Bug 434750 - Bad performance with equal row-header text

Improve performance with Thomas Schindl patch in Grid.setItemCount

Change-Id: I2699a4602d1600edb9b2d3cae20eb46ab9b2fde9
Signed-off-by: mpaturzo <caosmpz@yahoo.it>

examples/org.eclipse.nebula.snippets/src/org/eclipse/nebula/snippets/grid/viewer/GridVirtualTableViewer.java

@@ -11,13 +11,18 @@
  *     Mirko Paturzo - realize example
  *******************************************************************************/
 
-import org.eclipse.jface.viewers.ILazyContentProvider;
+import org.eclipse.jface.viewers.IStructuredContentProvider;
 import org.eclipse.jface.viewers.LabelProvider;
 import org.eclipse.jface.viewers.Viewer;
+import org.eclipse.jface.viewers.ViewerFilter;
 import org.eclipse.nebula.jface.gridviewer.GridTableViewer;
 import org.eclipse.nebula.widgets.grid.GridColumn;
 import org.eclipse.swt.SWT;
-import org.eclipse.swt.layout.FillLayout;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.events.SelectionListener;
+import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.layout.GridLayout;
+import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 
@@ -28,27 +33,28 @@
 public class GridVirtualTableViewer {
 
 	private static final int ROWS = 1000000;
-	private static final int COLUMNS = 1000;
+	private static final int COLUMNS = 10;
 
-	private class MyLazyContentProvider implements ILazyContentProvider {
-		  private final GridTableViewer viewer;
-		  private MyModel[] elements;
-
-		  public MyLazyContentProvider(GridTableViewer viewer) {
-		    this.viewer = viewer;
-		  }
-
-		  public void dispose() {
-		  }
+	private class MyContentProvider implements IStructuredContentProvider {
+		public MyContentProvider(GridTableViewer viewer) {
+
+		}
+		public void dispose() {
+			// TODO Auto-generated method stub
+
+		}
 
-		  public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
-		    this.elements = (MyModel[]) newInput;
-		  }
+		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
+			// TODO Auto-generated method stub
+
+		}
 
-		  public void updateElement(int index) {
-		    viewer.replace(elements[index], index);
-		  }
-		} 
+		public Object[] getElements(Object inputElement) {
+			return (Object[]) inputElement;
+		}
+
+	}
+
 	public class MyModel {
 		public int counter;
 
@@ -67,20 +73,45 @@ public GridVirtualTableViewer(Shell shell) {
 		final GridTableViewer v = new GridTableViewer(shell, SWT.V_SCROLL | SWT.H_SCROLL | SWT.VIRTUAL);
 
 		v.setLabelProvider(labelProvider);
-		v.setContentProvider(new MyLazyContentProvider(v));
+		v.setContentProvider(new MyContentProvider(v));
 		v.setUseHashlookup(true);
+		v.getGrid().setLinesVisible(true);
+		v.getGrid().setHeaderVisible(true);
+		v.getGrid().setVisibleLinesColumnPack(true);
+//		v.getGrid().setRowHeaderVisible(true);
+//		v.setRowHeaderLabelProvider(new ColumnLabelProvider() {
+//			@Override
+//			public String getText(Object element) {
+//				return "xyz";
+//			}
+//		});
+		v.getGrid().setLayoutData(new GridData(GridData.FILL_BOTH));
+
 		for (int i = 0; i < COLUMNS; i++)
 		{
 			createColumn(v, "Column");
 		}
 
 		MyModel[] model = createModel();
 		v.setInput(model);
-		v.getGrid().setItemCount(model.length);
-
-		v.getGrid().setLinesVisible(true);
-		v.getGrid().setHeaderVisible(true);
-		v.getGrid().setVisibleLinesColumnPack(true);
+
+		Button b = new Button(shell, SWT.PUSH);
+		b.setText("Filter items without 0");
+		b.addSelectionListener(new SelectionListener() {
+
+			public void widgetSelected(SelectionEvent arg0) {
+				v.addFilter(new ViewerFilter() {
+
+					@Override
+					public boolean select(Viewer viewer, Object parentElement, Object element) {
+						return element.toString().contains("0");
+					}
+				});
+			}
+
+			public void widgetDefaultSelected(SelectionEvent arg0) {
+			}
+		});
 	}
 	private void createColumn(final GridTableViewer v, String name) {
 		GridColumn column = new GridColumn(v.getGrid(), SWT.NONE);
@@ -103,7 +134,7 @@ private MyModel[] createModel() {
 	public static void main(String[] args) {
 		Display display = new Display();
 		Shell shell = new Shell(display);
-		shell.setLayout(new FillLayout());
+		shell.setLayout(new GridLayout());
 		new GridVirtualTableViewer(shell);
 		shell.open();
 

widgets/grid/org.eclipse.nebula.widgets.grid/src/org/eclipse/nebula/widgets/grid/Grid.java

@@ -714,7 +714,7 @@ public void clearItems() {
 	private boolean autoHeight = false;
 	private boolean autoWidth = true;
 	private boolean wordWrapRowHeader = false;
-
+	
 	private final DataVisualizer dataVisualizer;
 
 	private Listener defaultKeyListener;
@@ -7646,6 +7646,7 @@ else if (!root) {
 	 * @param item item to remove
 	 */
 	void removeItem(GridItem item) {
+
 		Point[] cells = getCells(item);
 		boolean selectionModified = false;
 
@@ -7684,12 +7685,13 @@ void removeItem(GridItem item) {
 		if (selectionModified && !disposing) {
 			updateColumnSelection();
 		}
-
+		
 		redraw();
 		// Need to update the scrollbars see see 375327
 		updateScrollbars();
 	}
 
+
 	/**
 	 * Creates the given column group at the given index. This method is only
 	 * called from the {@code GridColumnGroup}'s constructor.
@@ -8890,7 +8892,7 @@ public void setItemHeaderWidth(int width) {
 		setAutoWidth(false);
 		redraw();
 	}
-
+	
 	/**
 	 * Sets the number of items contained in the receiver.
 	 *
@@ -8910,9 +8912,23 @@ public void setItemCount(int count) {
 
 		if (count < items.size()) {
 
+			selectedCells.clear();
 			for(int i = items.size() - 1; i >= count; i--){
-				items.get(i).dispose();
+				GridItem removed = items.remove(i);
+				rootItems.remove(i);
+
+				selectedItems.remove(removed);
+
+				if(removed.isVisible())
+					currentVisibleItems--;
+				removed.disposeOnly();
+			}
+			if (!disposing) {
+				updateColumnSelection();
 			}
+			scrollValuesObsolete = true;
+			topIndex = -1;
+			bottomIndex = -1;
 		}
 
 		while (count > items.size()) {