Multi cell selection in a row using shift and control key – grid GXT

This post is an extension to this previous post. Code in the previous post is used to multi select cell in a row using the shift keys. It is updated to add functionality to select cells in a particular row using control key and also highlight the row that we are currently working on.

import java.util.ArrayList;
import java.util.List;
import com.extjs.gxt.ui.client.core.El;
import com.extjs.gxt.ui.client.data.ModelData;
import com.extjs.gxt.ui.client.event.GridEvent;
import com.extjs.gxt.ui.client.widget.grid.CellSelectionModel;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.Command;
import com.google.gwt.user.client.DeferredCommand;
/**
 * This class is an extension of CellSelectionModel. 
 * The CellSelectionModel allows us to select only one cell at a particular time. 
 * This Class allows us to select multiple cells in a particular row in a grid.
 * Multi select is performed by pressing the shift key with the mouse click
 *  
 * @author Ravikanth Kolli
 * @version 1.0
 * 
 * 
 * @param <M>
 */
public class RowCellSelectionModel<M extends ModelData> extends CellSelectionModel<M> { 
int lastSelectedRow = -1;
int lastSelectedCol = -1;
private CellSelection selected ;
List<CellSelection> cellsSelected = new ArrayList<CellSelection>();
/**
 * Overriding the handleMouseDown event.
 * MultiSelect is done by pressing the shiftkey 
 */
@Override
protected void handleMouseDown(GridEvent e) {
super.handleMouseDown(e);
if(lastSelectedRow == -1)
{
selected = new CellSelection(listStore.getAt(e.getRowIndex()),e.getRowIndex(),e.getColIndex());
cellsSelected.add(selected);
lastSelectedRow = e.getRowIndex();
lastSelectedCol = e.getColIndex();
}else if (lastSelectedRow == e.getRowIndex() && (e.isShiftKey() || e.isControlKey())) {
// control key press adding or removing cell from the cellsSelected list. 
if(e.isShiftKey())
{
if(cellsSelected.size() > 0)
El.fly(grid.getView().getRow(cellsSelected.get(0).row)).removeStyleName("x-grid3-row-selected");
cellsSelected.clear();
for (int i = 1 ; i < e.getGrid().getColumnModel().getColumnCount(); i++) {
Element cell = grid.getView().getCell(lastSelectedRow, i);
if (cell != null) {
El.fly(cell).removeStyleName("x-grid3-cell-selected");
}
}
if(lastSelectedCol > e.getColIndex()){
for (int iter = e.getColIndex(); iter < lastSelectedCol+1 ; iter++)
{
selected = new CellSelection(listStore.getAt(e.getRowIndex()),e.getRowIndex(),iter);
cellsSelected.add(selected);
}
lastSelectedRow = e.getRowIndex();
}else
{
for (int iter = lastSelectedCol; iter < e.getColIndex() + 1 ; iter++)
{
selected = new CellSelection(listStore.getAt(e.getRowIndex()),e.getRowIndex(),iter);
cellsSelected.add(selected);
}
lastSelectedRow  = e.getRowIndex();
} 
}
// control key press adding or removing cell from the cellsSelected list. 
else if(e.isControlKey())
{
if(cellsSelected.size() > 0)
El.fly(grid.getView().getRow(cellsSelected.get(0).row)).removeStyleName("x-grid3-row-selected");
boolean isSelected = false;
for (int i =0 ; i < cellsSelected.size();i++)
{
El.fly(grid.getView().getCell(cellsSelected.get(i).row, cellsSelected.get(i).cell)).removeStyleName("x-grid3-cell-selected");
if(cellsSelected.get(i).row == e.getRowIndex() && cellsSelected.get(i).cell == e.getColIndex())
{
isSelected = true;
cellsSelected.remove(i);
}
}
if(!isSelected)
{
selected = new CellSelection(listStore.getAt(e.getRowIndex()), e.getRowIndex(), e.getColIndex());
cellsSelected.add(selected);
}
lastSelectedRow = e.getRowIndex();
}
}
else
{
if(!e.isRightClick() 
||  cellsSelected.size() == 0
|| !(cellsSelected.get(0).row == e.getRowIndex() && cellsSelected.get(0).cell <= e.getColIndex() && e.getColIndex() <= cellsSelected.get(cellsSelected.size() - 1).cell) 
||  cellsSelected.get(0).row != e.getRowIndex()){
if(cellsSelected.size() > 0)
El.fly(grid.getView().getRow(cellsSelected.get(0).row)).removeStyleName("x-grid3-row-selected");
cellsSelected.clear();
for (int i = 1 ; i < e.getGrid().getColumnModel().getColumnCount(); i++)
{
Element cell = grid.getView().getCell(lastSelectedRow, i);
if (cell != null) {
El.fly(cell).removeStyleName("x-grid3-cell-selected");
}
}
selected = new CellSelection(listStore.getAt(e.getRowIndex()),e.getRowIndex(),e.getColIndex());
cellsSelected.add(selected);
lastSelectedRow = e.getRowIndex();
lastSelectedCol = e.getColIndex();
}
}
/**
 * Add the cell selected style after all the events are handled
 */
DeferredCommand.addCommand(new Command() {
public void execute() {
      if(cellsSelected.size() > 0)
       {
El.fly(grid.getView().getRow(cellsSelected.get(0).row)).addStyleName("x-grid3-row-selected");
       }
for (int iter = 0 ; iter < cellsSelected.size() ; iter++) {
Element element = grid.getView().getCell(cellsSelected.get(iter).row,cellsSelected.get(iter).cell);
if (element != null) {
El.fly(element).addStyleName("x-grid3-cell-selected");
}
El.fly(grid.getView().getHeaderCell(cellsSelected.get(iter).cell)).setStyleName("x-setItalics");
}     
}
});
}
/**
 * Method to get the list of all the selected cells at a particular time
 * @return list of selected CellSelections.
 */
public List<CellSelection> getSelectedCells()
{
return cellsSelected;
}
/**
 * clear the selections in cellsSelected
 */
public void clearSelections()
{
cellsSelected.clear();
}
}