[vtbackend] Add customizable indicator statusline

Signed-off-by: Christian Parpart <[email protected]>

Author: christianparpart

docs/configuration/indicator-statusline.md

@@ -0,0 +1,74 @@
+# Indicator Statusline
+
+The indicator statusline used to be a feature, from the old DEC VT level 4 terminals.
+Contour revives this feature to prominently show the terminal status.
+
+## Configuration
+
+```
+profiles:
+    your_profile:
+        status_line:
+            indicator:
+                left: "{VTType} │ {InputMode:Bold,Color=#C0C030}{SearchPrompt:Left= │ }{TraceMode:Bold,Color=#FFFF00,Left= │ }{ProtectedMode:Bold,Left= │ }"
+                middle: "{Title:Left= « ,Right= » ,Color=#20c0c0}"
+                right: "{HistoryLineCount:Faint,Color=#c0c0c0} │ {Clock:Bold} "
+```
+
+Each segment, `left`, `middle`, and `right` may contain text to be displayed in the
+left, middle, or right segment of the indicator statusline.
+
+This text may contain placeholders to be replaced by their respective dynamic content.
+
+## Variables
+
+Variable             | Description
+---------------------|--------------------------------------------------------------------
+`{Clock}`            | current clock in HH:MM format
+`{Command}`          | yields the result of the given command prompt, as specified via parameter `Program=...`
+`{HistoryLineCount}` | number of lines in history (only available in primary screen)
+`{Hyperlink}`        | reveals the hyperlink at the given mouse location
+`{InputMode}`        | current input mode (e.g. INSERT, NORMAL, VISUAL)
+`{ProtectedMode}`    | indicates protected mode, if currently enabled
+`{SearchMode}`       | indicates search highlight mode, if currently active
+`{SearchPrompt}`     | search input prompt, if currently active
+`{Text}`             | given text (makes only sense when customized with flags)
+`{Title}`            | current window title
+`{VTType}`           | currently active VT emulation type
+
+## Formatting Styles
+
+Each Variable, as specified above, can be parametrized for customizing the look of it.
+The common syntax to these variables and their parameters looks as follows:
+
+```
+{VariableName:SomeFlag,SomeKey=SomeValue}
+```
+
+So parameters can be specified after a colon (`:`) as a comma separated list of flags and key/value pairs.
+A key/value pair is further split by equal sign (`=`).
+
+The following list of formatting styles are supported:
+
+Parameter                 | Description
+--------------------------|--------------------------------------------------------------------
+`Left=TEXT`               | text to show on the left side, if the variable is to be shown
+`Right=TEXT`              | text to show on the right side, if the variable is to be shown
+`Color=#RRGGBB`           | text color in hexadecimal RGB notation
+`BackgroundColor=#RRGGBB` | background color in hexadecimal RGB notation
+`Bold`                    | text in bold font face
+`Italic`                  | text in italic font face
+`Underline`               | underline text (only one underline style can be active)
+`CurlyUnderline`          | curly underline text (only one underline style can be active)
+`DoubleUnderline`         | double underline text (only one underline style can be active)
+`DottedUnderline`         | dotted underline text (only one underline style can be active)
+`DashedUnderline`         | dashed underline text (only one underline style can be active)
+`Blinking`                | blinking text
+`RapidBlinking`           | rapid blinking text
+`Overline`                | overline text
+`Inverse`                 | inversed text/background coloring
+
+These parameters apply to all variables above.
+
+The `Command` variable is the only one that requires a special attribute, `Program` whose value
+is the command to execute.

metainfo.xml

@@ -107,6 +107,7 @@
     <release version="0.4.4" urgency="medium" type="development">
       <description>
         <ul>
+          <li>Add ability to customize the indicator statusline through configuration (#687)</li>
           <li>Add generation of config file from internal state (#1282)</li>
           <li>Add SGRSAVE and SGRRESTORE VT sequences to save and restore SGR state (They intentionally conflict with XTPUSHSGR and XTPOPSGR)</li>
           <li>Fixes corruption of sixel image on high resolution (#1049)</li>

mkdocs.yml

@@ -90,6 +90,7 @@ nav:
     - configuration/index.md
     - configuration/profiles.md
     - configuration/colors.md
+    - configuration/indicator-statusline.md
     #- Images (Advanced) : configuration/advanced/images.md
     #- Mouse (Advanced) : configuration/advanced/images.md
     #- Misc (Advanced) : configuration/advanced/mouse.md

