Event.java

/**
 * Copyright 2008 - 2015 The Loon Game Engine Authors
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * 
 * @project loon
 * @author cping
 * @email：javachenpeng@yahoo.com
 * @version 0.5
 */
package loon.event;

public abstract class Event {

	public static final int F_PREVENT_DEFAULT = 1 << 0;

	protected static final int F_ALT_DOWN = 1 << 1;
	protected static final int F_CTRL_DOWN = 1 << 2;
	protected static final int F_SHIFT_DOWN = 1 << 3;
	protected static final int F_META_DOWN = 1 << 4;

	public static class Input extends Event {

		public int flags;

		public final double time;

		public boolean isAltDown() {
			return isSet(F_ALT_DOWN);
		}

		public boolean isCtrlDown() {
			return isSet(F_CTRL_DOWN);
		}

		public boolean isShiftDown() {
			return isSet(F_SHIFT_DOWN);
		}

		public boolean isMetaDown() {
			return isSet(F_META_DOWN);
		}

		public boolean isSet(int flag) {
			return (flags & flag) != 0;
		}

		public void setFlag(int flag) {
			flags |= flag;
		}

		public void clearFlag(int flag) {
			flags &= ~flag;
		}

		public void updateFlag(int flag, boolean on) {
			if (on){
				setFlag(flag);
			}
			else{
				clearFlag(flag);
			}
		}

		@Override
		public String toString() {
			StringBuilder builder = new StringBuilder(name()).append('[');
			addFields(builder);
			return builder.append(']').toString();
		}

		public static int modifierFlags(boolean altP, boolean ctrlP,
				boolean metaP, boolean shiftP) {
			int flags = 0;
			if (altP)
				flags |= F_ALT_DOWN;
			if (ctrlP)
				flags |= F_CTRL_DOWN;
			if (metaP)
				flags |= F_META_DOWN;
			if (shiftP)
				flags |= F_SHIFT_DOWN;
			return flags;
		}

		protected Input(int flags, double time) {
			this.flags = flags;
			this.time = time;
		}

		protected String name() {
			return "Input";
		}

		protected void addFields(StringBuilder builder) {
			builder.append("time=").append(time).append(", flags=")
					.append(flags);
		}
	}

	public static class XY extends Input implements loon.geom.XY {

		public final float x;

		public final float y;

		@Override
		public float getX() {
			return x;
		}

		@Override
		public float getY() {
			return y;
		}

		protected XY(int flags, double time, float x, float y) {
			super(flags, time);
			this.x = x;
			this.y = y;
		}

		@Override
		protected String name() {
			return "XY";
		}

		@Override
		protected void addFields(StringBuilder builder) {
			super.addFields(builder);
			builder.append(", x=").append(x).append(", y=").append(y);
		}
	}

}