[markdown] add border-left/border-right support

NEWS.md

@@ -46,9 +46,12 @@ Features:
   the directory where cached data is stored, respectively.
 * The `<pre>` tag is now recognized in Markdown files.
 * The `style` attribute in `<span>` tags is now supported.
-  Basic properties like `color`, `background-color`,
-  `font-weight`, and `text-decoration` can be used. CSS
-  color names should work as well.
+  The following CSS properties and values are supported:
+  * `color` and `background-color` with CSS color names
+  * `font-weight` with a value of `bold` or `bolder`
+  * `text-decoration` with `underline`
+  * `border-left` and `border-right` with the `solid`,
+    `dashed` and `dotted` line styles and colors.
 
 Bug Fixes:
 * Binary data piped into stdin should now be treated the same

src/line_buffer.hh

@@ -368,7 +368,7 @@ private:
 
     nonstd::optional<auto_fd> lb_cached_fd;
 
-    file_header_t lb_header;
+    file_header_t lb_header{mapbox::util::no_init{}};
 };
 
 #endif

src/logfile.cc

@@ -134,25 +134,27 @@ logfile::open(std::string filename, const logfile_open_options& loo, auto_fd fd)
     lf->lf_indexing = lf->lf_options.loo_is_visible;
 
     const auto& hdr = lf->lf_line_buffer.get_header_data();
-    log_info("%s: has header %d", lf->lf_filename.c_str(), hdr.valid());
-    hdr.match(
-        [&lf](const lnav::gzip::header& gzhdr) {
-            if (!gzhdr.empty()) {
-                lf->lf_embedded_metadata["net.zlib.gzip.header"] = {
+    if (hdr.valid()) {
+        log_info("%s: has header %d", lf->lf_filename.c_str(), hdr.valid());
+        hdr.match(
+            [&lf](const lnav::gzip::header& gzhdr) {
+                if (!gzhdr.empty()) {
+                    lf->lf_embedded_metadata["net.zlib.gzip.header"] = {
+                        text_format_t::TF_JSON,
+                        file_header_handlers.to_string(gzhdr),
+                    };
+                }
+            },
+            [&lf](const lnav::piper::header& phdr) {
+                lf->lf_embedded_metadata["org.lnav.piper.header"] = {
                     text_format_t::TF_JSON,
-                    file_header_handlers.to_string(gzhdr),
+                    lnav::piper::header_handlers.to_string(phdr),
                 };
-            }
-        },
-        [&lf](const lnav::piper::header& phdr) {
-            lf->lf_embedded_metadata["org.lnav.piper.header"] = {
-                text_format_t::TF_JSON,
-                lnav::piper::header_handlers.to_string(phdr),
-            };
-            log_debug("setting file name: %s", phdr.h_name.c_str());
-            lf->set_filename(phdr.h_name);
-            lf->lf_valid_filename = false;
-        });
+                log_debug("setting file name: %s", phdr.h_name.c_str());
+                lf->set_filename(phdr.h_name);
+                lf->lf_valid_filename = false;
+            });
+    }
 
     ensure(lf->invariant());
 

src/md2attr_line.cc

@@ -488,6 +488,94 @@ md2attr_line::leave_span(const md4cpp::event_handler::span& sp)
     return Ok();
 }
 
