Refactor a very long wid-edit function and add additional checking

* lisp/wid-edit.el (widget-button--check-and-call-button): Factor
out a too-long condition/call...
(widget-button-click): From here.

diff --git a/lisp/wid-edit.el b/lisp/wid-edit.el
index bc2afc6a6fb9e454962c6b1fbf0ef6c9ec499a23..8be489bf08b33da0f27bc58696098e18ea0f2c1f 100644 (file)
--- a/lisp/wid-edit.el
+++ b/lisp/wid-edit.el
@@ -973,86 +973,91 @@ Note that such modes will need to require wid-edit.")
   "If non-nil, `widget-button-click' moves point to a button after invoking it.
 If nil, point returns to its original position after invoking a button.")
 
+(defun widget-button--check-and-call-button (event button)
+  "Call BUTTON if BUTTON is a widget and EVENT is correct for it.
+If nothing was called, return non-nil."
+  (let* ((oevent event)
+         (mouse-1 (memq (event-basic-type event) '(mouse-1 down-mouse-1)))
+         newpoint pos)
+    (catch 'button-press-cancelled
+      ;; Mouse click on a widget button.  Do the following
+      ;; in a save-excursion so that the click on the button
+      ;; doesn't change point.
+      (save-selected-window
+        (select-window (posn-window (event-start event)))
+        (save-excursion
+         (goto-char (posn-point (event-start event)))
+         (let* ((overlay (widget-get button :button-overlay))
+                (pressed-face (or (widget-get button :pressed-face)
+                                  widget-button-pressed-face))
+                (face (overlay-get overlay 'face))
+                (mouse-face (overlay-get overlay 'mouse-face)))
+           (unwind-protect
+               ;; Read events, including mouse-movement
+               ;; events, waiting for a release event.  If we
+               ;; began with a mouse-1 event and receive a
+               ;; movement event, that means the user wants
+               ;; to perform drag-selection, so cancel the
+               ;; button press and do the default mouse-1
+               ;; action.  For mouse-2, just highlight/
+               ;; unhighlight the button the mouse was
+               ;; initially on when we move over it.
+               (save-excursion
+                 (when face            ; avoid changing around image
+                   (overlay-put overlay 'face pressed-face)
+                   (overlay-put overlay 'mouse-face pressed-face))
+                 (unless (widget-apply button :mouse-down-action event)
+                   (let ((track-mouse t))
+                     (while (not (widget-button-release-event-p event))
+                       (setq event (read-event))
+                       (when (and mouse-1 (mouse-movement-p event))
+                         (push event unread-command-events)
+                         (setq event oevent)
+                         (throw 'button-press-cancelled t))
+                       (unless (or (integerp event)
+                                   (memq (car event)
+                                          '(switch-frame select-window))
+                                   (eq (car event) 'scroll-bar-movement))
+                         (setq pos (widget-event-point event))
+                         (if (and pos
+                                  (eq (get-char-property pos 'button)
+                                      button))
+                             (when face
+                               (overlay-put overlay 'face pressed-face)
+                               (overlay-put overlay 'mouse-face pressed-face))
+                           (overlay-put overlay 'face face)
+                           (overlay-put overlay 'mouse-face mouse-face))))))
+
+                 ;; When mouse is released over the button, run
+                 ;; its action function.
+                 (when (and pos (eq (get-char-property pos 'button) button))
+                   (goto-char pos)
+                   (widget-apply-action button event)
+                   (if widget-button-click-moves-point
+                       (setq newpoint (point)))))
+             (overlay-put overlay 'face face)
+             (overlay-put overlay 'mouse-face mouse-face))))
+
+        (when newpoint
+          (goto-char newpoint)))
+      nil)))
+
 (defun widget-button-click (event)
   "Invoke the button that the mouse is pointing at."
   (interactive "e")
   (if (widget-event-point event)
-      (let* ((oevent event)
-            (mouse-1 (memq (event-basic-type event) '(mouse-1 down-mouse-1)))
+      (let* ((mouse-1 (memq (event-basic-type event) '(mouse-1 down-mouse-1)))
             (pos (widget-event-point event))
             (start (event-start event))
-            (button (get-char-property
+             (button (get-char-property
                      pos 'button (and (windowp (posn-window start))
-                                      (window-buffer (posn-window start)))))
-            newpoint)
-       (when (or (null button)
-                 (catch 'button-press-cancelled
-             ;; Mouse click on a widget button.  Do the following
-             ;; in a save-excursion so that the click on the button
-             ;; doesn't change point.
-             (save-selected-window
-               (select-window (posn-window (event-start event)))
-               (save-excursion
-                 (goto-char (posn-point (event-start event)))
-                 (let* ((overlay (widget-get button :button-overlay))
-                        (pressed-face (or (widget-get button :pressed-face)
-                                          widget-button-pressed-face))
-                        (face (overlay-get overlay 'face))
-                        (mouse-face (overlay-get overlay 'mouse-face)))
-                   (unwind-protect
-                       ;; Read events, including mouse-movement
-                       ;; events, waiting for a release event.  If we
-                       ;; began with a mouse-1 event and receive a
-                       ;; movement event, that means the user wants
-                       ;; to perform drag-selection, so cancel the
-                       ;; button press and do the default mouse-1
-                       ;; action.  For mouse-2, just highlight/
-                       ;; unhighlight the button the mouse was
-                       ;; initially on when we move over it.
-                       (save-excursion
-                         (when face    ; avoid changing around image
-                           (overlay-put overlay 'face pressed-face)
-                           (overlay-put overlay 'mouse-face pressed-face))
-                         (unless (widget-apply button :mouse-down-action event)
-                           (let ((track-mouse t))
-                             (while (not (widget-button-release-event-p event))
-                               (setq event (read-event))
-                               (when (and mouse-1 (mouse-movement-p event))
-                                 (push event unread-command-events)
-                                 (setq event oevent)
-                                 (throw 'button-press-cancelled t))
-                               (unless (or (integerp event)
-                                           (memq (car event) '(switch-frame select-window))
-                                           (eq (car event) 'scroll-bar-movement))
-                                 (setq pos (widget-event-point event))
-                                 (if (and pos
-                                          (eq (get-char-property pos 'button)
-                                              button))
-                                     (when face
-                                       (overlay-put overlay 'face pressed-face)
-                                       (overlay-put overlay 'mouse-face pressed-face))
-                                   (overlay-put overlay 'face face)
-                                   (overlay-put overlay 'mouse-face mouse-face))))))
-
-                         ;; When mouse is released over the button, run
-                         ;; its action function.
-                         (when (and pos (eq (get-char-property pos 'button) button))
-                           (goto-char pos)
-                           (widget-apply-action button event)
-                           (if widget-button-click-moves-point
-                               (setq newpoint (point)))))
-                     (overlay-put overlay 'face face)
-                     (overlay-put overlay 'mouse-face mouse-face))))
-
-               (if newpoint (goto-char newpoint))
-               ;; This loses if the widget action switches windows. -- cyd
-               ;; (unless (pos-visible-in-window-p (widget-event-point event))
-               ;;   (mouse-set-point event)
-               ;;   (beginning-of-line)
-               ;;   (recenter))
-               )
-             nil))
-         (let ((up t) command)
+                                      (window-buffer (posn-window start))))))
+
+       (when (and (widget-get button :button-overlay)
+                   (or (null button)
+                       (widget-button--check-and-call-button event button)))
+         (let ((up t)
+                command)
            ;; Mouse click not on a widget button.  Find the global
            ;; command to run, and check whether it is bound to an
            ;; up event.