Padding takes KeyOrValue, TEXTBOX_INSETS moves back to Env

CHANGELOG.md

@@ -26,6 +26,7 @@ You can find its changes [documented below](#070---2021-01-01).
 - New `TextBox` widget with IME integration ([#1636] by [@cmyr])
 - `Notification`s can be submitted while handling other `Notification`s ([#1640] by [@cmyr])
 - Added ListIter implementations for OrdMap ([#1641] by [@Lejero])
+- `Padding` can now use `Key<Insets>` ([#1662] by [@cmyr])
 
 ### Changed
 
@@ -644,6 +645,7 @@ Last release without a changelog :(
 [#1640]: https://github.com/linebender/druid/pull/1640
 [#1641]: https://github.com/linebender/druid/pull/1641
 [#1647]: https://github.com/linebender/druid/pull/1647
+[#1662]: https://github.com/linebender/druid/pull/1662
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.7.0...master
 [0.7.0]: https://github.com/linebender/druid/compare/v0.6.0...v0.7.0

druid/src/env.rs

@@ -623,6 +623,24 @@ impl<T: ValueType> From<Key<T>> for KeyOrValue<T> {
     }
 }
 
+impl Into<KeyOrValue<Insets>> for f64 {
+    fn into(self) -> KeyOrValue<Insets> {
+        KeyOrValue::Concrete(self.into())
+    }
+}
+
+impl Into<KeyOrValue<Insets>> for (f64, f64) {
+    fn into(self) -> KeyOrValue<Insets> {
+        KeyOrValue::Concrete(self.into())
+    }
+}
+
+impl Into<KeyOrValue<Insets>> for (f64, f64, f64, f64) {
+    fn into(self) -> KeyOrValue<Insets> {
+        KeyOrValue::Concrete(self.into())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

druid/src/theme.rs

@@ -136,7 +136,7 @@ pub(crate) fn add_to_env(env: Env) -> Env {
         .adding(BORDERED_WIDGET_HEIGHT, 24.0)
         .adding(TEXTBOX_BORDER_RADIUS, 2.)
         .adding(TEXTBOX_BORDER_WIDTH, 1.)
-        .adding(TEXTBOX_INSETS, Insets::new(4.0, 2.0, 4.0, 4.0))
+        .adding(TEXTBOX_INSETS, Insets::new(4.0, 4.0, 4.0, 4.0))
         .adding(SCROLLBAR_COLOR, Color::rgb8(0xff, 0xff, 0xff))
         .adding(SCROLLBAR_BORDER_COLOR, Color::rgb8(0x77, 0x77, 0x77))
         .adding(SCROLLBAR_MAX_OPACITY, 0.7)

druid/src/widget/padding.rs

@@ -15,24 +15,23 @@
 //! A widget that just adds padding during layout.
 
 use crate::widget::{prelude::*, WidgetWrapper};
-use crate::{Data, Insets, Point, WidgetPod};
+use crate::{Data, Insets, KeyOrValue, Point, WidgetPod};
 
 use tracing::{instrument, trace};
 
 /// A widget that just adds padding around its child.
 pub struct Padding<T, W> {
-    left: f64,
-    right: f64,
-    top: f64,
-    bottom: f64,
-
+    insets: KeyOrValue<Insets>,
     child: WidgetPod<T, W>,
 }
 
 impl<T, W: Widget<T>> Padding<T, W> {
-    /// Create a new widget with the specified padding. This can either be an instance
-    /// of [`kurbo::Insets`], a f64 for uniform padding, a 2-tuple for axis-uniform padding
-    /// or 4-tuple with (left, top, right, bottom) values.
+    /// Create a new `Padding` with the specified padding and child.
+    ///
+    /// The `insets` argument can either be an instance of [`Insets`],
+    /// a [`Key`] referring to [`Insets`] in the [`Env`],
+    /// an `f64` for uniform padding, an `(f64, f64)` for axis-uniform padding,
+    /// or `(f64, f64, f64, f64)` (left, top, right, bottom) values.
     ///
     /// # Examples
     ///
@@ -58,14 +57,10 @@ impl<T, W: Widget<T>> Padding<T, W> {
     /// let _: Padding<(), _> = Padding::new(Insets::uniform_xy(10.0, 20.0), Label::new("ditto :)"));
     /// ```
     ///
-    /// [`kurbo::Insets`]: https://docs.rs/kurbo/0.5.3/kurbo/struct.Insets.html
-    pub fn new(insets: impl Into<Insets>, child: W) -> Padding<T, W> {
-        let insets = insets.into();
+    /// [`Key`]: crate::Key
+    pub fn new(insets: impl Into<KeyOrValue<Insets>>, child: W) -> Padding<T, W> {
         Padding {
-            left: insets.x0,
-            right: insets.x1,
-            top: insets.y0,
-            bottom: insets.y1,
+            insets: insets.into(),
             child: WidgetPod::new(child),
         }
     }
@@ -86,25 +81,25 @@ impl<T: Data, W: Widget<T>> Widget<T> for Padding<T, W> {
         self.child.lifecycle(ctx, event, data, env)
     }
 
-    #[instrument(
-        name = "Padding",
-        level = "trace",
-        skip(self, ctx, _old_data, data, env)
-    )]
-    fn update(&mut self, ctx: &mut UpdateCtx, _old_data: &T, data: &T, env: &Env) {
+    #[instrument(name = "Padding", level = "trace", skip(self, ctx, _old, data, env))]
+    fn update(&mut self, ctx: &mut UpdateCtx, _old: &T, data: &T, env: &Env) {
+        if ctx.env_key_changed(&self.insets) {
+            ctx.request_layout();
+        }
         self.child.update(ctx, data, env);
     }
 
