Assign ownership to many libs files (#6928)

Assign ownership to many of the remaining libs/common files.

Criteria for ownership:
* Files used by a single team, is now owned by that team.
* Files related to a domain owned by a team is now owned by that team.
* Where ownership is unclear the "lowest level" service takes ownership.

libs/angular/src/platform/services/theming/theme-builder.ts

@@ -0,0 +1,19 @@
+import { ThemeType } from "@bitwarden/common/platform/enums";
+
+import { Theme } from "./theme";
+
+export class ThemeBuilder implements Theme {
+  get effectiveTheme(): ThemeType {
+    return this.configuredTheme != ThemeType.System ? this.configuredTheme : this.systemTheme;
+  }
+
+  constructor(readonly configuredTheme: ThemeType, readonly systemTheme: ThemeType) {}
+
+  updateSystemTheme(systemTheme: ThemeType): ThemeBuilder {
+    return new ThemeBuilder(this.configuredTheme, systemTheme);
+  }
+
+  updateConfiguredTheme(configuredTheme: ThemeType): ThemeBuilder {
+    return new ThemeBuilder(configuredTheme, this.systemTheme);
+  }
+}

libs/angular/src/platform/services/theming/theme.ts

@@ -0,0 +1,6 @@
+import { ThemeType } from "@bitwarden/common/platform/enums";
+
+export interface Theme {
+  configuredTheme: ThemeType;
+  effectiveTheme: ThemeType;
+}

libs/angular/src/platform/services/theming/theming.service.abstraction.ts

@@ -0,0 +1,12 @@
+import { Observable } from "rxjs";
+
+import { ThemeType } from "@bitwarden/common/platform/enums";
+
+import { Theme } from "./theme";
+
+export abstract class AbstractThemingService {
+  theme$: Observable<Theme>;
+  monitorThemeChanges: () => Promise<void>;
+  updateSystemTheme: (systemTheme: ThemeType) => void;
+  updateConfiguredTheme: (theme: ThemeType) => Promise<void>;
+}

libs/angular/src/platform/services/theming/theming.service.ts

@@ -0,0 +1,72 @@
+import { DOCUMENT } from "@angular/common";
+import { Inject, Injectable } from "@angular/core";
+import { BehaviorSubject, filter, fromEvent, Observable } from "rxjs";
+
+import { StateService } from "@bitwarden/common/platform/abstractions/state.service";
+import { ThemeType } from "@bitwarden/common/platform/enums";
+
+import { WINDOW } from "../../../services/injection-tokens";
+
+import { Theme } from "./theme";
+import { ThemeBuilder } from "./theme-builder";
+import { AbstractThemingService } from "./theming.service.abstraction";
+
+@Injectable()
+export class ThemingService implements AbstractThemingService {
+  private _theme = new BehaviorSubject<ThemeBuilder | null>(null);
+  theme$: Observable<Theme> = this._theme.pipe(filter((x) => x !== null));
+
+  constructor(
+    private stateService: StateService,
+    @Inject(WINDOW) private window: Window,
+    @Inject(DOCUMENT) private document: Document
+  ) {
+    this.monitorThemeChanges();
+  }
+
+  async monitorThemeChanges(): Promise<void> {
+    this._theme.next(
+      new ThemeBuilder(await this.stateService.getTheme(), await this.getSystemTheme())
+    );
+    this.monitorConfiguredThemeChanges();
+    this.monitorSystemThemeChanges();
+  }
+
+  updateSystemTheme(systemTheme: ThemeType): void {
+    this._theme.next(this._theme.getValue().updateSystemTheme(systemTheme));
+  }
+
+  async updateConfiguredTheme(theme: ThemeType): Promise<void> {
+    await this.stateService.setTheme(theme);
+    this._theme.next(this._theme.getValue().updateConfiguredTheme(theme));
+  }
+
+  protected monitorConfiguredThemeChanges(): void {
+    this.theme$.subscribe((theme: Theme) => {
+      this.document.documentElement.classList.remove(
+        "theme_" + ThemeType.Light,
+        "theme_" + ThemeType.Dark,
+        "theme_" + ThemeType.Nord,
+        "theme_" + ThemeType.SolarizedDark
+      );
+      this.document.documentElement.classList.add("theme_" + theme.effectiveTheme);
+    });
+  }
+
+  // We use a media match query for monitoring the system theme on web and browser, but this doesn't work for electron apps on Linux.
+  // In desktop we override these methods to track systemTheme with the electron renderer instead, which works for all OSs.
+  protected async getSystemTheme(): Promise<ThemeType> {
+    return this.window.matchMedia("(prefers-color-scheme: dark)").matches
+      ? ThemeType.Dark
+      : ThemeType.Light;
+  }
+
+  protected monitorSystemThemeChanges(): void {
+    fromEvent<MediaQueryListEvent>(
+      window.matchMedia("(prefers-color-scheme: dark)"),
+      "change"
+    ).subscribe((event) => {
+      this.updateSystemTheme(event.matches ? ThemeType.Dark : ThemeType.Light);
+    });
+  }
+}