Live change of theme from Preferences dropdown (#1296)

Author: francescospissu

arduino-ide-extension/src/browser/dialogs/settings/settings-component.tsx

@@ -201,12 +201,7 @@ export class SettingsComponent extends React.Component<
             <div className="flex-line">
               <select
                 className="theia-select"
-                value={
-                  ThemeService.get()
-                    .getThemes()
-                    .find(({ id }) => id === this.state.themeId)?.label ||
-                  nls.localize('arduino/common/unknown', 'Unknown')
-                }
+                value={ThemeService.get().getCurrentTheme().label}
                 onChange={this.themeDidChange}
               >
                 {ThemeService.get()
@@ -591,6 +586,9 @@ export class SettingsComponent extends React.Component<
     const theme = ThemeService.get().getThemes()[selectedIndex];
     if (theme) {
       this.setState({ themeId: theme.id });
+      if (ThemeService.get().getCurrentTheme().id !== theme.id) {
+        ThemeService.get().setCurrentTheme(theme.id);
+      }
     }
   };
 

arduino-ide-extension/src/browser/dialogs/settings/settings-dialog.tsx

@@ -16,6 +16,7 @@ import { SettingsComponent } from './settings-component';
 import { AsyncLocalizationProvider } from '@theia/core/lib/common/i18n/localization';
 import { AdditionalUrls } from '../../../common/protocol';
 import { AbstractDialog } from '../../theia/dialogs/dialogs';
+import { ThemeService } from '@theia/core/lib/browser/theming';
 
 @injectable()
 export class SettingsWidget extends ReactWidget {
@@ -118,6 +119,17 @@ export class SettingsDialog extends AbstractDialog<Promise<Settings>> {
 
     this.widget.activate();
   }
+
+  override async open(): Promise<Promise<Settings> | undefined> {
+    const themeIdBeforeOpen = ThemeService.get().getCurrentTheme().id;
+    const result = await super.open();
+    if (!result) {
+      if (ThemeService.get().getCurrentTheme().id !== themeIdBeforeOpen) {
+        ThemeService.get().setCurrentTheme(themeIdBeforeOpen);
+      }
+    }
+    return result;
+  }
 }
 
 export class AdditionalUrlsDialog extends AbstractDialog<string[]> {