Fix size cache in ScrollView

src/views/box_view.rs

@@ -1,3 +1,4 @@
+use With;
 use vec::Vec2;
 use view::{SizeConstraint, View, ViewWrapper};
 use XY;
@@ -27,8 +28,11 @@ pub struct BoxView<T: View> {
     ///
     /// This means if the required size is less than the computed size,
     /// consider returning a smaller size.
-    /// For instance, try to return the child's desires size.
-    squishable: bool,
+    /// For instance, try to return the child's desired size.
+    squishable: bool, // TODO: remove?
+
+    /// Set to `true` whenever we change some settings. Means we should re-layout just in case.
+    invalidated: bool,
 
     /// The actual view we're wrapping.
     view: T,
@@ -44,6 +48,7 @@ impl<T: View> BoxView<T> {
         BoxView {
             size: (width, height).into(),
             squishable: false,
+            invalidated: true,
             view,
         }
     }
@@ -61,6 +66,7 @@ impl<T: View> BoxView<T> {
     /// Leaves the height unchanged.
     pub fn set_width(&mut self, width: SizeConstraint) {
         self.size.x = width;
+        self.invalidate();
     }
 
     /// Sets the height constraint for this view.
@@ -68,6 +74,7 @@ impl<T: View> BoxView<T> {
     /// Leaves the width unchanged.
     pub fn set_height(&mut self, height: SizeConstraint) {
         self.size.y = height;
+        self.invalidate();
     }
 
     /// Sets `self` to be squishable.
@@ -78,9 +85,14 @@ impl<T: View> BoxView<T> {
     ///
     /// More specifically, if the available space is less than the size we
     /// would normally ask for, return the child size.
-    pub fn squishable(mut self) -> Self {
-        self.squishable = true;
-        self
+    pub fn squishable(self) -> Self {
+        self.with(|s| s.set_squishable(true))
+    }
+
+    /// Controls the "squishability" of `self`.
+    pub fn set_squishable(&mut self, squishable: bool) {
+        self.squishable = squishable;
+        self.invalidate();
     }
 
     /// Wraps `view` in a new `BoxView` with the given size.
@@ -185,6 +197,12 @@ impl<T: View> BoxView<T> {
         )
     }
 
+    /// Should be called anytime something changes.
+    fn invalidate(&mut self) {
+        self.invalidated = true;
+    }
+
+
     inner_getters!(self.view: T);
 }
 
@@ -192,34 +210,42 @@ impl<T: View> ViewWrapper for BoxView<T> {
     wrap_impl!(self.view: T);
 
     fn wrap_required_size(&mut self, req: Vec2) -> Vec2 {
+        // This is what the child will see as request.
         let req = self.size.zip_map(req, SizeConstraint::available);
+
+        // This is the size the child would like to have.
         let child_size = self.view.required_size(req);
 
+        // Some of this request will be granted, but maybe not all.
         let result = self
             .size
             .zip_map(child_size.zip(req), SizeConstraint::result);
 
         debug!("{:?}", result);
 
-        if self.squishable {
+        if !self.squishable {
+            result
+        } else {
+            // When we're squishable, special behaviour:
+            //
+
             // We respect the request if we're less or equal.
             let respect_req = result.zip_map(req, |res, req| res <= req);
-            result.zip_map(
-                respect_req.zip(child_size),
-                |res, (respect, child)| {
-                    if respect {
-                        // If we respect the request, keep the result
-                        res
-                    } else {
-                        // Otherwise, take the child as squish attempt.
-                        child
-                    }
-                },
-            )
-        } else {
-            result
+
+            // If we respect the request, keep the result
+            // Otherwise, take the child as squish attempt.
+            respect_req.select_or(result, child_size)
         }
     }
+
+    fn wrap_layout(&mut self, size: Vec2) {
+        self.invalidated = false;
+        self.view.layout(size);
+    }
+
+    fn wrap_needs_relayout(&self) -> bool {
+        self.invalidated || self.view.needs_relayout()
+    }
 }
 
