Event dispatcher refactor (#463)

* Refactor EventDispatcher template type

* Update core types

* Update log

* Update clipboard monitor

* Update application events

* Update popup events

* Update text scanner

* Update cross frame API

* Update display events

* Type updates

* Update display history

* Update query parser

* Update search persistent state controller

* Update panel element

* Update popup menu

* Update audio system

* Update hotkey handler

* Update settings controller

* Update audio controller

* Update types

* Update types

* Update types

* Add event handler types

* Update type

* Fix issues

* Remove error suppression

* Fix typo

22 files changed, 276 insertions, 155 deletions

diff --git a/types/ext/application.d.ts b/types/ext/application.d.ts
index ac594abc..5c103fd7 100644
--- a/types/ext/application.d.ts
+++ b/types/ext/application.d.ts
@@ -19,6 +19,7 @@ import type {TokenString} from './core';
 import type {SearchMode} from './display';
 import type {FrameEndpointReadyDetails, FrameEndpointConnectedDetails} from './frame-client';
 import type {DatabaseUpdateType, DatabaseUpdateCause} from './backend';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 import type {
     ApiMap as BaseApiMap,
     ApiHandler as BaseApiHandler,
@@ -146,3 +147,22 @@ export type ApiMap = BaseApiMap<ApiSurface>;
 export type ApiHandler<TName extends ApiNames> = BaseApiHandler<ApiSurface[TName]>;
 
 export type ApiReturn<TName extends ApiNames> = BaseApiReturn<ApiSurface[TName]>;
+
+export type Events = {
+    extensionUnloaded: Record<string, never>;
+    optionsUpdated: {
+        source: string;
+    };
+    databaseUpdated: {
+        type: DatabaseUpdateType;
+        cause: DatabaseUpdateCause;
+    };
+    zoomChanged: {
+        oldZoomFactor: number;
+        newZoomFactor: number;
+    };
+    closePopups: Record<string, never>;
+    storageChanged: Record<string, never>;
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/audio-controller.d.ts b/types/ext/audio-controller.d.ts
index e8317aaf..cc1887fb 100644
--- a/types/ext/audio-controller.d.ts
+++ b/types/ext/audio-controller.d.ts
@@ -15,7 +15,13 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type EventType = 'voicesUpdated';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
+
+export type Events = {
+    voicesUpdated: Record<string, never>;
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type VoiceInfo = {
     voice: SpeechSynthesisVoice;
diff --git a/types/ext/audio-system.d.ts b/types/ext/audio-system.d.ts
index e9766ed1..715f6afe 100644
--- a/types/ext/audio-system.d.ts
+++ b/types/ext/audio-system.d.ts
@@ -15,4 +15,10 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type EventType = 'voiceschanged';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
+
+export type Events = {
+    voiceschanged: Event;
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/clipboard-monitor.d.ts b/types/ext/clipboard-monitor.d.ts
index f8cf7d02..b0bb840b 100644
--- a/types/ext/clipboard-monitor.d.ts
+++ b/types/ext/clipboard-monitor.d.ts
@@ -15,12 +15,16 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type EventType = 'change';
-
-export type ChangeEvent = {
-    text: string;
-};
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type ClipboardReaderLike = {
     getText: (useRichText: boolean) => Promise<string>;
 };
+
+export type Events = {
+    change: {
+        text: string;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/core.d.ts b/types/ext/core.d.ts
index c71a8ec4..b94b649b 100644
--- a/types/ext/core.d.ts
+++ b/types/ext/core.d.ts
@@ -88,3 +88,17 @@ export type MessageHandlerMapInit = MessageHandlerMapInitItem[];
 export type MessageHandlerMapInitItem = [key: string, handlerDetails: MessageHandler];
 
