[IOPID-1899] NumberPad optimization

example/src/pages/NumberPad.tsx

@@ -13,7 +13,7 @@ import {
   useIOTheme
 } from "@pagopa/io-app-design-system";
 import { useNavigation } from "@react-navigation/native";
-import * as React from "react";
+import React, { useCallback, useEffect, useState } from "react";
 import { Alert, View } from "react-native";
 
 const PIN_LENGTH = 6;
@@ -25,16 +25,20 @@ export const NumberPadScreen = () => {
   const theme = useIOTheme();
   const navigation = useNavigation();
 
-  const [value, setValue] = React.useState("");
-  const [blueBackground, setBlueBackground] = React.useState(false);
+  const [value, setValue] = useState("");
+  const [blueBackground, setBlueBackground] = useState(false);
 
-  const onValueChange = (v: string) => {
-    if (v.length <= PIN_LENGTH) {
-      setValue(v);
-    }
-  };
+  const onNumberPress = useCallback((v: number) => {
+    setValue((prev) => prev.length < PIN_LENGTH ? `${prev}${v}` : prev);
+  }, []);
 
-  React.useEffect(() => {
+  const onDeletePress = useCallback(() => {
+    setValue((prev) => prev.slice(0, -1));
+  }, []);
+
+  const onBiometricPress = useCallback(() => Alert.alert("biometric"),[]);
+
+  useEffect(() => {
     navigation.setOptions({
       headerStyle: {
         backgroundColor: blueBackground
@@ -74,18 +78,18 @@ export const NumberPadScreen = () => {
           value={value}
           length={PIN_LENGTH}
           variant={blueBackground ? "light" : "dark"}
-          onValueChange={onValueChange}
+          onValueChange={setValue}
           onValidate={v => v === "123456"}
         />
         <VSpacer size={48} />
         <NumberPad
-          value={value}
           deleteAccessibilityLabel="Delete"
-          onValueChange={onValueChange}
+          onNumberPress={onNumberPress}
+          onDeletePress={onDeletePress}
           variant={blueBackground ? "dark" : "light"}
           biometricType="FACE_ID"
           biometricAccessibilityLabel="Face ID"
-          onBiometricPress={() => Alert.alert("biometric")}
+          onBiometricPress={onBiometricPress}
         />
       </ContentWrapper>
     </View>

package.json

@@ -32,6 +32,7 @@
     "lint": "eslint \"**/*.{js,ts,tsx}\"",
     "prettify": "prettier --write \"src/**/*.(ts|tsx)\"",
     "prepack": "bob build",
+    "prepare": "bob build",
     "release": "release-it",
     "example": "yarn --cwd example",
     "bootstrap": "yarn example && yarn install",

src/components/numberpad/NumberButton.tsx

@@ -1,4 +1,4 @@
-import React, { useCallback, useMemo } from "react";
+import React, { memo, useCallback, useMemo } from "react";
 import { Pressable } from "react-native";
 import Animated, {
   Extrapolate,
@@ -22,8 +22,19 @@ import { H3 } from "../typography";
 type NumberButtonVariantType = "light" | "dark";
 
 type NumberButtonProps = {
+  /**
+   * Used to choose the component color variant between `dark` and `light`.
+  */
   variant: NumberButtonVariantType;
+  /**
+   * The button value.
+  */
   number: number;
+  /**
+   * The action to be executed when the button is pressed.
+   * @param number 
+   * @returns void
+   */
   onPress: (number: number) => void;
 };
 
@@ -58,8 +69,12 @@ const legacyColorMap: Record<NumberButtonVariantType, ColorMapVariant> = {
     foreground: "white"
   }
 };
-
-export const NumberButton = ({
+/**
+ * Based on a `Pressable` element, it displays a number button with animations on press In and Out.
+ * 
+ * @returns {JSX.Element} The rendered `NumberButton`
+ */
+export const NumberButton = memo(({
   number,
   variant,
   onPress
@@ -110,13 +125,17 @@ export const NumberButton = ({
     isPressed.value = 0;
   }, [isPressed]);
 
