Call ComplexRenderer.setContentVisible() from Grid body updater #13334

Change-Id: Icba9d9f3e5cdc6412c9c004356c33304024be33b

5 files changed, 320 insertions, 109 deletions

diff --git a/client/src/com/vaadin/client/ui/grid/Grid.java b/client/src/com/vaadin/client/ui/grid/Grid.java
index ceaa63c9b6..ca3c272491 100644
--- a/client/src/com/vaadin/client/ui/grid/Grid.java
+++ b/client/src/com/vaadin/client/ui/grid/Grid.java
@@ -58,7 +58,7 @@ import com.vaadin.shared.util.SharedUtil;
 /**
  * A data grid view that supports columns and lazy loading of data rows from a
  * data source.
- *
+ * 
  * <h3>Columns</h3>
  * <p>
  * The {@link GridColumn} class defines the renderer used to render a cell in
@@ -72,15 +72,15 @@ import com.vaadin.shared.util.SharedUtil;
  * specific column index using {@link Grid#getColumn(int)}.
  * </p>
  * <p>
- *
+ * 
  * TODO Explain about headers/footers once the multiple header/footer api has
  * been implemented
- *
+ * 
  * <h3>Data sources</h3>
  * <p>
  * TODO Explain about what a data source is and how it should be implemented.
  * </p>
- *
+ * 
  * @param <T>
  *            The row type of the grid. The row type is the POJO type from where
  *            the data is retrieved into the column cells.
@@ -217,6 +217,9 @@ public class Grid<T> extends Composite implements
 
     private SelectionColumn selectionColumn;
 
+    private String rowHasDataStyleName;
+    private String rowSelectedStyleName;
+
     /**
      * Current selection model.
      */
@@ -266,10 +269,10 @@ public class Grid<T> extends Composite implements
     /**
      * Base class for grid columns internally used by the Grid. The user should
      * use {@link GridColumn} when creating new columns.
-     *
+     * 
      * @param <C>
      *            the column type
-     *
+     * 
      * @param <T>
      *            the row type
      */
@@ -317,7 +320,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Constructs a new column with a custom renderer.
-         *
+         * 
          * @param renderer
          *            The renderer to use for rendering the cells
          */
@@ -331,7 +334,7 @@ public class Grid<T> extends Composite implements
         /**
          * Constructs a new column with custom renderers for rows, header and
          * footer cells.
-         *
+         * 
          * @param bodyRenderer
          *            The renderer to use for rendering body cells
          * @param headerRenderer
@@ -352,7 +355,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Internally used by the grid to set itself
-         *
+         * 
          * @param grid
          */
         private void setGrid(Grid<T> grid) {
@@ -375,7 +378,7 @@ public class Grid<T> extends Composite implements
         /**
          * Gets text in the header of the column. By default the header caption
          * is empty.
-         *
+         * 
          * @return the text displayed in the column caption
          */
         public String getHeaderCaption() {
@@ -384,7 +387,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Returns the renderer used for rendering the header cells
-         *
+         * 
          * @return a renderer that renders header cells
          */
         public Renderer<String> getHeaderRenderer() {
@@ -393,7 +396,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Sets the renderer that renders header cells. Should not be null.
-         *
+         * 
          * @param renderer
          *            The renderer to use for rendering header cells.
          */
@@ -409,7 +412,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Returns the renderer used for rendering the footer cells
-         *
+         * 
          * @return a renderer that renders footer cells
          */
         public Renderer<String> getFooterRenderer() {
@@ -418,7 +421,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Sets the renderer that renders footer cells. Should not be null.
-         *
+         * 
          * @param renderer
          *            The renderer to use for rendering footer cells.
          */
@@ -434,7 +437,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Sets the text in the header of the column.
-         *
+         * 
          * @param caption
          *            the text displayed in the column header
          */
@@ -453,7 +456,7 @@ public class Grid<T> extends Composite implements
         /**
          * Gets text in the footer of the column. By default the footer caption
          * is empty.
-         *
+         * 
          * @return The text displayed in the footer of the column
          */
         public String getFooterCaption() {
@@ -462,7 +465,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Sets text in the footer of the column.
-         *
+         * 
          * @param caption
          *            the text displayed in the footer of the column
          */
@@ -480,7 +483,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Is the column visible. By default all columns are visible.
-         *
+         * 
          * @return <code>true</code> if the column is visible
          */
         @Override
@@ -490,7 +493,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Sets a column as visible in the grid.
-         *
+         * 
          * @param visible
          *            <code>true</code> if the column should be displayed in the
          *            grid
@@ -525,10 +528,10 @@ public class Grid<T> extends Composite implements
          * <p>
          * To support other types you will need to pass a custom renderer to the
          * column via the column constructor.
-         *
+         * 
          * @param row
          *            The row object that provides the cell content.
-         *
+         * 
          * @return The cell content
          */
         public abstract C getValue(T row);
@@ -537,7 +540,7 @@ public class Grid<T> extends Composite implements
          * The renderer to render the cell width. By default renders the data as
          * a String or adds the widget into the cell if the column type is of
          * widget type.
-         *
+         * 
          * @return The renderer to render the cell content with
          */
         public Renderer<? super C> getRenderer() {
@@ -546,7 +549,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Finds the index of this column instance
-         *
+         * 
          */
         private int findIndexOfColumn() {
             return grid.findVisibleColumnIndex((GridColumn<?, T>) this);
@@ -555,7 +558,7 @@ public class Grid<T> extends Composite implements
         /**
          * Sets the pixel width of the column. Use a negative value for the grid
          * to autosize column based on content and available space
-         *
+         * 
          * @param pixels
          *            the width in pixels or negative for auto sizing
          */
@@ -572,7 +575,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Returns the pixel width of the column
-         *
+         * 
          * @return pixel width of the column
          */
         public int getWidth() {
@@ -605,7 +608,7 @@ public class Grid<T> extends Composite implements
 
