MD Settings: make [un]controlled radio buttons actionable (cursor: pointer)

chrome/browser/resources/settings/controls/controlled_radio_button.html

 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_pref_indicator.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys-behavior/iron-a11y-keys-behavior.html">
 <link rel="import" href="pref_control_behavior.html">
 <link rel="import" href="../prefs/pref_util.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="controlled-radio-button">
   <template>
     <style include="settings-shared">
@@ skipping 65 matching lines @@
         color: var(--paper-radio-button-unchecked-ink-color,
                    --primary-text-color);
         opacity: .6;
       }
 
       :host([checked]) paper-ripple {
         color: var(--paper-radio-button-checked-ink-color,
                    --primary-text-color);
       }
 
+      :host(:not([controlled_])) {

[dpapad, 2017/04/18 18:58:32]

Can radio buttons be disabled otherwise? For example with a |disabled|
attribute?

Would it be more robust as follows?

:host {
  ....
  @apply(--settings-actionable);
}

:host([controlled_]),
:host([disabled]) {
  cursor: initial;
  pointer-events: none;
}

[Dan Beam, 2017/04/18 19:00:37]

no

[Dan Beam, 2017/04/18 19:10:49]

that was the short answer.  the longer answer is that assuming what will be in a
CSS mixin to override it is not the best strategy, imo.  it also makes less
sense to me to apply a style then override it later... instead of only applying
it when needed.

[Dan Beam, 2017/04/18 19:12:22]

also, i'm not really sure how [disabled] works in the context.  most of this
file uses a private |controlled_| and determines it's own fate, whereas disabled
(if it's public, especially) can be set by the outside.  we generally want to
keep things private / up to the minimal scope possible until needed otherwise
(i.e. something outside of this class needs to disable this for reasons a
<controlled-radio-button> shouldn't really know about)

+        @apply(--settings-actionable);
+      }
+
       :host([controlled_]) {
         /* Disable pointer events for this whole element, as outer on-tap gets
          * triggered when clicking/tapping anywhere in :host. */
         pointer-events: none;
       }
 
       :host([controlled_]) :-webkit-any(.circle, .disc) {
         opacity: .5;
       }
 
@@ skipping 32 matching lines @@
 
     <template is="dom-if" if="[[showIndicator_(controlled_, name, pref.*)]]">
       <cr-policy-pref-indicator pref="[[pref]]" on-tap="onIndicatorTap_"
           icon-aria-label="[[label]]">
       </cr-policy-pref-indicator>
     </template>
 
   </template>
   <script src="controlled_radio_button.js"></script>
 </dom-module>