src/contour/Config.cpp

@@ -403,6 +403,13 @@ void YAMLConfigReader::loadFromEntry(YAML::Node const& node, std::string const&
             loadFromEntry(child["status_line"], "position", where.statusDisplayPosition);
             loadFromEntry(child["status_line"], "sync_to_window_title", where.syncWindowTitleWithHostWritableStatusDisplay);
             loadFromEntry(child["status_line"], "display", where.initialStatusDisplayType);
+
+            if (child["status_line"]["indicator"])
+            {
+                loadFromEntry(child["status_line"]["indicator"], "left", where.indicatorStatusLineLeft);
+                loadFromEntry(child["status_line"]["indicator"], "middle", where.indicatorStatusLineMiddle);
+                loadFromEntry(child["status_line"]["indicator"], "right", where.indicatorStatusLineRight);
+            }
         }
         if (child["background"])
         {
@@ -1933,6 +1940,14 @@ std::string YAMLConfigWriter::createString(Config const& c)
                     process(entry.initialStatusDisplayType);
                     process(entry.statusDisplayPosition);
                     process(entry.syncWindowTitleWithHostWritableStatusDisplay);
+
+                    doc.append(addOffset("indicator:\n", Offset::levels * OneOffset));
+                    {
+                        const auto _ = Offset {};
+                        process(entry.indicatorStatusLineLeft);
+                        process(entry.indicatorStatusLineMiddle);
+                        process(entry.indicatorStatusLineRight);
+                    }
                 }
 
                 doc.append(addOffset("\n"

src/contour/Config.h

@@ -319,6 +319,18 @@ struct TerminalProfile
     };
     ConfigEntry<vtbackend::StatusDisplayPosition, documentation::StatusDisplayPosition>
         statusDisplayPosition { vtbackend::StatusDisplayPosition::Bottom };
+    ConfigEntry<std::string, documentation::IndicatorStatusLineLeft> indicatorStatusLineLeft {
+        " {InputMode:Bold,Color=#FFFF00}"
+        "{SearchPrompt:Left= │ }"
+        "{TraceMode:Bold,Color=#FFFF00,Left= │ }"
+        "{ProtectedMode:Bold,Left= │ }"
+    };
+    ConfigEntry<std::string, documentation::IndicatorStatusLineMiddle> indicatorStatusLineMiddle {
+        " {Clock:Bold} {Title:Left= « ,Right= » }"
+    };
+    ConfigEntry<std::string, documentation::IndicatorStatusLineRight> indicatorStatusLineRight {
+        "{HistoryLineCount:Faint,Color=#c0c0c0} "
+    };
     ConfigEntry<bool, documentation::SyncWindowTitleWithHostWritableStatusDisplay>
         syncWindowTitleWithHostWritableStatusDisplay { false };
     ConfigEntry<bool, documentation::HideScrollbarInAltScreen> hideScrollbarInAltScreen { true };
@@ -351,7 +363,7 @@ struct TerminalProfile
     ConfigEntry<std::chrono::milliseconds, documentation::HighlightTimeout> highlightTimeout { 100 };
     ConfigEntry<bool, documentation::HighlightDoubleClickerWord> highlightDoubleClickedWord { true };
     ConfigEntry<vtbackend::StatusDisplayType, documentation::InitialStatusLine> initialStatusDisplayType {
-        vtbackend::StatusDisplayType::None
+        vtbackend::StatusDisplayType::Indicator
     };
     ConfigEntry<vtbackend::Opacity, documentation::BackgroundOpacity> backgroundOpacity { vtbackend::Opacity(
         0xFF) };

src/contour/ConfigDocumentation.h

@@ -171,6 +171,10 @@ constexpr StringLiteral StatusDisplayPosition {
     "\n"
 };
 
