Image support: buttons and auto-display in the REPL

When geiser-repl-inline-images-p is false (or we're in a terminal),
the inserted text replacement is a button that calls the external
viewer on click.  There's also a parameter controlling whether the
viewer should be invoked automatically upon insertion.

2 files changed, 38 insertions, 15 deletions

diff --git a/elisp/geiser-image.el b/elisp/geiser-image.el
index 222e0d3..dd90f05 100644
--- a/elisp/geiser-image.el
+++ b/elisp/geiser-image.el
@@ -22,7 +22,6 @@
   "Options for image displaying."
   :group 'geiser)
 
-
 (geiser-custom--defcustom geiser-system-image-viewer "display"
   "Which system image viewer program to invoke upon M-x
 `geiser-view-last-image'."
@@ -44,6 +43,9 @@ system wide tmp dir will be used."
   :type 'path
   :group 'geiser-image)
 
+(geiser-custom--defface image-button
+  'button geiser-image "image buttons in terminal buffers")
+
 
 
 (defun geiser-image--list-cache ()
@@ -64,7 +66,18 @@ images in `geiser-image-cache-dir'."
   (dolist (f (butlast (geiser-image--list-cache) geiser-image-cache-keep-last))
     (delete-file f)))
 
-(defun geiser-image--replace-images (inline-images-p)
+(defun geiser-image--display (file)
+  (start-process "Geiser image view" nil geiser-system-image-viewer file))
+
+(defun geiser-image--button-action (button)
+  (let ((file (button-get button 'geiser-image-file)))
+    (when (file-exists-p file) (geiser-image--display file))))
+
+(define-button-type 'geiser-image--button
+  'action 'geiser-image--button-action
+  'follow-link t)
+
+(defun geiser-image--replace-images (inline-images-p auto-p)
   "Replace all image patterns with actual images"
   (with-silent-modifications
     (save-excursion
@@ -78,9 +91,13 @@ images in `geiser-image-cache-dir'."
           (delete-region begin end)
           (if (and inline-images-p (display-images-p))
               (put-image (create-image file) begin "[image]")
-            (progn
-              (goto-char begin)
-              (insert "[image] ; use M-x geiser-view-last-image to view")))
+            (goto-char begin)
+            (insert-text-button "[image]"
+                                :type 'geiser-image--button
+                                'face 'geiser-font-lock-image-button
+                                'geiser-image-file file
+                                'help-echo "Click to display image")
+            (when auto-p (geiser-image--display file)))
           (setq geiser-image-cache-dir (file-name-directory file))
           (geiser-image--clean-cache))))))
 
@@ -92,10 +109,7 @@ image viewer."
   (interactive "p")
   (let ((images (reverse (geiser-image--list-cache))))
     (if (>= (length images) n)
-        (start-process "Geiser image view"
-                       nil
-                       geiser-system-image-viewer
-                       (nth (- n 1) images))
+        (geiser-image--display (nth (- n 1) images))
       (error "There aren't %d recent images" n))))
 
 
diff --git a/elisp/geiser-repl.el b/elisp/geiser-repl.el
index 7eb7cf0..ddcc6b8 100644
--- a/elisp/geiser-repl.el
+++ b/elisp/geiser-repl.el
@@ -46,8 +46,10 @@ REPL buffer."
   :type 'boolean
   :group 'geiser-repl)
 
-(geiser-custom--defcustom geiser-repl-history-filename (expand-file-name "~/.geiser_history")
+(geiser-custom--defcustom geiser-repl-history-filename
+    (expand-file-name "~/.geiser_history")
   "File where REPL input history is saved, so that it persists between sessions.
+
 This is actually the base name: the concrete Scheme
 implementation name gets appended to it."
   :type 'filename
@@ -114,10 +116,16 @@ If you have a slow system, try to increase this time."
   :type 'integer
   :group 'geiser-repl)
 
-(geiser-custom--defcustom geiser-repl-inline-images t
-   "Whether to display inline images in the REPL."
-   :type 'boolean
-   :group 'geiser-repl)
+(geiser-custom--defcustom geiser-repl-inline-images-p t
+  "Whether to display inline images in the REPL."
+  :type 'boolean
+  :group 'geiser-repl)
+
+(geiser-custom--defcustom geiser-repl-auto-display-images-p t
+  "Whether to automatically invoke the external viewer to display
+images pooping up in the REPL."
+  :type 'boolean
+  :group 'geiser-repl)
 
 (geiser-custom--defface repl-input
   'comint-highlight-input geiser-repl "evaluated input highlighting")
@@ -274,7 +282,8 @@ module command as a string")
 
 (defun geiser-repl--output-filter (txt)
   (geiser-con--connection-update-debugging geiser-repl--connection txt)
-  (geiser-image--replace-images geiser-repl-inline-images)
+  (geiser-image--replace-images geiser-repl-inline-images-p
+                                geiser-repl-auto-display-images-p)
   (when (string-match-p (geiser-con--connection-prompt geiser-repl--connection)
                         txt)
     (geiser-autodoc--disinhibit-autodoc)))