 export type Timeout = number | NodeJS.Timeout;
+
+export type EventSurface = {[name: string]: unknown};
+
+export type EventNames<TSurface extends EventSurface> = keyof TSurface & string;
+
+export type EventArgument<TSurface extends EventSurface, TName extends EventNames<TSurface>> = TSurface[TName];
+
+export type EventDispatcherOffGeneric = {
+    off(eventName: string, callback: (...args: SafeAny) => void): boolean;
+};
+
+export type EventHandler<TSurface extends EventSurface, TName extends EventNames<TSurface>> = (details: EventArgument<TSurface, TName>) => void;
+
+export type EventHandlerAny = (details: SafeAny) => void;
diff --git a/types/ext/cross-frame-api.d.ts b/types/ext/cross-frame-api.d.ts
index b9cf8ad1..8ddca6e7 100644
--- a/types/ext/cross-frame-api.d.ts
+++ b/types/ext/cross-frame-api.d.ts
@@ -15,9 +15,12 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import type {CrossFrameAPIPort} from '../../ext/js/comm/cross-frame-api.js';
 import type * as Core from './core';
 
-export type CrossFrameAPIPortEventType = 'disconnect';
+export type CrossFrameAPIPortEvents = {
+    disconnect: CrossFrameAPIPort;
+};
 
 export type AcknowledgeMessage = {
     type: 'ack';
diff --git a/types/ext/display-history.d.ts b/types/ext/display-history.d.ts
index 2ba5006b..3a99d443 100644
--- a/types/ext/display-history.d.ts
+++ b/types/ext/display-history.d.ts
@@ -15,6 +15,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 import type * as Display from './display';
 
 export type Entry = {
@@ -30,8 +31,10 @@ export type EntryState = Display.HistoryState;
 
 export type EntryContent = Display.HistoryContent;
 
-export type EventType = 'stateChanged';
-
-export type StateChangedEvent = {
-    synthetic: boolean;
+export type Events = {
+    stateChanged: {
+        synthetic: boolean;
+    };
 };
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/display.d.ts b/types/ext/display.d.ts
index aa0f0353..bafb1fa1 100644
--- a/types/ext/display.d.ts
+++ b/types/ext/display.d.ts
@@ -18,13 +18,12 @@
 import type {DisplayContentManager} from '../../ext/js/display/display-content-manager';
 import type {HotkeyHelpController} from '../../ext/js/input/hotkey-help-controller';
 import type {JapaneseUtil} from '../../ext/js/language/sandbox/japanese-util';
-import type {TextScanner} from '../../ext/js/language/text-scanner';
 import type * as Core from './core';
 import type * as Dictionary from './dictionary';
 import type * as Extension from './extension';
 import type * as Settings from './settings';
 import type * as TextScannerTypes from './text-scanner';
-import type * as TextSource from './text-source';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type HistoryMode = 'clear' | 'overwrite' | 'new';
 
@@ -114,8 +113,6 @@ export type HistoryContent = {
     contentOrigin?: Extension.ContentOrigin;
 };
 
-export type SearchPersistentStateControllerEventType = 'modeChange';
-
 export type SearchMode = null | 'popup' | 'action-popup';
 
 export type GetSearchContextCallback = TextScannerTypes.GetSearchContextCallbackSync;
@@ -134,56 +131,33 @@ export type QueryParserOptions = {
     scanning: TextScannerTypes.Options;
 };
 
