| /******************************************************************************* |
| * Copyright (c) 2012, 2020 Original authors and others. |
| * |
| * This program and the accompanying materials are made |
| * available under the terms of the Eclipse Public License 2.0 |
| * which is available at https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * Original authors and others - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.nebula.widgets.nattable.viewport.event; |
| |
| import java.util.Collection; |
| |
| import org.eclipse.nebula.widgets.nattable.coordinate.Range; |
| import org.eclipse.nebula.widgets.nattable.layer.IUniqueIndexLayer; |
| import org.eclipse.nebula.widgets.nattable.layer.event.ILayerEventHandler; |
| import org.eclipse.nebula.widgets.nattable.layer.event.IStructuralChangeEvent; |
| import org.eclipse.nebula.widgets.nattable.layer.event.StructuralDiff; |
| import org.eclipse.nebula.widgets.nattable.layer.event.StructuralDiff.DiffTypeEnum; |
| import org.eclipse.nebula.widgets.nattable.viewport.ViewportLayer; |
| |
| public class ViewportEventHandler implements ILayerEventHandler<IStructuralChangeEvent> { |
| |
| private final ViewportLayer viewportLayer; |
| |
| public ViewportEventHandler(ViewportLayer viewportLayer) { |
| this.viewportLayer = viewportLayer; |
| } |
| |
| @Override |
| public Class<IStructuralChangeEvent> getLayerEventClass() { |
| return IStructuralChangeEvent.class; |
| } |
| |
| @Override |
| public void handleLayerEvent(IStructuralChangeEvent event) { |
| IUniqueIndexLayer scrollableLayer = this.viewportLayer.getScrollableLayer(); |
| |
| if (event.isHorizontalStructureChanged()) { |
| this.viewportLayer.invalidateHorizontalStructure(); |
| |
| int columnOffset = 0; |
| int minimumOriginColumnPosition = this.viewportLayer |
| .getMinimumOriginColumnPosition(); |
| |
| Collection<StructuralDiff> columnDiffs = event.getColumnDiffs(); |
| if (columnDiffs != null) { |
| if (minimumOriginColumnPosition < 0) { |
| // this is for handling of hide/show behaviour |
| // the value can only be -1 in case the column for which the |
| // minimum origin was set before |
| // was hidden, so we try to determine the correct value now |
| // if it is shown again |
| minimumOriginColumnPosition = scrollableLayer |
| .getColumnPositionByX(this.viewportLayer |
| .getMinimumOrigin().getX()); |
| } |
| for (StructuralDiff columnDiff : columnDiffs) { |
| DiffTypeEnum diffType = columnDiff.getDiffType(); |
| if (diffType == DiffTypeEnum.ADD) { |
| Range afterPositionRange = columnDiff |
| .getAfterPositionRange(); |
| if (minimumOriginColumnPosition > 0) { |
| for (int i = afterPositionRange.start; i < afterPositionRange.end; i++) { |
| if (i < minimumOriginColumnPosition) { |
| minimumOriginColumnPosition++; |
| } |
| } |
| } |
| } else if (diffType == DiffTypeEnum.DELETE) { |
| Range beforePositionRange = columnDiff |
| .getBeforePositionRange(); |
| if (minimumOriginColumnPosition > 0) { |
| for (int i = beforePositionRange.start; i < beforePositionRange.end; i++) { |
| if (i < minimumOriginColumnPosition) { |
| columnOffset -= 1; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| int minimumOriginColumn = minimumOriginColumnPosition |
| + columnOffset; |
| |
| // in case of split viewports we use the min column position instead |
| // of the calculated value |
| if (this.viewportLayer.getMinColumnPosition() >= 0) { |
| minimumOriginColumn = this.viewportLayer.getMinColumnPosition(); |
| } |
| |
| // if the new origin is out of range (e.g. the last column in the |
| // viewport is moved |
| // to the frozen region, the minimum origin need to be updated in |
| // another way |
| int startX = scrollableLayer |
| .getStartXOfColumnPosition(minimumOriginColumn); |
| if (startX < 0 && minimumOriginColumnPosition > 0) { |
| int columnCount = scrollableLayer.getColumnCount(); |
| if (columnCount == 0) { |
| // special case when all columns are hidden |
| startX = 0; |
| } else { |
| startX = scrollableLayer |
| .getStartXOfColumnPosition(columnCount - 1) |
| + scrollableLayer |
| .getColumnWidthByPosition(columnCount - 1); |
| } |
| } |
| |
| this.viewportLayer.setMinimumOriginX(startX); |
| } |
| |
| if (event.isVerticalStructureChanged()) { |
| this.viewportLayer.invalidateVerticalStructure(); |
| |
| int rowOffset = 0; |
| int minimumOriginRowPosition = this.viewportLayer |
| .getMinimumOriginRowPosition(); |
| |
| Collection<StructuralDiff> rowDiffs = event.getRowDiffs(); |
| if (rowDiffs != null) { |
| if (minimumOriginRowPosition < 0) { |
| // this is for handling of hide/show behaviour |
| // the value can only be -1 in case the row for which the |
| // minimum origin was set before |
| // was hidden, so we try to determine the correct value now |
| // if it is shown again |
| minimumOriginRowPosition = scrollableLayer |
| .getRowPositionByY(this.viewportLayer.getMinimumOrigin() |
| .getY()); |
| } |
| for (StructuralDiff rowDiff : rowDiffs) { |
| DiffTypeEnum diffType = rowDiff.getDiffType(); |
| if (diffType == DiffTypeEnum.ADD) { |
| Range afterPositionRange = rowDiff |
| .getAfterPositionRange(); |
| if (minimumOriginRowPosition > 0) { |
| for (int i = afterPositionRange.start; i < afterPositionRange.end; i++) { |
| if (i < minimumOriginRowPosition) { |
| minimumOriginRowPosition++; |
| } |
| } |
| } |
| } else if (diffType == DiffTypeEnum.DELETE) { |
| Range beforePositionRange = rowDiff |
| .getBeforePositionRange(); |
| if (minimumOriginRowPosition > 0) { |
| for (int i = beforePositionRange.start; i < beforePositionRange.end; i++) { |
| if (i < minimumOriginRowPosition) { |
| rowOffset -= 1; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| int minimumOriginRow = minimumOriginRowPosition + rowOffset; |
| |
| // in case of split viewports we use the min row position instead of |
| // the calculated value |
| if (this.viewportLayer.getMinRowPosition() >= 0) { |
| minimumOriginRow = this.viewportLayer.getMinRowPosition(); |
| } |
| |
| // if the new origin is out of range (e.g. the last row in the |
| // viewport is moved |
| // to the frozen region, the minimum origin need to be updated in |
| // another way |
| int startY = scrollableLayer |
| .getStartYOfRowPosition(minimumOriginRow); |
| if (startY < 0 && minimumOriginRowPosition > 0) { |
| int rowCount = scrollableLayer.getRowCount(); |
| if (rowCount == 0) { |
| // special case when all rows are hidden |
| startY = 0; |
| } else { |
| startY = scrollableLayer |
| .getStartYOfRowPosition(rowCount - 1) |
| + scrollableLayer |
| .getRowHeightByPosition(rowCount - 1); |
| } |
| } |
| this.viewportLayer.setMinimumOriginY(startY); |
| } |
| } |
| |
| } |