ecommons.waltable/org.eclipse.statet.ecommons.waltable.core/src/org/eclipse/statet/ecommons/waltable/tickupdate/ITickUpdateHandler.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.tickupdate;


/**
 * Interface for handler that is responsible for handling tick updates.
 * Will return information about which type of objects it can handle and
 * will do the increment/decrement calculation. Also specifies the default
 * implementation that can handle {@link Number} values.
 */
public interface ITickUpdateHandler {
	
	/**
	 * Checks if the given object can be handled by this handler.
	 * Usually it will simply perform a instanceof check.
	 * @param value The value to check.
	 * @return <code>true</code> if this handler is able to perform
	 * 			tick updates on the given value, <code>false</code> 
	 * 			if not.
	 */
	boolean isApplicableFor(Object value);
	
	/**
	 * Perform an increment of the current value by a default value.
	 * @param currentValue The value to perform the increment on.
	 * @return The new value after increment it by a default value.
	 */
	public Object getIncrementedValue(Object currentValue);
	
	/**
	 * Perform an increment of the current value by the given increment value.
	 * @param currentValue The value to perform the increment on.
	 * @param incrementSize The value the currentValue should be incremented by.
	 * @return The new value after increment it by the specified value.
	 */
	public Object getIncrementedValue(Object currentValue, double incrementSize);

	/**
	 * Perform an decrement of the current value by a default value.
	 * @param currentValue The value to perform the decrement on.
	 * @return The new value after decrement it by a default value.
	 */
	public Object getDecrementedValue(Object currentValue);
	
	/**
	 * Perform an decrement of the current value by the given decrement value.
	 * @param currentValue The value to perform the decrement on.
	 * @param decrementSize The value the currentValue should be decremented by.
	 * @return The new value after decrement it by the specified value.
	 */
	public Object getDecrementedValue(Object currentValue, double decrementSize);

	/**
	 * The default implementation of {@link ITickUpdateHandler} that handles {@link Byte}, {@link Short}, 
	 * {@link Integer}, {@link Long}, {@link Double} and {@link Float} values.
	 */
	ITickUpdateHandler DEFAULT_TICK_UPDATE_HANDLER= new ITickUpdateHandler() {

		@Override
		public boolean isApplicableFor(final Object value) {
			return (value instanceof Byte
					 || value instanceof Short
					 || value instanceof Integer
					 || value instanceof Long
					 || value instanceof Double
					 || value instanceof Float);
		}
		
		@Override
		public Object getIncrementedValue(final Object currentValue) {
		    return getIncrementedValue(currentValue, 1);
		}

		@Override
		public Object getIncrementedValue(final Object currentValue, final double incrementSize) {
			if (currentValue instanceof Byte) {
				return Integer.valueOf(((Byte)currentValue) + Double.valueOf(Math.abs(incrementSize)).byteValue()).byteValue();
			}
			if (currentValue instanceof Short) {
				return Integer.valueOf(((Integer)currentValue) + Double.valueOf(Math.abs(incrementSize)).intValue());
			}
			if (currentValue instanceof Integer) {
				return Integer.valueOf(((Integer)currentValue) + Double.valueOf(Math.abs(incrementSize)).intValue());
			}
			if (currentValue instanceof Long) {
				return Long.valueOf(((Long)currentValue) + Double.valueOf(Math.abs(incrementSize)).longValue());
			}
			if (currentValue instanceof Double) {
				return Double.valueOf(((Double)currentValue) + Math.abs(incrementSize));
			}
			if (currentValue instanceof Float) {
				return Float.valueOf(((Float)currentValue) + Double.valueOf(Math.abs(incrementSize)).floatValue());
			}
			return currentValue;
		}
		
		@Override
		public Object getDecrementedValue(final Object currentValue) {
		    return getDecrementedValue(currentValue, 1);
		}

		@Override
        public Object getDecrementedValue(final Object currentValue, final double decrementSize) {
			if (currentValue instanceof Byte) {
				return Integer.valueOf(((Byte)currentValue) - Double.valueOf(Math.abs(decrementSize)).byteValue()).byteValue();
			}
			if (currentValue instanceof Short) {
				return Integer.valueOf(((Integer)currentValue) - Double.valueOf(Math.abs(decrementSize)).intValue());
			}
			if (currentValue instanceof Integer) {
				return Integer.valueOf(((Integer)currentValue) - Double.valueOf(Math.abs(decrementSize)).intValue());
			}
			if (currentValue instanceof Long) {
				return Long.valueOf(((Long)currentValue) - Double.valueOf(Math.abs(decrementSize)).longValue());
			}
			if (currentValue instanceof Double) {
				return Double.valueOf(((Double)currentValue) - Math.abs(decrementSize));
			}
			if (currentValue instanceof Float) {
				return Float.valueOf(((Float)currentValue) - Double.valueOf(Math.abs(decrementSize)).floatValue());
			}
			return currentValue;
        }
		
	};

}