Add PaddedView

src/views/mod.rs

@@ -51,6 +51,7 @@ mod list_view;
 mod menu_popup;
 mod menubar;
 mod on_event_view;
+mod padded_view;
 mod panel;
 mod progress_bar;
 mod radio;
@@ -81,6 +82,7 @@ pub use self::list_view::{ListChild, ListView};
 pub use self::menu_popup::MenuPopup;
 pub use self::menubar::Menubar;
 pub use self::on_event_view::OnEventView;
+pub use self::padded_view::PaddedView;
 pub use self::panel::Panel;
 pub use self::progress_bar::ProgressBar;
 pub use self::radio::{RadioButton, RadioGroup};

src/views/padded_view.rs

@@ -0,0 +1,65 @@
+use event::{Event, EventResult};
+use vec::Vec2;
+use view::{Margins, View, ViewWrapper};
+use Printer;
+
+/// Adds padding to another view.
+///
+/// This view wraps another view and adds some padding.
+///
+/// The wrapped view will see a reduced space available.
+///
+/// # Examples
+///
+/// ```rust
+/// # use cursive::views::{TextView, PaddedView};
+/// // Adds 2 columns of padding to the left and to the right.
+/// let view = PaddedView::new(
+///     ((2,2), (0,0)), // ((left, right), (top, bottom))
+///     TextView::new("Padded text")
+/// );
+/// ```
+pub struct PaddedView<V> {
+    view: V,
+    margins: Margins,
+}
+
+impl<V: View> PaddedView<V> {
+    /// Wraps `view` in a new `PaddedView` with the given margins.
+    pub fn new<M: Into<Margins>>(margins: M, view: V) -> Self {
+        let margins = margins.into();
+        PaddedView { view, margins }
+    }
+
+    /// Sets the margins for this view.
+    pub fn set_margins<M: Into<Margins>>(&mut self, margins: M) {
+        // TODO: invalidate?
+        self.margins = margins.into();
+    }
+}
+
+impl<V: View> ViewWrapper for PaddedView<V> {
+    wrap_impl!(self.view: V);
+
+    fn wrap_required_size(&mut self, req: Vec2) -> Vec2 {
+        let margins = self.margins.combined();
+        self.view.required_size(req.saturating_sub(margins)) + margins
+    }
+
+    fn wrap_layout(&mut self, size: Vec2) {
+        let margins = self.margins.combined();
+        self.view.layout(size.saturating_sub(margins));
+    }
+
+    fn wrap_on_event(&mut self, event: Event) -> EventResult {
+        let padding = self.margins.top_left();
+        self.view.on_event(event.relativized(padding))
+    }
+
+    fn wrap_draw(&self, printer: &Printer) {
+        let top_left = self.margins.top_left();
+        let bot_right = self.margins.bot_right();
+        let printer = &printer.offset(top_left).shrinked(bot_right);
+        self.view.draw(printer);
+    }
+}

src/views/shadow_view.rs

@@ -11,6 +11,7 @@ pub struct ShadowView<T: View> {
     view: T,
     top_padding: bool,
     left_padding: bool,
+    // TODO: invalidate if we change the padding?
 }
 
 impl<T: View> ShadowView<T> {