Bug 294303 [Markers] 'Queuing Viewer Updates' in Problems view
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
GC gc = new GC(tree);
				gc.setFont(tree.getFont());
				FontMetrics fontMetrics = gc.getFontMetrics();
				gc.dispose();
				columnWidth = Math.max(markerField.getDefaultColumnWidth(tree),
						fontMetrics.getAverageCharWidth() * 5);
			}
			if (columnWidths != null) {
				Integer value = columnWidths.getInteger(getFieldId(column
						.getColumn()));
				
				if (value != null && value.intValue() > 0)
					columnWidth = value.intValue();
			}
			
			
			if (columnWidth < 0)
				layout.addColumnData(new ColumnPixelData(markerField
						.getDefaultColumnWidth(tree), true, true));
			else
				layout.addColumnData(new ColumnPixelData(columnWidth, true));
		}
		
		if (currentColumns.length > fields.length) {
			for (int i = fields.length; i < currentColumns.length; i++) {
				currentColumns[i].dispose();
			}
		}
		viewer.getTree().setLayout(layout);