remove Screen::show

src/layout/align.rs

@@ -40,3 +40,6 @@ fn align <S: Screen> (
         }
     })
 }
+
+#[cfg(test)] #[test] fn test_align () {
+}

src/layout/full.rs

@@ -18,6 +18,7 @@ pub enum Full<T: Screen, I: Draw<T>> {
     H(I),
     WH(I),
 }
+
 impl_draw!(<T: Screen, I: Draw<T>,>|self: Full<T, I>, to: T|{
     let XYWH(x0, y0, w0, h0) = to.area();
     match self {

src/lib.rs

@@ -1359,10 +1359,6 @@ macro_rules! eval_xy (
     /// }
     /// impl Screen for TestOut {
     ///     type Unit = u16;
-    ///     fn show (&mut self, _: impl Draw<Self>) -> Perhaps<XYWH<u16>> {
-    ///         println!("placed");
-    ///         Ok(None)
-    ///     }
     ///     fn area (&self) -> XYWH<Self::Unit> {
     ///         Default::default()
     ///     }
@@ -1382,8 +1378,6 @@ macro_rules! eval_xy (
     /// ```
     pub trait Screen: Xy<Self::Unit> + Wh<Self::Unit> + Send + Sync + Sized {
         type Unit: Coord;
-        /// Render drawable in subarea specified by `area`
-        fn show (&mut self, content: impl Draw<Self>) -> Perhaps<XYWH<Self::Unit>>;
         /// Get current clipping area
         fn area (&self) -> XYWH<Self::Unit>;
         /// Set clipping area
@@ -2612,37 +2606,15 @@ macro_rules! eval_xy (
 
         /// Get mutable reference to current clipping area
         fn area_mut (&mut self) -> &mut XYWH<u16> {
-            match self {
+            self.into()
-                Self::Draw(_, area) => area,
-                Self::Layout(area) => area,
-            }
         }
     }
 
     impl Screen for Tui {
         type Unit = u16;
-        /// Render drawable in subarea specified by `area`
-        fn show (&mut self, content: impl Draw<Self>) -> Perhaps<XYWH<u16>> {
-            let previous_area = self.area();
-            Ok(if let Some(area) = content.layout(self.area())? {
-                *self.area_mut() = area;
-                if let Some(result_area) = content.draw(self)? {
-                    *self.area_mut() = previous_area;
-                    Some(result_area)
-                } else {
-                    None
-                }
-            } else {
-                None
-            })
-        }
 
-        /// Get current clipping area
         fn area (&self) -> XYWH<Self::Unit> {
-            match self {
+            self.into()
-                Self::Draw(_, area) => *area,
-                Self::Layout(area) => *area,
-            }
         }
 
         fn clip (
@@ -2660,6 +2632,24 @@ macro_rules! eval_xy (
         }
     }
 
+    impl From<&Tui> for XYWH<u16> {
+        fn from (screen: &Tui) -> XYWH<u16> {
+            match screen {
+                Tui::Draw(_, area) => *area,
+                Tui::Layout(area) => *area,
+            }
+        }
+    }
+
+    impl<'a: 'b, 'b> From<&'a mut Tui> for &'b mut XYWH<u16> {
+        fn from (screen: &'a mut Tui) -> &'b mut XYWH<u16> {
+            match screen {
+                Tui::Draw(_, area) => area,
+                Tui::Layout(area) => area,
+            }
+        }
+    }
+
     pub const fn fill_char (c: char) -> impl Draw<Tui> {
         draw(move|to: &mut Tui|Ok(Some(to.update(&|cell,_,_|{
             cell.set_char(c);