         /**
          * Constructs an updater for updating a header / footer
-         *
+         * 
          * @param rows
          *            The row container
          * @param inverted
@@ -618,17 +621,17 @@ public class Grid<T> extends Composite implements
 
         /**
          * Gets the header/footer caption value
-         *
+         * 
          * @param column
          *            The column to get the value for.
-         *
+         * 
          * @return The value that should be rendered for the column caption
          */
         public abstract String getColumnValue(GridColumn<?, T> column);
 
         /**
          * Gets the group caption value
-         *
+         * 
          * @param group
          *            The group for with the caption value should be returned
          * @return The value that should be rendered for the column caption
@@ -637,34 +640,34 @@ public class Grid<T> extends Composite implements
 
         /**
          * Is the row visible in the header/footer
-         *
+         * 
          * @param row
          *            the row to check
-         *
+         * 
          * @return <code>true</code> if the row should be visible
          */
         public abstract boolean isRowVisible(ColumnGroupRow<T> row);
 
         /**
          * Should the first row be visible
-         *
+         * 
          * @return <code>true</code> if the first row should be visible
          */
         public abstract boolean firstRowIsVisible();
 
         /**
          * The renderer that renders the cell
-         *
+         * 
          * @param column
          *            The column for which the cell should be rendered
-         *
+         * 
          * @return renderer used for rendering
          */
         public abstract Renderer<String> getRenderer(GridColumn<?, T> column);
 
         /**
          * The renderer that renders the cell for column groups
-         *
+         * 
          * @param group
          *            The group that should be rendered
          * @return renderer used for rendering
@@ -784,12 +787,14 @@ public class Grid<T> extends Composite implements
     public void setStylePrimaryName(String style) {
         super.setStylePrimaryName(style);
         escalator.setStylePrimaryName(style);
+        rowHasDataStyleName = getStylePrimaryName() + "-row-has-data";
+        rowSelectedStyleName = getStylePrimaryName() + "-row-selected";
     }
 
     /**
      * Creates the header updater that updates the escalator header rows from
      * the column and column group rows.
-     *
+     * 
      * @return the updater that updates the data in the escalator.
      */
     private EscalatorUpdater createHeaderUpdater() {
@@ -865,26 +870,63 @@ public class Grid<T> extends Composite implements
             @Override
             public void update(Row row, Iterable<FlyweightCell> cellsToUpdate) {
                 int rowIndex = row.getRow();
+                Element rowElement = row.getElement();
                 T rowData = dataSource.getRow(rowIndex);
-                if (rowData == null) {
-                    return;
+
+                boolean hasData = rowData != null;
+
+                // Assign stylename for rows with data
+                boolean usedToHaveData = rowElement
+                        .hasClassName(rowHasDataStyleName);
+
+                if (usedToHaveData != hasData) {
+                    setStyleName(rowElement, rowHasDataStyleName, hasData);
+                }
+
+                // Assign stylename for selected rows
+                if (hasData) {
+                    setStyleName(rowElement, rowSelectedStyleName,
+                            isSelected(rowData));
+                } else if (usedToHaveData) {
+                    setStyleName(rowElement, rowSelectedStyleName, false);
                 }
 