     #[instrument(name = "Padding", level = "trace", skip(self, ctx, bc, data, env))]
     fn layout(&mut self, ctx: &mut LayoutCtx, bc: &BoxConstraints, data: &T, env: &Env) -> Size {
         bc.debug_check("Padding");
+        let insets = self.insets.resolve(env);
 
-        let hpad = self.left + self.right;
-        let vpad = self.top + self.bottom;
+        let hpad = insets.x0 + insets.x1;
+        let vpad = insets.y0 + insets.y1;
 
         let child_bc = bc.shrink((hpad, vpad));
         let size = self.child.layout(ctx, &child_bc, data, env);
-        let origin = Point::new(self.left, self.top);
+        let origin = Point::new(insets.x0, insets.y0);
         self.child.set_origin(ctx, data, env, origin);
 
         let my_size = Size::new(size.width + hpad, size.height + vpad);

druid/src/widget/textbox.rs

@@ -26,7 +26,6 @@ use crate::{
     theme, Color, FontDescriptor, KeyOrValue, Point, Rect, TextAlignment, TimerToken, Vec2,
 };
 
-const TEXTBOX_INSETS: Insets = Insets::new(4.0, 2.0, 4.0, 2.0);
 const CURSOR_BLINK_DURATION: Duration = Duration::from_millis(500);
 const MAC_OR_LINUX: bool = cfg!(any(target_os = "macos", target_os = "linux"));
 
@@ -73,7 +72,7 @@ impl<T: EditableText + TextStorage> TextBox<T> {
         let mut scroll = Scroll::new(TextComponent::default()).content_must_fill(true);
         scroll.set_enabled_scrollbars(crate::scroll_component::ScrollbarsEnabled::None);
         Self {
-            inner: Padding::new(TEXTBOX_INSETS, scroll),
+            inner: Padding::new(theme::TEXTBOX_INSETS, scroll),
             scroll_to_selection_after_layout: false,
             placeholder,
             multiline: false,
@@ -471,6 +470,7 @@ impl<T: TextStorage + EditableText> Widget<T> for TextBox<T> {
             tracing::warn!("Widget::layout called with outstanding IME lock.");
         }
         let min_width = env.get(theme::WIDE_WIDGET_WIDTH);
+        let textbox_insets = env.get(theme::TEXTBOX_INSETS);
 
         self.placeholder.rebuild_if_needed(ctx.text(), env);
         let min_size = bc.constrain((min_width, 0.0));
@@ -488,7 +488,7 @@ impl<T: TextStorage + EditableText> Widget<T> for TextBox<T> {
         let baseline_off = layout_baseline
             - (self.inner.wrapped().child_size().height
                 - self.inner.wrapped().viewport_rect().height())
-            + TEXTBOX_INSETS.y1;
+            + textbox_insets.y1;
         ctx.set_baseline_offset(baseline_off);
         if self.scroll_to_selection_after_layout {
             self.scroll_to_selection_end();
@@ -513,6 +513,7 @@ impl<T: TextStorage + EditableText> Widget<T> for TextBox<T> {
         let background_color = env.get(theme::BACKGROUND_LIGHT);
         let cursor_color = env.get(theme::CURSOR_COLOR);
         let border_width = env.get(theme::TEXTBOX_BORDER_WIDTH);
+        let textbox_insets = env.get(theme::TEXTBOX_INSETS);
 
         let is_focused = ctx.is_focused();
 
@@ -537,7 +538,7 @@ impl<T: TextStorage + EditableText> Widget<T> for TextBox<T> {
             ctx.with_save(|ctx| {
                 ctx.clip(clip_rect);
                 self.placeholder
-                    .draw(ctx, (TEXTBOX_INSETS.x0, TEXTBOX_INSETS.y0));
+                    .draw(ctx, (textbox_insets.x0, textbox_insets.y0));
             })
         }
 
@@ -551,7 +552,7 @@ impl<T: TextStorage + EditableText> Widget<T> for TextBox<T> {
                 .borrow()
                 .cursor_line_for_text_position(cursor_pos);
 
-            let padding_offset = Vec2::new(TEXTBOX_INSETS.x0, TEXTBOX_INSETS.y0);
+            let padding_offset = Vec2::new(textbox_insets.x0, textbox_insets.y0);
 
             let cursor = if data.is_empty() {
                 cursor_line + padding_offset

druid/src/widget/widget_ext.rs

@@ -28,9 +28,12 @@ use crate::{
 pub trait WidgetExt<T: Data>: Widget<T> + Sized + 'static {
     /// Wrap this widget in a [`Padding`] widget with the given [`Insets`].
     ///
-    /// [`Padding`]: widget/struct.Padding.html
-    /// [`Insets`]: kurbo/struct.Insets.html
-    fn padding(self, insets: impl Into<Insets>) -> Padding<T, Self> {
+    /// Like [`Padding::new`], this can accept a variety of arguments, including
+    /// a [`Key`] referring to [`Insets`] in the [`Env`].
+    ///
+    /// [`Key`]: crate::Key
+    /// [`Insets`]: crate::Insets
+    fn padding(self, insets: impl Into<KeyOrValue<Insets>>) -> Padding<T, Self> {
         Padding::new(insets, self)
     }