feat: add accessibility support (#117)

* chore: added accessibility base support

* chore: updated backdrop to avoid covering whole screen when its invisible

* chore: remove unused comments

src/components/bottomSheet/BottomSheet.tsx

@@ -9,7 +9,7 @@ import React, {
   useLayoutEffect,
   useEffect,
 } from 'react';
-import { ViewStyle } from 'react-native';
+import { ViewStyle, AccessibilityInfo } from 'react-native';
 import isEqual from 'lodash.isequal';
 import invariant from 'invariant';
 import Animated, {
@@ -486,6 +486,28 @@ const BottomSheetComponent = forwardRef<BottomSheet, BottomSheetProps>(
             ) {
               return;
             }
+
+            /**
+             * Here we announce the bottom sheet position
+             * for accessibility service.
+             */
+            AccessibilityInfo.isScreenReaderEnabled().then(isEnabled => {
+              if (!isEnabled) {
+                return;
+              }
+              const positionInScreen = Math.max(
+                Math.floor(
+                  ((WINDOW_HEIGHT - snapPoints[currentPositionIndex] || 1) /
+                    WINDOW_HEIGHT) *
+                    100
+                ),
+                0
+              ).toFixed(0);
+              AccessibilityInfo.announceForAccessibility(
+                `Bottom sheet snapped to ${positionInScreen}% of the screen`
+              );
+            });
+
             currentIndexRef.current = currentPositionIndex;
             refreshUIElements();
             handleOnChange(currentPositionIndex);
@@ -536,7 +558,12 @@ const BottomSheetComponent = forwardRef<BottomSheet, BottomSheetProps>(
             ref={containerTapGestureRef}
             {...containerTapGestureHandler}
           >
-            <Animated.View style={containerStyle}>
+            <Animated.View
+              accessible={true}
+              accessibilityRole="adjustable"
+              accessibilityLabel="Bottom Sheet"
+              style={containerStyle}
+            >
               <BottomSheetInternalProvider value={internalContextVariables}>
                 <BottomSheetBackgroundContainer
                   key="BottomSheetBackgroundContainer"

src/components/bottomSheetBackdrop/BottomSheetBackdrop.tsx

@@ -20,6 +20,7 @@ import {
   DEFAULT_ENABLE_TOUCH_THROUGH,
   DEFAULT_CLOSE_ON_PRESS,
 } from './constants';
+import { WINDOW_HEIGHT } from '../../constants';
 import type { BottomSheetDefaultBackdropProps } from './types';
 import { styles } from './styles';
 
@@ -29,6 +30,10 @@ const {
 } = require('react-native-reanimated');
 const interpolate = interpolateV2 || interpolateV1;
 
+const AnimatedTouchableWithoutFeedback = Animated.createAnimatedComponent(
+  TouchableWithoutFeedback
+);
+
 const BottomSheetBackdropComponent = ({
   animatedIndex,
   animatedPosition,
@@ -70,6 +75,15 @@ const BottomSheetBackdropComponent = ({
   //#endregion
 
   //#region styles
+  const buttonStyle = useMemo(
+    () => [
+      style,
+      {
+        top: cond(eq(animatedIndex, disappearsOnIndex), WINDOW_HEIGHT, 0),
+      },
+    ],
+    [disappearsOnIndex, style, animatedIndex]
+  );
   const containerStyle = useMemo(
     () => [
       style,
@@ -81,20 +95,22 @@ const BottomSheetBackdropComponent = ({
     [style, animatedOpacity]
   );
   //#endregion
-
-  //#region effects
-
-  //#endregion
-
   return closeOnPress ? (
     <>
-      <TouchableWithoutFeedback onPress={handleOnPress} style={style}>
+      <AnimatedTouchableWithoutFeedback
+        accessible={true}
+        accessibilityRole="button"
+        accessibilityLabel="Bottom Sheet backdrop"
+        accessibilityHint="Tap to close the Bottom Sheet"
+        onPress={handleOnPress}
+        style={buttonStyle}
+      >
         <Animated.View ref={containerRef} style={containerStyle} />
-      </TouchableWithoutFeedback>
+      </AnimatedTouchableWithoutFeedback>
       <Animated.Code>
         {() =>
           cond(
-            and(eq(animatedPosition, 0), isTouchable),
+            and(eq(animatedPosition, disappearsOnIndex), isTouchable),
             [
               set(isTouchable, 0),
               call([], () => {
@@ -104,15 +120,18 @@ const BottomSheetBackdropComponent = ({
                 });
               }),
             ],
-            cond(and(neq(animatedPosition, 0), not(isTouchable)), [
-              set(isTouchable, 1),
-              call([], () => {
-                // @ts-ignore
-                containerRef.current.setNativeProps({
-                  pointerEvents: 'auto',
-                });
-              }),
-            ])
+            cond(
+              and(neq(animatedPosition, disappearsOnIndex), not(isTouchable)),
+              [
+                set(isTouchable, 1),
+                call([], () => {
+                  // @ts-ignore
+                  containerRef.current.setNativeProps({
+                    pointerEvents: 'auto',
+                  });
+                }),
+              ]
+            )
           )
         }
       </Animated.Code>

src/components/bottomSheetHandleContainer/BottomSheetHandleContainer.tsx

@@ -68,6 +68,10 @@ const BottomSheetHandleContainerComponent = ({
       onHandlerStateChange={onHandlerStateChange}
     >
       <Animated.View
+        accessible={true}
+        accessibilityRole="adjustable"
+        accessibilityLabel="Bottom Sheet handle"
+        accessibilityHint="Drag up or down to extend or minimize the Bottom Sheet"
         onLayout={shouldMeasureHeight ? handleOnLayout : undefined}
       >
         {renderHandle()}