Electron: Rotate sidebar icon when it is hidden

ElectronClient/app/gui/Header.jsx

@@ -72,9 +72,10 @@ class HeaderComponent extends React.Component {
 		if (options.iconName) {
 			const iconStyle = {
 				fontSize: Math.round(style.fontSize * 1.4),
-				color: style.color
+				color: style.color,
 			};
 			if (options.title) iconStyle.marginRight = 5;
+			if (options.iconRotation) iconStyle.transform = 'rotate(' + options.iconRotation + 'deg)';
 			icon = <i style={iconStyle} className={"fa " + options.iconName}></i>
 		}
 

ElectronClient/app/gui/MainScreen.jsx

@@ -311,6 +311,7 @@ class MainScreenComponent extends React.Component {
 		headerItems.push({
 			title: _('Toggle sidebar'),
 			iconName: 'fa-bars',
+			iconRotation: this.props.sidebarVisibility ? 0 : 90,
 			onClick: () => { this.doCommand({ name: 'toggleSidebar'}) }
 		});
 
@@ -426,6 +427,7 @@ const mapStateToProps = (state) => {
 		hasDisabledSyncItems: state.hasDisabledSyncItems,
 		showMissingMasterKeyMessage: state.notLoadedMasterKeys.length && state.masterKeys.length,
 		selectedFolderId: state.selectedFolderId,
+		sidebarVisibility: state.sidebarVisibility,
 	};
 };