master 2084f4ada3 1/2: hideshow.el: Improve hs-toggle-hiding behavior

[Stefan Monnier]

branch: master
commit 2084f4ada38c3ebaaf77806f32a79073fc9f0bf4
Author: kobarity <kobarity@gmail.com>
Commit: Stefan Monnier <monnier@iro.umontreal.ca>

    hideshow.el: Improve hs-toggle-hiding behavior
    
    * lisp/progmodes/hideshow.el
    (hs-find-block-beginning-match): New function to be used in
    `hs-already-hidden-p'.
    (hs-already-hidden-p): Add check if beginning of line is inside a
    block.
    (hs-toggle-hiding): Don't change to selected-window's buffer when
    event arg is absent.
    
    * test/lisp/progmodes/hideshow-tests.el
    (hideshow-tests-with-temp-buffer-selected): New helper macro.
    (hideshow-tests-make-event-at): New helper function.
    (hideshow-already-hidden-p-1): New test.
    (hideshow-toggle-hiding-1): New test.
    (hideshow-mouse-toggle-hiding-1): New test (bug#52092).
---
 lisp/progmodes/hideshow.el            |  25 +++++---
 test/lisp/progmodes/hideshow-tests.el | 106 ++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+), 9 deletions(-)

diff --git a/lisp/progmodes/hideshow.el b/lisp/progmodes/hideshow.el
index 359fd42932..2a1b6d6b7b 100644
--- a/lisp/progmodes/hideshow.el
+++ b/lisp/progmodes/hideshow.el
@@ -786,6 +786,14 @@ and `case-fold-search' are both t."
            (case-fold-search t))
        ,@body)))
 
+(defun hs-find-block-beginning-match ()
+  "Reposition point at the end of match of the block-start regexp.
+Return point, or nil if original point was not in a block."
+  (when (and (funcall hs-find-block-beginning-func)
+            (funcall hs-looking-at-block-start-p-func))
+    ;; point is inside a block
+    (goto-char (match-end 0))))
+
 (defun hs-overlay-at (position)
   "Return hideshow overlay at POSITION, or nil if none to be found."
   (let ((overlays (overlays-at position))
@@ -797,19 +805,18 @@ and `case-fold-search' are both t."
 
 (defun hs-already-hidden-p ()
   "Return non-nil if point is in an already-hidden block, otherwise nil."
-  ;; FIXME: We should probably also consider ourselves "in" a hidden block
-  ;; when point is right at the edge after a hidden block (bug#52092).
   (save-excursion
     (let ((c-reg (hs-inside-comment-p)))
       (if (and c-reg (nth 0 c-reg))
           ;; point is inside a comment, and that comment is hideable
           (goto-char (nth 0 c-reg))
-        (end-of-line)
-        (when (and (not c-reg)
-                   (funcall hs-find-block-beginning-func)
-                  (funcall hs-looking-at-block-start-p-func))
-          ;; point is inside a block
-          (goto-char (match-end 0)))))
+        (when (not c-reg)
+          (end-of-line)
+          (when (not (hs-find-block-beginning-match))
+            ;; We should also consider ourselves "in" a hidden block when
+            ;; point is right at the edge after a hidden block (bug#52092).
+            (beginning-of-line)
+            (hs-find-block-beginning-match)))))
     (end-of-line)
     (hs-overlay-at (point))))
 
@@ -952,7 +959,7 @@ See `hs-hide-block' and `hs-show-block'.
 Argument E should be the event that triggered this action."
   (interactive (list last-nonmenu-event))
   (hs-life-goes-on
-   (posn-set-point (event-end e))
+   (when e (posn-set-point (event-end e)))
    (if (hs-already-hidden-p)
        (hs-show-block)
      (hs-hide-block))))
diff --git a/test/lisp/progmodes/hideshow-tests.el 
b/test/lisp/progmodes/hideshow-tests.el
index ee2a0c7c4c..22d73fb3c4 100644
--- a/test/lisp/progmodes/hideshow-tests.el
+++ b/test/lisp/progmodes/hideshow-tests.el
@@ -41,6 +41,18 @@ always located at the beginning of buffer."
      (goto-char (point-min))
      ,@body))
 