-export type QueryParserEventType = 'searched';
-
-export type QueryParserSearchedEvent = {
-    textScanner: TextScanner;
-    type: PageType;
-    dictionaryEntries: Dictionary.DictionaryEntry[];
-    sentence: HistoryStateSentence;
-    inputInfo: TextScannerTypes.InputInfo;
-    textSource: TextSource.TextSource;
-    optionsContext: Settings.OptionsContext;
-    sentenceOffset: number | null;
-};
-
-export type DisplayEventType = (
-    'optionsUpdated' |
-    'frameVisibilityChange' |
-    'logDictionaryEntryData' |
-    'contentClear' |
-    'contentUpdateStart' |
-    'contentUpdateEntry' |
-    'contentUpdateComplete'
-);
-
-export type OptionsUpdatedEvent = {
-    options: Settings.ProfileOptions;
-};
-
-export type FrameVisibilityChangeEvent = {
-    value: boolean;
-};
-
-export type LogDictionaryEntryDataEvent = {
-    dictionaryEntry: Dictionary.DictionaryEntry;
-    promises: Promise<unknown>[];
-};
-
-export type ContentUpdateStartEvent = {
-    type: PageType;
-    query: string;
-};
-
-export type ContentUpdateEntryEvent = {
-    dictionaryEntry: Dictionary.DictionaryEntry;
-    element: Element;
-    index: number;
-};
-
-export type ContentUpdateCompleteEvent = {
-    type: PageType;
-};
+export type Events = {
+    optionsUpdated: {
+        options: Settings.ProfileOptions;
+    };
+    frameVisibilityChange: {
+        value: boolean;
+    };
+    logDictionaryEntryData: {
+        dictionaryEntry: Dictionary.DictionaryEntry;
+        promises: Promise<unknown>[];
+    };
+    contentClear: Record<string, never>;
+    contentUpdateStart: {
+        type: PageType;
+        query: string;
+    };
+    contentUpdateEntry: {
+        dictionaryEntry: Dictionary.DictionaryEntry;
+        element: Element;
+        index: number;
+    };
+    contentUpdateComplete: {
+        type: PageType;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type ConfigureMessageDetails = {
     depth: number;
diff --git a/types/ext/dynamic-property.d.ts b/types/ext/dynamic-property.d.ts
index ba15257a..8dde372b 100644
--- a/types/ext/dynamic-property.d.ts
+++ b/types/ext/dynamic-property.d.ts
@@ -15,8 +15,12 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type EventType = 'change';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type ChangeEventDetails<T = unknown> = {
-    value: T;
+export type Events<T = unknown> = {
+    change: {
+        value: T;
+    };
 };
+
+export type EventArgument<T, TName extends EventNames<Events<T>>> = BaseEventArgument<Events<T>, TName>;
diff --git a/types/ext/event-listener-collection.d.ts b/types/ext/event-listener-collection.d.ts
index 988baa76..415c48c4 100644
--- a/types/ext/event-listener-collection.d.ts
+++ b/types/ext/event-listener-collection.d.ts
@@ -15,7 +15,6 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-import type {EventDispatcher} from '../../ext/js/core';
 import type * as Core from './core';
 
 export type EventListenerFunction = (...args: Core.SafeAny[]) => unknown;
@@ -55,7 +54,7 @@ export type ExtensionEventDetails = {
 
 export type EventDispatcherDetails = {
     type: 'off';
-    target: EventDispatcher<string>;
+    target: Core.EventDispatcherOffGeneric;
     eventName: string;
     callback: EventListenerFunction;
 };
@@ -68,9 +67,3 @@ export type AddEventListenerArgs = [
     listener: EventListener | EventListenerObject | EventListenerFunction,
     options?: AddEventListenerOptions | boolean,
 ];
-
-export type OnArgs = [
-    target: EventDispatcher<string>,
-    eventName: string,
-    callback: (details: Core.SafeAny) => void,
-];
diff --git a/types/ext/extension.d.ts b/types/ext/extension.d.ts
index 5a244566..5c4aa175 100644
--- a/types/ext/extension.d.ts
+++ b/types/ext/extension.d.ts
@@ -47,8 +47,6 @@ export type ChromeRuntimeSendMessageArgs5 = [
 
 export type ChromeRuntimeSendMessageArgs = ChromeRuntimeSendMessageArgs1 | ChromeRuntimeSendMessageArgs2 | ChromeRuntimeSendMessageArgs3 | ChromeRuntimeSendMessageArgs4 | ChromeRuntimeSendMessageArgs5;
 
