key/available-lines))
          (max-keys/page (when max-height (* n-columns max-height)))
-         (n-pages (if max-keys/page
+         (n-pages (if (> max-keys/page 0)
                       (ceiling (/ (float n-keys) max-keys/page)) 1))
          pages act-height first-page)
-    (when (and (> n-keys 0) (> n-columns 0))
-      (dotimes (p n-pages)
-        (setq pages
-              (push (which-key/create-page
-                     prefix-len max-height n-columns
-                     (cl-subseq formatted-keys (* p max-keys/page)
-                                (min (* (1+ p) max-keys/page) n-keys))) pages)))
-      ;; not doing anything with other pages for now
-      (setq pages (reverse pages)
-            act-height (1+  (s-count-matches "\n" (car pages))))
-      (setq first-page (concat prefix-w-face "  " (car pages)))
-      (when (> (length pages) 1) (setq first-page (concat first-page "...")))
-      (if (eq which-key-popup-type 'minibuffer)
-          (let (message-log-max) (message "%s" first-page))
-        (with-current-buffer which-key--buffer
-          (erase-buffer)
-          (insert first-page)
-          (goto-char (point-min)))))
-    (cons act-height act-width)))
+    (if (and (> n-keys 0) (> act-width 0))
+        (progn
+          (dotimes (p n-pages)
+            (setq pages
+                  (push (which-key/create-page
+                         prefix-len max-height n-columns
+                         (cl-subseq formatted-keys (* p max-keys/page)
+                                    (min (* (1+ p) max-keys/page) n-keys))) pages)))
+          ;; not doing anything with other pages for now
+          (setq pages (reverse pages)
+                first-page (concat prefix-string (car pages))
+                act-height (s-count-matches "\n" first-page))
+          ;; (when (> (length pages) 1) (setq first-page (concat first-page "...")))
+          (if (eq which-key-popup-type 'minibuffer)
+              (let (message-log-max) (message "%s" first-page))
+            (with-current-buffer which-key--buffer
+              (erase-buffer)
+              (insert first-page)
+              (goto-char (point-min))))
+          (cons act-height act-width))
+      (if (<= n-keys 0)
+          (message "Can't display which-key buffer: There are no keys to show.")
+        (message "Can't display which-key buffer: A minimum width of %s chars is required, but your settings only allow for %s chars." column-width max-width)
+        )
+      (cons 0 act-width))))
 
 (defun which-key/maybe-replace (string repl-alist &optional keys literal)
   "Perform replacements on STRING.