GXT 4 override the row and cell selected styles at runtime

GridResources.java

import com.google.gwt.core.client.GWT;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.CssResource;

public interface GridResources extends ClientBundle {

  public GridResources INSTANCE = GWT.create(GridResources.class);

  public interface GridStyles extends CssResource {

    String gridRowSelected();

    String gridCellSelected();
    
  }

  @Source("GridStyles.gss")
  public GridStyles styles();
 
}

GridStyles.gss

.gridRowSelected td {
	background-color: red;
}

.gridCellSelected {
	
}

GridWithCustomSelectStyleExample.java

package com.sencha.gxt.test.client.grid_custom_selected_css;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.editor.client.Editor.Path;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.user.client.ui.RootPanel;
import com.sencha.gxt.core.client.ValueProvider;
import com.sencha.gxt.core.client.util.DateWrapper;
import com.sencha.gxt.data.shared.ListStore;
import com.sencha.gxt.data.shared.ModelKeyProvider;
import com.sencha.gxt.data.shared.PropertyAccess;
import com.sencha.gxt.widget.core.client.container.Viewport;
import com.sencha.gxt.widget.core.client.grid.ColumnConfig;
import com.sencha.gxt.widget.core.client.grid.ColumnModel;
import com.sencha.gxt.widget.core.client.grid.Grid;
import com.sencha.gxt.widget.core.client.grid.GridSelectionModel;
import com.sencha.gxt.widget.core.client.grid.GridView;

public class GridWithCustomSelectStyleExample implements EntryPoint {

  // ~~~ override GridView
  public class GridViewExt<M> extends GridView<M> {

    public GridViewExt() {
      super();

      GridResources.INSTANCE.styles().ensureInjected();
    }

    // ~~~~ Define style
    public String getRowSelectedStyle() {
      return GridResources.INSTANCE.styles().gridRowSelected();
    }

    // ~~~~ Define style
    public String getCellSelectedStyle() {
      return GridResources.INSTANCE.styles().gridCellSelected();
    }

    // ~~~~ override onSelect
    @Override
    protected void onRowSelect(int rowIndex) {
      Element row = getRow(rowIndex);
      if (row != null) {
        onRowOut(row);
        getAppearance().onRowSelect(row, true);
        // row.addClassName(states.rowSelected());
        row.addClassName(getRowSelectedStyle());
      }
    }

    // ~~~~ override on desdelect
    @Override
    protected void onRowDeselect(int rowIndex) {
      Element row = getRow(rowIndex);
      if (row != null) {
        getAppearance().onRowSelect(row, false);
        getAppearance().onRowHighlight(row, false);
        // row.removeClassName(states.rowSelected());
        row.removeClassName(getRowSelectedStyle());
      }
    }

    @Override
    protected void onCellSelect(int row, int col) {
      Element cell = getCell(row, col);
      if (cell != null) {
        getAppearance().onCellSelect(cell, true);
        // cell.addClassName(states.cellSelected());
        cell.addClassName(getCellSelectedStyle());
      }
    }

    @Override
    protected void onCellDeselect(int row, int col) {
      Element cell = getCell(row, col);
      if (cell != null) {
        getAppearance().onCellSelect(cell, false);
        //cell.removeClassName(states.cellSelected());
        cell.removeClassName(getCellSelectedStyle());
      }
    }

  }

  private static int COUNTER = 0;
  private static final StockProperties props = GWT.create(StockProperties.class);

  @Override
  public void onModuleLoad() {
    Viewport viewport = new Viewport();
    RootPanel.get().add(viewport);
    viewport.add(createGrid());
  }

  private Grid<Stock> createGrid() {
    ColumnConfig<Stock, String> nameCol = new ColumnConfig<Stock, String>(props.name(), 100, "Company");
    ColumnConfig<Stock, String> symbolCol = new ColumnConfig<Stock, String>(props.symbol(), 100, "Symbol");
    ColumnConfig<Stock, Double> lastCol = new ColumnConfig<Stock, Double>(props.last(), 100, "Last");
    ColumnConfig<Stock, Double> changeCol = new ColumnConfig<Stock, Double>(props.change(), 100, "Change");
    ColumnConfig<Stock, Date> lastTransCol = new ColumnConfig<Stock, Date>(props.lastTrans(), 100, "Last Updated");

    nameCol.setCell(new AbstractCell<String>() {
      @Override
      public void render(com.google.gwt.cell.client.Cell.Context context, String value, SafeHtmlBuilder sb) {
        sb.append(SafeHtmlUtils.fromString(value));
      }
    });