+constexpr StringLiteral IndicatorStatusLineLeft { "left: \"{}\"\n" };
+constexpr StringLiteral IndicatorStatusLineMiddle { "middle: \"{}\"\n" };
+constexpr StringLiteral IndicatorStatusLineRight { "right: \"{}\"\n" };
+
 constexpr StringLiteral SyncWindowTitleWithHostWritableStatusDisplay {
     "{comment} Synchronize the window title with the Host Writable status_line if\n"
     "{comment} and only if the host writable status line was denied to be shown.\n"

src/contour/TerminalSession.cpp

@@ -141,6 +141,9 @@ namespace
         settings.maxImageRegisterCount = config.maxImageColorRegisters.value();
         settings.statusDisplayType = profile.initialStatusDisplayType.value();
         settings.statusDisplayPosition = profile.statusDisplayPosition.value();
+        settings.indicatorStatusLine.left = profile.indicatorStatusLineLeft.value();
+        settings.indicatorStatusLine.middle = profile.indicatorStatusLineMiddle.value();
+        settings.indicatorStatusLine.right = profile.indicatorStatusLineRight.value();
         settings.syncWindowTitleWithHostWritableStatusDisplay =
             profile.syncWindowTitleWithHostWritableStatusDisplay.value();
         if (auto const* p = preferredColorPalette(profile.colors.value(), colorPreference))

src/crispy/interpolated_string_test.cpp

@@ -22,8 +22,7 @@ TEST_CASE("interpolated_string.parse_interpolated_string")
 {
     using crispy::parse_interpolated_string;
 
-    auto const interpolated = parse_interpolated_string(
-        "< {Clock:Bold,Italic,Color=#FFFF00} | {VTType}");
+    auto const interpolated = parse_interpolated_string("< {Clock:Bold,Italic,Color=#FFFF00} | {VTType}");
 
     CHECK(interpolated.size() == 4);
 

src/vtbackend/CMakeLists.txt

@@ -39,6 +39,7 @@ set(vtbackend_HEADERS
     Sequence.h
     Sequencer.h
     SixelParser.h
+    StatusLineBuilder.h
     Terminal.h
     VTType.h
     VTWriter.h
@@ -69,6 +70,7 @@ set(vtbackend_SOURCES
     Sequence.cpp
     Sequencer.cpp
     SixelParser.cpp
+    StatusLineBuilder.cpp
     Terminal.cpp
     TerminalState.cpp
     VTType.cpp

src/vtbackend/Color.cpp

@@ -2,6 +2,7 @@
 #include <vtbackend/Color.h>
 
 #include <crispy/overloaded.h>
+#include <crispy/utils.h>
 
 using namespace std;
 
@@ -128,4 +129,47 @@ string to_string(RGBAColor c)
     return fmt::format("#{:02X}{:02X}{:02X}{:02X}", c.red(), c.green(), c.blue(), c.alpha());
 }
 
+optional<RGBColor> parseColor(string_view const& value)
+{
+    try
+    {
+        // "rgb:RR/GG/BB"
+        //  0123456789a
+        if (value.size() == 12 && value.substr(0, 4) == "rgb:" && value[6] == '/' && value[9] == '/')
+        {
+            auto const r = crispy::to_integer<16, uint8_t>(value.substr(4, 2));
+            auto const g = crispy::to_integer<16, uint8_t>(value.substr(7, 2));
+            auto const b = crispy::to_integer<16, uint8_t>(value.substr(10, 2));
+            return RGBColor { r.value(), g.value(), b.value() };
+        }
+
+        // "#RRGGBB"
+        if (value.size() == 7 && value[0] == '#')
+        {
+            auto const r = crispy::to_integer<16, uint8_t>(value.substr(1, 2));
+            auto const g = crispy::to_integer<16, uint8_t>(value.substr(3, 2));
+            auto const b = crispy::to_integer<16, uint8_t>(value.substr(5, 2));
+            return RGBColor { r.value(), g.value(), b.value() };
+        }
+
+        // "#RGB"
+        if (value.size() == 4 && value[0] == '#')
+        {
+            auto const r = crispy::to_integer<16, uint8_t>(value.substr(1, 1));
+            auto const g = crispy::to_integer<16, uint8_t>(value.substr(2, 1));
+            auto const b = crispy::to_integer<16, uint8_t>(value.substr(3, 1));
+            auto const rr = static_cast<uint8_t>(r.value() << 4);
+            auto const gg = static_cast<uint8_t>(g.value() << 4);
+            auto const bb = static_cast<uint8_t>(b.value() << 4);
+            return RGBColor { rr, gg, bb };
+        }
+
+        return std::nullopt;
+    }
+    catch (...)
+    {
+        // that will be a formatting error in stoul() then.
+        return std::nullopt;
+    }
+}
 } // namespace vtbackend