add ClearToEndOfLine

src/render/terminfo.rs

@@ -2,7 +2,7 @@
 use caps::{Capabilities, ColorLevel};
 use cell::{AttributeChange, Blink, CellAttributes, Intensity, Underline};
 use color::{ColorAttribute, ColorSpec};
-use escape::csi::{Cursor, Edit, EraseInDisplay, Sgr, CSI};
+use escape::csi::{Cursor, Edit, EraseInDisplay, EraseInLine, Sgr, CSI};
 use escape::osc::OperatingSystemCommand;
 use failure;
 use screen::{Change, Position};
@@ -307,6 +307,30 @@ impl TerminfoRenderer {
                         out.write(buf.as_slice())?;
                     }
                 }
+                Change::ClearToEndOfLine(color) => {
+                    // ClearScreen implicitly resets all to default
+                    let defaults = CellAttributes::default()
+                        .set_background(color.clone())
+                        .clone();
+                    if self.current_attr != defaults {
+                        self.pending_attr = Some(defaults);
+                        self.flush_pending_attr(out)?;
+                    }
+                    self.pending_attr = None;
+
+                    // FIXME: this doesn't behave correctly for terminals without bce.
+                    // If we knew the current cursor position, we would be able to
+                    // emit the correctly colored background for that case.
+                    if let Some(clr) = self.get_capability::<cap::ClrEol>() {
+                        clr.expand().to(out.by_ref())?;
+                    } else {
+                        write!(
+                            out,
+                            "{}",
+                            CSI::Edit(Edit::EraseInLine(EraseInLine::EraseToEndOfLine))
+                        )?;
+                    }
+                }
                 Change::Attribute(AttributeChange::Intensity(value)) => {
                     record!(set_intensity, value);
                 }

src/render/windows.rs

@@ -153,6 +153,23 @@ impl WindowsConsoleRenderer {
                     )?;
                     out.set_cursor_position(0, info.srWindow.Top)?;
                 }
+                Change::ClearToEndOfLine(color) => {
+                    out.flush()?;
+                    self.current_attr = CellAttributes::default()
+                        .set_background(color.clone())
+                        .clone();
+
+                    let info = out.get_buffer_info()?;
+                    let width =
+                        (info.dwSize.X as u32).saturating_sub(info.dwCursorPosition.X as u32);
+                    out.fill_char(' ', info.dwCursorPosition.X, info.dwCursorPosition.Y, width)?;
+                    out.fill_attr(
+                        to_attr_word(&self.current_attr),
+                        info.dwCursorPosition.X,
+                        info.dwCursorPosition.Y,
+                        width,
+                    )?;
+                }
                 Change::Text(text) => {
                     out.flush()?;
                     out.set_attr(to_attr_word(&self.current_attr))?;

src/screen.rs

@@ -40,8 +40,10 @@ pub enum Change {
     /// Implicitly clears all attributes prior to clearing the screen.
     /// Moves the cursor to the home position (top left).
     ClearScreen(ColorAttribute),
-    //   ClearToStartOfLine,
+    /// Clear from the current cursor X position to the rightmost
-    //   ClearToEndOfLine,
+    /// edge of the screen.  The background color is set to the
+    /// provided color.  The cursor position remains unchanged.
+    ClearToEndOfLine(ColorAttribute),
     //   ClearToEndOfScreen,
     /// Move the cursor to the specified `Position`.
     CursorPosition { x: Position, y: Position },
@@ -247,6 +249,7 @@ impl Screen {
             Change::Attribute(change) => self.change_attribute(change),
             Change::CursorPosition { x, y } => self.set_cursor_pos(x, y),
             Change::ClearScreen(color) => self.clear_screen(color),
+            Change::ClearToEndOfLine(color) => self.clear_eol(color),
         }
     }
 
@@ -262,6 +265,16 @@ impl Screen {
         }
     }
 
+    fn clear_eol(&mut self, color: &ColorAttribute) {
+        self.attributes = CellAttributes::default()
+            .set_background(color.clone())
+            .clone();
+        let cleared = Cell::new(' ', self.attributes.clone());
+        for cell in self.lines[self.ypos].cells.iter_mut().skip(self.xpos) {
+            *cell = cleared.clone();
+        }
+    }
+
     fn scroll_screen_up(&mut self) {
         self.lines.remove(0);
         self.lines.push(Line::with_width(self.width));
@@ -725,6 +738,26 @@ mod test {
         assert_eq!(s.screen_chars_to_string(), "  \n  \n");
     }
 
+    #[test]
+    fn clear_eol() {
+        let mut s = Screen::new(3, 3);
+        s.add_change("helwowfoo");
+        s.add_change(Change::ClearToEndOfLine(Default::default()));
+        assert_eq!(s.screen_chars_to_string(), "hel\nwow\nfoo\n");
+        s.add_change(Change::CursorPosition {
+            x: Position::Absolute(0),
+            y: Position::Absolute(0),
+        });
+        s.add_change(Change::ClearToEndOfLine(Default::default()));
+        assert_eq!(s.screen_chars_to_string(), "   \nwow\nfoo\n");
+        s.add_change(Change::CursorPosition {
+            x: Position::Absolute(1),
+            y: Position::Absolute(1),
+        });
+        s.add_change(Change::ClearToEndOfLine(Default::default()));
+        assert_eq!(s.screen_chars_to_string(), "   \nw  \nfoo\n");
+    }
+
     #[test]
     fn cursor_movement() {
         let mut s = Screen::new(4, 3);