-export type ExtensionEventType = 'extensionUnloaded' | 'optionsUpdated' | 'databaseUpdated' | 'zoomChanged' | 'closePopups' | 'dynamicLoaderSentinel' | 'storageChanged';
-
 export type HtmlElementWithContentWindow = HTMLIFrameElement | HTMLFrameElement | HTMLObjectElement;
 
 export type ContentOrigin = {
diff --git a/types/ext/hotkey-handler.d.ts b/types/ext/hotkey-handler.d.ts
index 7b2b4cb3..c108d347 100644
--- a/types/ext/hotkey-handler.d.ts
+++ b/types/ext/hotkey-handler.d.ts
@@ -15,12 +15,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-import type * as Input from './input';
-
-export type EventType = 'keydownNonHotkey';
+import type {ModifierKey} from './input';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type HotkeyInfo = {
-    modifiers: Set<Input.ModifierKey>;
+    modifiers: Set<ModifierKey>;
     action: string;
     argument: unknown;
 };
@@ -28,3 +27,9 @@ export type HotkeyInfo = {
 export type HotkeyHandlers = {
     handlers: HotkeyInfo[];
 };
+
+export type Events = {
+    keydownNonHotkey: KeyboardEvent;
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/keyboard-mouse-input-field.d.ts b/types/ext/keyboard-mouse-input-field.d.ts
index 321e49cc..572ffc56 100644
--- a/types/ext/keyboard-mouse-input-field.d.ts
+++ b/types/ext/keyboard-mouse-input-field.d.ts
@@ -15,11 +15,14 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-import type * as Input from './input';
+import type {Modifier} from './input';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type EventType = 'change';
-
-export type ChangeEvent = {
-    key: string | null;
-    modifiers: Input.Modifier[];
+export type Events = {
+    change: {
+        key: string | null;
+        modifiers: Modifier[];
+    };
 };
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/log.d.ts b/types/ext/log.d.ts
index 904bf848..e8ca4c43 100644
--- a/types/ext/log.d.ts
+++ b/types/ext/log.d.ts
@@ -15,9 +15,9 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type LogLevel = 'log' | 'info' | 'debug' | 'warn' | 'error';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type LoggerEventType = 'log';
+export type LogLevel = 'log' | 'info' | 'debug' | 'warn' | 'error';
 
 export type LogContext = {
     url: string;
@@ -33,3 +33,13 @@ export type LogContext = {
  * `2` _error_ level.
  */
 export type LogErrorLevelValue = 0 | 1 | 2;
+
+export type Events = {
+    log: {
+        error: unknown;
+        level: LogLevel;
+        context: LogContext;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/panel-element.d.ts b/types/ext/panel-element.d.ts
index d267b836..164acba5 100644
--- a/types/ext/panel-element.d.ts
+++ b/types/ext/panel-element.d.ts
@@ -15,23 +15,18 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-export type EventType = 'visibilityChanged' | 'closeCompleted';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type VisibilityChangedEvent = {
-    visible: boolean;
+export type Events = {
+    visibilityChanged: {
+        visible: boolean;
+    };
+    closeCompleted: {
+        reopening: boolean;
+    };
 };
 
-export type CloseCompletedEvent = {
-    reopening: boolean;
-};
-
-/* eslint-disable @stylistic/ts/indent */
-export type Event<T extends EventType> = (
-    T extends 'visibilityChanged' ? VisibilityChangedEvent :
-    T extends 'closeCompleted' ? CloseCompletedEvent :
-    never
-);
-/* eslint-enable @stylistic/ts/indent */
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type ConstructorDetails = {
     node: HTMLElement;
diff --git a/types/ext/popup-menu.d.ts b/types/ext/popup-menu.d.ts
index b6e37316..71b94468 100644
--- a/types/ext/popup-menu.d.ts
+++ b/types/ext/popup-menu.d.ts
@@ -16,8 +16,22 @@
  */
 
 import type {PopupMenu} from '../../ext/js/dom/popup-menu';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type EventType = 'close';
+export type Events = {
+    close: {
+        menu: PopupMenu;
+        item: HTMLElement | null;
+        action: string | null;
+        cause: CloseReason;
+        altKey: boolean;
+        ctrlKey: boolean;
+        metaKey: boolean;
+        shiftKey: boolean;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type CloseReason = 'close' | 'outside' | 'item' | 'resize';
 
