Draft Editor API and TextEditor widget

core/src/renderer/null.rs

@@ -43,6 +43,7 @@ impl Renderer for Null {
 impl text::Renderer for Null {
     type Font = Font;
     type Paragraph = ();
+    type Editor = ();
 
     const ICON_FONT: Font = Font::DEFAULT;
     const CHECKMARK_ICON: char = '0';
@@ -66,6 +67,14 @@ impl text::Renderer for Null {
     ) {
     }
 
+    fn fill_editor(
+        &mut self,
+        _editor: &Self::Editor,
+        _position: Point,
+        _color: Color,
+    ) {
+    }
+
     fn fill_text(
         &mut self,
         _paragraph: Text<'_, Self::Font>,
@@ -106,3 +115,32 @@ impl text::Paragraph for () {
         None
     }
 }
+
+impl text::Editor for () {
+    type Font = Font;
+
+    fn with_text(_text: &str) -> Self {}
+
+    fn cursor(&self) -> text::editor::Cursor {
+        text::editor::Cursor::Caret(Point::ORIGIN)
+    }
+
+    fn perform(&mut self, _action: text::editor::Action) {}
+
+    fn bounds(&self) -> Size {
+        Size::ZERO
+    }
+
+    fn min_bounds(&self) -> Size {
+        Size::ZERO
+    }
+
+    fn update(
+        &mut self,
+        _new_bounds: Size,
+        _new_font: Self::Font,
+        _new_size: Pixels,
+        _new_line_height: text::LineHeight,
+    ) {
+    }
+}