                 for (FlyweightCell cell : cellsToUpdate) {
                     GridColumn<?, T> column = getColumnFromVisibleIndex(cell
                             .getColumn());
+
                     assert column != null : "Column was not found from cell ("
                             + cell.getColumn() + "," + cell.getRow() + ")";
-                    Object value = column.getValue(rowData);
-                    Renderer renderer = findRenderer(cell);
-                    renderer.render(cell, value);
-                }
 
-                final String selectedClassName = getStylePrimaryName()
-                        + "-row-selected";
+                    Renderer renderer = column.getRenderer();
 
-                setStyleName(row.getElement(), selectedClassName,
-                        isSelected(rowData));
+                    // Hide cell content if needed
+                    if (renderer instanceof ComplexRenderer) {
+                        ComplexRenderer clxRenderer = (ComplexRenderer) renderer;
+                        if (hasData) {
+                            if (!usedToHaveData) {
+                                // Prepare cell for rendering
+                                clxRenderer.setContentVisible(cell, true);
+                            }
+
+                            Object value = column.getValue(rowData);
+                            clxRenderer.render(cell, value);
+
+                        } else if (usedToHaveData) {
+                            // Prepare cell for no data
+                            clxRenderer.setContentVisible(cell, false);
+                        }
+
+                    } else if (hasData) {
+                        // Simple renderers just render
+                        Object value = column.getValue(rowData);
+                        renderer.render(cell, value);
+
+                    } else {
+                        // Clear cell if there is no data
+                        cell.getElement().removeAllChildren();
+                    }
+                }
             }
 
             @Override
@@ -922,7 +964,7 @@ public class Grid<T> extends Composite implements
     /**
      * Creates the footer updater that updates the escalator footer rows from
      * the column and column group rows.
-     *
+     * 
      * @return the updater that updates the data in the escalator.
      */
     private EscalatorUpdater createFooterUpdater() {
@@ -962,7 +1004,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Refreshes header or footer rows on demand
-     *
+     * 
      * @param rows
      *            The row container
      * @param firstRowIsVisible
@@ -1014,7 +1056,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Adds a column as the last column in the grid.
-     *
+     * 
      * @param column
      *            the column to add
      */
@@ -1024,7 +1066,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Inserts a column into a specific position in the grid.
-     *
+     * 
      * @param index
      *            the index where the column should be inserted into
      * @param column
@@ -1128,7 +1170,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Removes a column from the grid.
-     *
+     * 
      * @param column
      *            the column to remove
      */
@@ -1163,7 +1205,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Returns the amount of columns in the grid.
-     *
+     * 
      * @return The number of columns in the grid
      */
     public int getColumnCount() {
@@ -1172,7 +1214,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Returns a list of columns in the grid.
-     *
+     * 
      * @return A unmodifiable list of the columns in the grid
      */
     public List<GridColumn<?, T>> getColumns() {
@@ -1182,7 +1224,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Returns a column by its index in the grid.
-     *
+     * 
      * @param index
      *            the index of the column
      * @return The column in the given index
@@ -1199,30 +1241,30 @@ public class Grid<T> extends Composite implements
 
     /**
      * Set the column headers visible.
-     *
+     * 
      * <p>
      * A column header is a single cell header on top of each column reserved
      * for a specific header for that column. The column header can be set by
      * {@link GridColumn#setHeaderCaption(String)} and column headers cannot be
      * merged with other column headers.
      * </p>
-     *
+     * 
      * <p>
      * All column headers occupy the first header row of the grid. If you do not
      * wish to show the column headers in the grid you should hide the row by
      * setting visibility of the header row to <code>false</code>.
      * </p>
-     *
+     * 
      * <p>
      * If you want to merge the column headers into groups you can use
      * {@link ColumnGroupRow}s to group columns together and give them a common
      * header. See {@link #addColumnGroupRow()} for details.
      * </p>
-     *
+     * 
      * <p>
      * The header row is by default visible.
      * </p>
-     *
+     * 
      * @param visible
      *            <code>true</code> if header rows should be visible
      */
@@ -1236,7 +1278,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Are the column headers visible
-     *
+     * 
      * @return <code>true</code> if they are visible
      */
     public boolean isColumnHeadersVisible() {
@@ -1245,30 +1287,30 @@ public class Grid<T> extends Composite implements
 