+enum class border_side {
+    left,
+    right,
+};
+
+enum class border_line_width {
+    thin,
+    medium,
+    thick,
+};
+
+static const char*
+left_border_string(border_line_width width)
+{
+    switch (width) {
+        case border_line_width::thin:
+            return "\u258F";
+        case border_line_width::medium:
+            return "\u258E";
+        case border_line_width::thick:
+            return "\u258C";
+    }
+}
+
+static const char*
+right_border_string(border_line_width width)
+{
+    switch (width) {
+        case border_line_width::thin:
+            return "\u2595";
+        case border_line_width::medium:
+            return "\u2595";
+        case border_line_width::thick:
+            return "\u2590";
+    }
+}
+
+static attr_line_t
+span_style_border(border_side side, const string_fragment& value)
+{
+    static const auto NAME_THIN = string_fragment::from_const("thin");
+    static const auto NAME_MEDIUM = string_fragment::from_const("medium");
+    static const auto NAME_THICK = string_fragment::from_const("thick");
+    static const auto NAME_SOLID = string_fragment::from_const("solid");
+    static const auto NAME_DASHED = string_fragment::from_const("dashed");
+    static const auto NAME_DOTTED = string_fragment::from_const("dotted");
+    static const auto& vc = view_colors::singleton();
+
+    text_attrs border_attrs;
+    auto border_sf = value;
+    auto width = border_line_width::thick;
+    auto ch = side == border_side::left ? left_border_string(width)
+                                        : right_border_string(width);
+
+    while (!border_sf.empty()) {
+        auto border_split_res
+            = border_sf.split_when(string_fragment::tag1{' '});
+        auto bval = border_split_res.first;
+
+        if (bval == NAME_THIN) {
+            width = border_line_width::thin;
+        } else if (bval == NAME_MEDIUM) {
+            width = border_line_width::medium;
+        } else if (bval == NAME_THICK) {
+            width = border_line_width::thick;
+        } else if (bval == NAME_DOTTED) {
+            ch = "\u250A";
+        } else if (bval == NAME_DASHED) {
+            ch = "\u254F";
+        } else if (bval == NAME_SOLID) {
+            ch = side == border_side::left ? left_border_string(width)
+                                           : right_border_string(width);
+        } else {
+            auto color_res = styling::color_unit::from_str(bval);
+            if (color_res.isErr()) {
+                log_error("invalid border color: %.*s -- %s",
+                          bval.length(),
+                          bval.data(),
+                          color_res.unwrapErr().c_str());
+            } else {
+                border_attrs.ta_fg_color = vc.match_color(color_res.unwrap());
+            }
+        }
+        border_sf = border_split_res.second;
+    }
+    return attr_line_t(ch).with_attr_for_all(VC_STYLE.value(border_attrs));
+}
+
 static attr_line_t
 to_attr_line(const pugi::xml_node& doc)
 {
@@ -499,6 +587,10 @@ to_attr_line(const pugi::xml_node& doc)
         = string_fragment::from_const("font-weight");
     static const auto NAME_TEXT_DECO
         = string_fragment::from_const("text-decoration");
+    static const auto NAME_BORDER_LEFT
+        = string_fragment::from_const("border-left");
+    static const auto NAME_BORDER_RIGHT
+        = string_fragment::from_const("border-right");
     static const auto& vc = view_colors::singleton();
 
     attr_line_t retval;
@@ -507,6 +599,8 @@ to_attr_line(const pugi::xml_node& doc)
     }
     for (const auto& child : doc.children()) {
         if (child.name() == NAME_SPAN) {
+            nonstd::optional<attr_line_t> left_border;
+            nonstd::optional<attr_line_t> right_border;
             auto styled_span = attr_line_t(child.text().get());
 
             auto span_class = child.attribute("class");
@@ -578,6 +672,12 @@ to_attr_line(const pugi::xml_node& doc)
 
                                 deco_sf = deco_split_res.second;
                             }
+                        } else if (key == NAME_BORDER_LEFT) {
+                            left_border
+                                = span_style_border(border_side::left, value);
+                        } else if (key == NAME_BORDER_RIGHT) {
+                            right_border
+                                = span_style_border(border_side::right, value);
                         }
                     }
                     style_sf = split_res.second;
@@ -586,7 +686,13 @@ to_attr_line(const pugi::xml_node& doc)
                     styled_span.with_attr_for_all(VC_STYLE.value(ta));
                 }
             }
+            if (left_border) {
+                retval.append(left_border.value());
+            }
             retval.append(styled_span);
+            if (right_border) {
+                retval.append(right_border.value());
+            }
         } else if (child.name() == NAME_PRE) {
             auto pre_al = attr_line_t();
 
@@ -643,7 +749,8 @@ md2attr_line::text(MD_TEXTTYPE tt, const string_fragment& sf)
                 std::string ct_name;
             };
 
-            mapbox::util::variant<open_tag, close_tag> tag;
+            mapbox::util::variant<open_tag, close_tag> tag{
+                mapbox::util::no_init{}};
 
             if (sf.startswith("</")) {
                 tag = close_tag{

test/expected/test_text_file.sh_d59b67113864ef5e77267d7fd8ad4072f5aef0fc.out

@@ -11,3 +11,6 @@
 
   Hello,
   World!
+
+
+Goodbye, ▌World╏!

test/textfile_0.md

@@ -16,3 +16,5 @@
   Hello,
   <span class="name">World</span>!
 </pre>
+
+Goodbye, <span style="border-left: solid cyan; border-right: dashed green">World</span>!