added mouse hold support (#48)

This adds support for the escape codes generated in rxvt and xterm
format by holding a button and moving the mouse around.

examples/mouse.rs

@@ -9,20 +9,24 @@ fn main() {
     let stdin = stdin();
     let mut stdout = MouseTerminal::from(stdout().into_raw_mode().unwrap());
 
-    write!(stdout, "{}{}q to exit. Type stuff, use alt, click around...", termion::clear::All, termion::cursor::Goto(1, 1)).unwrap();
+    writeln!(stdout,
+             "{}{}q to exit. Type stuff, use alt, click around...",
+             termion::clear::All,
+             termion::cursor::Goto(1, 1))
+        .unwrap();
 
-    let mut x = 1;
+    let mut x = 5;
-    let mut y = 1;
+    let mut y = 5;
 
     for c in stdin.events() {
         let evt = c.unwrap();
-        writeln!(stdout, "{:?}{}{}", evt, termion::cursor::Goto(5, 5), termion::clear::CurrentLine).unwrap();
         match evt {
             Event::Key(Key::Char('q')) => break,
             Event::Mouse(me) => {
                 match me {
                     MouseEvent::Press(_, a, b) |
-                    MouseEvent::Release(a, b) => {
+                    MouseEvent::Release(a, b) |
+                    MouseEvent::Hold(a, b) => {
                         x = a;
                         y = b;
                     }
@@ -30,7 +34,13 @@ fn main() {
             }
             _ => {}
         }
-        writeln!(stdout, "{:?}{}", evt, termion::cursor::Goto(x, y)).unwrap();
+        write!(stdout,
+               "{}{}  {:?}{}",
+               termion::clear::All,
+               termion::cursor::Goto(x, y),
+               evt,
+               termion::cursor::Goto(x, y))
+            .unwrap();
         stdout.flush().unwrap();
     }
 

src/event.rs

@@ -26,6 +26,10 @@ pub enum MouseEvent {
     ///
     /// The coordinates are one-based.
     Release(u16, u16),
+    /// A mouse button is held over the given coordinates.
+    ///
+    /// The coordinates are one-based.
+    Hold(u16, u16),
 }
 
 /// A mouse button.
@@ -159,6 +163,8 @@ where I: Iterator<Item = Result<u8, Error>>
                             let cx = nums.next().unwrap().parse::<u16>().unwrap();
                             let cy = nums.next().unwrap().parse::<u16>().unwrap();
 
+                            let event = match cb {
+                                0...2 | 64...65 => {
                                     let button = match cb {
                                         0 => MouseButton::Left,
                                         1 => MouseButton::Middle,
@@ -167,12 +173,18 @@ where I: Iterator<Item = Result<u8, Error>>
                                         65 => MouseButton::WheelDown,
                                         _ => return error,
                                     };
-                            Event::Mouse(match c {
+                                    match c {
                                         b'M' => MouseEvent::Press(button, cx, cy),
                                         b'm' => MouseEvent::Release(cx, cy),
                                         _ => return error,
 
-                            })
+                                    }
+                                }
+                                32 => MouseEvent::Hold(cx, cy),
+                                _ => return error,
+                            };
+
+                            Event::Mouse(event)
                         }
                         Some(Ok(c @ b'0'...b'9')) => {
                             // Numbered escape code.
@@ -203,6 +215,7 @@ where I: Iterator<Item = Result<u8, Error>>
                                         33 => MouseEvent::Press(MouseButton::Middle, cx, cy),
                                         34 => MouseEvent::Press(MouseButton::Right, cx, cy),
                                         35 => MouseEvent::Release(cx, cy),
+                                        64 => MouseEvent::Hold(cx, cy),
                                         96 |
                                         97 => MouseEvent::Press(MouseButton::WheelUp, cx, cy),
                                         _ => return error,