Added fix for issue 409 with minimal test

Author: genusistimelord

.vscode/launch.json

@@ -145,6 +145,38 @@
       "args": [],
       "cwd": "${workspaceFolder}"
     },
+    {
+      "type": "lldb",
+      "request": "launch",
+      "name": "Debug example 'dropdown_pos'",
+      "cargo": {
+        "args": [
+          "build",
+          "--example=dropdown_pos",
+        ],
+        "filter": {
+          "name": "dropdown_pos",
+          "kind": "example"
+        }
+      },
+      "args": [],
+      "cwd": "${workspaceFolder}"
+    },
+    {
+      "name": "(Windows) Launch example 'dropdown_pos'",
+      "type": "cppvsdbg",
+      "request": "launch",
+      "program": "${workspaceRoot}/target/debug/examples/dropdown_pos.exe",
+      "args": [
+        "--example",
+        "dropdown_pos"
+      ],
+      "stopAtEntry": false,
+      "cwd": "${workspaceRoot}",
+      "environment": [],
+      "preLaunchTask": "build_dropdown_pos",
+      "console": "integratedTerminal",
+    },
     {
       "type": "lldb",
       "request": "launch",

.vscode/tasks.json

@@ -0,0 +1,22 @@
+// .vscode/tasks.json
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build_dropdown_pos",
+            "type": "cargo",
+            "command": "build",
+            "args": [
+                "--example",
+                "dropdown_pos"
+            ],
+            "problemMatcher": [
+                "$rustc"
+            ],
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            }
+        }
+    ]
+}

examples/dropdown_pos.rs

@@ -0,0 +1,107 @@
+use iced::{
+    Alignment, Element,
+    Length::{Fill, FillPortion, Shrink},
+    widget::{button, column, container, row, scrollable, text},
+};
+use iced_aw::{DropDown, drop_down};
+use std::str::FromStr;
+
+fn main() -> iced::Result {
+    iced::application(App::default, App::update, App::view).run()
+}
+
+#[derive(Default, Debug, Clone)]
+enum DropDownItem {
+    #[default]
+    A,
+    B,
+    C,
+}
+
+impl ToString for DropDownItem {
+    fn to_string(&self) -> String {
+        match self {
+            DropDownItem::A => String::from_str("A").unwrap(),
+            DropDownItem::B => String::from_str("B").unwrap(),
+            DropDownItem::C => String::from_str("C").unwrap(),
+        }
+    }
+}
+
+impl DropDownItem {
+    const ALL: &'static [Self] = &[DropDownItem::A, DropDownItem::B, DropDownItem::C];
+}
+
+#[derive(Default)]
+struct App {
+    is_open: bool,
+    selected: DropDownItem,
+}
+
+#[derive(Debug, Clone)]
+enum Message {
+    DropdownOpen,
+    DropdownSelect(DropDownItem),
+}
+
+impl App {
+    fn view(&self) -> Element<'_, Message> {
+        row![
+            container(column![
+                container(
+                    column![text("Placeholder").size(18), text("text").size(12)]
+                        .spacing(2)
+                        .width(Fill)
+                        .align_x(Alignment::Center)
+                )
+                .padding(4),
+                column![
+                    row![
+                        text("Placeholder"),
+                        button("scaffold").padding(1).height(Shrink)
+                    ],
+                    scrollable(text("Lorem")).height(Fill)
+                ]
+            ])
+            .width(FillPortion(1)),
+            column![
+                row![
+                    text("Dropdowns"),
+                    prepare_dropdown(self.selected.clone(), self.is_open)
+                ]
+                .spacing(4)
+                .padding(5),
+                scrollable("Lorem").height(Fill)
+            ]
+            .width(FillPortion(2))
+        ]
+        .into()
+    }
+
+    fn update(&mut self, message: Message) {
+        match message {
+            Message::DropdownOpen => self.is_open = !self.is_open,
+            Message::DropdownSelect(drop_down_item) => self.selected = drop_down_item,
+        }
+    }
+}
+
+fn prepare_dropdown<'a>(selected: DropDownItem, expanded: bool) -> DropDown<'a, Message> {
+    let underlay = button(
+        row![
+            text(selected.to_string()).width(90),
+            if expanded { text("V") } else { text("<") }
+        ]
+        .align_y(Alignment::Center),
+    )
+    .on_press(Message::DropdownOpen);
+    let overlay = container(column(DropDownItem::ALL.iter().map(|r| {
+        button(text(r.to_string()).size(18).wrapping(text::Wrapping::None))
+            .width(Fill)
+            .on_press(Message::DropdownSelect(r.clone()))
+            .into()
+    })));
+    DropDown::new(underlay, overlay, expanded)
+        .alignment(drop_down::Alignment::Bottom)
+        .on_dismiss(Message::DropdownOpen)
+}

src/widget/drop_down.rs

@@ -321,7 +321,7 @@ where
             Alignment::Start | Alignment::End => limits.max_height(max_height_symmetric),
         };
 
-        let mut node = self
+        let node = self
             .element
             .as_widget_mut()
             .layout(self.state, renderer, &limits);
@@ -364,23 +364,23 @@ where
                     - node.bounds().height / 2.0,
             ),
         };
+        //commenting these out for now as we have no way of knowing the actual screen size here.. maybe in a later iced update?
+        /*if new_position.x + node.bounds().width > max.width {
+            new_position.x -= max.width - node.bounds().width;
+        }*/
 
-        if new_position.x + node.bounds().width > max.width {
-            new_position.x = max.width - node.bounds().width;
-        }
         if new_position.x < 0.0 {
             new_position.x = 0.0;
         }
 
-        if new_position.y + node.bounds().height > max.height {
-            new_position.y = max.height - node.bounds().height;
-        }
+        /*if new_position.y + node.bounds().height > max.height {
+            new_position.y -= max.height - node.bounds().height;
+        }*/
         if new_position.y < 0.0 {
             new_position.y = 0.0;
         }
 
-        node.move_to_mut(new_position);
-        node
+        node.move_to(new_position)
     }
 
     fn draw(