ensure that we set the cursor attributes

Set the cursor to match the positioning info reported
by the focused widget

examples/widgets_basic.rs

@@ -1,7 +1,10 @@
+//! This example shows how to make a basic widget that accumulates
+//! text input and renders it to the screen
 extern crate failure;
 extern crate termwiz;
 
 use failure::Error;
+use std::cell::Cell;
 use termwiz::caps::Capabilities;
 use termwiz::color::AnsiColor;
 use termwiz::input::*;
@@ -14,6 +17,7 @@ use termwiz::widgets::*;
 #[derive(Default)]
 struct MainScreen {
     buf: String,
+    cursor: Cell<ParentRelativeCoords>,
 }
 
 impl WidgetImpl for MainScreen {
@@ -45,6 +49,18 @@ impl WidgetImpl for MainScreen {
     fn render_to_surface(&self, surface: &mut Surface) {
         surface.add_change(Change::ClearScreen(AnsiColor::Blue.into()));
         surface.add_change(self.buf.clone());
+        // Allow the surface rendering code to figure out where the
+        // cursor ends up, then stash a copy of that information for
+        // later retrieval by get_cursor_shape_and_position().
+        let (x, y) = surface.cursor_position();
+        self.cursor.set(ParentRelativeCoords::new(x, y));
+    }
+
+    fn get_cursor_shape_and_position(&self) -> CursorShapeAndPosition {
+        CursorShapeAndPosition {
+            coords: self.cursor.get(),
+            ..Default::default()
+        }
     }
 }
 

src/render/terminfo.rs

@@ -6,7 +6,7 @@ use escape::csi::{Cursor, Edit, EraseInDisplay, EraseInLine, Sgr, CSI};
 use escape::osc::OperatingSystemCommand;
 use failure;
 use std::io::{Read, Write};
-use surface::{Change, Position};
+use surface::{Change, CursorShape, Position};
 use terminal::unix::UnixTty;
 use terminfo::{capability as cap, Capability as TermInfoCapability};
 
@@ -14,6 +14,8 @@ pub struct TerminfoRenderer {
     caps: Capabilities,
     current_attr: CellAttributes,
     pending_attr: Option<CellAttributes>,
+    /* TODO: we should record cursor position, shape and color here
+     * so that we can optimize updating them on screen. */
 }
 
 impl TerminfoRenderer {
@@ -477,6 +479,39 @@ impl TerminfoRenderer {
                         change
                     );
                 }
+                Change::CursorColor(_color) => {
+                    // TODO: this isn't spec'd by terminfo, but some terminals
+                    // support it.  Add this to capabilities?
+                }
+                Change::CursorShape(shape) => match shape {
+                    CursorShape::Default => {
+                        if let Some(reset) = self.get_capability::<cap::ResetCursorStyle>() {
+                            reset.expand().to(out.by_ref())?;
+                        }
+                    }
+                    CursorShape::Hidden => {
+                        if let Some(hide) = self.get_capability::<cap::CursorInvisible>() {
+                            hide.expand().to(out.by_ref())?;
+                        }
+                    }
+                    _ => {
+                        if let Some(show) = self.get_capability::<cap::CursorVisible>() {
+                            show.expand().to(out.by_ref())?;
+                        }
+                        let param = match shape {
+                            CursorShape::Default | CursorShape::Hidden => unreachable!(),
+                            CursorShape::BlinkingBlock => 1,
+                            CursorShape::SteadyBlock => 2,
+                            CursorShape::BlinkingUnderline => 3,
+                            CursorShape::SteadyUnderline => 4,
+                            CursorShape::BlinkingBar => 6,
+                            CursorShape::SteadyBar => 7,
+                        };
+                        if let Some(set) = self.get_capability::<cap::SetCursorStyle>() {
+                            set.expand().kind(param).to(out.by_ref())?;
+                        }
+                    }
+                },
             }
         }
 

src/render/windows.rs

@@ -260,6 +260,8 @@ impl WindowsConsoleRenderer {
                 Change::AllAttributes(all) => {
                     self.current_attr = all.clone();
                 }
+                Change::CursorColor(_color) => {}
+                Change::CursorShape(_shape) => {}
             }
         }
         out.flush()?;

src/surface.rs

@@ -19,6 +19,24 @@ pub enum Position {
     EndRelative(usize),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CursorShape {
+    Hidden,
+    Default,
+    BlinkingBlock,
+    SteadyBlock,
+    BlinkingUnderline,
+    SteadyUnderline,
+    BlinkingBar,
+    SteadyBar,
+}
+
+impl Default for CursorShape {
+    fn default() -> CursorShape {
+        CursorShape::Default
+    }
+}
+
 /// `Change` describes an update operation to be applied to a `Surface`.
 /// Changes to the active attributes (color, style), moving the cursor
 /// and outputting text are examples of some of the values.
@@ -52,8 +70,11 @@ pub enum Change {
     ClearToEndOfScreen(ColorAttribute),
     /// Move the cursor to the specified `Position`.
     CursorPosition { x: Position, y: Position },
-    /*   CursorVisibility(bool),
-     *   ChangeScrollRegion{top: usize, bottom: usize}, */
+    /// Change the cursor color.
+    CursorColor(ColorAttribute),
+    /// Change the cursor shape
+    CursorShape(CursorShape),
+    /* ChangeScrollRegion{top: usize, bottom: usize}, */
 }
 
 impl Change {
@@ -206,6 +227,8 @@ pub struct Surface {
     ypos: usize,
     seqno: SequenceNo,
     changes: Vec<Change>,
+    cursor_shape: CursorShape,
+    cursor_color: ColorAttribute,
 }
 
 impl Surface {
@@ -225,6 +248,10 @@ impl Surface {
         (self.width, self.height)
     }
 