     /**
      * Set the column footers visible.
-     *
+     * 
      * <p>
      * A column footer is a single cell footer below of each column reserved for
      * a specific footer for that column. The column footer can be set by
      * {@link GridColumn#setFooterCaption(String)} and column footers cannot be
      * merged with other column footers.
      * </p>
-     *
+     * 
      * <p>
      * All column footers occupy the first footer row of the grid. If you do not
      * wish to show the column footers in the grid you should hide the row by
      * setting visibility of the footer row to <code>false</code>.
      * </p>
-     *
+     * 
      * <p>
      * If you want to merge the column footers into groups you can use
      * {@link ColumnGroupRow}s to group columns together and give them a common
      * footer. See {@link #addColumnGroupRow()} for details.
      * </p>
-     *
+     * 
      * <p>
      * The footer row is by default hidden.
      * </p>
-     *
+     * 
      * @param visible
      *            <code>true</code> if the footer row should be visible
      */
@@ -1282,9 +1324,9 @@ public class Grid<T> extends Composite implements
 
     /**
      * Are the column footers visible
-     *
+     * 
      * @return <code>true</code> if they are visible
-     *
+     * 
      */
     public boolean isColumnFootersVisible() {
         return columnFootersVisible;
@@ -1292,15 +1334,15 @@ public class Grid<T> extends Composite implements
 
     /**
      * Adds a new column group row to the grid.
-     *
+     * 
      * <p>
      * Column group rows are rendered in the header and footer of the grid.
      * Column group rows are made up of column groups which groups together
      * columns for adding a common auxiliary header or footer for the columns.
      * </p>
-     *
+     * 
      * Example usage:
-     *
+     * 
      * <pre>
      * // Add a new column group row to the grid
      * ColumnGroupRow row = grid.addColumnGroupRow();
@@ -1314,7 +1356,7 @@ public class Grid<T> extends Composite implements
      * // Set a common footer for &quot;Column1&quot; and &quot;Column2&quot;
      * column12.setFooter(&quot;Column 1&amp;2&quot;);
      * </pre>
-     *
+     * 
      * @return a column group row instance you can use to add column groups
      */
     public ColumnGroupRow<T> addColumnGroupRow() {
@@ -1327,10 +1369,10 @@ public class Grid<T> extends Composite implements
 
     /**
      * Adds a new column group row to the grid at a specific index.
-     *
+     * 
      * @see #addColumnGroupRow() {@link Grid#addColumnGroupRow()} for example
      *      usage
-     *
+     * 
      * @param rowIndex
      *            the index where the column group row should be added
      * @return a column group row instance you can use to add column groups
@@ -1345,7 +1387,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Removes a column group row
-     *
+     * 
      * @param row
      *            The row to remove
      */
@@ -1357,9 +1399,9 @@ public class Grid<T> extends Composite implements
 
