From: Frederick Yin <fkfd@macaw.me>
To: ~nhanb/mcross-devel@lists.sr.ht
Cc: Frederick Yin <fkfd@macaw.me>
Subject: [PATCH] Support alt text for preformatted text
Date: Sun, 14 Jun 2020 22:16:54 +0800
Message-Id: <20200614141653.12420-1-fkfd@macaw.me>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable

In Gemini's new, pending spec:

=3D> gemini://gemini.circumlunar.space/docs/specification-modified.gmi

...section 5.4.3:

> Any text following the leading "```" of a preformat toggle line which
> toggles preformatted mode on MAY be interpreted by the client as "alt
> text" pertaining to the preformatted text lines which follow the
> toggle line.

Since McRoss didn't adhere to the spec in the first place:

> Any line whose first three characters are "```"

"first three characters" means simply `if line =3D=3D "```"` won't do. I
resolved this as a side effect.

This patch may be postponed until the modified spec takes effect.
---
 src/mcross/document.py  | 16 +++++++++++++---
 src/mcross/gui/model.py |  2 +-
 src/mcross/gui/view.py  |  2 +-
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/mcross/document.py b/src/mcross/document.py
index 821f673..f285642 100644
--- a/src/mcross/document.py
+++ b/src/mcross/document.py
@@ -54,7 +54,15 @@ class LinkNode(GeminiNode):
=20
=20
 class PreformattedNode(GeminiNode):
-    pass
+    __slots__ =3D ("alt",)
+    alt: str
+
+    def __init__(self, text, alt):
+        self.text =3D text
+        self.alt =3D alt  # optional alt-text for preformatted text
+
+    def __repr__(self):
+        return f"{self.__class__.__name__}: {self.alt.__repr__()}"
=20
=20
 def parse(text):
@@ -63,15 +71,17 @@ def parse(text):
     """
     nodes =3D []
     preformatted =3D None
+    preformatted_alt =3D ""
=20
     for line in text.strip().split(NEWLINE):
=20
-        if line =3D=3D "```":
+        if line.startswith("```"):
             if preformatted is None:
                 # start preformatted mode
                 preformatted =3D ""
+                preformatted_alt =3D line[3:]
             else:
-                nodes.append(PreformattedNode(preformatted))
+                nodes.append(PreformattedNode(preformatted, preformatted=
_alt))
                 preformatted =3D None
=20
         elif preformatted is not None:
diff --git a/src/mcross/gui/model.py b/src/mcross/gui/model.py
index 23667bd..98a5823 100644
--- a/src/mcross/gui/model.py
+++ b/src/mcross/gui/model.py
@@ -26,7 +26,7 @@ DEMO_TEXT =3D """\
=20
 ## Codes
=20
-```
+```a snippet from pyproject.toml
 [tool.poetry]
 name =3D "mcross"
 version =3D "0.1.0"
diff --git a/src/mcross/gui/view.py b/src/mcross/gui/view.py
index 7e5ed33..0bc8f23 100644
--- a/src/mcross/gui/view.py
+++ b/src/mcross/gui/view.py
@@ -266,7 +266,7 @@ def render_node(node: GeminiNode, widget: Text):
         if node.name:
             widget.insert("end", f" {node.name}")
     elif nodetype is PreformattedNode:
-        widget.insert("end", f"```\n{node.text}\n```", ("pre",))
+        widget.insert("end", f"```{node.alt}\n{node.text}\n```", ("pre",=
))
     elif nodetype is ListItemNode:
         widget.insert("end", node.text, ("listitem",))
     elif nodetype is H1Node:
--=20
2.27.0