public async resolveCustomTextEditor()

in src/formatter-settings/index.ts [72:148]
73 lines of code
18 McCabe index (conditional complexity)

    public async resolveCustomTextEditor(document: vscode.TextDocument, webviewPanel: vscode.WebviewPanel, _token: vscode.CancellationToken): Promise<void> {

        // restrict one webviewpanel only
        if (this.webviewPanel) {
            vscode.commands.executeCommand("vscode.open", document.uri);
            webviewPanel.dispose();
            return;
        } else {
            this.webviewPanel = webviewPanel;
        }

        this.webviewPanel.webview.options = {
            enableScripts: true,
            enableCommandUris: true,
        };
        this.webviewPanel.onDidDispose(() => {
            this.webviewPanel = undefined;
        });
        this.webviewPanel.webview.html = this.getHtmlForWebview(path.join(this.context.extensionPath, "out", "assets", "formatter-settings", "index.js"));
        this.webviewPanel.webview.onDidReceiveMessage(async (e) => {
            switch (e.command) {
                case "onWillInitialize":
                    if (!await this.initialize(document)) {
                        this.webviewPanel?.dispose();
                    }
                    break;
                case "onWillChangeExampleKind":
                    if (this.exampleKind !== e.exampleKind) {
                        sendInfo("", { formatterExample: e.exampleKind });
                        this.exampleKind = e.exampleKind;
                        this.format();
                    }
                    break;
                case "onWillChangeSetting":
                    const settingValue: string | undefined = FormatterConverter.webView2ProfileConvert(e.id, e.value.toString());
                    sendInfo("", { formatterSetting: e.id });
                    // "" represents an empty inputbox, we regard it as a valid value.
                    if (settingValue === undefined) {
                        return;
                    }
                    if (SupportedSettings.indentationSettings.includes(e.id)) {
                        const config = vscode.workspace.getConfiguration(undefined, { languageId: "java" });
                        if (e.id === SupportedSettings.TABULATION_CHAR) {
                            const targetValue = (settingValue === "tab") ? false : true;
                            await config.update(VSCodeSettings.INSERT_SPACES, targetValue, undefined, true);
                        } else if (e.id === SupportedSettings.TABULATION_SIZE) {
                            await config.update(VSCodeSettings.TAB_SIZE, (settingValue === "") ? "" : Number(settingValue), undefined, true);
                        }
                        this.profileSettings.set(e.id, settingValue);
                    } else if (e.id === VSCodeSettings.DETECT_INDENTATION) {
                        const config = vscode.workspace.getConfiguration(undefined, { languageId: "java" });
                        await config.update(VSCodeSettings.DETECT_INDENTATION, (settingValue === "true"), undefined, true);
                    } else {
                        await this.modifyProfile(e.id, settingValue, document);
                    }
                    break;
                case "onWillDownloadAndUse": {
                    const settingsUrl = vscode.workspace.getConfiguration("java").get<string>(JavaConstants.SETTINGS_URL_KEY);
                    if (!settingsUrl || !isRemote(settingsUrl)) {
                        vscode.window.showErrorMessage("The active formatter profile does not exist or is not remote, please check it in the Settings and try again.",
                            "Open Settings").then((result) => {
                                if (result === "Open Settings") {
                                    openFormatterSettings();
                                }
                            });
                        return;
                    }
                    this.webviewPanel?.dispose();
                    await this.downloadAndUse(settingsUrl);
                    break;
                }
                default:
                    break;
            }
        });
        await this.checkRequirement();
    }