improv(grid): add justify_content and fix padding

src/widget/grid/layout.rs

@@ -10,8 +10,9 @@ use iced_core::{Alignment, Length, Padding, Point, Size};
 use taffy::geometry::{Line, Rect};
 use taffy::style::{AlignItems, Dimension, Display, GridPlacement, Style};
 use taffy::style_helpers::{auto, length};
-use taffy::TaffyTree;
+use taffy::{AlignContent, TaffyTree};
 
+#[allow(clippy::too_many_arguments)]
 #[allow(clippy::too_many_lines)]
 pub fn resolve<Message>(
     renderer: &Renderer,
@@ -23,6 +24,7 @@ pub fn resolve<Message>(
     padding: Padding,
     column_alignment: Alignment,
     row_alignment: Alignment,
+    justify_content: Option<AlignContent>,
     column_spacing: f32,
     row_spacing: f32,
     tree: &mut [Tree],
@@ -44,23 +46,29 @@ pub fn resolve<Message>(
         nodes.push(child_node);
 
         let c_size = child_widget.size();
-        let (width, justify_self) = match c_size.width {
+        let (width, flex_grow, justify_self) = match c_size.width {
-            Length::Fill | Length::FillPortion(_) => (Dimension::Auto, Some(AlignItems::Stretch)),
+            Length::Fill | Length::FillPortion(_) => {
-            _ => (length(size.width), None),
+                (Dimension::Auto, 1.0, Some(AlignItems::Stretch))
+            }
+            _ => (length(size.width), 0.0, None),
         };
 
         // Attach widget as leaf to be later assigned to grid.
         let leaf = taffy.new_leaf(Style {
+            flex_grow,
+
             grid_column: Line {
                 start: GridPlacement::Line((assignment.column as i16).into()),
                 end: GridPlacement::Line(
                     (assignment.column as i16 + assignment.width as i16).into(),
                 ),
             },
+
             grid_row: Line {
                 start: GridPlacement::Line((assignment.row as i16).into()),
                 end: GridPlacement::Line((assignment.row as i16 + assignment.height as i16).into()),
             },
+
             size: taffy::geometry::Size {
                 width,
                 height: match c_size.height {
@@ -68,7 +76,9 @@ pub fn resolve<Message>(
                     _ => length(size.height),
                 },
             },
+
             justify_self,
+
             ..Style::default()
         });
 
@@ -108,6 +118,8 @@ pub fn resolve<Message>(
                 },
             }),
 
+            justify_content,
+
             padding: Rect {
                 left: length(padding.left),
                 right: length(padding.right),
@@ -187,5 +199,5 @@ pub fn resolve<Message>(
         height: grid_layout.content_size.height,
     };
 
-    Node::with_children(grid_size.expand(padding), nodes)
+    Node::with_children(grid_size, nodes)
 }

src/widget/grid/widget.rs

@@ -26,6 +26,9 @@ pub struct Grid<'a, Message> {
     column_alignment: Alignment,
     /// Alignment across rows
     row_alignment: Alignment,
+    /// Defines how the content will be justified.
+    #[setters(into, strip_option)]
+    justify_content: Option<crate::widget::JustifyContent>,
     /// Sets the space between each column of items.
     column_spacing: u16,
     /// Sets the space between each item in a row.
@@ -50,6 +53,7 @@ impl<'a, Message> Grid<'a, Message> {
             padding: Padding::ZERO,
             column_alignment: Alignment::Start,
             row_alignment: Alignment::Start,
+            justify_content: None,
             column_spacing: 4,
             row_spacing: 4,
             width: Length::Shrink,
@@ -138,6 +142,7 @@ impl<'a, Message: 'static + Clone> Widget<Message, crate::Theme, Renderer> for G
             self.padding,
             self.column_alignment,
             self.row_alignment,
+            self.justify_content,
             f32::from(self.column_spacing),
             f32::from(self.row_spacing),
             &mut tree.children,