input: Change InputState::disabled to as builder method. (#898)

## Break Changes

- The `disabled` method now is for builder method, and `is_disabled` for
get state.

```diff
- pub fn disabled(mut self) -> bool
+ pub fn is_disabled(&self) -> bool
+ pub fn disabled(mut self, disabled: bool) -> Self
```

crates/ui/src/input/state.rs

@@ -665,12 +665,27 @@ impl InputState {
         self.replace_text_in_range(Some(range), &text, window, cx);
     }
 
+    /// Set with disabled mode.
+    ///
+    /// See also: [`Self::set_disabled`], [`Self::is_disabled`].
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
     /// Set the disabled state of the input field.
+    ///
+    /// See also: [`Self::disabled`], [`Self::is_disabled`].
     pub fn set_disabled(&mut self, disabled: bool, _: &mut Window, cx: &mut Context<Self>) {
         self.disabled = disabled;
         cx.notify();
     }
 
+    /// Return is the input field is disabled.
+    pub fn is_disabled(&self) -> bool {
+        self.disabled
+    }
+
     /// Set with password masked state.
     pub fn masked(mut self, masked: bool) -> Self {
         self.masked = masked;
@@ -734,10 +749,6 @@ impl InputState {
         self.mask_pattern.unmask(&self.text).into()
     }
 
-    pub fn disabled(&self) -> bool {
-        self.disabled
-    }
-
     /// Focus the input field.
     pub fn focus(&self, window: &mut Window, _: &mut Context<Self>) {
         self.focus_handle.focus(window);

crates/ui/src/inspector.rs

@@ -67,11 +67,10 @@ impl DivInspector {
         };
 
         let input_state = cx.new(|cx| {
-            let mut state = InputState::new(window, cx)
+            InputState::new(window, cx)
                 .code_editor(Some("json"), theme)
-                .line_number(false);
-            state.set_disabled(true, window, cx);
-            state
+                .line_number(false)
+                .disabled(true)
         });
 
         Self {