ecommons.waltable/org.eclipse.statet.ecommons.waltable.core/src/org/eclipse/statet/ecommons/waltable/freeze/FreezeHelper.java

/*=============================================================================#
 # Copyright (c) 2012, 2021 Dirk Fauth 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:
 #     Dirk Fauth <dirk.fauth@gmail.com> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.waltable.freeze;

import static org.eclipse.statet.ecommons.waltable.coordinate.Orientation.HORIZONTAL;
import static org.eclipse.statet.ecommons.waltable.coordinate.Orientation.VERTICAL;

import org.eclipse.statet.ecommons.waltable.coordinate.Orientation;
import org.eclipse.statet.ecommons.waltable.coordinate.PositionCoordinate;
import org.eclipse.statet.ecommons.waltable.freeze.FreezeLayer.Dim;
import org.eclipse.statet.ecommons.waltable.viewport.ViewportLayer;


/**
 * Helper class to deal with freeze and unfreeze of a NatTable.
 * 
 * <p>This class is intended for internal use only. Consider using the
 * appropriate commands instead of using this helper directly.
 * 
 * @see FreezeDimPositionCommand
 * @see FreezeRowCommand
 * @see FreezeCellPositionCommand
 * @see FreezeSelectionCommand
 * @see UnFreezeGridCommand
 */
public class FreezeHelper {
	
	/**
	 * Freezes the grid at the specified position.
	 * This method is for internal use. Consider using the appropriate commands
	 * on the NatTable instead to freeze the grid programmatically.
	 * 
	 * @param freezeLayer The FreezeLayer of the grid to perform the freeze action.
	 * @param viewportLayer The ViewportLayer of the grid to perform the freeze action.
	 * @param topLeftPosition The top left position of the freeze area
	 * @param bottomRightPosition The bottom right position of the freeze area
	 * 
	 * @see FreezeDimPositionCommand
	 * @see FreezeRowCommand
	 * @see FreezeCellPositionCommand
	 * @see FreezeSelectionCommand
	 */
	public static void freeze(final FreezeLayer freezeLayer, final ViewportLayer viewportLayer, 
			final PositionCoordinate topLeftPosition, final PositionCoordinate bottomRightPosition) {
		
		if (freezeLayer == null || viewportLayer == null) {
			throw new IllegalArgumentException("freezeLayer and viewportLayer can not be null!"); //$NON-NLS-1$
		}
		
		if (topLeftPosition != null && bottomRightPosition != null) {
			freezeLayer.setFreeze(topLeftPosition.columnPosition, topLeftPosition.rowPosition,
					bottomRightPosition.columnPosition, bottomRightPosition.rowPosition );
			
			viewportLayer.getDim(HORIZONTAL).setMinimumOriginPosition(bottomRightPosition.columnPosition + 1);
			viewportLayer.getDim(VERTICAL).setMinimumOriginPosition(bottomRightPosition.rowPosition + 1);
			
			viewportLayer.fireLayerEvent(new FreezeEvent(viewportLayer));
		}
	}
	
	/**
	 * Unfreezes the grid at the specified position.
	 * This method is for internal use. Consider using the appropriate command
	 * on the NatTable instead to unfreeze the grid programmatically.
	 * 
	 * @param freezeLayer The FreezeLayer of the grid to perform the freeze action.
	 * @param viewportLayer The ViewportLayer of the grid to perform the freeze action.
	 * 
	 * @see UnFreezeGridCommand
	 */
	public static void unfreeze(final FreezeLayer freezeLayer, final ViewportLayer viewportLayer) {
		if (freezeLayer == null || viewportLayer == null) {
			throw new IllegalArgumentException("freezeLayer and viewportLayer can not be null!"); //$NON-NLS-1$
		}
		
		resetViewport(freezeLayer, viewportLayer);
		
		viewportLayer.fireLayerEvent(new UnfreezeEvent(viewportLayer));
	}
	
	/**
	 * Helper method to reset the origin coordinates of the viewport. Is needed to perform an 
	 * unfreeze or to override a current frozen state.
	 * @param freezeLayer The FreezeLayer of the grid to perform the freeze action.
	 * @param viewportLayer The ViewportLayer of the grid to perform the freeze action.
	 */
	public static void resetViewport(final FreezeLayer freezeLayer, final ViewportLayer viewportLayer) {
		for (final Orientation orientation : Orientation.values()) {
			if (freezeLayer.isFrozen()) {
				final Dim freezeDim= freezeLayer.get(orientation);
				
				final long position= freezeDim.getStartPosition();
				freezeDim.setFreeze(0, 0);
				viewportLayer.getDim(orientation).reset(position);
			}
		}
	}
	
}