Adapt status bar color to modal backdrop

src/components/CustomStatusBar/index.web.js

@@ -0,0 +1,16 @@
+import React from 'react';
+import {StatusBar} from 'react-native';
+import themeColors from '../../styles/themes/default';
+
+export default class CustomStatusBar extends React.Component {
+    componentDidMount() {
+        StatusBar.setBarStyle('light-content', true);
+
+        // Match the default status bar color to the app's background color.
+        document.querySelector('meta[name=theme-color]').content = themeColors.appBG;
+    }
+
+    render() {
+        return <StatusBar />;
+    }
+}

src/components/Modal/index.web.js

@@ -0,0 +1,41 @@
+import React from 'react';
+import withWindowDimensions from '../withWindowDimensions';
+import BaseModal from './BaseModal';
+import {propTypes, defaultProps} from './modalPropTypes';
+import * as StyleUtils from '../../styles/StyleUtils';
+import themeColors from '../../styles/themes/default';
+
+const Modal = (props) => {
+    const setStatusBarColor = (color = themeColors.appBG) => {
+        if (!props.fullscreen) {
+            return;
+        }
+
+        // Change the color of the status bar to align with the modal's backdrop (refer to https://github.com/Expensify/App/issues/12156).
+        document.querySelector('meta[name=theme-color]').content = color;
+    };
+    const hideModal = () => {
+        setStatusBarColor();
+        props.onModalHide();
+    };
+    const showModal = () => {
+        setStatusBarColor(StyleUtils.getThemeBackgroundColor());
+        props.onModalShow();
+    };
+
+    return (
+        <BaseModal
+            // eslint-disable-next-line react/jsx-props-no-spreading
+            {...props}
+            onModalHide={hideModal}
+            onModalShow={showModal}
+        >
+            {props.children}
+        </BaseModal>
+    );
+};
+
+Modal.propTypes = propTypes;
+Modal.defaultProps = defaultProps;
+Modal.displayName = 'Modal';
+export default withWindowDimensions(Modal);

src/styles/StyleUtils.js

@@ -202,6 +202,20 @@ function getBackgroundColorStyle(backgroundColor) {
     };
 }
 
+/**
+ * Converts a color in hexadecimal notation into RGB notation.
+ *
+ * @param {String} hexadecimal A color in hexadecimal notation.
+ * @returns {Array} `undefined` if the input color is not in hexadecimal notation. Otherwise, the RGB components of the input color.
+ */
+function hexadecimalToRGBArray(hexadecimal) {
+    const components = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hexadecimal);
+
+    if (components === null) { return undefined; }
+
+    return _.map(components.slice(1), component => parseInt(component, 16));
+}
+
 /**
  * Returns a background color with opacity style
  *
@@ -210,13 +224,10 @@ function getBackgroundColorStyle(backgroundColor) {
  * @returns {Object}
  */
 function getBackgroundColorWithOpacityStyle(backgroundColor, opacity) {
-    const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(backgroundColor);
-    if (result !== null) {
-        const r = parseInt(result[1], 16);
-        const g = parseInt(result[2], 16);
-        const b = parseInt(result[3], 16);
+    const result = hexadecimalToRGBArray(backgroundColor);
+    if (result !== undefined) {
         return {
-            backgroundColor: `rgba(${r}, ${g}, ${b}, ${opacity})`,
+            backgroundColor: `rgba(${result[0]}, ${result[1]}, ${result[2]}, ${opacity})`,
         };
     }
     return {};
@@ -448,6 +459,76 @@ function getPaymentMethodMenuWidth(isSmallScreenWidth) {
     return {width: !isSmallScreenWidth ? variables.sideBarWidth - (margin * 2) : undefined};
 }
 