     /**
      * Get the column group rows
-     *
+     * 
      * @return a unmodifiable list of column group rows
-     *
+     * 
      */
     public List<ColumnGroupRow<T>> getColumnGroupRows() {
         return Collections.unmodifiableList(new ArrayList<ColumnGroupRow<T>>(
@@ -1368,7 +1410,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Returns the column group for a row and column
-     *
+     * 
      * @param row
      *            The row of the column
      * @param column
@@ -1392,7 +1434,7 @@ public class Grid<T> extends Composite implements
      * <p>
      * <em>Note:</em> This method will change the widget's size in the browser
      * only if {@link #getHeightMode()} returns {@link HeightMode#CSS}.
-     *
+     * 
      * @see #setHeightMode(HeightMode)
      */
     @Override
@@ -1407,7 +1449,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Sets the data source used by this grid.
-     *
+     * 
      * @param dataSource
      *            the data source to use, not null
      * @throws IllegalArgumentException
@@ -1460,7 +1502,7 @@ public class Grid<T> extends Composite implements
      * <p>
      * All columns up to and including the given column will be frozen in place
      * when the grid is scrolled sideways.
-     *
+     * 
      * @param lastFrozenColumn
      *            the rightmost column to freeze, or <code>null</code> to not
      *            have any columns frozen
@@ -1493,7 +1535,7 @@ public class Grid<T> extends Composite implements
      * <em>Note:</em> Most usually, this method returns the very value set with
      * {@link #setLastFrozenColumn(GridColumn)}. This value, however, can be
      * reset to <code>null</code> if the column is removed from this grid.
-     *
+     * 
      * @return the rightmost frozen column in the grid, or <code>null</code> if
      *         no columns are frozen.
      */
@@ -1513,7 +1555,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Scrolls to a certain row, using {@link ScrollDestination#ANY}.
-     *
+     * 
      * @param rowIndex
      *            zero-based index of the row to scroll to.
      * @throws IllegalArgumentException
@@ -1527,7 +1569,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Scrolls to a certain row, using user-specified scroll destination.
-     *
+     * 
      * @param rowIndex
      *            zero-based index of the row to scroll to.
      * @param destination
@@ -1546,7 +1588,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Scrolls to a certain row using only user-specified parameters.
-     *
+     * 
      * @param rowIndex
      *            zero-based index of the row to scroll to.
      * @param destination
@@ -1603,7 +1645,7 @@ public class Grid<T> extends Composite implements
      * <p>
      * If Grid is currently not in {@link HeightMode#ROW}, the given value is
      * remembered, and applied once the mode is applied.
-     *
+     * 
      * @param rows
      *            The height in terms of number of rows displayed in Grid's
      *            body. If Grid doesn't contain enough rows, white space is
@@ -1615,7 +1657,7 @@ public class Grid<T> extends Composite implements
      *             infinite}
      * @throws IllegalArgumentException
      *             if {@code rows} is {@link Double#isNaN(double) NaN}
-     *
+     * 
      * @see #setHeightMode(HeightMode)
      */
     public void setHeightByRows(double rows) throws IllegalArgumentException {
@@ -1627,7 +1669,7 @@ public class Grid<T> extends Composite implements
      * {@link #getHeightMode()} is {@link HeightMode#ROW}.
      * <p>
      * By default, it is {@value Escalator#DEFAULT_HEIGHT_BY_ROWS}.
-     *
+     * 
      * @return the amount of rows that should be shown in Grid's body, while in
      *         {@link HeightMode#ROW}.
      * @see #setHeightByRows(double)
@@ -1647,7 +1689,7 @@ public class Grid<T> extends Composite implements
      * <em>Note:</em> If headers/footers are inserted or removed, the widget
      * will resize itself to still display the required amount of rows in its
      * body. It also takes the horizontal scrollbar into account.
-     *
+     * 
      * @param heightMode
      *            the mode in to which Grid should be set
      */
@@ -1669,7 +1711,7 @@ public class Grid<T> extends Composite implements
      * Returns the current {@link HeightMode} the Grid is in.
      * <p>
      * Defaults to {@link HeightMode#CSS}.
-     *
+     * 
      * @return the current HeightMode
      */
     public HeightMode getHeightMode() {
@@ -1832,7 +1874,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Accesses the package private method Widget#setParent()
-     *
+     * 
      * @param widget
      *            The widget to access
      * @param parent
@@ -1845,7 +1887,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Sets the current selection model.
-     *
+     * 
      * @param selectionModel
      *            a selection model implementation.
      * @throws IllegalArgumentException
@@ -1863,7 +1905,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Gets a reference to the current selection model.
-     *
+     * 
      * @return the currently used SelectionModel instance.
      */
     public SelectionModel<T> getSelectionModel() {
@@ -1874,7 +1916,7 @@ public class Grid<T> extends Composite implements
      * Sets current selection mode.
      * <p>
      * This is a shorthand method for {@link Grid#setSelectionModel}.
-     *
+     * 
      * @param mode
      *            a selection mode value
      * @see {@link SelectionMode}.
@@ -1886,7 +1928,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Test if a row is selected.
-     *
+     * 
      * @param row
      *            a row object
      * @return true, if the current selection model considers the provided row
@@ -1902,7 +1944,7 @@ public class Grid<T> extends Composite implements
      * Only selection models implementing {@link SelectionModel.Single} and
      * {@link SelectionModel.Multi} are supported; for anything else, an
      * exception will be thrown.
-     *
+     * 
      * @param row
      *            a row object
      * @return <code>true</code> iff the current selection changed
@@ -1927,7 +1969,7 @@ public class Grid<T> extends Composite implements
      * Only selection models implementing {@link SelectionModel.Single} and
      * {@link SelectionModel.Multi} are supported; for anything else, an
      * exception will be thrown.
-     *
+     * 
      * @param row
      *            a row object
      * @return <code>true</code> iff the current selection changed
@@ -1952,7 +1994,7 @@ public class Grid<T> extends Composite implements
      * Only selection models implementing {@link SelectionModel.Single} are
      * valid for this method; for anything else, use the
      * {@link Grid#getSelectedRows()} method.
-     *
+     * 
      * @return a selected row reference, or null, if no row is selected
      * @throws IllegalStateException
      *             if the current selection model is not an instance of
@@ -1969,7 +2011,7 @@ public class Grid<T> extends Composite implements
 
