fix(selectable): prevent clash with other's custom operations

- Make the `global_selection` operation check for the new
  `IndependentSelection` when trying to downcast_mut.
- `IndependentSelection` uses wraps a `RefCell` so it can change its
  inner value. Theres some helper methods to create this
  `IndependentSelection` from an existing value and to then get the
  changed value once the operation is done. This way the `Text` and
  `Rich` simply need to pass this `IndependentSelection` to the
  operation `custom` method which will make sure it wont clash with any
  other custom operations that could be using `&mut bool` as well.

3 files changed, 37 insertions, 28 deletions

diff --git a/src/operation.rs b/src/operation.rs
index 584f61f..2bfd6d8 100644
--- a/src/operation.rs
+++ b/src/operation.rs
@@ -13,12 +13,17 @@ pub struct Selection(pub String);
 ///
 /// [`Text`]: crate::text::Text
 /// [`Rich`]: crate::text::Rich
-pub struct IndependentSelection<'a>(pub &'a mut bool);
+pub struct IndependentSelection(pub std::cell::RefCell<bool>);
 
-impl<'a> IndependentSelection<'a> {
-    /// Creates a new [`IndependentSelection`] with the given mutable reference
-    pub fn new(isel: &'a mut bool) -> Self {
-        Self(isel)
+impl IndependentSelection {
+    /// Creates a new [`IndependentSelection`] with the given value.
+    pub fn new(value: bool) -> Self {
+        Self(std::cell::RefCell::new(value))
+    }
+
+    /// Gets the inner bool value of this [`IndependentSelection`].
+    pub fn get(&self) -> bool {
+        *self.0.borrow()
     }
 }
 
@@ -29,8 +34,10 @@ pub fn selected() -> impl Operation<String> {
     }
 
     impl Operation<String> for CopySelection {
-
-        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<String>)) {
+        fn traverse(
+            &mut self,
+            operate: &mut dyn FnMut(&mut dyn Operation<String>),
+        ) {
             operate(self);
         }
 
@@ -47,15 +54,16 @@ pub fn selected() -> impl Operation<String> {
 
         fn finish(&self) -> operation::Outcome<String> {
             if !self.contents.is_empty() {
-                let clipboard = self.contents.iter().fold(String::new(), |mut str, s| {
-                    if str.is_empty() {
-                        str = s.to_owned();
-                    } else {
-                        str.push('\n');
-                        str.push_str(s);
-                    }
-                    str
-                });
+                let clipboard =
+                    self.contents.iter().fold(String::new(), |mut str, s| {
+                        if str.is_empty() {
+                            str = s.to_owned();
+                        } else {
+                            str.push('\n');
+                            str.push_str(s);
+                        }
+                        str
+                    });
                 operation::Outcome::Some(clipboard)
             } else {
                 operation::Outcome::None
@@ -87,11 +95,10 @@ pub fn global_selection() -> impl Operation {
             _bounds: iced_widget::core::Rectangle,
             _state: &mut dyn std::any::Any,
         ) {
-            // if let Some(selection) = _state.downcast_mut::<IndependentSelection<'_>>() {
-            //     *selection.0 = false;
-            // }
-            if let Some(selection) = _state.downcast_mut::<bool>() {
-                *selection = false;
+            if let Some(selection) =
+                _state.downcast_mut::<IndependentSelection>()
+            {
+                let _ = selection.0.replace(false);
             }
         }
     }
diff --git a/src/text.rs b/src/text.rs
index 76560ce..4b789c9 100644
--- a/src/text.rs
+++ b/src/text.rs
@@ -752,8 +752,11 @@ where
             }
         }
 
-        // let mut isel = crate::operation::IndependentSelection::new(&mut self.independent_selection);
-        operation.custom(None, layout.bounds(), &mut self.independent_selection);
+        let mut isel = crate::operation::IndependentSelection::new(
+            self.independent_selection,
+        );
+        operation.custom(None, layout.bounds(), &mut isel);
+        self.independent_selection = isel.get();
     }
 
     fn mouse_interaction(
diff --git a/src/text/rich.rs b/src/text/rich.rs
index b49adbd..eb8b6b2 100644
--- a/src/text/rich.rs
+++ b/src/text/rich.rs
@@ -954,12 +954,11 @@ where
             }
         }
 
-        // let mut isel = crate::operation::IndependentSelection::new(&mut self.independent_selection);
-        operation.custom(
-            None,
-            layout.bounds(),
-            &mut self.independent_selection,
+        let mut isel = crate::operation::IndependentSelection::new(
+            self.independent_selection,
         );
+        operation.custom(None, layout.bounds(), &mut isel);
+        self.independent_selection = isel.get();
     }
 
     fn mouse_interaction(