Enable add row/column buttons after having added one (#23508)

* Enable add row/column buttons after having added one.

This just allows to be able to add more rows, by enabling the corresponding buttons.

It needs to be revised when programmatically focus to RichText is handled.

* set selected cell in state

* Change comment description

Co-authored-by: Miguel Fonseca <miguelcsf@gmail.com>

* Change comment description

Co-authored-by: Miguel Fonseca <miguelcsf@gmail.com>

Co-authored-by: Miguel Fonseca <miguelcsf@gmail.com>

packages/block-library/src/table/edit.js

@@ -291,14 +291,23 @@ export class TableEdit extends Component {
 
 		const { attributes, setAttributes } = this.props;
 		const { sectionName, rowIndex } = selectedCell;
+		const newRowIndex = rowIndex + delta;
 
-		this.setState( { selectedCell: null } );
 		setAttributes(
 			insertRow( attributes, {
 				sectionName,
-				rowIndex: rowIndex + delta,
+				rowIndex: newRowIndex,
 			} )
 		);
+		// Select the first cell of the new row
+		this.setState( {
+			selectedCell: {
+				sectionName,
+				rowIndex: newRowIndex,
+				columnIndex: 0,
+				type: 'cell',
+			},
+		} );
 	}
 
 	/**
@@ -346,13 +355,21 @@ export class TableEdit extends Component {
 
 		const { attributes, setAttributes } = this.props;
 		const { columnIndex } = selectedCell;
+		const newColumnIndex = columnIndex + delta;
 
-		this.setState( { selectedCell: null } );
 		setAttributes(
 			insertColumn( attributes, {
-				columnIndex: columnIndex + delta,
+				columnIndex: newColumnIndex,
 			} )
 		);
+		// Select the first cell of the new column
+		this.setState( {
+			selectedCell: {
+				rowIndex: 0,
+				columnIndex: newColumnIndex,
+				type: 'cell',
+			},
+		} );
 	}
 
 	/**