+  const handleOnPress = useCallback(() => {
+    onPress(number);
+  }, [number, onPress]);
+
   return (
     <Pressable
-      accessible={true}
-      accessibilityRole={"button"}
+      accessible
+      accessibilityRole="button"
       onPressIn={onPressIn}
       onPressOut={onPressOut}
-      onPress={() => onPress(number)}
+      onPress={handleOnPress}
     >
       <Animated.View
         style={[
@@ -130,4 +149,4 @@ export const NumberButton = ({
       </Animated.View>
     </Pressable>
   );
-};
+});

src/components/numberpad/NumberPad.tsx

@@ -1,6 +1,6 @@
-import React, { ComponentProps } from "react";
-import { View } from "react-native";
-import { BiometricsValidType } from "../../utils/types";
+import React, { ComponentProps, Fragment, useCallback, useMemo } from "react";
+import { StyleSheet, View } from "react-native";
+import { BiometricsValidType, Optional } from "../../utils/types";
 import { IONumberPadButtonStyles, IOStyles } from "../../core";
 import { VSpacer } from "../spacer";
 import { IconButton } from "../buttons";
@@ -9,21 +9,49 @@ import { NumberButton } from "./NumberButton";
 
 type BiometricAuthProps =
   | {
-      biometricType: BiometricsValidType;
-      onBiometricPress: () => void;
-      biometricAccessibilityLabel: string;
-    }
+    /**
+     * Type of device biometric.
+     */
+    biometricType: BiometricsValidType;
+    /**
+    * Function to be executed when the biometric button is pressed.
+    * @returns void
+    */
+    onBiometricPress: () => void;
+    /**
+    * This label will be read from ScreenReaders and give informations about biometric button.
+    */
+    biometricAccessibilityLabel: string;
+  }
   | {
-      biometricType?: never;
-      onBiometricPress?: never;
-      biometricAccessibilityLabel?: never;
-    };
+    biometricType?: never;
+    onBiometricPress?: never;
+    biometricAccessibilityLabel?: never;
+  };
 
 type NumberPadProps = {
-  value: string;
-  onValueChange: (value: string) => void;
-  variant: ComponentProps<typeof NumberButton>["variant"];
+  /**
+   * Used to choose the component color variant between `dark` and `light`.
+   * 
+   * The default value is `dark`.
+   */
+  variant?: ComponentProps<typeof NumberButton>["variant"];
+  /**
+    * This label will be read  from ScreenReaders and give informations about delete button.
+    */
   deleteAccessibilityLabel: string;
+  /**
+  * This function is passed to all numeric buttons to handle their press action.
+  * @param value 
+  * @returns void
+  */
+  onNumberPress: (value: number) => void;
+  /**
+ * This function is passed to the delete button to handle the action to trigger when it's pressed.
+ * 
+ * @returns void
+ */
+  onDeletePress: () => void;
 } & BiometricAuthProps;
 
 const mapIconSpecByBiometric: Record<
@@ -35,79 +63,53 @@ const mapIconSpecByBiometric: Record<
   BIOMETRICS: { icon: "fingerprint", size: 24 }
 };
 
-const ButtonWrapper = ({ children }: { children: React.ReactNode }) => (
-  <View
-    style={[
-      IONumberPadButtonStyles.buttonSize,
-      IOStyles.alignCenter,
-      IOStyles.centerJustified
-    ]}
-  >
-    {children}
-  </View>
-);
+/**
+ * This component displays a custom numeric keyboard. 
+ * 
+ * It accepts an optional `biometricType` prop which enables an extra keyboard button that accepts a `onBiometricPress` prop used to handle the action to be executed when it's pressed.
+ * @returns {JSX.Element} The rendered numeric keyboard component.
+ */
 export const NumberPad = ({
-  value,
   variant = "dark",
-  onValueChange,
   biometricType,
-  onBiometricPress,
   biometricAccessibilityLabel,
-  deleteAccessibilityLabel
-}: NumberPadProps) => {
-  const numberPadPress = (number: number) => {
-    const newValue = `${value}${number}`;
-    onValueChange(newValue);
-  };
-
-  const onDeletePress = () => {
-    const newValue = value.slice(0, -1);
-    onValueChange(newValue);
-  };
-
-  type ButtonType = "biometric" | "delete";
+  deleteAccessibilityLabel,
+  onNumberPress,
+  onBiometricPress,
+  onDeletePress
+}: NumberPadProps): JSX.Element => {
+  /** 
+   * Renders the buttons row from a given array.
+  */
+  // eslint-disable-next-line arrow-body-style
+  const renderButtonsRow = useCallback((row: Array<Optional<number | string>>) => {
+    return row.map((item) => {
+      if (typeof item === "number") {
+        return (
+          <NumberButton
+            key={item}
+            number={item}
+            onPress={onNumberPress}
+            variant={variant}
+          />
+        );
+      }
 
