i_slint_compiler/passes/
repeater_component.rs

1// Copyright © SixtyFPS GmbH <info@slint.dev>
2// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
3
4/*!
5Make sure that the Repeated expression are just components without any children
6 */
7
8use crate::expression_tree::{Expression, NamedReference};
9use crate::langtype::ElementType;
10use crate::object_tree::*;
11use smol_str::SmolStr;
12use std::cell::RefCell;
13use std::rc::{Rc, Weak};
14
15pub fn process_repeater_components(component: &Rc<Component>) {
16    create_repeater_components(component);
17    adjust_references(component);
18}
19
20fn create_repeater_components(component: &Rc<Component>) {
21    recurse_elem(&component.root_element, &(), &mut |original_elem_rc, _| {
22        let is_listview = match &original_elem_rc.borrow().repeated {
23            Some(r) => r.is_listview.clone(),
24            None => return,
25        };
26        let original_elem_as_weak = Rc::downgrade(original_elem_rc);
27        let mut original_elem = original_elem_rc.borrow_mut();
28
29        if matches!(&original_elem.base_type, ElementType::Component(c) if c.parent_element().is_some())
30        {
31            debug_assert!(std::rc::Weak::ptr_eq(
32                &original_elem_as_weak,
33                &*original_elem.base_type.as_component().parent_element.borrow()
34            ));
35            // Already processed (can happen if a component is both used and exported root)
36            return;
37        }
38
39        let repeated_component = Rc::new(Component {
40            root_element: Rc::new(RefCell::new(Element {
41                id: original_elem.id.clone(),
42                base_type: std::mem::take(&mut original_elem.base_type),
43                bindings: std::mem::take(&mut original_elem.bindings),
44                change_callbacks: std::mem::take(&mut original_elem.change_callbacks),
45                property_analysis: std::mem::take(&mut original_elem.property_analysis),
46                children: std::mem::take(&mut original_elem.children),
47                property_declarations: std::mem::take(&mut original_elem.property_declarations),
48                named_references: Default::default(),
49                repeated: None,
50                is_component_placeholder: false,
51                debug: original_elem.debug.clone(),
52                enclosing_component: Default::default(),
53                states: std::mem::take(&mut original_elem.states),
54                transitions: std::mem::take(&mut original_elem.transitions),
55                child_of_layout: original_elem.child_of_layout || is_listview.is_some(),
56                layout_info_prop: original_elem.layout_info_prop.take(),
57                default_fill_parent: original_elem.default_fill_parent,
58                accessibility_props: std::mem::take(&mut original_elem.accessibility_props),
59                geometry_props: original_elem.geometry_props.clone(),
60                is_flickable_viewport: original_elem.is_flickable_viewport,
61                has_popup_child: original_elem.has_popup_child,
62                item_index: Default::default(), // Not determined yet
63                item_index_of_first_children: Default::default(),
64                is_legacy_syntax: original_elem.is_legacy_syntax,
65                inline_depth: 0,
66                grid_layout_cell: original_elem.grid_layout_cell.clone(),
67            })),
68            parent_element: RefCell::new(Weak::clone(&original_elem_as_weak)),
69            ..Component::default()
70        });
71
72        if let Some(listview) = is_listview {
73            if !repeated_component.root_element.borrow().is_binding_set("height", false) {
74                let preferred = Expression::PropertyReference(NamedReference::new(
75                    &repeated_component.root_element,
76                    SmolStr::new_static("preferred-height"),
77                ));
78                repeated_component
79                    .root_element
80                    .borrow_mut()
81                    .bindings
82                    .insert("height".into(), RefCell::new(preferred.into()));
83            }
84            if !repeated_component.root_element.borrow().is_binding_set("width", false) {
85                repeated_component.root_element.borrow_mut().bindings.insert(
86                    "width".into(),
87                    RefCell::new(Expression::PropertyReference(listview.listview_width).into()),
88                );
89            }
90        }
91
92        let repeated_component_weak = Rc::downgrade(&repeated_component);
93        recurse_elem(&repeated_component.root_element, &(), &mut |e, _| {
94            e.borrow_mut().enclosing_component = repeated_component_weak.clone()
95        });
96        // Remove the mutable borrow from the RefCell, so that we can later compare it with the parent_element of the menu items
97        drop(original_elem);
98
99        // Move all the menus that belong to the newly created component
100        // Could use Vec::extract_if if MSRV >= 1.87
101        component.menu_item_tree.borrow_mut().retain(|menu_item| {
102            let mut parent_elem = menu_item.parent_element.borrow_mut();
103
104            // When parent_element IS the element being split, update the parent_elem
105            // to point to the new sub-component's root.
106            if Weak::ptr_eq(&parent_elem, &original_elem_as_weak) {
107                *parent_elem = Rc::downgrade(&repeated_component.root_element);
108            }
109
110            let enclosing_component =
111                parent_elem.upgrade().unwrap().borrow().enclosing_component.clone();
112            let should_move = Weak::ptr_eq(&enclosing_component, &repeated_component_weak);
113            if should_move {
114                repeated_component.menu_item_tree.borrow_mut().push(menu_item.clone());
115                false
116            } else {
117                true
118            }
119        });
120
121        create_repeater_components(&repeated_component);
122        original_elem_rc.borrow_mut().base_type = ElementType::Component(repeated_component);
123    });
124
125    for p in component.popup_windows.borrow().iter() {
126        create_repeater_components(&p.component);
127    }
128    for c in component.menu_item_tree.borrow().iter() {
129        create_repeater_components(c);
130    }
131}
132
133/// Make sure that references to properties within the repeated element actually point to the reference
134/// to the root of the newly created component
135pub fn adjust_references(component: &Rc<Component>) {
136    visit_all_named_references(component, &mut |reference| {
137        if reference.name() == "$model" {
138            return;
139        }
140        let referred_element = reference.element();
141        if referred_element.borrow().repeated.is_some()
142            && let ElementType::Component(created_component) =
143                referred_element.borrow().base_type.clone()
144        {
145            *reference =
146                NamedReference::new(&created_component.root_element, reference.name().clone())
147        };
148    });
149    // Transform any references to the repeated element to refer to the root of each instance.
150    visit_all_expressions(component, |expr, _| {
151        expr.visit_recursive_mut(&mut |expr| {
152            if let Expression::ElementReference(element_ref) = expr
153                && let Some(repeater_element) =
154                    element_ref.upgrade().filter(|e| e.borrow().repeated.is_some())
155            {
156                let inner_element =
157                    repeater_element.borrow().base_type.as_component().root_element.clone();
158                *element_ref = Rc::downgrade(&inner_element);
159            }
160        })
161    });
162}
i_slint_compiler/passes/repeater_component.rs

i_slint_compiler/passes/
repeater_component.rs