@@ -25,17 +39,6 @@ export type MenuOpenEventDetails = {
     menu: PopupMenu;
 };
 
-export type MenuCloseEventDetails = {
-    menu: PopupMenu;
-    item: HTMLElement | null;
-    action: string | null;
-    cause: CloseReason;
-    altKey: boolean;
-    ctrlKey: boolean;
-    metaKey: boolean;
-    shiftKey: boolean;
-};
-
 export type MenuOpenEvent = CustomEvent<MenuOpenEventDetails>;
 
-export type MenuCloseEvent = CustomEvent<MenuCloseEventDetails>;
+export type MenuCloseEvent = CustomEvent<EventArgument<'close'>>;
diff --git a/types/ext/popup.d.ts b/types/ext/popup.d.ts
index 65725f96..6f39f1e4 100644
--- a/types/ext/popup.d.ts
+++ b/types/ext/popup.d.ts
@@ -21,6 +21,7 @@ import type {PopupWindow} from '../../ext/js/app/popup-window';
 import type {FrameOffsetForwarder} from '../../ext/js/comm/frame-offset-forwarder';
 import type * as DocumentUtil from './document-util';
 import type * as Settings from './settings';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type PopupAny = Popup | PopupWindow | PopupProxy;
 
@@ -90,20 +91,6 @@ export type ValidSize = {
     valid: boolean;
 };
 
-export type CustomOuterCssChangedEvent = {
-    node: HTMLStyleElement | HTMLLinkElement | null;
-    useWebExtensionApi: boolean;
-    inShadow: boolean;
-};
-
-export type PopupAnyEventType = PopupEventType | PopupProxyEventType | PopupWindowEventType;
-
-export type PopupEventType = 'customOuterCssChanged' | 'framePointerOver' | 'framePointerOut' | 'offsetNotFound';
-
-export type PopupProxyEventType = 'offsetNotFound';
-
-export type PopupWindowEventType = never;
-
 export type PopupConstructorDetails = {
     /** The ID of the popup. */
     id: string;
@@ -134,3 +121,16 @@ export type PopupProxyConstructorDetails = {
     /** A `FrameOffsetForwarder` instance which is used to determine frame positioning. */
     frameOffsetForwarder: FrameOffsetForwarder | null;
 };
+
+export type Events = {
+    customOuterCssChanged: {
+        node: HTMLStyleElement | HTMLLinkElement | null;
+        useWebExtensionApi: boolean;
+        inShadow: boolean;
+    };
+    framePointerOver: Record<string, never>;
+    framePointerOut: Record<string, never>;
+    offsetNotFound: Record<string, never>;
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/profile-conditions-ui.d.ts b/types/ext/profile-conditions-ui.d.ts
index 7aa22e93..4e326781 100644
--- a/types/ext/profile-conditions-ui.d.ts
+++ b/types/ext/profile-conditions-ui.d.ts
@@ -16,8 +16,16 @@
  */
 
 import type * as Settings from './settings';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
-export type EventType = 'conditionGroupCountChanged';
+export type Events = {
+    conditionGroupCountChanged: {
+        count: number;
+        profileIndex: number;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type DescriptorType = Settings.ProfileConditionType;
 
@@ -49,11 +57,6 @@ export type Operator = {
     normalize: NormalizeFunction | null;
 };
 
