working center

src/main.rs

@@ -13,7 +13,7 @@ fn main() {
 
     screen
         .draw("Hello, World".to_string())
-        .component(Transform::new());
+        .component(Transform::center());
 
     screen.run(&mut events, &mut extensions).unwrap();
 }

src/render_scope.rs

@@ -10,8 +10,6 @@ enum RenderMethod {
 pub struct RenderScope {
     transform: RawTransform,
     render_stack: Vec<RenderMethod>,
-    width: u16,
-    height: u16,
     parent_width: u16,
     parent_height: u16,
 }
@@ -21,22 +19,22 @@ impl RenderScope {
         RenderScope {
             transform: RawTransform::new(),
             render_stack: Vec::new(),
-            width: 0,
-            height: 0,
             parent_width: 0,
             parent_height: 0,
         }
     }
 
     pub fn set_transform(&mut self, transform: &Transform) {
+        (self.parent_width, self.parent_height) = crossterm::terminal::size().unwrap();
         transform.use_dimensions(&mut self.transform);
+        transform.use_position(self.parent_width, self.parent_height, &mut self.transform);
     }
 
     pub fn draw_text(&mut self, text: &str) {
         self.render_stack.push(RenderMethod::Text(text.to_string()));
         let (w, h) = utils::str_size(text);
-        self.width = std::cmp::max(self.width, w);
-        self.height = std::cmp::max(self.height, h);
+        self.transform.width = self.transform.width.max(w);
+        self.transform.height = self.transform.height.max(h);
     }
 
     pub fn draw(&self) {

src/style.rs

@@ -58,6 +58,11 @@ impl Transform {
         self.width.use_dimension(&mut raw.width);
         self.height.use_dimension(&mut raw.height);
     }
+
+    pub fn use_position(&self, parent_width: u16, parent_height: u16, raw: &mut RawTransform) {
+        self.x.use_position(raw.width, parent_width, &mut raw.x);
+        self.y.use_position(raw.height, parent_height, &mut raw.y);
+    }
 }
 
 impl RawTransform {
@@ -74,8 +79,17 @@ impl RawTransform {
 impl Dimension {
     pub fn use_dimension(&self, r: &mut u16) {
         match self {
-            Dimension::Auto => {}
-            Dimension::Const(n) => *r = *n,
+            Self::Auto => {}
+            Self::Const(n) => *r = *n,
+        }
+    }
+}
+
+impl Position {
+    pub fn use_position(&self, size: u16, parent: u16, r: &mut u16) {
+        match self {
+            Self::Center => *r = (parent - size) / 2,
+            Self::Const(n) => *r = *n,
         }
     }
 }