[elpa] externals/show-font 97b3301dd3 12/54: Add error checking in show-font--prepare-text

[ELPA Syncer]

branch: externals/show-font
commit 97b3301dd3787a178ad8c1c88e42721f4fd92d69
Author: Protesilaos Stavrou <info@protesilaos.com>
Commit: Protesilaos Stavrou <info@protesilaos.com>

    Add error checking in show-font--prepare-text
---
 show-font.el | 46 +++++++++++++++++++++++++++++-----------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/show-font.el b/show-font.el
index 3f35623602..0ccb8f1614 100644
--- a/show-font.el
+++ b/show-font.el
@@ -192,23 +192,35 @@ With optional ATTRIBUTE use it instead of \"family\"."
 
 (defun show-font--prepare-text ()
   "Prepare pangram text at varying font heights."
-  (let ((pangram (show-font--get-pangram))
-        (faces '(show-font-small show-font-regular show-font-medium 
show-font-large))
-        (list-of-lines nil)
-        (list-of-blocks nil)
-        (name (show-font--get-attribute "fullname"))
-        (family (show-font--get-attribute "family")))
-    (dolist (face faces)
-      (push (propertize pangram 'face (list face :family family)) 
list-of-lines)
-      (push (propertize show-font-character-sample 'face (list face :family 
family)) list-of-blocks))
-    (concat
-     (propertize name 'face (list 'show-font-title :family family)) "\n"
-     (propertize (make-string (length name) ?-) 'face (list 'show-font-title 
:family family)) "\n"
-     (propertize "Rendered with parent family:" 'face (list 'show-font-regular 
:family family)) "\n"
-     (propertize family 'face (list 'show-font-subtitle :family family)) "\n"
-     (propertize (make-string (length family) ?=) 'face (list 
'show-font-subtitle :family family)) "\n\n"
-     (mapconcat #'identity (nreverse list-of-lines) "\n") "\n"
-     (mapconcat #'identity (nreverse list-of-blocks) "\n") "\n")))
+  (let* ((pangram (show-font--get-pangram))
+         (appeasement-message (concat "But here is a pangram to make you 
happy..." "\n\n" pangram)))
+    (cond
+     ((not (display-graphic-p))
+      (concat (propertize "Fonts cannot be displayed in a terminal or TTY." 
'face 'show-font-title)
+              "\n\n" appeasement-message))
+     ((not (show-font--installed-p buffer-file-name))
+      (concat (propertize "Cannot preview this font" 'face 'show-font-title)
+              "\n\n"
+              (propertize buffer-file-name 'face 'bold)
+              " is not installed"
+              "\n\n" appeasement-message))
+     (t
+      (let ((faces '(show-font-small show-font-regular show-font-medium 
show-font-large))
+            (list-of-lines nil)
+            (list-of-blocks nil)
+            (name (show-font--get-attribute "fullname"))
+            (family (show-font--get-attribute "family")))
+        (dolist (face faces)
+          (push (propertize pangram 'face (list face :family family)) 
list-of-lines)
+          (push (propertize show-font-character-sample 'face (list face 
:family family)) list-of-blocks))
+        (concat
+         (propertize name 'face (list 'show-font-title :family family)) "\n"
+         (propertize (make-string (length name) ?-) 'face (list 
'show-font-title :family family)) "\n"
+         (propertize "Rendered with parent family:" 'face (list 
'show-font-regular :family family)) "\n"
+         (propertize family 'face (list 'show-font-subtitle :family family)) 
"\n"
+         (propertize (make-string (length family) ?=) 'face (list 
'show-font-subtitle :family family)) "\n\n"
+         (mapconcat #'identity (nreverse list-of-lines) "\n") "\n"
+         (mapconcat #'identity (nreverse list-of-blocks) "\n") "\n"))))))
 
 (defmacro show-font-with-unmodified-buffer (&rest body)
   "Run BODY while not making the buffer appear modified."