Merge pull request #888 from Ace4896/picklist-placeholder

Add Placeholders to PickList

1 files changed, 35 insertions, 13 deletions

diff --git a/native/src/widget/pick_list.rs b/native/src/widget/pick_list.rs
index 92c183f3..4f4e751e 100644
--- a/native/src/widget/pick_list.rs
+++ b/native/src/widget/pick_list.rs
@@ -25,6 +25,7 @@ where
     last_selection: &'a mut Option<T>,
     on_selected: Box<dyn Fn(T) -> Message>,
     options: Cow<'a, [T]>,
+    placeholder: Option<String>,
     selected: Option<T>,
     width: Length,
     padding: Padding,
@@ -82,6 +83,7 @@ where
             last_selection,
             on_selected: Box::new(on_selected),
             options: options.into(),
+            placeholder: None,
             selected,
             width: Length::Shrink,
             text_size: None,
@@ -91,6 +93,12 @@ where
         }
     }
 
+    /// Sets the placeholder of the [`PickList`].
+    pub fn placeholder(mut self, placeholder: impl Into<String>) -> Self {
+        self.placeholder = Some(placeholder.into());
+        self
+    }
+
     /// Sets the width of the [`PickList`].
     pub fn width(mut self, width: Length) -> Self {
         self.width = width;
@@ -154,24 +162,34 @@ where
             .pad(self.padding);
 
         let text_size = self.text_size.unwrap_or(renderer.default_size());
+        let font = self.font;
 
         let max_width = match self.width {
             Length::Shrink => {
+                let measure = |label: &str| -> u32 {
+                    let (width, _) = renderer.measure(
+                        label,
+                        text_size,
+                        font,
+                        Size::new(f32::INFINITY, f32::INFINITY),
+                    );
+
+                    width.round() as u32
+                };
+
                 let labels = self.options.iter().map(ToString::to_string);
 
-                labels
-                    .map(|label| {
-                        let (width, _) = renderer.measure(
-                            &label,
-                            text_size,
-                            self.font,
-                            Size::new(f32::INFINITY, f32::INFINITY),
-                        );
-
-                        width.round() as u32
-                    })
-                    .max()
-                    .unwrap_or(100)
+                let labels_width =
+                    labels.map(|label| measure(&label)).max().unwrap_or(100);
+
+                let placeholder_width = self
+                    .placeholder
+                    .as_ref()
+                    .map(String::as_str)
+                    .map(measure)
+                    .unwrap_or(100);
+
+                labels_width.max(placeholder_width)
             }
             _ => 0,
         };
@@ -195,6 +213,8 @@ where
 
         match self.width {
             Length::Shrink => {
+                self.placeholder.hash(state);
+
                 self.options
                     .iter()
                     .map(ToString::to_string)
@@ -265,6 +285,7 @@ where
             layout.bounds(),
             cursor_position,
             self.selected.as_ref().map(ToString::to_string),
+            self.placeholder.as_ref().map(String::as_str),
             self.padding,
             self.text_size.unwrap_or(renderer.default_size()),
             self.font,
@@ -325,6 +346,7 @@ pub trait Renderer: text::Renderer + menu::Renderer {
         bounds: Rectangle,
         cursor_position: Point,
         selected: Option<String>,
+        placeholder: Option<&str>,
         padding: Padding,
         text_size: u16,
         font: Self::Font,