Add inspection utility methods to Env and Key

CHANGELOG.md

@@ -29,6 +29,7 @@ While some features like the clipboard, menus or file dialogs are not yet availa
 - `Label::with_font` and `set_font`. ([#785] by [@thecodewarrior])
 - `InternalEvent::RouteTimer` to route timer events. ([#831] by [@sjoshid])
 - `MouseButtons` to `MouseEvent` to track which buttons are being held down during an event. ([#843] by [@xStrom])
+- `Env` and `Key` gained methods for inspecting an `Env` at runtime ([#880] by [@Zarenor])
 - `UpdateCtx::request_timer` and `UpdateCtx::request_anim_frame`. ([#898] by [@finnerale])
 
 ### Changed
@@ -140,6 +141,7 @@ While some features like the clipboard, menus or file dialogs are not yet availa
 [#861]: https://github.com/xi-editor/druid/pull/861
 [#869]: https://github.com/xi-editor/druid/pull/869
 [#878]: https://github.com/xi-editor/druid/pull/878
+[#880]: https://github.com/xi-editor/druid/pull/880
 [#889]: https://github.com/xi-editor/druid/pull/889
 [#894]: https://github.com/xi-editor/druid/pull/894
 [#897]: https://github.com/xi-editor/druid/pull/897
@@ -172,6 +174,7 @@ Last release without a changelog :(
 [@thecodewarrior]: https://github.com/thecodewarrior
 [@sjoshid]: https://github.com/sjoshid
 [@mastfissh]: https://github.com/mastfissh
+[@Zarenor]: https://github.com/Zarenor
 
 [Unreleased]: https://github.com/xi-editor/druid/compare/v0.5.0...master
 [0.5.0]: https://github.com/xi-editor/druid/compare/v0.4.0...v0.5.0

druid/src/env.rs

@@ -208,6 +208,39 @@ impl Env {
             .map(|value| value.to_inner_unchecked())
     }
 
+    /// Gets a value from the environment, in its encapsulated [`Value`] form,
+    /// expecting the key to be present.
+    ///
+    /// *WARNING:* This is not intended for general use, but only for inspecting an `Env` e.g.
+    /// for debugging, theme editing, and theme loading.
+    /// [`Value`]: enum.Value.html
+    pub fn get_untyped(&self, key: impl Borrow<Key<()>>) -> &Value {
+        let key = key.borrow();
+        if let Some(value) = self.0.map.get(key.key) {
+            value
+        } else {
+            panic!("key for {} not found", key.key)
+        }
+    }
+
+    /// Gets a value from the environment, in its encapsulated [`Value`] form,
+    /// returning None if a value isn't found.
+    ///
+    /// *WARNING:* This is not intended for general use, but only for inspecting an `Env` e.g.
+    /// for debugging, theme editing, and theme loading.
+    /// [`Value`]: enum.Value.html
+    pub fn try_get_untyped(&self, key: impl Borrow<Key<()>>) -> Option<&Value> {
+        self.0.map.get(key.borrow().key)
+    }
+
+    /// Gets the entire contents of the `Env`, in key-value pairs.
+    ///
+    /// *WARNING:* This is not intended for general use, but only for inspecting an `Env` e.g.
+    /// for debugging, theme editing, and theme loading.
+    pub fn get_all(&self) -> impl ExactSizeIterator<Item = (&String, &Value)> {
+        self.0.map.iter()
+    }
+
     /// Adds a key/value, acting like a builder.
     pub fn adding<'a, V: ValueType<'a>>(mut self, key: Key<V>, value: impl Into<V::Owned>) -> Env {
         let env = Arc::make_mut(&mut self.0);
@@ -274,6 +307,22 @@ impl<T> Key<T> {
     }
 }
 
+impl Key<()> {
+    /// Create an untyped `Key` with the given string value.
+    ///
+    /// *WARNING:* This is not for general usage - it's only useful
+    /// for inspecting the contents of an [`Env`]  - this is expected to be
+    /// used for debugging, loading, and manipulating themes.
+    ///
+    /// [`Env`]: struct.Env.html
+    pub const fn untyped(key: &'static str) -> Self {
+        Key {
+            key,
+            value_type: PhantomData,
+        }
+    }
+}
+
 impl Value {
     /// Get a reference to the inner object.
     ///