com.navercorp.volleyextensions.view.LimitedLevelZoomableComponent Maven / Gradle / Ivy

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/*
 * Copyright (C) 2014 Naver Corp.
 * 
 * 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.navercorp.volleyextensions.view;

import com.navercorp.volleyextensions.util.Assert;
/**
 *  * A Decorator class for limiting zoom levels from ZoomableComponent.
 * 
 * You can set a minimum level and maximum level only at the constructor.
 * 
 */
class LimitedLevelZoomableComponent implements ZoomableComponent {

	public static final float ORIGINAL_LEVEL = 1.0f;
	public static final float INFINITE_LEVEL = Float.MAX_VALUE;

	private final ZoomableComponent delegate;
	private float maximumZoomLevel;
	private float minimumZoomLevel;
	/**
	 * Create a decorator for {@code delegate}
	 * @param delegate Delegated ZoomableComponent
	 * @param minimumZoomLevel Minimum zoom level (must be over {@code ORIGINAL_LEVEL} and under {@code maximumZoomLevel})
	 * @param maximumZoomLevel Maximum zoom level (must be under {@code INFINITE_LEVEL} and over {@code minimumZoomLevel})
	 */
	public LimitedLevelZoomableComponent(ZoomableComponent delegate, float minimumZoomLevel, float maximumZoomLevel) {
		Assert.notNull(delegate, "The delegated ZoomableComponent");
		setMinimumZoomLevel(minimumZoomLevel);
		setMaximumZoomLevel(maximumZoomLevel);
		this.delegate = delegate;
	}

	@Override
	public void zoomTo(float targetLevel, float zoomX, float zoomY) {
		targetLevel = limitLevelSizeRange(targetLevel);
		delegate.zoomTo(targetLevel, zoomX, zoomY);
	}

	@Override
	public void panTo(float dx, float dy) {
		delegate.panTo(dx, dy);
	}

	@Override
	public void restore(ZoomInfo value) {
		delegate.restore(value);
	}

	@Override
	public ZoomInfo save() {
		return delegate.save();
	}

	@Override
	public float getZoomLevel() {
		return delegate.getZoomLevel();
	}

	private final float limitLevelSizeRange(float targetLevel) {
		if (targetLevel < minimumZoomLevel) {
			targetLevel = minimumZoomLevel;
		}
		if (targetLevel > maximumZoomLevel) {
			targetLevel = maximumZoomLevel;
		}
		return targetLevel;
	}

	private void setMinimumZoomLevel(float minimumLevel) {
		if (minimumLevel < ORIGINAL_LEVEL) {
			minimumLevel = ORIGINAL_LEVEL;
		}
		if (minimumLevel > maximumZoomLevel) {
			this.maximumZoomLevel = minimumLevel;
		}

		this.minimumZoomLevel = minimumLevel;
	}

	private void setMaximumZoomLevel(float maximumLevel) {
		if(maximumLevel < ORIGINAL_LEVEL) {
			maximumLevel = ORIGINAL_LEVEL;
		}
		if (minimumZoomLevel > maximumLevel) {
			this.minimumZoomLevel = maximumLevel;
		}

		this.maximumZoomLevel = maximumLevel;
	}
}