From f27d1e1cc34b60b2a9b0ebf4894f729f3ccc6545 Mon Sep 17 00:00:00 2001
From: Pierre-Charles David <pierre-charles.david@obeo.fr>
Date: Tue, 29 Oct 2024 15:21:08 +0100
Subject: [PATCH] [4059] Deselect descendants of collapsed tree items

Bug: https://github.com/eclipse-sirius/sirius-web/issues/4059
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>
---
 CHANGELOG.adoc                                |  2 +
 .../src/views/explorer/ExplorerView.tsx       | 47 ++++++++++++++++++-
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 40bb582ebe0..a120a23f8aa 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -59,6 +59,8 @@ This provider is in charge of getting the icon list of the representation.
 This was first fixed in 2022.3.0 but broken in 2024.3.0; it is now fixed again.
 - https://github.com/eclipse-sirius/sirius-web/issues/4280[#4280] [diagram] Fix direct edit with F2 when the palette is opened
 - https://github.com/eclipse-sirius/sirius-web/issues/4302[#4302] [diagram] Fix edges label flashing
+- https://github.com/eclipse-sirius/sirius-web/issues/4059[#4059] [explorer] When a part of the explorer is collapsed, all items inside the collapsed sub-tree are deselected.
+This prevents the automatic re-opening of the collapsed sections to reveal the selected items.
 
 === New Features
 
diff --git a/packages/sirius-web/frontend/sirius-web-application/src/views/explorer/ExplorerView.tsx b/packages/sirius-web/frontend/sirius-web-application/src/views/explorer/ExplorerView.tsx
index 0268d6811c4..64194fd68b2 100644
--- a/packages/sirius-web/frontend/sirius-web-application/src/views/explorer/ExplorerView.tsx
+++ b/packages/sirius-web/frontend/sirius-web-application/src/views/explorer/ExplorerView.tsx
@@ -10,9 +10,11 @@
  * Contributors:
  *     Obeo - initial API and implementation
  *******************************************************************************/
-import { WorkbenchViewComponentProps } from '@eclipse-sirius/sirius-components-core';
+import { useSelection, WorkbenchViewComponentProps } from '@eclipse-sirius/sirius-components-core';
 import {
   FilterBar,
+  GQLTree,
+  GQLTreeItem,
   TreeFilter,
   TreeToolBar,
   TreeToolBarContext,
@@ -44,8 +46,36 @@ const useStyles = makeStyles()((theme: Theme) => ({
 const isTreeRefreshedEventPayload = (payload: GQLTreeEventPayload): payload is GQLTreeRefreshedEventPayload =>
   payload && payload.__typename === 'TreeRefreshedEventPayload';
 
+const findTreeItemById = (items: GQLTreeItem[], id: string) => {
+  for (const child of items) {
+    if (child.id === id) {
+      return child;
+    } else if (child.hasChildren) {
+      const descendant = findTreeItemById(child.children, id);
+      if (descendant) {
+        return descendant;
+      }
+    }
+  }
+  return null;
+};
+
+const findSelectedDescendants = (tree: GQLTree, rootIds: string[], selectedIds: string[]) => {
+  const result = [];
+  for (const rootId of rootIds) {
+    const root = findTreeItemById(tree.children, rootId);
+    for (const selectedId of selectedIds) {
+      if (findTreeItemById(root.children, selectedId)) {
+        result.push(selectedId);
+      }
+    }
+  }
+  return result;
+};
+
 export const ExplorerView = ({ editingContextId, readOnly }: WorkbenchViewComponentProps) => {
   const { classes: styles } = useStyles();
+  const { selection, setSelection } = useSelection();
 
   const initialState: ExplorerViewState = {
     synchronizedWithSelection: true,
@@ -146,7 +176,22 @@ export const ExplorerView = ({ editingContextId, readOnly }: WorkbenchViewCompon
       />
     );
   }
+
   const onExpandedElementChange = (expanded: string[], maxDepth: number) => {
+    // Remove all descendants of collapsed elements from the selection
+    const expandedBefore = state.expanded[state.activeTreeDescriptionId] || [];
+    const collapsedElements = [...expandedBefore].filter((item) => !expanded.includes(item));
+    if (collapsedElements) {
+      const selectedDescendants = findSelectedDescendants(
+        state.tree,
+        collapsedElements,
+        selection.entries.map((entry) => entry.id)
+      );
+      setSelection({
+        entries: selection.entries.filter((entry) => !selectedDescendants.includes(entry.id)),
+      });
+    }
+
     setState((prevState) => ({
       ...prevState,
       expanded: {