From 2798c50b50e308546c8f43e332579697bc1cd145 Mon Sep 17 00:00:00 2001
From: Zhurbin <zhurbin.alexander@gmail.com>
Date: Wed, 15 May 2019 17:19:39 +0300
Subject: [PATCH] Handle shift modifier to add/subtract selected cells.

---
 lib/DataCell.js  |  2 +-
 lib/DataSheet.js | 24 ++++++++++++++++++++----
 src/DataCell.js  |  2 +-
 src/DataSheet.js | 23 +++++++++++++++++++----
 4 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/lib/DataCell.js b/lib/DataCell.js
index 1e381d2..53ef0d5 100644
--- a/lib/DataCell.js
+++ b/lib/DataCell.js
@@ -155,7 +155,7 @@ var DataCell = function (_PureComponent) {
           cell = _props2.cell;
 
       if (!cell.disableEvents) {
-        onMouseDown(row, col);
+        onMouseDown(row, col, e);
       }
     }
   }, {
diff --git a/lib/DataSheet.js b/lib/DataSheet.js
index ec05908..e70f706 100644
--- a/lib/DataSheet.js
+++ b/lib/DataSheet.js
@@ -438,14 +438,23 @@ var DataSheet = function (_PureComponent) {
 
       if (offsets && (offsets.i || offsets.j)) {
         var _getState6 = this.getState(),
-            start = _getState6.start;
+            start = _getState6.start,
+            end = _getState6.end;
 
         var data = this.props.data;
 
+        var oldStartLocation = { i: start.i, j: start.j };
+        var newEndLocation = { i: end.i + offsets.i, j: end.j + offsets.j };
+
         var newLocation = { i: start.i + offsets.i, j: start.j + offsets.j };
+
         var updateLocation = function updateLocation() {
           if (data[newLocation.i] && typeof data[newLocation.i][newLocation.j] !== 'undefined') {
-            _this3._setState({ start: newLocation, end: newLocation, editing: {} });
+            _this3._setState({
+              start: e.shiftKey && !jumpRow ? oldStartLocation : newLocation,
+              end: e.shiftKey && !jumpRow ? newEndLocation : newLocation,
+              editing: {}
+            });
             e.preventDefault();
             return true;
           }
@@ -515,9 +524,16 @@ var DataSheet = function (_PureComponent) {
     }
   }, {
     key: 'onMouseDown',
-    value: function onMouseDown(i, j) {
+    value: function onMouseDown(i, j, e) {
       var editing = isEmpty(this.state.editing) || this.state.editing.i !== i || this.state.editing.j !== j ? {} : this.state.editing;
-      this._setState({ selecting: true, start: { i: i, j: j }, end: { i: i, j: j }, editing: editing, forceEdit: false });
+
+      this._setState({
+        selecting: true,
+        start: e.shiftKey ? this.state.start : { i: i, j: j },
+        end: { i: i, j: j },
+        editing: editing,
+        forceEdit: false
+      });
 
       // Keep listening to mouse if user releases the mouse (dragging outside)
       document.addEventListener('mouseup', this.onMouseUp);
diff --git a/src/DataCell.js b/src/DataCell.js
index 7bb0257..26516dd 100644
--- a/src/DataCell.js
+++ b/src/DataCell.js
@@ -89,7 +89,7 @@ export default class DataCell extends PureComponent {
   handleMouseDown (e) {
     const {row, col, onMouseDown, cell} = this.props
     if (!cell.disableEvents) {
-      onMouseDown(row, col)
+      onMouseDown(row, col, e)
     }
   }
 
diff --git a/src/DataSheet.js b/src/DataSheet.js
index 31a1c1b..ca081bf 100644
--- a/src/DataSheet.js
+++ b/src/DataSheet.js
@@ -323,12 +323,20 @@ export default class DataSheet extends PureComponent {
 
   handleNavigate (e, offsets, jumpRow) {
     if (offsets && (offsets.i || offsets.j)) {
-      const {start} = this.getState()
+      const {start, end} = this.getState()
       const {data} = this.props
+      const oldStartLocation = {i: start.i, j: start.j}
+      const newEndLocation = {i: end.i + offsets.i, j: end.j + offsets.j}
+
       let newLocation = {i: start.i + offsets.i, j: start.j + offsets.j}
+
       const updateLocation = () => {
         if (data[newLocation.i] && typeof (data[newLocation.i][newLocation.j]) !== 'undefined') {
-          this._setState({start: newLocation, end: newLocation, editing: {}})
+          this._setState({
+            start: e.shiftKey && !jumpRow ? oldStartLocation : newLocation,
+            end: e.shiftKey && !jumpRow ? newEndLocation : newLocation,
+            editing: {}
+          })
           e.preventDefault()
           return true
         }
@@ -385,10 +393,17 @@ export default class DataSheet extends PureComponent {
     }
   }
 
-  onMouseDown (i, j) {
+  onMouseDown (i, j, e) {
     let editing = (isEmpty(this.state.editing) || this.state.editing.i !== i || this.state.editing.j !== j)
       ? {} : this.state.editing
-    this._setState({selecting: true, start: {i, j}, end: {i, j}, editing: editing, forceEdit: false})
+
+    this._setState({
+      selecting: true,
+      start: e.shiftKey ? this.state.start : {i, j},
+      end: {i, j},
+      editing: editing,
+      forceEdit: false
+    })
 
     // Keep listening to mouse if user releases the mouse (dragging outside)
     document.addEventListener('mouseup', this.onMouseUp)