Merge pull request #286 from RyotaUshio/fix/issue284

Add an option to disable snippet expansion when IME is on

src/latex_suite.ts

@@ -20,6 +20,7 @@ import { concealPlugin } from "./editor_extensions/conceal";
 import { LatexSuiteCMSettings } from "./settings/settings";
 import { colorPairedBracketsPluginLowestPrec, highlightCursorBracketsPlugin } from "./editor_extensions/highlight_brackets";
 import { cursorTooltipBaseTheme, cursorTooltipField } from "./editor_extensions/math_tooltip";
+import { isComposing } from "./utils/editor_utils";
 
 export const handleUpdate = (update: ViewUpdate) => {
 	const cursorTriggeredByChange = update.state.field(cursorTriggerStateField, false);
@@ -37,12 +38,12 @@ export const handleUpdate = (update: ViewUpdate) => {
 }
 
 export const onKeydown = (event: KeyboardEvent, view: EditorView) => {
-	const success = handleKeydown(event.key, event.shiftKey, event.ctrlKey || event.metaKey, view);
+	const success = handleKeydown(event.key, event.shiftKey, event.ctrlKey || event.metaKey, isComposing(view, event), view);
 
 	if (success) event.preventDefault();
 }
 
-export const handleKeydown = (key: string, shiftKey: boolean, ctrlKey: boolean, view: EditorView) => {
+export const handleKeydown = (key: string, shiftKey: boolean, ctrlKey: boolean, isIME: boolean, view: EditorView) => {
 
 	const settings = getLatexSuiteConfig(view);
 	const ctx = Context.fromView(view);
@@ -51,6 +52,9 @@ export const handleKeydown = (key: string, shiftKey: boolean, ctrlKey: boolean,
 
 	if (settings.snippetsEnabled) {
 
+		// Prevent IME from triggering keydown events.
+		if (settings.suppressSnippetTriggerOnIME && isIME) return;
+
 		// Allows Ctrl + z for undo, instead of triggering a snippet ending with z
 		if (!ctrlKey) {
 			try {

src/settings/settings.ts

@@ -6,6 +6,7 @@ import { DEFAULT_SNIPPET_VARIABLES } from "src/utils/default_snippet_variables";
 interface LatexSuiteBasicSettings {
 	snippetsEnabled: boolean;
 	snippetsTrigger: "Tab" | " "
+	suppressSnippetTriggerOnIME: boolean;
 	removeSnippetWhitespace: boolean;
 	loadSnippetsFromFile: boolean;
 	loadSnippetVariablesFromFile: boolean;
@@ -52,6 +53,7 @@ export const DEFAULT_SETTINGS: LatexSuitePluginSettings = {
 	// Basic settings
 	snippetsEnabled: true,
 	snippetsTrigger: "Tab",
+	suppressSnippetTriggerOnIME: true,
 	removeSnippetWhitespace: true,
 	loadSnippetsFromFile: false,
 	loadSnippetVariablesFromFile: false,

src/settings/settings_tab.ts

@@ -410,6 +410,17 @@ export class LatexSuiteSettingTab extends PluginSettingTab {
 				await this.plugin.saveSettings();
 			}));
 
+		new Setting(containerEl)
+			.setName("Don't trigger snippets when IME is active")
+			.setDesc("Whether to suppress the snippet triggering when an IME is active.")
+			.addToggle((toggle) => toggle
+				.setValue(this.plugin.settings.suppressSnippetTriggerOnIME)
+				.onChange(async (value) => {
+					this.plugin.settings.suppressSnippetTriggerOnIME = value;
+					await this.plugin.saveSettings();
+				})
+			);
+
 		new Setting(containerEl)
 		.setName("Code languages to interpret as math mode")
 		.setDesc("Codeblock languages where the whole code block should be treated like a math block, separated by commas.")

src/utils/editor_utils.ts

@@ -134,3 +134,15 @@ export function escalateToToken(cursor: TreeCursor, dir: Direction, target: stri
 
 	return null;
 }
+
+
+/**
+ * Check if the user is typing in an IME composition.
+ * Returns true even if the given event is the first keydown event of an IME composition.
+ */
+export function isComposing(view: EditorView, event: KeyboardEvent): boolean {
+	// view.composing and event.isComposing are false for the first keydown event of an IME composition,
+	// so we need to check for event.keyCode === 229 to prevent IME from triggering keydown events.
+	// Note that keyCode is deprecated - it is used here because it is apparently the only way to detect the first keydown event of an IME composition.
+	return view.composing || event.keyCode === 229;
+}