+/**
+ * Converts a color in RGBA notation to an equivalent color in RGB notation.
+ *
+ * @param {Array} foregroundRGB The three components of the foreground color in RGB notation.
+ * @param {Array} backgroundRGB The three components of the background color in RGB notation.
+ * @param {number} opacity The desired opacity of the foreground color.
+ * @returns {Array} The RGB components of the RGBA color converted to RGB.
+ */
+function convertRGBAToRGB(foregroundRGB, backgroundRGB, opacity) {
+    const [foregroundRed, foregroundGreen, foregroundBlue] = foregroundRGB;
+    const [backgroundRed, backgroundGreen, backgroundBlue] = backgroundRGB;
+
+    return [
+        ((1 - opacity) * backgroundRed) + (opacity * foregroundRed),
+        ((1 - opacity) * backgroundGreen) + (opacity * foregroundGreen),
+        ((1 - opacity) * backgroundBlue) + (opacity * foregroundBlue),
+    ];
+}
+
+/**
+ * Converts three unit values to the three components of a color in RGB notation.
+ *
+ * @param {number} red A unit value representing the first component of a color in RGB notation.
+ * @param {number} green A unit value representing the second component of a color in RGB notation.
+ * @param {number} blue A unit value representing the third component of a color in RGB notation.
+ * @returns {Array} An array with the three components of a color in RGB notation.
+ */
+function convertUnitValuesToRGB(red, green, blue) {
+    return [Math.floor(red * 255), Math.floor(green * 255), Math.floor(blue * 255)];
+}
+
+/**
+ * Converts the three components of a color in RGB notation to three unit values.
+ *
+ * @param {number} red The first component of a color in RGB notation.
+ * @param {number} green The second component of a color in RGB notation.
+ * @param {number} blue The third component of a color in RGB notation.
+ * @returns {Array} An array with three unit values representing the components of a color in RGB notation.
+ */
+function convertRGBToUnitValues(red, green, blue) {
+    return [red / 255, green / 255, blue / 255];
+}
+
+/**
+ * Determines the theme color for a modal based on the app's background color,
+ * the modal's backdrop, and the backdrop's opacity.
+ *
+ * @returns {String} The theme color as an RGB value.
+ */
+function getThemeBackgroundColor() {
+    const backdropOpacity = variables.modalFullscreenBackdropOpacity;
+
+    const [backgroundRed, backgroundGreen, backgroundBlue] = hexadecimalToRGBArray(themeColors.appBG);
+    const [backdropRed, backdropGreen, backdropBlue] = hexadecimalToRGBArray(themeColors.modalBackdrop);
+    const normalizedBackdropRGB = convertRGBToUnitValues(backdropRed, backdropGreen, backdropBlue);
+    const normalizedBackgroundRGB = convertRGBToUnitValues(
+        backgroundRed,
+        backgroundGreen,
+        backgroundBlue,
+    );
+    const themeRGBNormalized = convertRGBAToRGB(
+        normalizedBackdropRGB,
+        normalizedBackgroundRGB,
+        backdropOpacity,
+    );
+    const themeRGB = convertUnitValuesToRGB(...themeRGBNormalized);
+
+    return `rgb(${themeRGB.join(', ')})`;
+}
+
 /**
  * Parse styleParam and return Styles array
  * @param {Object|Object[]} styleParam
@@ -565,6 +646,7 @@ export {
     getMiniReportActionContextMenuWrapperStyle,
     getKeyboardShortcutsModalWidth,
     getPaymentMethodMenuWidth,
+    getThemeBackgroundColor,
     parseStyleAsArray,
     combineStyles,
     getPaddingLeft,

src/styles/variables.js

@@ -42,6 +42,7 @@ export default {
     emojiLineHeight: 28,
     iouAmountTextSize: 40,
     mobileResponsiveWidthBreakpoint: 800,
+    modalFullscreenBackdropOpacity: 0.5,
     tabletResponsiveWidthBreakpoint: 1024,
     safeInsertPercentage: 0.7,
     sideBarWidth: 375,

web/index.html

@@ -4,6 +4,7 @@
     <meta charset="utf-8" />
     <title>New Expensify</title>
     <meta name="description" content="Corporate cards, reimbursements, receipt scanning, invoicing, and bill pay. One app, all free.">
+    <meta name="theme-color" content="">
     <meta property="twitter:card" content="summary">
     <meta property="twitter:site" content="@expensify">
     <meta property="og:type" content="website">