InputProcessor.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * 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.
 ******************************************************************************/

package com.badlogic.gdx;

import com.badlogic.gdx.Input.Buttons;

/**
 * An InputProcessor is used to receive input events from the keyboard and the touch screen (mouse on the desktop). For
 * this it has to be registered with the {@link Input#setInputProcessor(InputProcessor)} method. It will be called each
 * frame before the call to {@link ApplicationListener#render()}. The methods return a* boolean in case you want to
 * write a multiplexing InputProcessor that has a chain of child processors that signal whether they processed the
 * event. The {@link InputMultiplexer} offers you exactly this functionality.
 * 
 * @author badlogicgames@gmail.com
 */
public interface InputProcessor {
	/**
	 * Called when a key was pressed
	 * 
	 * @param keycode
	 *            one of the constants in {@link Input.Keys}
	 * @return whether the input was processed
	 */
	public boolean keyDown(int keycode);

	/**
	 * Called when a key was released
	 * 
	 * @param keycode
	 *            one of the constants in {@link Input.Keys}
	 * @return whether the input was processed
	 */
	public boolean keyUp(int keycode);

	/**
	 * Called when a key was typed
	 * 
	 * @param character
	 *            The character
	 * @return whether the input was processed
	 */
	public boolean keyTyped(char character);

	/**
	 * Called when the screen was touched or a mouse button was pressed. The button parameter will be
	 * {@link Buttons#LEFT} on Android.
	 * 
	 * @param screenX
	 *            The x coordinate, origin is in the upper left corner
	 * @param screenY
	 *            The y coordinate, origin is in the upper left corner
	 * @param pointer
	 *            the pointer for the event.
	 * @param button
	 *            the button
	 * @return whether the input was processed
	 */
	public boolean touchDown(int screenX, int screenY, int pointer, int button);

	/**
	 * Called when a finger was lifted or a mouse button was released. The button parameter will be {@link Buttons#LEFT}
	 * on Android.
	 * 
	 * @param pointer
	 *            the pointer for the event.
	 * @param button
	 *            the button
	 * @return whether the input was processed
	 */
	public boolean touchUp(int screenX, int screenY, int pointer, int button);

	/**
	 * Called when a finger or the mouse was dragged.
	 * 
	 * @param pointer
	 *            the pointer for the event.
	 * @return whether the input was processed
	 */
	public boolean touchDragged(int screenX, int screenY, int pointer);

	/**
	 * Called when the mouse was moved without any buttons being pressed. Will not be called on Android.
	 * 
	 * @return whether the input was processed
	 */
	public boolean mouseMoved(int screenX, int screenY);

	/**
	 * Called when the mouse wheel was scrolled. Will not be called on Android.
	 * 
	 * @param amount
	 *            the scroll amount, -1 or 1 depending on the direction the wheel was scrolled.
	 * @return whether the input was processed.
	 */
	public boolean scrolled(int amount);
}