Add a canvas with scroll_kids set and a list to demonstrate cropping …

…problems

backends/conrod_example_shared/src/lib.rs

@@ -22,6 +22,7 @@ pub struct DemoApp {
     ball_color: conrod_core::Color,
     sine_frequency: f32,
     rust_logo: conrod_core::image::Id,
+    list: Vec<bool>,
 }
 
 
@@ -33,6 +34,7 @@ impl DemoApp {
             ball_color: conrod_core::color::WHITE,
             sine_frequency: 1.0,
             rust_logo: rust_logo,
+            list: vec![true; 16],
         }
     }
 }
@@ -68,6 +70,9 @@ widget_ids! {
         // The title and introduction widgets.
         title,
         introduction,
+        // Nested canvas and list
+        section_canvas,
+        list,
         // Shapes.
         shapes_canvas,
         rounded_rectangle,
@@ -103,7 +108,7 @@ widget_ids! {
 
 /// Instantiate a GUI demonstrating every widget available in conrod.
 pub fn gui(ui: &mut conrod_core::UiCell, ids: &Ids, app: &mut DemoApp) {
-    use conrod_core::{widget, Colorable, Labelable, Positionable, Sizeable, Widget};
+    use conrod_core::{widget, Colorable, Borderable, Labelable, Positionable, Sizeable, Widget};
     use std::iter::once;
 
     const MARGIN: conrod_core::Scalar = 30.0;
@@ -143,6 +148,50 @@ pub fn gui(ui: &mut conrod_core::UiCell, ids: &Ids, app: &mut DemoApp) {
         .set(ids.introduction, ui);
 
 
+    /////////////////////////
+    ///// Nested canvas /////
+    /////////////////////////
+
+
+    // Nest a canvas in the scroll region to illustrate a bug
+    widget::Canvas::new()
+        .down_from(ids.introduction, 10.0)
+        .padded_w_of(ids.canvas, MARGIN)
+        .h(320.0)
+        .border(2.0) // border makes bug easier to see
+        .color(conrod_core::color::LIGHT_BLUE.alpha(0.5))
+        .scroll_kids() // Got to have this set for the bug to happen
+        .set(ids.section_canvas, ui);
+
+
+    ////////////////
+    ///// List /////
+    ////////////////
+
+
+    let (mut items, scrollbar) = widget::List::flow_down(app.list.len())
+        .down_from(ids.section_canvas, 10.0)
+        .item_size(50.0)
+        .scrollbar_on_top()
+        .padded_w_of(ids.canvas, MARGIN)
+        .h(300.0)
+        .set(ids.list, ui);
+
+    while let Some(item) = items.next(ui) {
+        let i = item.i;
+        let label = format!("item {}: {}", i, app.list[i]);
+        let toggle = widget::Toggle::new(app.list[i])
+            .label(&label)
+            .label_color(conrod_core::color::WHITE)
+            .color(conrod_core::color::LIGHT_BLUE);
+        for v in item.set(toggle, ui) {
+            app.list[i] = v;
+        }
+    }
+
+    if let Some(s) = scrollbar { s.set(ui) }
+
+
     ////////////////////////////
     ///// Lines and Shapes /////
     ////////////////////////////