Add basis for ScrollView

src/printer.rs

@@ -14,15 +14,24 @@ use vec::Vec2;
 pub struct Printer<'a> {
     /// Offset into the window this printer should start drawing at.
     pub offset: Vec2,
+
+    /// Offset into the view for this printer.
+    pub content_offset: Vec2,
+
     /// Size of the area we are allowed to draw on.
+    ///
+    /// Anything outside of this should be discarded.
     pub size: Vec2,
+
     /// Whether the view to draw is currently focused or not.
     pub focused: bool,
+
     /// Currently used theme
     pub theme: &'a Theme,
 
     /// `true` if nothing has been drawn yet.
     new: Rc<Cell<bool>>,
+
     /// Backend used to actually draw things
     backend: &'a backend::Concrete,
 }
@@ -37,6 +46,7 @@ impl<'a> Printer<'a> {
     ) -> Self {
         Printer {
             offset: Vec2::zero(),
+            content_offset: Vec2::zero(),
             size: size.into(),
             focused: true,
             theme: theme,

src/views/mod.rs

@@ -53,6 +53,7 @@ mod menu_popup;
 mod panel;
 mod progress_bar;
 mod radio;
+mod scroll_view;
 mod select_view;
 mod slider_view;
 mod shadow_view;
@@ -79,6 +80,7 @@ pub use self::on_event_view::OnEventView;
 pub use self::panel::Panel;
 pub use self::progress_bar::{Counter, ProgressBar};
 pub use self::radio::{RadioButton, RadioGroup};
+pub use self::scroll_view::ScrollView;
 pub use self::select_view::SelectView;
 pub use self::shadow_view::ShadowView;
 pub use self::sized_view::SizedView;

src/views/scroll_view.rs

@@ -0,0 +1,17 @@
+use view::View;
+use Printer;
+use vec::Vec2;
+
+/// Wraps a view in a scrollable area.
+pub struct ScrollView<V> {
+    inner: V,
+    offset: Vec2,
+}
+
+impl <V> View for ScrollView<V> where V: View {
+
+    fn draw(&self, printer: &Printer) {
+        self.printer.offset
+        self.inner.draw(printer);
+    }
+}