     /**
      * Gets currently selected rows from the current selection model.
-     *
+     * 
      * @return a non-null collection containing all currently selected rows.
      */
     public Collection<T> getSelectedRows() {
diff --git a/client/src/com/vaadin/client/ui/grid/renderers/ComplexRenderer.java b/client/src/com/vaadin/client/ui/grid/renderers/ComplexRenderer.java
index cf3e43c88a..289f3809be 100644
--- a/client/src/com/vaadin/client/ui/grid/renderers/ComplexRenderer.java
+++ b/client/src/com/vaadin/client/ui/grid/renderers/ComplexRenderer.java
@@ -17,7 +17,10 @@ package com.vaadin.client.ui.grid.renderers;
 
 import java.util.Collection;
 
+import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.NativeEvent;
+import com.google.gwt.dom.client.Node;
+import com.google.gwt.dom.client.Style.Visibility;
 import com.vaadin.client.ui.grid.Cell;
 import com.vaadin.client.ui.grid.FlyweightCell;
 import com.vaadin.client.ui.grid.Renderer;
@@ -96,18 +99,33 @@ public abstract class ComplexRenderer<T> implements Renderer<T> {
     }
 
     /**
-     * Hides content by setting visibility: hidden to all elements inside the
-     * cell. Text nodes are left as is for now - renderers that add such to the
-     * root element need to implement explicit support hiding them
+     * Used by Grid to toggle whether to show actual data or just an empty
+     * placeholder while data is loading. This method is invoked whenever a cell
+     * changes between data being available and data missing.
+     * <p>
+     * Default implementation hides content by setting visibility: hidden to all
+     * elements inside the cell. Text nodes are left as is - renderers that add
+     * such to the root element need to implement explicit support hiding them.
      * 
      * @param cell
      *            The cell
-     * @param visible
-     *            Is the cell content be visible
-     * @return <code>true</code> if the content should be set visible
+     * @param hasData
+     *            Has the cell content been loaded from the data source
+     * 
      */
-    public boolean setContentVisible(FlyweightCell cell, boolean visible) {
-        return false;
+    public void setContentVisible(FlyweightCell cell, boolean hasData) {
+        Element cellElement = cell.getElement();
+        for (int n = 0; n < cellElement.getChildCount(); n++) {
+            Node node = cellElement.getChild(n);
+            if (Element.is(node)) {
+                Element e = Element.as(node);
+                if (hasData) {
+                    e.getStyle().clearVisibility();
+                } else {
+                    e.getStyle().setVisibility(Visibility.HIDDEN);
+                }
+            }
+        }
     }
 
