From 8b98c33c4c8ed9cc1dc3964576bad93e33c0e8cb Mon Sep 17 00:00:00 2001
From: Lutz Helm <helm@ub.uni-leipzig.de>
Date: Thu, 13 Feb 2020 14:42:16 +0100
Subject: [PATCH] Toggle nodes with keyboard interaction

onClick and onKeyDown should be replaced once material-ui TreeItem has
node selection support:
https://github.com/mui-org/material-ui/issues/16795
---
 src/components/SidebarIndexTableOfContents.js | 13 +++-
 src/state/selectors/ranges.js                 | 63 +++++++++++++++----
 2 files changed, 62 insertions(+), 14 deletions(-)

diff --git a/src/components/SidebarIndexTableOfContents.js b/src/components/SidebarIndexTableOfContents.js
index 8130e83eaf..c018c82ee1 100644
--- a/src/components/SidebarIndexTableOfContents.js
+++ b/src/components/SidebarIndexTableOfContents.js
@@ -12,15 +12,25 @@ export class SidebarIndexTableOfContents extends Component {
   /** */
   selectTreeItem(node) {
     const { setCanvas, toggleRange, windowId } = this.props;
-    toggleRange(node.data.id);
     // Do not select if there are child nodes
     if (node.nodes.length > 0) {
+      toggleRange(node.data.id);
       return;
     }
     const canvas = node.data.getCanvasIds()[0];
     setCanvas(windowId, canvas);
   }
 
+  /** */
+  handleKeyPressed(event, node) {
+    if (event.key === 'Enter'
+      || event.key === ' '
+      || event.key === 'ArrowLeft' && this.props.expandedRangeIds.indexOf(node.data.id) !== -1
+      || event.key === 'ArrowRight' && this.props.expandedRangeIds.indexOf(node.data.id) === -1) {
+      this.selectTreeItem(node);
+    }
+  }
+
   /** */
   buildTreeItems(nodes, canvasIds, visibleRangeIds, containerRef) {
     return (
@@ -42,6 +52,7 @@ export class SidebarIndexTableOfContents extends Component {
               </ScrollTo>
           )}
           onClick={() => this.selectTreeItem(node)}
+          onKeyDown={e => this.handleKeyPressed(e, node)}
         >
           {node.nodes.length > 0 ? this.buildTreeItems(node.nodes, canvasIds, visibleRangeIds, containerRef) : null}
         </TreeItem>
diff --git a/src/state/selectors/ranges.js b/src/state/selectors/ranges.js
index 13056c78ab..e141ffd4b8 100644
--- a/src/state/selectors/ranges.js
+++ b/src/state/selectors/ranges.js
@@ -6,40 +6,77 @@ import { getCompanionWindow } from './companionWindows';
 
 /** */
 function getVisibleRangeIdsInSubTree(nodes, canvasIds) {
-  return nodes.reduce((rangeIds, node) => {
-    const currentRangeIds = [];
+  return nodes.reduce((rangeIdAcc, node) => {
+    const currentBranchRangeIds = [];
+    const currentLeafRangeIds = [];
     const nodeContainsVisibleCanvas = canvasIds.reduce(
       (acc, canvasId) => acc || node.data.getCanvasIds().indexOf(canvasId) !== -1,
       false,
     );
     if (node.nodes.length > 0) {
       const subTreeVisibleRangeIds = node.nodes.length > 0
-        ? getVisibleRangeIdsInSubTree(node.nodes, canvasIds) : [];
-      currentRangeIds.push(...subTreeVisibleRangeIds);
+        ? getVisibleRangeIdsInSubTree(node.nodes, canvasIds) : {
+          branchRangeIds: [],
+          leafRangeIds: [],
+        };
+      currentBranchRangeIds.push(...subTreeVisibleRangeIds.branchRangeIds);
+      currentLeafRangeIds.push(...subTreeVisibleRangeIds.leafRangeIds);
     }
-    if (currentRangeIds.length > 0 || nodeContainsVisibleCanvas) {
-      currentRangeIds.push(node.data.id);
+    if (currentBranchRangeIds.length > 0
+      || currentLeafRangeIds.length > 0
+      || nodeContainsVisibleCanvas) {
+      if (node.nodes.length > 0) {
+        currentBranchRangeIds.push(node.data.id);
+      } else {
+        currentLeafRangeIds.push(node.data.id);
+      }
     }
-    rangeIds.push(...currentRangeIds);
-    return rangeIds;
-  }, []);
+    rangeIdAcc.branchRangeIds.push(...currentBranchRangeIds);
+    rangeIdAcc.leafRangeIds.push(...currentLeafRangeIds);
+    return rangeIdAcc;
+  }, {
+    branchRangeIds: [],
+    leafRangeIds: [],
+  });
 }
 
 /** */
-export const getVisibleRangeIds = createSelector(
+const getVisibleLeafAndBranchRangeIds = createSelector(
   [
     getManifestTreeStructure,
     getVisibleCanvases,
   ],
   (tree, canvases) => {
     if (!canvases) {
-      return [];
+      return {
+        branchRangeIds: [],
+        leafRangeIds: [],
+      };
     }
     const canvasIds = canvases.map(canvas => canvas.id);
     return getVisibleRangeIdsInSubTree(tree.nodes, canvasIds);
   },
 );
 
+/** */
+export const getVisibleRangeIds = createSelector(
+  [
+    getVisibleLeafAndBranchRangeIds,
+  ],
+  (visibleLeafAndBranchRangeIds) => {
+    return union(visibleLeafAndBranchRangeIds.leafRangeIds, visibleLeafAndBranchRangeIds.branchRangeIds);
+  },
+);
+
+const getVisibleBranchRangeIds = createSelector(
+  [
+    getVisibleLeafAndBranchRangeIds,
+  ],
+  (visibleLeafAndBranchRangeIds) => {
+    return visibleLeafAndBranchRangeIds.branchRangeIds;
+  },
+);
+
 /** */
 export function getManuallyExpandedRangeIds(state, { companionWindowId }) {
   const companionWindow = getCompanionWindow(state, { companionWindowId });
@@ -48,7 +85,7 @@ export function getManuallyExpandedRangeIds(state, { companionWindowId }) {
 
 /** */
 export function getExpandedRangeIds(state, { ...args }) {
-  const visibleRangeIds = getVisibleRangeIds(state, { ...args });
+  const visibleBranchRangeIds = getVisibleBranchRangeIds(state, { ...args });
   const manuallyExpandedRangeIds = getManuallyExpandedRangeIds(state, { ...args });
-  return union(manuallyExpandedRangeIds, visibleRangeIds);
+  return union(manuallyExpandedRangeIds, visibleBranchRangeIds);
 }