feat(selectable): draft implementation of selectable widget

1 files changed, 100 insertions, 0 deletions

diff --git a/src/operation.rs b/src/operation.rs
new file mode 100644
index 0000000..584f61f
--- /dev/null
+++ b/src/operation.rs
@@ -0,0 +1,100 @@
+//! Provides some operations to be used on the [`Text`] or [`Rich`].
+//!
+//! [`Text`]: crate::text::Text
+//! [`Rich`]: crate::text::Rich
+
+use crate::core::widget::operation::{self, Operation};
+
+/// Some selected text
+pub struct Selection(pub String);
+
+/// Some mutable independent selection field of a [`Text`] or [`Rich`] that can be changed through
+/// an operation.
+///
+/// [`Text`]: crate::text::Text
+/// [`Rich`]: crate::text::Rich
+pub struct IndependentSelection<'a>(pub &'a mut bool);
+
+impl<'a> IndependentSelection<'a> {
+    /// Creates a new [`IndependentSelection`] with the given mutable reference
+    pub fn new(isel: &'a mut bool) -> Self {
+        Self(isel)
+    }
+}
+
+/// Gets all the currently selected text
+pub fn selected() -> impl Operation<String> {
+    struct CopySelection {
+        contents: Vec<String>,
+    }
+
+    impl Operation<String> for CopySelection {
+
+        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<String>)) {
+            operate(self);
+        }
+
+        fn custom(
+            &mut self,
+            _id: Option<&iced_widget::Id>,
+            _bounds: iced_widget::core::Rectangle,
+            _state: &mut dyn std::any::Any,
+        ) {
+            if let Some(selection) = _state.downcast_ref::<Selection>() {
+                self.contents.push(selection.0.clone());
+            }
+        }
+
+        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
+                });
+                operation::Outcome::Some(clipboard)
+            } else {
+                operation::Outcome::None
+            }
+        }
+    }
+
+    CopySelection {
+        contents: Vec::new(),
+    }
+}
+
+/// Sets all children instances of [`Text`] or [`Rich`] to be globally selectable instead of
+/// independently selectable.
+///
+/// [`Text`]: crate::text::Text
+/// [`Rich`]: crate::text::Rich
+pub fn global_selection() -> impl Operation {
+    struct SetGlobalSelection;
+
+    impl Operation for SetGlobalSelection {
+        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation)) {
+            operate(self);
+        }
+
+        fn custom(
+            &mut self,
+            _id: Option<&iced_widget::Id>,
+            _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;
+            }
+        }
+    }
+
+    SetGlobalSelection
+}