    List<ColumnConfig<Stock, ?>> columns = new ArrayList<ColumnConfig<Stock, ?>>();
    columns.add(nameCol);
    columns.add(symbolCol);
    columns.add(lastCol);
    columns.add(changeCol);
    columns.add(lastTransCol);
    ColumnModel<Stock> columnModel = new ColumnModel<Stock>(columns);

    ListStore<Stock> store = new ListStore<Stock>(props.key());
    store.addAll(getStocks());

    // ~~~~ workaround use extended grid view that overrides methods on row
    // select and deselect
    GridView<Stock> gridView = new GridViewExt<Stock>();

    GridSelectionModel<Stock> sm = new GridSelectionModel<Stock>();

    final Grid<Stock> grid = new Grid<Stock>(store, columnModel, gridView);
    grid.setSelectionModel(sm);

    return grid;
  }

  public class Stock implements Serializable {
    private Integer id;
    private Double change;
    private Date date = new Date();
    private String industry = getType();
    private Double last;
    private String name;
    private Double open;
    private String symbol;
    private boolean split = Boolean.valueOf(Math.random() > .5);

    public Stock() {
      this.id = Integer.valueOf(COUNTER++);
    }

    public Stock(String name, String symbol, double open, double last, Date date) {
      this();
      this.name = name;
      this.symbol = symbol;
      this.change = last - open;
      this.open = open;
      this.last = last;
      this.date = date;
    }

    public Double getChange() {
      return change;
    }

    public Integer getId() {
      return id;
    }

    public String getIndustry() {
      return industry;
    }

    public Double getLast() {
      return last;
    }

    public Date getLastTrans() {
      return date;
    }

    public String getName() {
      return name;
    }

    public Double getOpen() {
      return open;
    }

    /**
     * Read-only property, based on other values
     * 
     * @return the percent change
     */
    public double getPercentChange() {
      return getChange() / getOpen();
    }

    public String getSymbol() {
      return symbol;
    }

    public boolean isSplit() {
      return split;
    }

    public void setChange(Double change) {
      this.change = change;
    }

    public void setId(Integer id) {
      this.id = id;
    }

    public void setIndustry(String industry) {
      this.industry = industry;
    }

    public void setLast(Double last) {
      this.last = last;
    }

    public void setLastTrans(Date date) {
      this.date = date;
    }

    public void setName(String name) {
      this.name = name;
    }

    public void setOpen(Double open) {
      this.open = open;
    }

    public void setSplit(boolean split) {
      this.split = split;
    }

    public void setSymbol(String symbol) {
      this.symbol = symbol;
    }

    public String toString() {
      return getName();
    }

    private String getType() {
      double r = Math.random();
      if (r <= .25) {
        return "Auto";
      } else if (r > .25 && r <= .50) {
        return "Media";
      } else if (r > .5 && r <= .75) {
        return "Medical";
      } else {
        return "Tech";
      }
    }
  }

  private List<Stock> getStocks() {
    List<Stock> stocks = new ArrayList<Stock>();
    stocks.add(new Stock("Apple Inc. <font>font tag</font>", "AAPL", 125.64, 123.43, randomDate()));
    stocks.add(new Stock("cisco Systems, Inc.", "CSCO", 25.84, 26.3, randomDate()));
    stocks.add(new Stock("Cisco Inc.", "GOOG", 516.2, 512.6, randomDate()));
    stocks.add(new Stock("Intel Corporation", "INTC", 21.36, 21.53, randomDate()));
    stocks.add(new Stock("Level 3 Communications, Inc.", "LVLT", 5.55, 5.54, randomDate()));
    stocks.add(new Stock("Microsoft Corporation", "MSFT", 29.56, 29.72, randomDate()));
    stocks.add(new Stock("Nokia Corporation (ADR)", "NOK", 27.83, 27.93, randomDate()));
    stocks.add(new Stock("Oracle Corporation", "ORCL", 18.73, 18.98, randomDate()));
    return stocks;
  }

  private Date randomDate() {
    DateWrapper w = new DateWrapper();
    int r = (int) (Math.random() * 10) * 10;
    w = w.addDays(-r);
    return w.asDate();
  }

  public interface StockProperties extends PropertyAccess<Stock> {
    @Path("symbol")
    ModelKeyProvider<Stock> key();

    ValueProvider<Stock, String> name();

    ValueProvider<Stock, String> symbol();

    ValueProvider<Stock, Double> last();

    ValueProvider<Stock, Double> change();

    ValueProvider<Stock, Date> lastTrans();

    ValueProvider<Stock, String> industry();
  }
}

Example: