Make checkboxes more accessible

Make the underlying native checkboxes more accessible to screen readers and touch.

Resolves #276. Addresses parts of #163.

Co-Authored-By: Dickson Tan <16471962+Neurrone@users.noreply.github.com>

Author: jakezatecky

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 #### Accessibility
 
+* Make the underlying checkbox accessible to screen readers and touch (#276)
 * Hide the pseudo-checkbox from the accessibility tree
 * Change the clickable label from `role="link"` to `role="button"`
 

src/js/components/TreeNode.jsx

@@ -53,7 +53,6 @@ class TreeNode extends React.PureComponent {
         super(props);
 
         this.onCheck = this.onCheck.bind(this);
-        this.onCheckboxKeyPress = this.onCheckboxKeyPress.bind(this);
         this.onCheckboxKeyUp = this.onCheckboxKeyUp.bind(this);
         this.onClick = this.onClick.bind(this);
         this.onExpand = this.onExpand.bind(this);
@@ -68,19 +67,14 @@ class TreeNode extends React.PureComponent {
         });
     }
 
-    onCheckboxKeyPress(event) {
+    onCheckboxKeyUp(event) {
         const { checkKeys } = this.props;
         const { key } = event;
 
-        // Prevent browser scroll when pressing space on the checkbox
-        if (key === KEYS.SPACEBAR && checkKeys.includes(key)) {
+        // Prevent default spacebar behavior from interfering with user settings
+        if (KEYS.SPACEBAR) {
             event.preventDefault();
         }
-    }
-
-    onCheckboxKeyUp(event) {
-        const { checkKeys } = this.props;
-        const { key } = event;
 
         if (checkKeys.includes(key)) {
             this.onCheck();
@@ -224,16 +218,12 @@ class TreeNode extends React.PureComponent {
                     indeterminate={checked === 2}
                     onChange={() => {}}
                     onClick={this.onCheck}
+                    onKeyUp={this.onCheckboxKeyUp}
                 />
                 <span
-                    aria-checked={checked === 1}
-                    aria-disabled={disabled}
                     aria-hidden="true"
                     className="rct-checkbox"
-                    role="checkbox"
-                    tabIndex={0}
-                    onKeyPress={this.onCheckboxKeyPress}
-                    onKeyUp={this.onCheckboxKeyUp}
+                    role="presentation"
                 >
                     {this.renderCheckboxIcon()}
                 </span>

src/scss/react-checkbox-tree.scss

@@ -4,6 +4,11 @@ $rct-label-hover: rgba($rct-icon-color, .1) !default;
 $rct-label-active: rgba($rct-icon-color, .15) !default;
 $rct-clickable-hover: rgba($rct-icon-color, .1) !default;
 $rct-clickable-focus: rgba($rct-icon-color, .2) !default;
+$rct-checkbox-outline-offset: 2px !default;
+$rct-outline-color: rgba($rct-icon-color, .5) !default;
+$rct-outline-radius: 2px;
+$rct-outline-size: 2px !default;
+$rct-outline-offset: -2px !default;
 
 // Force ASCII output until Sass supports it
 // https://github.com/sass/dart-sass/issues/568
@@ -30,20 +35,38 @@ $rct-clickable-focus: rgba($rct-icon-color, .2) !default;
     }
   }
 
+  button,
+  input {
+    &:focus {
+      outline: $rct-outline-size solid $rct-outline-color;
+      border-radius: $rct-outline-radius;
+    }
+
+    &:not(:focus-visible) {
+      outline: none;
+    }
+  }
+
   button {
     line-height: normal;
     color: inherit;
 
     &:disabled {
       cursor: not-allowed;
     }
+
+    &:focus {
+      outline-offset: $rct-outline-offset;
+    }
   }
 
   .rct-bare-label {
     cursor: default;
   }
 
   label {
+    display: flex;
+    align-items: center;
     margin-bottom: 0;
     cursor: pointer;
 
@@ -57,12 +80,32 @@ $rct-clickable-focus: rgba($rct-icon-color, .2) !default;
     }
   }
 
-  &:not(.rct-native-display) input {
-    display: none;
+  input {
+    margin: 0 5px;
+    cursor: pointer;
+
+    &:focus {
+      outline-offset: $rct-checkbox-outline-offset;
+    }
   }
 
-  &.rct-native-display input {
-    margin: 0 5px;
+  &:not(.rct-native-display) input {
+    // Hide the native checkbox (but keep in accessibility tree and accessible via touch)
+    position: absolute;
+    opacity: 0;
+
+    // Show focus effect on pseudo-checkbox
+    &:focus {
+      + .rct-checkbox {
+        outline: $rct-outline-size solid $rct-outline-color;
+        outline-offset: $rct-outline-offset;
+        border-radius: $rct-outline-radius;
+      }
+
+      &:not(:focus-visible) + .rct-checkbox {
+        outline: none;
+      }
+    }
   }
 
   .rct-icon {

test/CheckboxTree.jsx

@@ -160,7 +160,7 @@ describe('<CheckboxTree />', () => {
         it('should trigger a check event when pressing one of the supplied values', async () => {
             let actual = null;
 
-            const { container } = render(
+            render(
                 <CheckboxTree
                     checkKeys={['Shift']}
                     checked={[]}
@@ -171,7 +171,7 @@ describe('<CheckboxTree />', () => {
                 />,
             );
 
-            await fireEvent.keyUp(container.querySelector('.rct-checkbox'), { key: 'Shift' });
+            await fireEvent.keyUp(screen.getByRole('checkbox'), { key: 'Shift' });
 
             assert.deepEqual(actual, ['jupiter']);
         });

test/TreeNode.jsx

@@ -378,7 +378,7 @@ describe('<TreeNode />', () => {
         it('should trigger on key press', async () => {
             let actual = {};
 
-            const { container } = render(
+            render(
                 <TreeNode
                     {...baseProps}
                     checked={2}
@@ -389,7 +389,7 @@ describe('<TreeNode />', () => {
                 />,
             );
 
-            await fireEvent.keyUp(container.querySelector('.rct-checkbox'), { key: 'Enter' });
+            await fireEvent.keyUp(screen.getByRole('checkbox'), { key: 'Enter' });
 
             assert.isTrue(actual.checked);
         });