+(defmacro hideshow-tests-with-temp-buffer-selected (mode contents &rest body)
+  "Create and switch to a `hs-minor-mode' enabled MODE temp buffer with 
CONTENTS.
+BODY is code to be executed within the temp buffer.  Point is
+always located at the beginning of buffer."
+  (declare (indent 1) (debug t))
+  `(ert-with-test-buffer-selected ()
+     (,mode)
+     (hs-minor-mode 1)
+     (insert ,contents)
+     (goto-char (point-min))
+     ,@body))
+
 (defun hideshow-tests-look-at (string &optional num restore-point)
   "Move point at beginning of STRING in the current buffer.
 Optional argument NUM defaults to 1 and is an integer indicating
@@ -96,6 +108,39 @@ default to `point-min' and `point-max' respectively."
                            (overlay-end overlay))))
       (buffer-substring-no-properties (point-min) (point-max)))))
 
+(defun hideshow-tests-make-event-at (string)
+  "Make dummy mouse event at beginning of STRING."
+  (save-excursion
+    (let ((pos (hideshow-tests-look-at string)))
+      (vector
+       `(S-mouse-2
+         (,(get-buffer-window) ,pos (1 . 1) 0 nil ,pos (1 . 1)
+          nil (1 . 1) (1 . 1)))))))
+
+(ert-deftest hideshow-already-hidden-p-1 ()
+  (let ((contents "
+int
+main()
+{
+  printf(\"Hello\\n\");
+}
+"))
+    (hideshow-tests-with-temp-buffer
+     c-mode
+     contents
+     (hideshow-tests-look-at "printf")
+     (should (not (hs-already-hidden-p)))
+     (hs-hide-block)
+     (goto-char (point-min))
+     (hideshow-tests-look-at "{")
+     (should (hs-already-hidden-p))
+     (forward-line -1)
+     (should (not (hs-already-hidden-p)))
+     (hideshow-tests-look-at "}")
+     (should (hs-already-hidden-p))
+     (forward-line)
+     (should (not (hs-already-hidden-p))))))
+
 (ert-deftest hideshow-hide-block-1 ()
   "Should hide current block."
   (let ((contents "
@@ -263,6 +308,67 @@ main(int argc, char **argv)
 }
 "))))
 
+(ert-deftest hideshow-toggle-hiding-1 ()
+  "Should toggle hiding/showing of a block."
+  (let ((contents "
+int
+main()
+{
+  printf(\"Hello\\n\");
+}
+"))
+    (hideshow-tests-with-temp-buffer
+     c-mode
+     contents
+     (hideshow-tests-look-at "printf")
+     (hs-toggle-hiding)
+     (should (string=
+              (hideshow-tests-visible-string)
+              "
+int
+main()
+{}
+"))
+     (hs-toggle-hiding)
+     (should (string= (hideshow-tests-visible-string) contents)))))
+
+(ert-deftest hideshow-mouse-toggle-hiding-1 ()
+  "Should toggle hiding/showing of a block by mouse events."
+  (let ((contents "
+int
+main()
+{
+  printf(\"Hello\\n\");
+}
+")
+        (hidden "
+int
+main()
+{}
+")
+        (call-at (lambda (str)
+                   (let* ((events (hideshow-tests-make-event-at str))
+                          (last-nonmenu-event (aref events 0)))
+                     (call-interactively #'hs-toggle-hiding nil events)))))
+    (hideshow-tests-with-temp-buffer-selected
+     c-mode
+     contents
+     ;; Should not hide the block when clicked outside of the block.
+     (funcall call-at "int")
+     (should (string= (hideshow-tests-visible-string) contents))
+     ;; Should hide the block when clicked inside of the block.
+     (goto-char (point-min))
+     (funcall call-at "printf")
+     (should (string= (hideshow-tests-visible-string) hidden))
+     ;; Should not show the block when clicked outside of the block.
+     (goto-char (point-min))
+     (funcall call-at "int")
+     (should (string= (hideshow-tests-visible-string) hidden))
+     ;; Should show the block when clicked inside of the block.
+     (goto-char (point-min))
+     (funcall call-at "}")
+     (should (string= (hideshow-tests-visible-string) contents)))))
+
 (provide 'hideshow-tests)
 
 ;;; hideshow-tests.el ends here