 #[cfg(test)]

src/views/button.rs

@@ -23,6 +23,8 @@ pub struct Button {
     callback: Callback,
     enabled: bool,
     last_size: Vec2,
+
+    invalidated: bool,
 }
 
 impl Button {
@@ -46,6 +48,7 @@ impl Button {
             callback: Callback::from_fn(cb),
             enabled: true,
             last_size: Vec2::zero(),
+            invalidated: true,
         }
     }
 
@@ -121,11 +124,16 @@ impl Button {
         S: Into<String>,
     {
         self.label = label.into();
+        self.invalidate();
     }
 
     fn req_size(&self) -> Vec2 {
         Vec2::new(self.label.width(), 1)
     }
+
+    fn invalidate(&mut self) {
+        self.invalidated = true;
+    }
 }
 
 impl View for Button {
@@ -152,6 +160,7 @@ impl View for Button {
 
     fn layout(&mut self, size: Vec2) {
         self.last_size = size;
+        self.invalidated = false;
     }
 
     fn required_size(&mut self, _: Vec2) -> Vec2 {
@@ -195,4 +204,8 @@ impl View for Button {
 
         Rect::from_size((offset, 0), (width, 1))
     }
+
+    fn needs_relayout(&self) -> bool {
+        self.invalidated
+    }
 }

src/views/dialog.rs

@@ -75,6 +75,9 @@ pub struct Dialog {
 
     // How to align the buttons under the view.
     align: Align,
+
+    // `true` when we needs to relayout
+    invalidated: bool,
 }
 
 new_default!(Dialog);
@@ -98,6 +101,7 @@ impl Dialog {
             padding: Margins::new(1, 1, 0, 0),
             borders: Margins::new(1, 1, 1, 1),
             align: Align::top_right(),
+            invalidated: true,
         }
     }
 
@@ -126,6 +130,7 @@ impl Dialog {
 
     /// Gets mutable access to the content.
     pub fn get_content_mut(&mut self) -> &mut View {
+        self.invalidate();
         &mut *self.content.view
     }
 
@@ -134,6 +139,7 @@ impl Dialog {
     /// Previous content will be dropped.
     pub fn set_content<V: View + 'static>(&mut self, view: V) {
         self.content = SizedView::new(ViewBox::boxed(view));
+        self.invalidate();
     }
 
     /// Convenient method to create a dialog with a simple text content.
@@ -164,6 +170,7 @@ impl Dialog {
         F: 'static + Fn(&mut Cursive),
     {
         self.buttons.push(ChildButton::new(label, cb));
+        self.invalidate();
     }
 
     /// Returns the number of buttons on this dialog.
@@ -174,6 +181,7 @@ impl Dialog {
     /// Removes any button from `self`.
     pub fn clear_buttons(&mut self) {
         self.buttons.clear();
+        self.invalidate();
     }
 
     /// Removes a button from this dialog.
@@ -183,6 +191,7 @@ impl Dialog {
     /// Panics if `i >= self.buttons_len()`.
     pub fn remove_button(&mut self, i: usize) {
         self.buttons.remove(i);
+        self.invalidate();
     }
 
     /// Sets the horizontal alignment for the buttons, if any.
@@ -224,6 +233,7 @@ impl Dialog {
     /// Sets the title of the dialog.
     pub fn set_title<S: Into<String>>(&mut self, label: S) {
         self.title = label.into();
+        self.invalidate();
     }
 
     /// Sets the horizontal position of the title in the dialog.
@@ -271,6 +281,7 @@ impl Dialog {
 
     /// Returns an iterator on this buttons for this dialog.
     pub fn buttons_mut(&mut self) -> impl Iterator<Item = &mut Button> {
+        self.invalidate();
         self.buttons.iter_mut().map(|b| &mut b.button.view)
     }
 