-export type ConditionGroupCountChangedEvent = {
-    count: number;
-    profileIndex: number;
-};
-
 export type DescriptorInfo = {
     name: DescriptorType;
     displayName: string;
diff --git a/types/ext/query-parser.d.ts b/types/ext/query-parser.d.ts
new file mode 100644
index 00000000..ea711d9e
--- /dev/null
+++ b/types/ext/query-parser.d.ts
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import type {TextScanner} from '../../ext/js/language/text-scanner';
+import type {DictionaryEntry} from './dictionary';
+import type {OptionsContext} from './settings';
+import type {InputInfo} from './text-scanner';
+import type {TextSource} from './text-source';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
+import type {HistoryStateSentence, PageType} from './display';
+
+export type Events = {
+    searched: {
+        textScanner: TextScanner;
+        type: PageType;
+        dictionaryEntries: DictionaryEntry[];
+        sentence: HistoryStateSentence;
+        inputInfo: InputInfo;
+        textSource: TextSource;
+        optionsContext: OptionsContext;
+        sentenceOffset: number | null;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/search-persistent-state-controller.d.ts b/types/ext/search-persistent-state-controller.d.ts
new file mode 100644
index 00000000..47b07119
--- /dev/null
+++ b/types/ext/search-persistent-state-controller.d.ts
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import type {SearchMode} from './display';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
+
+export type Events = {
+    modeChange: {
+        mode: SearchMode;
+    };
+};
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
diff --git a/types/ext/settings-controller.d.ts b/types/ext/settings-controller.d.ts
index 697de878..e0633c21 100644
--- a/types/ext/settings-controller.d.ts
+++ b/types/ext/settings-controller.d.ts
@@ -21,29 +21,30 @@ import type {ScanInputsSimpleController} from '../../ext/js/pages/settings/scan-
 import type * as Core from './core';
 import type * as Settings from './settings';
 import type * as SettingsModifications from './settings-modifications';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type PageExitPrevention = {
     end: () => void;
 };
 
-export type EventType = 'optionsChanged' | 'optionsContextChanged' | 'permissionsChanged' | 'dictionarySettingsReordered' | 'scanInputsChanged';
-
-export type OptionsChangedEvent = {
-    options: Settings.ProfileOptions;
-    optionsContext: Settings.OptionsContext;
-};
-
-export type PermissionsChangedEvent = {
-    permissions: chrome.permissions.Permissions;
+export type Events = {
+    optionsChanged: {
+        options: Settings.ProfileOptions;
+        optionsContext: Settings.OptionsContext;
+    };
+    optionsContextChanged: Record<string, never>;
+    permissionsChanged: {
+        permissions: chrome.permissions.Permissions;
+    };
+    dictionarySettingsReordered: {
+        source: DictionaryController;
+    };
+    scanInputsChanged: {
+        source: ScanInputsController | ScanInputsSimpleController;
+    };
 };
 
-export type DictionarySettingsReorderedEvent = {
-    source: DictionaryController;
-};
-
-export type ScanInputsChangedEvent = {
-    source: ScanInputsController | ScanInputsSimpleController;
-};
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type SettingsRead<THasScope extends boolean> = THasScope extends true ? SettingsModifications.ScopedRead : SettingsModifications.Read;
 
diff --git a/types/ext/text-scanner.d.ts b/types/ext/text-scanner.d.ts
index d56d623a..e2779e4d 100644
--- a/types/ext/text-scanner.d.ts
+++ b/types/ext/text-scanner.d.ts
@@ -21,6 +21,7 @@ import type * as Display from './display';
 import type * as Input from './input';
 import type * as Settings from './settings';
 import type * as TextSource from './text-source';
+import type {EventNames, EventArgument as BaseEventArgument} from './core';
 
 export type SearchResultDetail = {
     documentTitle: string;
@@ -118,7 +119,16 @@ export type InputInfoDetail = {
     restoreSelection: boolean;
 };
 
-export type EventType = 'searched' | 'clear';
+export type Events = {
+    searched: SearchedEventDetails;
+    clear: {
+        reason: ClearReason;
+    };
+};
+
+export type ClearReason = 'mousedown';
+
+export type EventArgument<TName extends EventNames<Events>> = BaseEventArgument<Events, TName>;
 
 export type GetSearchContextCallback = GetSearchContextCallbackSync | GetSearchContextCallbackAsync;