Added theme toggle

+Added dark-mode and light-mode component icons
+Added ThemeToggle in the toolbar
+Added ThemeManager and ThemeContext

src/components/App.js

@@ -10,12 +10,14 @@ import DistanceMeterContext from '../contexts/DistanceMeterContext';
 import {GradientsManager} from "./GradientsManager";
 import SideMenuContext from '../contexts/SideMenuContext';
 import SceneryManager from './SceneryManager';
+import ThemeManager from './ThemeManager';
 
 function App() {
     const [sideMenuOpen, setSideMenuOpen] = useState(false);
     const [distancePoints, setDistancePoints] = useState(null);
 
     return (
+        <ThemeManager>
             <SettingsManager>
                 <SceneryManager>
                     <GradientsManager>
@@ -27,6 +29,7 @@ function App() {
                     </GradientsManager>
                 </SceneryManager>
             </SettingsManager>
+        </ThemeManager>
     );
 }
 

src/components/ThemeManager.js

@@ -0,0 +1,20 @@
+import { useState } from "react";
+import ThemeContext from "../contexts/ThemeContext";
+
+export default function ThemeManager(props) {
+    const [ lightMode, setLightMode ] = useState(false);
+
+    if(lightMode === true) {
+        document.body.classList.add('light-mode');
+    } else {
+        document.body.classList.remove('light-mode');
+    }
+
+    return (
+        <ThemeContext.Provider value={{
+            lightMode, setLightMode
+        }}>
+            { props.children }
+        </ThemeContext.Provider>
+    );
+}

src/components/toolbar/ThemeToggle.js

@@ -0,0 +1,19 @@
+import { useContext } from 'react';
+import { LightModeIcon, DarkModeIcon } from '../../icons';
+import ThemeContext from '../../contexts/ThemeContext';
+
+export default function ThemeToggle() {
+    const { setLightMode, lightMode } = useContext(ThemeContext);
+
+    const toggleLightMode = () => {
+        setLightMode((prev) => !prev);
+    }
+
+    return (
+        <div className='theme-toggle'>
+            <button onClick={toggleLightMode} className='invis-button'>
+                {lightMode ? <LightModeIcon /> : <DarkModeIcon />}
+            </button>
+        </div>
+    );
+}

src/components/toolbar/Toolbar.css

@@ -54,10 +54,12 @@
     width: 2rem;
 }
 
+.theme-toggle g,
 .side-menu-toggle g {
     stroke: #aaa;
 }
 
+.theme-toggle:hover g,
 .side-menu-toggle:hover g {
     stroke: #fff;
 }

src/components/toolbar/Toolbar.js

@@ -4,6 +4,7 @@ import CustomFileSelect from './CustomFileSelect';
 import SideMenuToggle from './SideMenuToggle';
 import SceneryList from './SceneryList';
 import ElectrificationStepMode from './ElectrificationStepMode';
+import ThemeToggle from './ThemeToggle';
 
 export default function Toolbar() {
     return (
@@ -14,6 +15,7 @@ export default function Toolbar() {
                 <CustomFileSelect />
                 <ElectrificationStepMode />
                 <div className='toolbar-spacer'></div>
+                <ThemeToggle />
                 <SideMenuToggle />
             </div>
             <div className='loading-indicator-cont'>

src/contexts/ThemeContext.js

@@ -0,0 +1,4 @@
+import { createContext } from 'react';
+
+const ThemeContext = createContext();
+export default ThemeContext;

src/icons/index.js

@@ -1,4 +1,6 @@
 /* Toolbar Icons */
+export { DarkModeIcon } from "./toolbar/dark-mode";
+export { LightModeIcon } from "./toolbar/light-mode";
 export { SideMenuIcon } from "./toolbar/side-menu";
 
 /* TrackHoverInfo Icons */

src/icons/toolbar/dark-mode.js

@@ -0,0 +1,7 @@
+export const DarkModeIcon = ({color = '#aaa', strokeWidth = 9}) => (
+    <svg version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+        <g fill="none" stroke={color} strokeLinecap="round" strokeLinejoin="round" strokeWidth={strokeWidth}>
+            <path d="m52.52 19c-17.021 0.12272-30.775 13.978-30.775 31 1.6e-4 17.109 13.891 31 31 31 10.113 3.5e-5 19.594-4.936 25.394-13.221 0.46456-0.66594-0.01618-1.5787-0.82812-1.5723-0.06911 5.69e-4 -0.13791-7.4e-5 -0.20703 0h-2e-3c-16.027-0.0012-28.998-12.973-28.998-29-5.3e-5 -5.951 1.831-11.758 5.2441-16.633 0.41109-0.63002-0.01926-1.5353-0.82807-1.5742z" />
+        </g>
+    </svg>
+);

src/icons/toolbar/light-mode.js

@@ -0,0 +1,18 @@
+export const LightModeIcon = ({color = '#aaa', strokeWidth = 10}) => (
+    <svg version="1.1" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+        <g stroke={color} fill="none">
+            <circle cx="50" cy="50" r="14" strokeWidth={strokeWidth * 0.8} />
+            <g strokeLinecap="round" strokeWidth={strokeWidth} >
+                <path d="m14 50h7"/>
+                <path d="m79 50h7"/>
+                <path d="m24.544 75.456 4.9497-4.9497"/>
+                <path d="m70.506 29.494 4.9497-4.9497"/>
+                <path d="m50 86v-7"/>
+                <path d="m50 21v-7"/>
+                <path d="m75.456 75.456-4.9497-4.9497"/>
+                <path d="m29.494 29.494-4.9497-4.9497"/>
+            </g>
+        </g>
+    </svg>
+    
+);