terminal: improve function and control key handling

1 files changed, 137 insertions, 22 deletions

diff --git a/ttwhy/terminal/policies.cppm b/ttwhy/terminal/policies.cppm
index 83694b8..49712aa 100644
--- a/ttwhy/terminal/policies.cppm
+++ b/ttwhy/terminal/policies.cppm
@@ -12,29 +12,99 @@ namespace ttwhy::terminal
 
   namespace detail
   {
-    constexpr auto map_vt220_keypad(char terminator) -> std::optional<navigation_key>
+    constexpr auto parse_primary_parameter(std::string_view buffer) -> std::optional<unsigned int>
     {
-      switch (terminator)
+      auto delimiter = buffer.find(';');
+      auto primary_slice = buffer.substr(0, delimiter);
+      if (primary_slice.empty())
+      {
+        return std::nullopt;
+      }
+
+      auto value = 0u;
+      for (auto character : primary_slice)
+      {
+        if (character < '0' || character > '9')
+        {
+          return std::nullopt;
+        }
+        value = value * 10 + static_cast<unsigned int>(character - '0');
+      }
+      return value;
+    }
+
+    constexpr auto map_vt220_navigation(unsigned int code) -> std::optional<navigation_key>
+    {
+      switch (code)
       {
-        case '1':
-        case '7':
+        case 1:
+        case 7:
           return navigation_key::home;
-        case '2':
+        case 2:
           return navigation_key::insert_key;
-        case '3':
+        case 3:
           return navigation_key::delete_key;
-        case '4':
-        case '8':
+        case 4:
+        case 8:
           return navigation_key::end;
-        case '5':
+        case 5:
           return navigation_key::page_up;
-        case '6':
+        case 6:
           return navigation_key::page_down;
         default:
           return std::nullopt;
       }
     }
 
+    constexpr auto map_vt220_function(unsigned int code) -> std::optional<function_key>
+    {
+      switch (code)
+      {
+        case 11:
+          return function_key::f1;
+        case 12:
+          return function_key::f2;
+        case 13:
+          return function_key::f3;
+        case 14:
+          return function_key::f4;
+        case 15:
+          return function_key::f5;
+        case 17:
+          return function_key::f6;
+        case 18:
+          return function_key::f7;
+        case 19:
+          return function_key::f8;
+        case 20:
+          return function_key::f9;
+        case 21:
+          return function_key::f10;
+        case 23:
+          return function_key::f11;
+        case 24:
+          return function_key::f12;
+        case 25:
+          return function_key::f13;
+        case 26:
+          return function_key::f14;
+        case 28:
+          return function_key::f15;
+        case 29:
+          return function_key::f16;
+        case 31:
+          return function_key::f17;
+        case 32:
+          return function_key::f18;
+        case 33:
+          return function_key::f19;
+        case 34:
+          return function_key::f20;
+        default:
+          return std::nullopt;
+      }
+    }
+
     constexpr auto map_vt100_cursor(char terminator) -> std::optional<navigation_key>
     {
       switch (terminator)
@@ -56,15 +126,32 @@ namespace ttwhy::terminal
       }
     }
 
+    constexpr auto map_ss3_function(char terminator) -> std::optional<function_key>
+    {
+      switch (terminator)
+      {
+        case 'P':
+          return function_key::f1;
+        case 'Q':
+          return function_key::f2;
+        case 'R':
+          return function_key::f3;
+        case 'S':
+          return function_key::f4;
+        default:
+          return std::nullopt;
+      }
+    }
+
   }  // namespace detail
 
   //! Policy for decoding standard ANSI/VT escape sequences.
   export struct ansi_policy
   {
-    //! Resolve a VT220 keypad sequence and emit the corresponding navigation event.
+    //! Resolve a VT220 keypad sequence and emit the corresponding navigation or function event.
     //!
     //! @param buffer The CSI parameter buffer.
-    //! @param sink The event sink to receive the resolved navigation event.
+    //! @param sink The event sink to receive the resolved event.
     constexpr auto static resolve_vt220_keypad(std::string & buffer, event_sink auto & sink) -> void
     {
       if (buffer.empty())
@@ -72,9 +159,16 @@ namespace ttwhy::terminal
         return;
       }
 