     /**
diff --git a/shared/src/com/vaadin/shared/ui/grid/GridConstants.java b/shared/src/com/vaadin/shared/ui/grid/GridConstants.java
index d5fdd40120..8b264bf426 100644
--- a/shared/src/com/vaadin/shared/ui/grid/GridConstants.java
+++ b/shared/src/com/vaadin/shared/ui/grid/GridConstants.java
@@ -31,5 +31,4 @@ public final class GridConstants implements Serializable {
      * explicitly defined padding value.
      */
     public static final int DEFAULT_PADDING = 0;
-
 }
diff --git a/uitest/src/com/vaadin/tests/components/grid/GridClientRenderers.java b/uitest/src/com/vaadin/tests/components/grid/GridClientRenderers.java
index 2e1a9ab4a7..2f14ccf3f3 100644
--- a/uitest/src/com/vaadin/tests/components/grid/GridClientRenderers.java
+++ b/uitest/src/com/vaadin/tests/components/grid/GridClientRenderers.java
@@ -16,6 +16,7 @@
 package com.vaadin.tests.components.grid;
 
 import static org.junit.Assert.assertEquals;
+import junit.framework.Assert;
 
 import org.junit.Test;
 import org.openqa.selenium.Alert;
@@ -38,15 +39,31 @@ import com.vaadin.tests.widgetset.server.grid.GridClientColumnRenderers;
  */
 public class GridClientRenderers extends MultiBrowserTest {
 
+    private int latency = 0;
+
     @Override
     protected Class<?> getUIClass() {
         return GridClientColumnRenderers.class;
     }
 
+    @Override
+    protected String getDeploymentPath() {
+        if (latency > 0) {
+            return super.getDeploymentPath() + "?latency=" + latency;
+        }
+        return super.getDeploymentPath();
+    }
+
     @ServerClass("com.vaadin.tests.widgetset.server.grid.GridClientColumnRenderers.GridController")
     public static class MyClientGridElement extends GridElement {
     }
 
+    @Override
+    public void setup() throws Exception {
+        latency = 0; // reset
+        super.setup();
+    }
+
     @Test
     public void addWidgetRenderer() throws Exception {
         openTestURL();
@@ -88,7 +105,60 @@ public class GridClientRenderers extends MultiBrowserTest {
         assertEquals(alert.getText(), "Click");
     }
 
+    @Test
+    public void rowsWithDataHasStyleName() throws Exception {
+
+        // Simulate network latency with 1000ms
+        latency = 1000;
+
+        openTestURL();
+
+        TestBenchElement row = getGrid().getRow(1);
+        String className = row.getAttribute("class");
+        Assert.assertFalse(className.contains("v-grid-row-has-data"));
+
+        // Wait for data to arrive
+        sleep(3000);
+
+        row = getGrid().getRow(1);
+        className = row.getAttribute("class");
+        Assert.assertTrue(className.contains("v-grid-row-has-data"));
+    }
+
+    @Test
+    public void complexRendererSetVisibleContent() throws Exception {
+
+        // Simulate network latency with 1000ms
+        latency = 1000;
+
+        openTestURL();
+
+        addColumn(Renderers.CPLX_RENDERER);
+
+        // Fetch data
+        getGrid().scrollToRow(50);
+
+        // Cell should be red (setContentVisible set cell red)
+        String backgroundColor = getGrid().getCell(1, 1).getCssValue(
+                "backgroundColor");
+        assertEquals("rgba(255, 0, 0, 1)", backgroundColor);
+
+        // Wait for data to arrive
+        sleep(3000);
+
+        // Cell should no longer be red
+        backgroundColor = getGrid().getCell(1, 1)
+                .getCssValue("backgroundColor");
+        assertEquals("rgba(255, 255, 255, 1)", backgroundColor);
+    }
+
     private GridElement getGrid() {
         return $(MyClientGridElement.class).first();
     }
+
+    private void addColumn(Renderers renderer) {
+        // Add widget renderer column
+        $(NativeSelectElement.class).first().selectByText(renderer.toString());
+        $(NativeButtonElement.class).caption("Add").first().click();
+    }
 }
diff --git a/uitest/src/com/vaadin/tests/widgetset/client/grid/GridClientColumnRendererConnector.java b/uitest/src/com/vaadin/tests/widgetset/client/grid/GridClientColumnRendererConnector.java
index a4403f54fc..e4d8042605 100644
--- a/uitest/src/com/vaadin/tests/widgetset/client/grid/GridClientColumnRendererConnector.java
+++ b/uitest/src/com/vaadin/tests/widgetset/client/grid/GridClientColumnRendererConnector.java
@@ -21,15 +21,20 @@ import java.util.List;
 