-  const RowButtons = ({
-    buttons
-  }: {
-    buttons: ReadonlyArray<number | ButtonType>;
-  }) => (
-    <View
-      style={[
-        IOStyles.rowSpaceBetween,
-        {
-          justifyContent: "space-between",
-          alignItems: "center",
-          flexGrow: 1
-        }
-      ]}
-    >
-      {buttons.map(elem => {
-        if (typeof elem === "number") {
-          return (
-            <NumberButton
-              key={elem}
-              number={elem}
-              onPress={numberPadPress}
-              variant={variant}
+      if (item === "delete") {
+        return (
+          <ButtonWrapper key={item}>
+            <IconButton
+              icon="cancel"
+              color={variant === "dark" ? "contrast" : "primary"}
+              onPress={onDeletePress}
+              accessibilityLabel={deleteAccessibilityLabel}
             />
-          );
-        }
-
-        if (elem === "delete") {
-          return (
-            <ButtonWrapper key={elem}>
-              <IconButton
-                icon="cancel"
-                color={variant === "dark" ? "contrast" : "primary"}
-                onPress={onDeletePress}
-                accessibilityLabel={deleteAccessibilityLabel}
-              />
-            </ButtonWrapper>
-          );
-        }
-        return biometricType ? (
-          <ButtonWrapper key={elem}>
+          </ButtonWrapper>
+        );
+      }
+      if (biometricType && mapIconSpecByBiometric[biometricType]) {
+        return (
+          <ButtonWrapper key={item}>
             <IconButton
               icon={mapIconSpecByBiometric[biometricType].icon}
               iconSize={mapIconSpecByBiometric[biometricType].size}
@@ -116,22 +118,53 @@ export const NumberPad = ({
               accessibilityLabel={biometricAccessibilityLabel}
             />
           </ButtonWrapper>
-        ) : (
-          <View key={"emptyElem"} style={IONumberPadButtonStyles.buttonSize} />
         );
-      })}
-    </View>
-  );
+      }
+
+      return <View key={"emptyElem"} style={IONumberPadButtonStyles.buttonSize} />;
+    });
+  }, [biometricAccessibilityLabel, biometricType, deleteAccessibilityLabel, onBiometricPress, onDeletePress, onNumberPress, variant]);
+
+  // eslint-disable-next-line arrow-body-style
+  const numberPad = useMemo(() => {
+    return [[1, 2, 3], [4, 5, 6], [7, 8, 9], [biometricType, 0, 'delete']].map((row, i, self) =>
+      <Fragment key={i}>
+        <View
+          style={[
+            IOStyles.rowSpaceBetween,
+            styles.numberPad
+          ]}
+        >
+          {renderButtonsRow(row)}
+        </View>
+        {i < self.length - 1 && <VSpacer />}
+      </Fragment>
+    );
+  }, [biometricType, renderButtonsRow]);
 
   return (
     <View style={IOStyles.horizontalContentPadding}>
-      <RowButtons buttons={[1, 2, 3]} />
-      <VSpacer />
-      <RowButtons buttons={[4, 5, 6]} />
-      <VSpacer />
-      <RowButtons buttons={[7, 8, 9]} />
-      <VSpacer />
-      <RowButtons buttons={["biometric", 0, "delete"]} />
+      {numberPad}
     </View>
   );
 };
+
+const ButtonWrapper = ({ children }: { children: React.ReactNode }) => (
+  <View
+    style={[
+      IONumberPadButtonStyles.buttonSize,
+      IOStyles.alignCenter,
+      IOStyles.centerJustified
+    ]}
+  >
+    {children}
+  </View>
+);
+
+const styles = StyleSheet.create({
+  numberPad: {
+    justifyContent: "space-between",
+    alignItems: "center",
+    flexGrow: 1
+  }
+});