Cursor shape support

src/terminal/terminaldisplay.cc

@@ -119,6 +119,11 @@ std::string Display::new_frame( bool initialized, const Framebuffer& last, const
     frame.append( tmp );
   }
 
+  if ( f.ds.cursor_shape != frame.last_frame.ds.cursor_shape && f.ds.cursor_shape != -1 ) {
+    snprintf(tmp, sizeof(tmp), "\033[%d q", f.ds.cursor_shape);
+    frame.append(tmp);
+  }
+
   /* has size changed? */
   if ( ( !initialized ) || ( f.ds.get_width() != frame.last_frame.ds.get_width() )
        || ( f.ds.get_height() != frame.last_frame.ds.get_height() ) ) {

src/terminal/terminalframebuffer.cc

@@ -64,9 +64,9 @@ DrawState::DrawState( int s_width, int s_height )
     combining_char_row( 0 ), default_tabs( true ), tabs( s_width ), scrolling_region_top_row( 0 ),
     scrolling_region_bottom_row( height - 1 ), renditions( 0 ), save(), next_print_will_wrap( false ),
     origin_mode( false ), auto_wrap_mode( true ), insert_mode( false ), cursor_visible( true ),
-    reverse_video( false ), bracketed_paste( false ), mouse_reporting_mode( MOUSE_REPORTING_NONE ),
-    mouse_focus_event( false ), mouse_alternate_scroll( false ), mouse_encoding_mode( MOUSE_ENCODING_DEFAULT ),
-    application_mode_cursor_keys( false )
+    reverse_video( false ), bracketed_paste( false ), cursor_shape( -1 ),
+    mouse_reporting_mode( MOUSE_REPORTING_NONE ), mouse_focus_event( false ), mouse_alternate_scroll( false ),
+    mouse_encoding_mode( MOUSE_ENCODING_DEFAULT ), application_mode_cursor_keys( false )
 {
   reinitialize_tabs( 0 );
 }

src/terminal/terminalframebuffer.h

@@ -255,6 +255,8 @@ class SavedCursor
 class DrawState
 {
 private:
+  static const int cursor_shape_count = 7; /* 0-6 are valid cursor control code */
+
   int width, height;
 
   void new_grapheme( void );
@@ -282,6 +284,7 @@ class DrawState
   bool cursor_visible;
   bool reverse_video;
   bool bracketed_paste;
+  int cursor_shape;
 
   enum MouseReportingMode
   {
@@ -317,6 +320,12 @@ class DrawState
   int get_combining_char_row( void ) const { return combining_char_row; }
   int get_width( void ) const { return width; }
   int get_height( void ) const { return height; }
+  void set_cursor_shape(int shape)
+  {
+    if ( shape >= 0 && shape < cursor_shape_count ) {
+      cursor_shape = shape;
+    }
+  }
 
   void set_tab( void );
   void clear_tab( int col );
@@ -355,7 +364,7 @@ class DrawState
            && ( reverse_video == x.reverse_video ) && ( renditions == x.renditions )
            && ( bracketed_paste == x.bracketed_paste ) && ( mouse_reporting_mode == x.mouse_reporting_mode )
            && ( mouse_focus_event == x.mouse_focus_event ) && ( mouse_alternate_scroll == x.mouse_alternate_scroll )
-           && ( mouse_encoding_mode == x.mouse_encoding_mode );
+           && ( mouse_encoding_mode == x.mouse_encoding_mode ) && (cursor_shape == x.cursor_shape);
   }
 };
 

src/terminal/terminalfunctions.cc

@@ -134,6 +134,17 @@ static Function func_CSI_cursormove_D( CSI, "D", CSI_cursormove );
 static Function func_CSI_cursormove_H( CSI, "H", CSI_cursormove );
 static Function func_CSI_cursormove_f( CSI, "f", CSI_cursormove );
 
+/* cursor shape */
+static void CSI_cursorshape( Framebuffer* fb, Dispatcher* dispatch )
+{
+  int shape = dispatch->getparam( 0, -1 );
+
+  fb->ds.set_cursor_shape(shape);
+}
+
+static Function func_CSI_cursorshape( CSI, " q", CSI_cursorshape );
+
+
 /* device attributes */
 static void CSI_DA( Framebuffer* fb __attribute( ( unused ) ), Dispatcher* dispatch )
 {

src/tests/emulation-cursor-shape.test

@@ -0,0 +1,44 @@
+#!/bin/sh
+
+#
+# This test exercises the cursor shape ascii sequence in Mosh.
+#
+
+# shellcheck source=e2e-test-subrs
+. "$(dirname "$0")/e2e-test-subrs"
+PATH=$PATH:.:$srcdir
+# Top-level wrapper.
+if [ $# -eq 0 ]; then
+    e2e-test "$0" baseline direct verify
+    exit
+fi
+
+# OK, we have arguments, we're one of the test hooks.
+if [ $# -ne 1 ]; then
+    fail "bad arguments %s\n" "$@"
+fi
+
+baseline()
+{
+    while read -r shape sleep_time text; do
+        printf '\n\033[%d q%s' "$shape" "$text"
+        sleep $sleep_time
+    done <<EOF
+0 1 Block
+1 1 Block
+2 2 BlinkBlock
+3 1 Underline
+4 2 BlinkUnderline
+5 1 Bar
+6 2 BlinkBar
+0 0 done
+EOF
+    echo
+}
+
+case $1 in
+    baseline|direct)
+        baseline;;
+    *)
+        fail "unknown test argument %s\n" "$1";;
+esac