compiler: forbid setting row/col in a callback, in a grid with auto numbering

Author: dfaure-kdab

internal/compiler/layout.rs

@@ -468,6 +468,9 @@ pub struct GridLayout {
     /// When this GridLayout is actually the layout of a Dialog, then the cells start with all the buttons,
     /// and this variable contains their roles. The string is actually one of the values from the i_slint_core::layout::DialogButtonRole
     pub dialog_button_roles: Option<Vec<SmolStr>>,
+
+    /// Whether any of the row/column expressions use 'auto'
+    pub uses_auto: bool,
 }
 
 impl GridLayout {

internal/compiler/passes/binding_analysis.rs

@@ -261,6 +261,31 @@ fn analyze_element(
         process_property(&h.clone().into(), P, context, reverse_aliases, diag);
         process_property(&v.clone().into(), P, context, reverse_aliases, diag);
     }
+
+    for info in elem.borrow().debug.iter() {
+        if let Some(crate::layout::Layout::GridLayout(grid)) = &info.layout {
+            if grid.uses_auto {
+                for rowcol_prop_name in ["row", "col"] {
+                    for it in grid.elems.iter() {
+                        let child = &it.item.element;
+                        if child
+                            .borrow()
+                            .property_analysis
+                            .borrow()
+                            .get(rowcol_prop_name)
+                            .is_some_and(|a| a.is_set || a.is_set_externally)
+                        {
+                            diag.push_error(
+                                            format!("Cannot set property '{}' on '{}' because parent GridLayout uses auto-numbering",
+                                             rowcol_prop_name, child.borrow().id),
+                                            &child.borrow().to_source_location(), // not ideal, the location of the property being set would be better
+                                        );
+                        }
+                    }
+                }
+            }
+        }
+    }
 }
 
 #[derive(Copy, Clone, dm::BitAnd, dm::BitOr, dm::BitAndAssign, dm::BitOrAssign)]

internal/compiler/passes/lower_layout.rs

@@ -181,6 +181,7 @@ fn lower_grid_layout(
         elems: Default::default(),
         geometry: LayoutGeometry::new(grid_layout_element),
         dialog_button_roles: None,
+        uses_auto: false,
     };
 
     let layout_organized_data_prop = create_new_prop(
@@ -264,6 +265,7 @@ fn lower_grid_layout(
         }
     }
     grid_layout_element.borrow_mut().children = collected_children;
+    grid.uses_auto = numbering_type == Some(RowColExpressionType::Auto);
     let span = grid_layout_element.borrow().to_source_location();
 
     layout_organized_data_prop.element().borrow_mut().bindings.insert(
@@ -630,6 +632,7 @@ fn lower_dialog_layout(
         elems: Default::default(),
         geometry: LayoutGeometry::new(dialog_element),
         dialog_button_roles: None,
+        uses_auto: true,
     };
     let metrics = &style_metrics.root_element;
     grid.geometry

internal/compiler/tests/syntax/basic/gridlayout_no_mixing.slint

@@ -0,0 +1,24 @@
+// Copyright © Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
+
+export component TestCase inherits Window {
+
+    lay1 := GridLayout {
+        spacing: 20px;
+        text1 := Text {
+//               ^error{Cannot set property 'col' on 'text1' because parent GridLayout uses auto-numbering}
+            row: 0;
+            col: 1;
+            text: "text 1";
+        }
+        text2 := Text {
+//               ^error{Cannot set property 'row' on 'text2' because parent GridLayout uses auto-numbering}
+            text: "text 2";
+        }
+    }
+
+    init => {
+        text1.col = 3; // should be an error
+        text2.row = 2; // too (making sure this is detected even when row is not set initially)
+    }
+}