+    pub fn cursor_position(&self) -> (usize, usize) {
+        (self.xpos, self.ypos)
+    }
+
     /// Resize the Surface to the specified width and height.
     /// If the width and/or height are smaller than previously, the rows and/or
     /// columns are truncated.  If the width and/or height are larger than
@@ -294,6 +321,8 @@ impl Surface {
             Change::ClearScreen(color) => self.clear_screen(color),
             Change::ClearToEndOfLine(color) => self.clear_eol(color),
             Change::ClearToEndOfScreen(color) => self.clear_eos(color),
+            Change::CursorColor(color) => self.cursor_color = color.clone(),
+            Change::CursorShape(shape) => self.cursor_shape = shape.clone(),
         }
     }
 

src/terminal/buffered.rs

@@ -55,7 +55,7 @@ impl<T: Terminal> BufferedTerminal<T> {
             // renders all.
             self.seqno = 0;
             self.terminal.render(&changes)?;
-            self.terminal.flush()?;
+            //self.terminal.flush()?;
             self.seqno = seq;
         }
         self.surface.flush_changes_older_than(self.seqno);

src/widgets/mod.rs

@@ -1,7 +1,8 @@
+use color::ColorAttribute;
 use input::InputEvent;
 use std::cell::{Ref, RefCell, RefMut};
 use std::rc::{Rc, Weak};
-use surface::{SequenceNo, Surface};
+use surface::{Change, CursorShape, Position, SequenceNo, Surface};
 
 /// Describes an event that may need to be processed by the widget
 pub enum WidgetEvent {
@@ -46,6 +47,13 @@ impl SizeConstraints {
     }
 }
 
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct CursorShapeAndPosition {
+    pub shape: CursorShape,
+    pub coords: ParentRelativeCoords,
+    pub color: ColorAttribute,
+}
+
 pub trait WidgetImpl {
     /// Called once by the widget manager to inform the widget
     /// of its identifier
@@ -58,12 +66,17 @@ pub trait WidgetImpl {
     fn get_size_constraints(&self) -> SizeConstraints;
 
     fn render_to_surface(&self, surface: &mut Surface);
+
+    /// Called for the focused widget to determine how to render
+    /// the cursor.
+    fn get_cursor_shape_and_position(&self) -> CursorShapeAndPosition;
 }
 
 /// Relative to the top left of the parent container
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub struct ParentRelativeCoords {
-    x: usize,
-    y: usize,
+    pub x: usize,
+    pub y: usize,
 }
 
 impl ParentRelativeCoords {
@@ -73,9 +86,10 @@ impl ParentRelativeCoords {
 }
 
 /// Relative to the top left of the screen
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub struct ScreenRelativeCoords {
-    x: usize,
-    y: usize,
+    pub x: usize,
+    pub y: usize,
 }
 
 impl ScreenRelativeCoords {
@@ -192,6 +206,25 @@ impl Widget {
     pub fn add_child(&mut self, widget: &WidgetHandle) {
         self.children.push(widget.clone());
     }
+
+    pub fn to_screen_coords(&self, coords: &ParentRelativeCoords) -> ScreenRelativeCoords {
+        let mut x = coords.x;
+        let mut y = coords.y;
+        let mut widget = self.parent();
+        loop {
+            let parent = match widget {
+                Some(parent) => {
+                    let p = parent.borrow();
+                    x += p.coordinates.x;
+                    y += p.coordinates.y;
+                    p.parent()
+                }
+                None => break,
+            };
+            widget = parent;
+        }
+        ScreenRelativeCoords { x, y }
+    }
 }
 
 pub struct Screen {
@@ -243,5 +276,18 @@ impl Screen {
     /// and then progresses up through its children.
     pub fn render_to_screen(&mut self, screen: &mut Surface) {
         self.root_widget.borrow_mut().render_to_screen(screen);
+
+        let focused = self.focused_widget.borrow();
+        let cursor = focused.inner.get_cursor_shape_and_position();
+        let coords = focused.to_screen_coords(&cursor.coords);
+
+        screen.add_changes(vec![
+            Change::CursorShape(cursor.shape),
+            Change::CursorColor(cursor.color),
+            Change::CursorPosition {
+                x: Position::Absolute(coords.x),
+                y: Position::Absolute(coords.y),
+            },
+        ]);
     }
 }