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.Window;
+import com.google.gwt.user.client.Window.Location;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.HasWidgets;
+import com.vaadin.client.data.DataChangeHandler;
+import com.vaadin.client.data.DataSource;
 import com.vaadin.client.ui.AbstractComponentConnector;
 import com.vaadin.client.ui.grid.FlyweightCell;
 import com.vaadin.client.ui.grid.Grid;
 import com.vaadin.client.ui.grid.GridColumn;
 import com.vaadin.client.ui.grid.Renderer;
 import com.vaadin.client.ui.grid.datasources.ListDataSource;
+import com.vaadin.client.ui.grid.renderers.ComplexRenderer;
 import com.vaadin.client.ui.grid.renderers.DateRenderer;
 import com.vaadin.client.ui.grid.renderers.HtmlRenderer;
 import com.vaadin.client.ui.grid.renderers.NumberRenderer;
@@ -43,7 +48,57 @@ public class GridClientColumnRendererConnector extends
         AbstractComponentConnector {
 
     public static enum Renderers {
-        TEXT_RENDERER, WIDGET_RENDERER, HTML_RENDERER, NUMBER_RENDERER, DATE_RENDERER;
+        TEXT_RENDERER, WIDGET_RENDERER, HTML_RENDERER, NUMBER_RENDERER, DATE_RENDERER, CPLX_RENDERER;
+    }
+
+    /**
+     * Datasource for simulating network latency
+     */
+    private class DelayedDataSource implements DataSource<String> {
+
+        private DataSource<String> ds;
+        private int firstRowIndex;
+        private int numberOfRows;
+        private DataChangeHandler dataChangeHandler;
+        private int latency;
+
+        public DelayedDataSource(DataSource<String> ds, int latency) {
+            this.ds = ds;
+            this.latency = latency;
+        }
+
+        @Override
+        public void ensureAvailability(final int firstRowIndex,
+                final int numberOfRows) {
+            new Timer() {
+
+                @Override
+                public void run() {
+                    DelayedDataSource.this.firstRowIndex = firstRowIndex;
+                    DelayedDataSource.this.numberOfRows = numberOfRows;
+                    dataChangeHandler.dataUpdated(firstRowIndex, numberOfRows);
+                }
+            }.schedule(latency);
+        }
+
+        @Override
+        public String getRow(int rowIndex) {
+            if (rowIndex >= firstRowIndex
+                    && rowIndex <= firstRowIndex + numberOfRows) {
+                return ds.getRow(rowIndex);
+            }
+            return null;
+        }
+
+        @Override
+        public int getEstimatedSize() {
+            return ds.getEstimatedSize();
+        }
+
+        @Override
+        public void setDataChangeHandler(DataChangeHandler dataChangeHandler) {
+            this.dataChangeHandler = dataChangeHandler;
+        }
     }
 
     @Override
@@ -58,7 +113,13 @@ public class GridClientColumnRendererConnector extends
         }
 
         // Provide data as data source
-        grid.setDataSource(new ListDataSource<String>(columnData));
+        if (Location.getParameter("latency") != null) {
+            grid.setDataSource(new DelayedDataSource(
+                    new ListDataSource<String>(columnData), Integer
+                            .parseInt(Location.getParameter("latency"))));
+        } else {
+            grid.setDataSource(new ListDataSource<String>(columnData));
+        }
 
         // Add a column to display the data in
         grid.addColumn(createColumnWithRenderer(Renderers.TEXT_RENDERER));
@@ -141,6 +202,27 @@ public class GridClientColumnRendererConnector extends
         case DATE_RENDERER:
             return new DateRenderer();
 
+        case CPLX_RENDERER:
+            return new ComplexRenderer<String>() {
+
+                @Override
+                public void render(FlyweightCell cell, String data) {
+                    cell.getElement().setInnerHTML("<span>" + data + "</span>");
+                    cell.getElement().getStyle().clearBackgroundColor();
+                }
+
+                @Override
+                public void setContentVisible(FlyweightCell cell,
+                        boolean hasData) {
+
+                    // Visualize content visible property
+                    cell.getElement().getStyle()
+                            .setBackgroundColor(hasData ? "green" : "red");
+
+                    super.setContentVisible(cell, hasData);
+                }
+            };
+
         default:
             return new TextRenderer();
         }