Introduce `viewport` to `Widget::draw`

This should eventually allow us to only generate primitives that are
visible.

7 files changed, 34 insertions, 12 deletions

diff --git a/graphics/src/renderer.rs b/graphics/src/renderer.rs
index 5d51e6d4..a880e22a 100644
--- a/graphics/src/renderer.rs
+++ b/graphics/src/renderer.rs
@@ -96,10 +96,11 @@ where
         widget: &dyn Widget<Message, Self>,
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
         color: Color,
     ) -> Self::Output {
         let (primitive, cursor) =
-            widget.draw(self, defaults, layout, cursor_position);
+            widget.draw(self, defaults, layout, cursor_position, viewport);
 
         let mut primitives = Vec::new();
 
diff --git a/graphics/src/widget/button.rs b/graphics/src/widget/button.rs
index ecabc868..a1afc940 100644
--- a/graphics/src/widget/button.rs
+++ b/graphics/src/widget/button.rs
@@ -62,6 +62,7 @@ where
             },
             content_layout,
             cursor_position,
+            &bounds,
         );
 
         (
diff --git a/graphics/src/widget/canvas.rs b/graphics/src/widget/canvas.rs
index bc0802e5..73778d16 100644
--- a/graphics/src/widget/canvas.rs
+++ b/graphics/src/widget/canvas.rs
@@ -8,8 +8,8 @@
 //! [`Frame`]: struct.Frame.html
 use crate::{Backend, Defaults, Primitive, Renderer};
 use iced_native::{
-    layout, mouse, Clipboard, Element, Hasher, Layout, Length, Point, Size,
-    Vector, Widget,
+    layout, mouse, Clipboard, Element, Hasher, Layout, Length, Point,
+    Rectangle, Size, Vector, Widget,
 };
 use std::hash::Hash;
 use std::marker::PhantomData;
@@ -196,6 +196,7 @@ where
         _defaults: &Defaults,
         layout: Layout<'_>,
         cursor_position: Point,
+        _viewport: &Rectangle,
     ) -> (Primitive, mouse::Interaction) {
         let bounds = layout.bounds();
         let translation = Vector::new(bounds.x, bounds.y);
diff --git a/graphics/src/widget/column.rs b/graphics/src/widget/column.rs
index 6c7235c7..0cf56842 100644
--- a/graphics/src/widget/column.rs
+++ b/graphics/src/widget/column.rs
@@ -1,7 +1,7 @@
 use crate::{Backend, Primitive, Renderer};
 use iced_native::column;
 use iced_native::mouse;
-use iced_native::{Element, Layout, Point};
+use iced_native::{Element, Layout, Point, Rectangle};
 
 /// A container that distributes its contents vertically.
 pub type Column<'a, Message, Backend> =
@@ -17,6 +17,7 @@ where
         content: &[Element<'_, Message, Self>],
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
     ) -> Self::Output {
         let mut mouse_interaction = mouse::Interaction::default();
 
@@ -26,8 +27,13 @@ where
                     .iter()
                     .zip(layout.children())
                     .map(|(child, layout)| {
-                        let (primitive, new_mouse_interaction) =
-                            child.draw(self, defaults, layout, cursor_position);
+                        let (primitive, new_mouse_interaction) = child.draw(
+                            self,
+                            defaults,
+                            layout,
+                            cursor_position,
+                            viewport,
+                        );
 
                         if new_mouse_interaction > mouse_interaction {
                             mouse_interaction = new_mouse_interaction;
diff --git a/graphics/src/widget/container.rs b/graphics/src/widget/container.rs
index 5b3a01d2..4854f589 100644
--- a/graphics/src/widget/container.rs
+++ b/graphics/src/widget/container.rs
@@ -24,6 +24,7 @@ where
         defaults: &Defaults,
         bounds: Rectangle,
         cursor_position: Point,
+        viewport: &Rectangle,
         style_sheet: &Self::Style,
         content: &Element<'_, Message, Self>,
         content_layout: Layout<'_>,
@@ -36,8 +37,13 @@ where
             },
         };
 
-        let (content, mouse_interaction) =
-            content.draw(self, &defaults, content_layout, cursor_position);
+        let (content, mouse_interaction) = content.draw(
+            self,
+            &defaults,
+            content_layout,
+            cursor_position,
+            viewport,
+        );
 
         if let Some(background) = background(bounds, &style) {
             (
diff --git a/graphics/src/widget/pane_grid.rs b/graphics/src/widget/pane_grid.rs
index aa8a3f7c..5b0eb391 100644
--- a/graphics/src/widget/pane_grid.rs
+++ b/graphics/src/widget/pane_grid.rs
@@ -137,7 +137,7 @@ where
         let (body, body_layout) = body;
 
         let (body_primitive, body_interaction) =
-            body.draw(self, defaults, body_layout, cursor_position);
+            body.draw(self, defaults, body_layout, cursor_position, &bounds);
 
         let background = crate::widget::container::background(bounds, &style);
 
@@ -224,6 +224,7 @@ where
                 &defaults,
                 controls_layout,
                 cursor_position,
+                &bounds,
             );
 
             (
diff --git a/graphics/src/widget/row.rs b/graphics/src/widget/row.rs
index 4c1dbadc..397d80bf 100644
--- a/graphics/src/widget/row.rs
+++ b/graphics/src/widget/row.rs
@@ -1,7 +1,7 @@
 use crate::{Backend, Primitive, Renderer};
 use iced_native::mouse;
 use iced_native::row;
-use iced_native::{Element, Layout, Point};
+use iced_native::{Element, Layout, Point, Rectangle};
 
 /// A container that distributes its contents horizontally.
 pub type Row<'a, Message, Backend> =
@@ -17,6 +17,7 @@ where
         content: &[Element<'_, Message, Self>],
         layout: Layout<'_>,
         cursor_position: Point,
+        viewport: &Rectangle,
     ) -> Self::Output {
         let mut mouse_interaction = mouse::Interaction::default();
 
@@ -26,8 +27,13 @@ where
                     .iter()
                     .zip(layout.children())
                     .map(|(child, layout)| {
-                        let (primitive, new_mouse_interaction) =
-                            child.draw(self, defaults, layout, cursor_position);
+                        let (primitive, new_mouse_interaction) = child.draw(
+                            self,
+                            defaults,
+                            layout,
+                            cursor_position,
+                            viewport,
+                        );
 
                         if new_mouse_interaction > mouse_interaction {
                             mouse_interaction = new_mouse_interaction;