Implement reordering records with drag-and-drop

src/ui/file_pane.rs

@@ -26,6 +26,7 @@ mod imp {
     use crate::model::record::RECORD_TYPES;
     use crate::primary_accel;
     use crate::ui::record_type_popover::RecordTypePopoverBuilder;
+    use crate::ui::record_view::item::DropOption;
     use crate::utils::typed_list_store::TypedListStore;
     use crate::utils::ui::{action_button, action_popover_button};
     use std::cell::RefCell;
@@ -154,6 +155,7 @@ mod imp {
                         imp.go_up().await
                     });
                 }));
+            self.view.connect_move_record(glib::clone!(@weak self as imp => move |_, src, dst, opt| imp.move_record(src, dst, opt)));
 
             self.set_view_model(&self.file.borrow().records);
 
@@ -254,6 +256,31 @@ mod imp {
                 self.obj().emit_edit_record(position, &record);
             }
         }
+
+        fn move_record(&self, src: &RecordNode, dst: &RecordNode, option: DropOption) {
+            let Some(src_pos) = self.current_records.borrow().iter().position(|r| r == *src) else {
+                return;
+            };
+            self.current_records.borrow().remove(src_pos as u32);
+
+            let dst_pos = self.current_records.borrow().iter().position(|r| r == *dst);
+            match option {
+                DropOption::Above => {
+                    self.current_records
+                        .borrow()
+                        .insert(dst_pos.unwrap_or(0), src);
+                }
+                DropOption::Below => {
+                    self.current_records
+                        .borrow()
+                        .insert(dst_pos.map(|p| p + 1), src);
+                }
+                DropOption::Into => {
+                    self.obj().append_records_to(Some(dst), &[src.clone()]);
+                }
+            }
+            self.obj().emit_file_changed();
+        }
     }
 }
 

src/ui/record_view/compose_paintable.rs

@@ -0,0 +1,60 @@
+use gtk::{gdk, glib, graphene, prelude::*, subclass::prelude::*};
+
+mod imp {
+    use super::*;
+    use std::cell::OnceCell;
+
+    #[derive(Default)]
+    pub struct PSBackgroundPaintable {
+        pub next: OnceCell<gdk::Paintable>,
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for PSBackgroundPaintable {
+        const NAME: &'static str = "PSBackgroundPaintable";
+        type Type = super::PSBackgroundPaintable;
+        type ParentType = glib::Object;
+        type Interfaces = (gdk::Paintable,);
+    }
+
+    impl ObjectImpl for PSBackgroundPaintable {}
+
+    impl PaintableImpl for PSBackgroundPaintable {
+        fn intrinsic_width(&self) -> i32 {
+            match self.next.get() {
+                Some(next) => next.intrinsic_width(),
+                None => self.parent_intrinsic_width(),
+            }
+        }
+
+        fn intrinsic_height(&self) -> i32 {
+            match self.next.get() {
+                Some(next) => next.intrinsic_height(),
+                None => self.parent_intrinsic_height(),
+            }
+        }
+
+        fn snapshot(&self, snapshot: &gdk::Snapshot, width: f64, height: f64) {
+            snapshot.append_color(
+                &gdk::RGBA::new(0.5, 0.5, 0.8, 1.0),
+                &graphene::Rect::new(0.0, 0.0, width as f32, height as f32),
+            );
+            if let Some(next) = self.next.get() {
+                next.snapshot(snapshot, width, height);
+            }
+        }
+    }
+}
+
+glib::wrapper! {
+    pub struct PSBackgroundPaintable(ObjectSubclass<imp::PSBackgroundPaintable>)
+        @implements gdk::Paintable;
+}
+
+impl PSBackgroundPaintable {
+    pub fn new(next: impl glib::IsA<gdk::Paintable>) -> Self {
+        let obj: Self = glib::Object::builder().build();
+        obj.imp().next.set(next.upcast()).unwrap();
+        obj
+    }
+}

src/ui/record_view/item.css

@@ -0,0 +1,10 @@
+.ps-list-item.drop-above:drop(active) {
+  box-shadow: inset 0 2px 0 0 #08c;
+}
+.ps-list-item.drop-into:drop(active) {
+  box-shadow: inset 0 0 0 0 #08c;
+  background-color: #5ac;
+}
+.ps-list-item.drop-below:drop(active) {
+  box-shadow: inset 0 -2px 0 0 #08c;
+}