refactor: simplify to io::Result (#1016)

Simplifies the code, logic stays exactly the same.

Author: EdJoPaTo

src/backend/crossterm.rs

@@ -228,7 +228,7 @@ where
         Ok(Rect::new(0, 0, width, height))
     }
 
-    fn window_size(&mut self) -> Result<WindowSize, io::Error> {
+    fn window_size(&mut self) -> io::Result<WindowSize> {
         let crossterm::terminal::WindowSize {
             columns,
             rows,

src/backend/termion.rs

@@ -198,7 +198,7 @@ where
         Ok(Rect::new(0, 0, terminal.0, terminal.1))
     }
 
-    fn window_size(&mut self) -> Result<WindowSize, io::Error> {
+    fn window_size(&mut self) -> io::Result<WindowSize> {
         Ok(WindowSize {
             columns_rows: termion::terminal_size()?.into(),
             pixels: termion::terminal_size_pixels()?.into(),

src/backend/termwiz.rs

@@ -111,7 +111,7 @@ impl TermwizBackend {
 }
 
 impl Backend for TermwizBackend {
-    fn draw<'a, I>(&mut self, content: I) -> Result<(), io::Error>
+    fn draw<'a, I>(&mut self, content: I) -> io::Result<()>
     where
         I: Iterator<Item = (u16, u16, &'a Cell)>,
     {
@@ -181,13 +181,13 @@ impl Backend for TermwizBackend {
         Ok(())
     }
 
-    fn hide_cursor(&mut self) -> Result<(), io::Error> {
+    fn hide_cursor(&mut self) -> io::Result<()> {
         self.buffered_terminal
             .add_change(Change::CursorVisibility(CursorVisibility::Hidden));
         Ok(())
     }
 
-    fn show_cursor(&mut self) -> Result<(), io::Error> {
+    fn show_cursor(&mut self) -> io::Result<()> {
         self.buffered_terminal
             .add_change(Change::CursorVisibility(CursorVisibility::Visible));
         Ok(())
@@ -207,18 +207,18 @@ impl Backend for TermwizBackend {
         Ok(())
     }
 
-    fn clear(&mut self) -> Result<(), io::Error> {
+    fn clear(&mut self) -> io::Result<()> {
         self.buffered_terminal
             .add_change(Change::ClearScreen(termwiz::color::ColorAttribute::Default));
         Ok(())
     }
 
-    fn size(&self) -> Result<Rect, io::Error> {
+    fn size(&self) -> io::Result<Rect> {
         let (cols, rows) = self.buffered_terminal.dimensions();
         Ok(Rect::new(0, 0, u16_max(cols), u16_max(rows)))
     }
 
-    fn window_size(&mut self) -> Result<WindowSize, io::Error> {
+    fn window_size(&mut self) -> io::Result<WindowSize> {
         let ScreenSize {
             cols,
             rows,
@@ -241,7 +241,7 @@ impl Backend for TermwizBackend {
         })
     }
 
-    fn flush(&mut self) -> Result<(), io::Error> {
+    fn flush(&mut self) -> io::Result<()> {
         self.buffered_terminal
             .flush()
             .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;

src/backend/test.rs

@@ -114,7 +114,7 @@ impl Display for TestBackend {
 }
 
 impl Backend for TestBackend {
-    fn draw<'a, I>(&mut self, content: I) -> Result<(), io::Error>
+    fn draw<'a, I>(&mut self, content: I) -> io::Result<()>
     where
         I: Iterator<Item = (u16, u16, &'a Cell)>,
     {
@@ -125,26 +125,26 @@ impl Backend for TestBackend {
         Ok(())
     }
 
-    fn hide_cursor(&mut self) -> Result<(), io::Error> {
+    fn hide_cursor(&mut self) -> io::Result<()> {
         self.cursor = false;
         Ok(())
     }
 
-    fn show_cursor(&mut self) -> Result<(), io::Error> {
+    fn show_cursor(&mut self) -> io::Result<()> {
         self.cursor = true;
         Ok(())
     }
 
-    fn get_cursor(&mut self) -> Result<(u16, u16), io::Error> {
+    fn get_cursor(&mut self) -> io::Result<(u16, u16)> {
         Ok(self.pos)
     }
 
-    fn set_cursor(&mut self, x: u16, y: u16) -> Result<(), io::Error> {
+    fn set_cursor(&mut self, x: u16, y: u16) -> io::Result<()> {
         self.pos = (x, y);
         Ok(())
     }
 
-    fn clear(&mut self) -> Result<(), io::Error> {
+    fn clear(&mut self) -> io::Result<()> {
         self.buffer.reset();
         Ok(())
     }
@@ -214,11 +214,11 @@ impl Backend for TestBackend {
         Ok(())
     }
 
-    fn size(&self) -> Result<Rect, io::Error> {
+    fn size(&self) -> io::Result<Rect> {
         Ok(Rect::new(0, 0, self.width, self.height))
     }
 
-    fn window_size(&mut self) -> Result<WindowSize, io::Error> {
+    fn window_size(&mut self) -> io::Result<WindowSize> {
         // Some arbitrary window pixel size, probably doesn't need much testing.
         static WINDOW_PIXEL_SIZE: Size = Size {
             width: 640,
@@ -230,7 +230,7 @@ impl Backend for TestBackend {
         })
     }
 
-    fn flush(&mut self) -> Result<(), io::Error> {
+    fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
 }