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

/*=============================================================================#
 # Copyright (c) 2012, 2020 Original NatTable 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 NatTable authors and others - initial API and implementation
 #=============================================================================*/

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

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

import org.eclipse.statet.ecommons.waltable.command.AbstractLayerCommandHandler;
import org.eclipse.statet.ecommons.waltable.coordinate.PositionCoordinate;
import org.eclipse.statet.ecommons.waltable.selection.SelectionLayer;
import org.eclipse.statet.ecommons.waltable.viewport.ViewportLayer;


public class FreezeCommandHandler extends AbstractLayerCommandHandler<IFreezeCommand> {
	
	
	protected final FreezeLayer freezeLayer;
	
	protected final ViewportLayer viewportLayer;
	
	protected final SelectionLayer selectionLayer;
	
	
	public FreezeCommandHandler(final FreezeLayer freezeLayer, final ViewportLayer viewportLayer, final SelectionLayer selectionLayer) {
		this.freezeLayer= freezeLayer;
		this.viewportLayer= viewportLayer;
		this.selectionLayer= selectionLayer;
	}
	
	
	@Override
	public Class<IFreezeCommand> getCommandClass() {
		return IFreezeCommand.class;
	}
	
	@Override
	public boolean doCommand(final IFreezeCommand command) {
		if (command instanceof FreezeDimPositionCommand) {
			//freeze for a whole column
			final FreezeDimPositionCommand dimPositionCommand= (FreezeDimPositionCommand) command;
			final IFreezeCoordinatesProvider coordinatesProvider= (dimPositionCommand.getOrientation() == HORIZONTAL) ?
					new FreezeColumnStrategy(this.freezeLayer, dimPositionCommand.getPosition()) :
					new FreezeRowStrategy(this.freezeLayer, dimPositionCommand.getPosition());
			handleFreezeCommand(coordinatesProvider, dimPositionCommand.isToggle(), command.isOverrideFreeze());
			return true;
		} 
		else if (command instanceof FreezeCellPositionCommand) {
			//freeze for a given position
			final FreezeCellPositionCommand freezeCellPositionCommand= (FreezeCellPositionCommand) command;
			final IFreezeCoordinatesProvider coordinatesProvider= 
				new FreezePositionStrategy(this.freezeLayer, freezeCellPositionCommand.getColumnPosition(), freezeCellPositionCommand.getRowPosition());
			handleFreezeCommand(coordinatesProvider, freezeCellPositionCommand.isToggle(), command.isOverrideFreeze());
			return true;
		} 
		else if (command instanceof FreezeSelectionCommand) {
			//freeze at the current selection anchor
			final IFreezeCoordinatesProvider coordinatesProvider= 
					new FreezeSelectionStrategy(this.freezeLayer, this.viewportLayer, this.selectionLayer);
			handleFreezeCommand(coordinatesProvider, command.isToggle(), command.isOverrideFreeze());
			return true;
		} 
		else if (command instanceof UnFreezeGridCommand) {
			//unfreeze
			handleUnfreeze();
			return true;
		}
		
		return false;
	}

	/**
	 * Performs freeze actions dependent on the coordinates specified by the given 
	 * {@link IFreezeCoordinatesProvider} and the configuration flags.
	 * If a freeze state is already active it is checked if this state should be overriden
	 * or toggled. Otherwise the freeze state is applied.
	 * @param coordinatesProvider The {@link IFreezeCoordinatesProvider} to retrieve the freeze
	 * 			coordinates from
	 * @param toggle whether to unfreeze if the freeze layer is already in a frozen state
	 * @param override whether to override a current frozen state.
	 */
	protected void handleFreezeCommand(final IFreezeCoordinatesProvider coordinatesProvider, 
			final boolean toggle, final boolean override) {
		
		if (!this.freezeLayer.isFrozen() || override) {
			//if we are in a frozen state and be configured to override, reset the viewport first
			if (this.freezeLayer.isFrozen() && override) {
				FreezeHelper.resetViewport(this.freezeLayer, this.viewportLayer);
			}
			
			final PositionCoordinate topLeftPosition= coordinatesProvider.getTopLeftPosition();
			final PositionCoordinate bottomRightPosition= coordinatesProvider.getBottomRightPosition();
	
			FreezeHelper.freeze(this.freezeLayer, this.viewportLayer, topLeftPosition, bottomRightPosition);
		} 
		else if (toggle) {  
			// if frozen and toggle= true
			handleUnfreeze();
		}
	}
	
	/**
	 * Unfreeze a current frozen state.
	 */
	protected void handleUnfreeze() {
		FreezeHelper.unfreeze(this.freezeLayer, this.viewportLayer);
	}
	
}