@@ -504,6 +515,10 @@ impl Dialog {
             }
         }
     }
+
+    fn invalidate(&mut self) {
+        self.invalidated = true;
+    }
 }
 
 impl View for Dialog {
@@ -583,8 +598,11 @@ impl View for Dialog {
         if buttons_height > size.y {
             buttons_height = size.y;
         }
+
         self.content
             .layout(size.saturating_sub((0, buttons_height)));
+
+        self.invalidated = false;
     }
 
     fn on_event(&mut self, event: Event) -> EventResult {
@@ -627,4 +645,8 @@ impl View for Dialog {
             + self.borders.top_left()
             + self.padding.top_left()
     }
+
+    fn needs_relayout(&self) -> bool {
+        self.invalidated || self.content.needs_relayout()
+    }
 }

src/views/dummy.rs

@@ -8,4 +8,6 @@ pub struct DummyView;
 
 impl View for DummyView {
     fn draw(&self, _: &Printer) {}
+
+    fn needs_relayout(&self) -> bool { false }
 }

src/views/hideable_view.rs

@@ -1,4 +1,5 @@
 use view::{Selector, View, ViewWrapper};
+use vec::Vec2;
 use With;
 
 use std::any::Any;
@@ -14,6 +15,7 @@ use std::any::Any;
 pub struct HideableView<V> {
     view: V,
     visible: bool,
+    invalidated: bool,
 }
 
 impl<V> HideableView<V> {
@@ -24,12 +26,14 @@ impl<V> HideableView<V> {
         HideableView {
             view,
             visible: true,
+            invalidated: true,
         }
     }
 
     /// Sets the visibility for this view.
     pub fn set_visible(&mut self, visible: bool) {
         self.visible = visible;
+        self.invalidate();
     }
 
     /// Sets the visibility for this view to `false`.
@@ -49,6 +53,10 @@ impl<V> HideableView<V> {
         self.with(Self::hide)
     }
 
+    fn invalidate(&mut self) {
+        self.invalidated = true;
+    }
+
     inner_getters!(self.view: V);
 }
 
@@ -91,4 +99,13 @@ impl<V: View> ViewWrapper for HideableView<V> {
     {
         Ok(self.view)
     }
+
+    fn wrap_layout(&mut self, size: Vec2)  {
+        self.invalidated = false;
+        self.with_view_mut(|v| v.layout(size));
+    }
+
+    fn wrap_needs_relayout(&self) -> bool {
+        self.invalidated || (self.visible && self.view.needs_relayout())
+    }
 }

src/views/scroll_view.rs

@@ -323,11 +323,13 @@ where
     /// Returns `(inner_size, desired_size)`
     fn sizes(&mut self, constraint: Vec2, strict: bool) -> (Vec2, Vec2) {
         // First: try the cache
-        if self
+        if !self.inner.needs_relayout() && self
             .size_cache
             .map(|cache| cache.zip_map(constraint, SizeCache::accept).both())
             .unwrap_or(false)
         {
+            // eprintln!("Cache: {:?}; constraint: {:?}", self.size_cache, constraint);
+
             // The new constraint shouldn't change much,
             // so we can re-use previous values
             return (

src/views/text_view.rs

@@ -336,12 +336,6 @@ impl TextView {
 
         // Desired width
         self.width = self.rows.iter().map(|row| row.width).max();
-
-        // The entire "virtual" size (includes all rows)
-        let my_size = Vec2::new(self.width.unwrap_or(0), self.rows.len());
-
-        // Build a fresh cache.
-        content.size_cache = Some(SizeCache::build(my_size, size));
     }
 
     // Invalidates the cache, so next call will recompute everything.
@@ -390,5 +384,12 @@ impl View for TextView {
         // Compute the text rows.
         self.last_size = size;
         self.compute_rows(size);
+
+        // The entire "virtual" size (includes all rows)
+        let my_size = Vec2::new(self.width.unwrap_or(0), self.rows.len());
+
+        // Build a fresh cache.
+        let mut content = self.content.lock().unwrap();
+        content.size_cache = Some(SizeCache::build(my_size, size));
     }
 }