Document and demonstrate how to expand a TextEdit to fill a Ui

egui/src/ui.rs

@@ -817,6 +817,8 @@ impl Ui {
     /// Add a [`Widget`] to this `Ui` with a given size.
     /// The widget will attempt to fit within the given size, but some widgets may overflow.
     ///
+    /// To fill all remaining area, use `ui.add_sized(ui.available_size(), widget);`
+    ///
     /// See also [`Self::add`] and [`Self::put`].
     ///
     /// ```

egui/src/widgets/text_edit.rs

@@ -125,6 +125,15 @@ impl CCursorPair {
 ///     // …
 /// }
 /// ```
+///
+/// To fill an [`Ui`] with a [`TextEdit`] use [`Ui::add_sized`]:
+///
+/// ```
+/// # let mut ui = egui::Ui::__test();
+/// # let mut my_string = String::new();
+/// ui.add_sized(ui.available_size(), egui::TextEdit::multiline(&mut my_string));
+/// ```
+///
 #[must_use = "You should put this widget in an ui with `ui.add(widget);`"]
 #[derive(Debug)]
 pub struct TextEdit<'t> {

egui_demo_lib/src/apps/demo/tests.rs

@@ -319,8 +319,17 @@ impl super::View for InputTest {
 
 // ----------------------------------------------------------------------------
 
-#[derive(Default)]
+pub struct WindowResizeTest {
-pub struct WindowResizeTest {}
+    text: String,
+}
+
+impl Default for WindowResizeTest {
+    fn default() -> Self {
+        Self {
+            text: crate::LOREM_IPSUM.to_owned(),
+        }
+    }
+}
 
 impl super::Demo for WindowResizeTest {
     fn name(&self) -> &'static str {
@@ -381,5 +390,14 @@ impl super::Demo for WindowResizeTest {
                 ui.separator();
                 ui.code(crate::LOREM_IPSUM);
             });
+
+        Window::new("↔ resizable with TextEdit")
+            .open(open)
+            .scroll(false)
+            .resizable(true)
+            .show(ctx, |ui| {
+                ui.label("Shows how you can fill an area with a widget.");
+                ui.add_sized(ui.available_size(), TextEdit::multiline(&mut self.text));
+            });
     }
 }