-      if (auto key = detail::map_vt220_keypad(buffer.front()))
+      if (auto code = detail::parse_primary_parameter(buffer))
       {
-        sink(navigation_event{*key});
+        if (auto key = detail::map_vt220_navigation(*code))
+        {
+          sink(navigation_event{*key});
+        }
+        else if (auto key = detail::map_vt220_function(*code))
+        {
+          sink(function_key_event{*key});
+        }
       }
       buffer.clear();
     }
@@ -91,16 +185,20 @@ namespace ttwhy::terminal
       }
     }
 
-    //! Resolve an SS3 single-shift sequence and emit the corresponding navigation event.
+    //! Resolve an SS3 single-shift sequence and emit the corresponding navigation or function event.
     //!
     //! @param terminator The SS3 terminator character indicating direction or key.
-    //! @param sink The event sink to receive the resolved navigation event.
+    //! @param sink The event sink to receive the resolved event.
     constexpr auto static resolve_ss3(char terminator, event_sink auto & sink) -> void
     {
       if (auto key = detail::map_vt100_cursor(terminator))
       {
         sink(navigation_event{*key});
       }
+      else if (auto key = detail::map_ss3_function(terminator))
+      {
+        sink(function_key_event{*key});
+      }
     }
   };
 
@@ -120,6 +218,12 @@ namespace ttwhy::terminal
       }
 
       auto modifier_string = buffer.substr(delimiter + 1);
+      auto next_delimiter = modifier_string.find(';');
+      if (next_delimiter != std::string_view::npos)
+      {
+        modifier_string = modifier_string.substr(0, next_delimiter);
+      }
+
       auto modifier_value = 0u;
 
       for (auto character : modifier_string)
@@ -138,10 +242,10 @@ namespace ttwhy::terminal
       return static_cast<modifier_set>(modifier_value - 1);
     }
 
-    //! Resolve a VT220 keypad sequence with modifiers and emit the navigation event.
+    //! Resolve a VT220 keypad sequence with modifiers and emit the navigation or function event.
     //!
     //! @param buffer The CSI parameter buffer containing key and modifier values.
-    //! @param sink The event sink to receive the resolved navigation event.
+    //! @param sink The event sink to receive the resolved event.
     constexpr auto static resolve_vt220_keypad(std::string & buffer, event_sink auto & sink) -> void
     {
       if (buffer.empty())
@@ -151,9 +255,16 @@ namespace ttwhy::terminal
 
       auto modifiers = parse_modifiers(buffer);
 
-      if (auto key = detail::map_vt220_keypad(buffer.front()))
+      if (auto code = detail::parse_primary_parameter(buffer))
       {
-        sink(navigation_event{*key, modifiers});
+        if (auto key = detail::map_vt220_navigation(*code))
+        {
+          sink(navigation_event{*key, modifiers});
+        }
+        else if (auto key = detail::map_vt220_function(*code))
+        {
+          sink(function_key_event{*key, modifiers});
+        }
       }
       buffer.clear();
     }
@@ -173,16 +284,20 @@ namespace ttwhy::terminal
       }
     }
 
-    //! Resolve an SS3 single-shift sequence and emit the corresponding navigation event.
+    //! Resolve an SS3 single-shift sequence and emit the corresponding navigation or function event.
     //!
     //! @param terminator The SS3 terminator character indicating direction or key.
-    //! @param sink The event sink to receive the resolved navigation event.
+    //! @param sink The event sink to receive the resolved event.
     constexpr auto static resolve_ss3(char terminator, event_sink auto & sink) -> void
     {
       if (auto key = detail::map_vt100_cursor(terminator))
       {
         sink(navigation_event{*key});
       }
+      else if (auto key = detail::map_ss3_function(terminator))
+      {
+        sink(function_key_event{*key});
+      }
     }
   };