From 4ac0eaaa88b0b61860795f23657cc206d94ffa13 Mon Sep 17 00:00:00 2001
From: RomanTsukanov <sergeich16@gmail.com>
Date: Fri, 15 Mar 2024 16:24:39 +0400
Subject: [PATCH] Describe the `onMatrixDetailPanelVisibleChanged` event

---
 src/survey-events-api.ts | 10 ++++++++--
 src/survey.ts            |  3 +++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/survey-events-api.ts b/src/survey-events-api.ts
index 3518bccd9b..ec3a19d858 100644
--- a/src/survey-events-api.ts
+++ b/src/survey-events-api.ts
@@ -711,15 +711,21 @@ export interface MatrixAllowRemoveRowEvent extends MatrixDynamicQuestionEventMix
 }
 export interface MatrixDetailPanelVisibleChangedEvent extends MatrixDropdownQuestionEventMixin {
   /**
-   * A matrix row for which the event is raised.
+   * A matrix row to which the detail section belongs.
    */
   row: MatrixDropdownRowModelBase;
   /**
    * A zero-based row index.
    */
   rowIndex: number;
-  isShowing: boolean;
+  /**
+   * A [PanelModel](https://surveyjs.io/form-library/documentation/panelmodel) that represents the detail section.
+   */
   detailPanel: PanelModel;
+  /**
+   * Indicates whether the detail section is visible now.
+   */
+  isShowing: boolean;
 }
 
 export interface MatrixCellCreatingBaseEvent extends MatrixDropdownQuestionEventMixin {
diff --git a/src/survey.ts b/src/survey.ts
index 68161c88bc..57eb61aa68 100644
--- a/src/survey.ts
+++ b/src/survey.ts
@@ -673,6 +673,9 @@ export class SurveyModel extends SurveyElementCore
    * This event is obsolete. Use the [`onMatrixRenderRemoveButton`](https://surveyjs.io/form-library/documentation/api-reference/survey-data-model#onMatrixRenderRemoveButton) event instead.
    */
   public onMatrixAllowRemoveRow: EventBase<SurveyModel, MatrixAllowRemoveRowEvent> = this.onMatrixRenderRemoveButton;
+  /**
+   * An event that is raised after the visibility of an [expandable detail section](https://surveyjs.io/form-library/examples/add-expandable-details-section-under-matrix-rows/) is changed. This event can be raised for [Multi-Select](https://surveyjs.io/form-library/documentation/api-reference/matrix-table-with-dropdown-list) and [Dynamic Matrix](https://surveyjs.io/form-library/documentation/api-reference/dynamic-matrix-table-question-model) questions.
+   */
   public onMatrixDetailPanelVisibleChanged: EventBase<SurveyModel, MatrixDetailPanelVisibleChangedEvent> = this.addEvent<SurveyModel, MatrixDetailPanelVisibleChangedEvent >();
   /**
    * An event that is raised before a cell in a [Multi-Select Matrix](https://surveyjs.io/form-library/examples/questiontype-matrixdropdown/) or [Dynamic Matrix](https://surveyjs.io/form-library/examples/questiontype-matrixdynamic/) is created. Use this event to change the type of individual matrix cells.