ActorGestureListener.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.scenes.scene2d.utils;

import com.badlogic.gdx.input.GestureDetector;
import com.badlogic.gdx.input.GestureDetector.GestureAdapter;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.Event;
import com.badlogic.gdx.scenes.scene2d.EventListener;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.utils.Null;

/** Detects tap, long press, fling, pan, zoom, and pinch gestures on an actor. If there is only a need to detect tap, use
 * {@link ClickListener}.
 * @see GestureDetector
 * @author Nathan Sweet */
public class ActorGestureListener implements EventListener {
	static final Vector2 tmpCoords = new Vector2(), tmpCoords2 = new Vector2();

	private final GestureDetector detector;
	InputEvent event;
	Actor actor, touchDownTarget;

	/** @see GestureDetector#GestureDetector(com.badlogic.gdx.input.GestureDetector.GestureListener) */
	public ActorGestureListener () {
		this(20, 0.4f, 1.1f, Integer.MAX_VALUE);
	}

	/** @see GestureDetector#GestureDetector(float, float, float, float, com.badlogic.gdx.input.GestureDetector.GestureListener) */
	public ActorGestureListener (float halfTapSquareSize, float tapCountInterval, float longPressDuration, float maxFlingDelay) {
		detector = new GestureDetector(halfTapSquareSize, tapCountInterval, longPressDuration, maxFlingDelay, new GestureAdapter() {
			private final Vector2 initialPointer1 = new Vector2(), initialPointer2 = new Vector2();
			private final Vector2 pointer1 = new Vector2(), pointer2 = new Vector2();

			public boolean tap (float stageX, float stageY, int count, int button) {
				actor.stageToLocalCoordinates(tmpCoords.set(stageX, stageY));
				ActorGestureListener.this.tap(event, tmpCoords.x, tmpCoords.y, count, button);
				return true;
			}

			public boolean longPress (float stageX, float stageY) {
				actor.stageToLocalCoordinates(tmpCoords.set(stageX, stageY));
				return ActorGestureListener.this.longPress(actor, tmpCoords.x, tmpCoords.y);
			}

			public boolean fling (float velocityX, float velocityY, int button) {
				stageToLocalAmount(tmpCoords.set(velocityX, velocityY));
				ActorGestureListener.this.fling(event, tmpCoords.x, tmpCoords.y, button);
				return true;
			}

			public boolean pan (float stageX, float stageY, float deltaX, float deltaY) {
				stageToLocalAmount(tmpCoords.set(deltaX, deltaY));
				deltaX = tmpCoords.x;
				deltaY = tmpCoords.y;
				actor.stageToLocalCoordinates(tmpCoords.set(stageX, stageY));
				ActorGestureListener.this.pan(event, tmpCoords.x, tmpCoords.y, deltaX, deltaY);
				return true;
			}

			public boolean panStop (float stageX, float stageY, int pointer, int button) {
				actor.stageToLocalCoordinates(tmpCoords.set(stageX, stageY));
				ActorGestureListener.this.panStop(event, tmpCoords.x, tmpCoords.y, pointer, button);
				return true;
			}

			public boolean zoom (float initialDistance, float distance) {
				ActorGestureListener.this.zoom(event, initialDistance, distance);
				return true;
			}

			public boolean pinch (Vector2 stageInitialPointer1, Vector2 stageInitialPointer2, Vector2 stagePointer1,
				Vector2 stagePointer2) {
				actor.stageToLocalCoordinates(initialPointer1.set(stageInitialPointer1));
				actor.stageToLocalCoordinates(initialPointer2.set(stageInitialPointer2));
				actor.stageToLocalCoordinates(pointer1.set(stagePointer1));
				actor.stageToLocalCoordinates(pointer2.set(stagePointer2));
				ActorGestureListener.this.pinch(event, initialPointer1, initialPointer2, pointer1, pointer2);
				return true;
			}

			private void stageToLocalAmount (Vector2 amount) {
				actor.stageToLocalCoordinates(amount);
				amount.sub(actor.stageToLocalCoordinates(tmpCoords2.set(0, 0)));
			}
		});
	}

	public boolean handle (Event e) {
		if (!(e instanceof InputEvent)) return false;
		InputEvent event = (InputEvent)e;

		switch (event.getType()) {
		case touchDown:
			actor = event.getListenerActor();
			touchDownTarget = event.getTarget();
			detector.touchDown(event.getStageX(), event.getStageY(), event.getPointer(), event.getButton());
			actor.stageToLocalCoordinates(tmpCoords.set(event.getStageX(), event.getStageY()));
			touchDown(event, tmpCoords.x, tmpCoords.y, event.getPointer(), event.getButton());
			if (event.getTouchFocus()) event.getStage().addTouchFocus(this, event.getListenerActor(), event.getTarget(),
				event.getPointer(), event.getButton());
			return true;
		case touchUp:
			boolean touchFocusCancel = event.isTouchFocusCancel();
			if (touchFocusCancel)
				detector.reset();
			else {
				this.event = event;
				actor = event.getListenerActor();
				detector.touchUp(event.getStageX(), event.getStageY(), event.getPointer(), event.getButton());
				actor.stageToLocalCoordinates(tmpCoords.set(event.getStageX(), event.getStageY()));
				touchUp(event, tmpCoords.x, tmpCoords.y, event.getPointer(), event.getButton());
			}
			this.event = null;
			actor = null;
			touchDownTarget = null;
			return !touchFocusCancel;
		case touchDragged:
			this.event = event;
			actor = event.getListenerActor();
			detector.touchDragged(event.getStageX(), event.getStageY(), event.getPointer());
			return true;
		}
		return false;
	}

	public void touchDown (InputEvent event, float x, float y, int pointer, int button) {
	}

	public void touchUp (InputEvent event, float x, float y, int pointer, int button) {
	}

	public void tap (InputEvent event, float x, float y, int count, int button) {
	}

	/** If true is returned, additional gestures will not be triggered. No event is provided because this event is triggered by
	 * time passing, not by an InputEvent. */
	public boolean longPress (Actor actor, float x, float y) {
		return false;
	}

	public void fling (InputEvent event, float velocityX, float velocityY, int button) {
	}

	/** The delta is the difference in stage coordinates since the last pan. */
	public void pan (InputEvent event, float x, float y, float deltaX, float deltaY) {
	}

	public void panStop (InputEvent event, float x, float y, int pointer, int button) {
	}

	public void zoom (InputEvent event, float initialDistance, float distance) {
	}

	public void pinch (InputEvent event, Vector2 initialPointer1, Vector2 initialPointer2, Vector2 pointer1, Vector2 pointer2) {
	}

	public GestureDetector getGestureDetector () {
		return detector;
	}

	public @Null Actor getTouchDownTarget () {
		return touchDownTarget;
	}
}