ImageScaleType.java

/*******************************************************************************
 * Copyright 2011-2013 Sergey Tarasevich
 *
 * 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.smartandroid.sa.zUImageLoader.core.assist;

/**
 * Type of image scaling during decoding.
 * 
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.5.0
 */
public enum ImageScaleType {
	/** Image won't be scaled */
	NONE,
	/**
	 * Image will be scaled down only if image size is greater than
	 * {@linkplain javax.microedition.khronos.opengles.GL10#GL_MAX_TEXTURE_SIZE
	 * maximum acceptable texture size}. Usually it's 2048x2048.<br />
	 * If Bitmap is expected to display than it must not exceed this size
	 * (otherwise you'll get the exception
	 * "OpenGLRenderer: Bitmap too large to be uploaded into a texture".<br />
	 * Image will be subsampled in an integer number of times (1, 2, 3, ...) to
	 * maximum texture size of device.
	 */
	NONE_SAFE,
	/**
	 * Image will be reduces 2-fold until next reduce step make image smaller
	 * target size.<br />
	 * It's <b>fast</b> type and it's preferable for usage in
	 * lists/grids/galleries (and other {@linkplain android.widget.AdapterView
	 * adapter-views}) .<br />
	 * Relates to {@link android.graphics.BitmapFactory.Options#inSampleSize}<br />
	 * Note: If original image size is smaller than target size then original
	 * image <b>won't</b> be scaled.
	 */
	IN_SAMPLE_POWER_OF_2,
	/**
	 * Image will be subsampled in an integer number of times (1, 2, 3, ...).
	 * Use it if memory economy is quite important.<br />
	 * Relates to {@link android.graphics.BitmapFactory.Options#inSampleSize}<br />
	 * Note: If original image size is smaller than target size then original
	 * image <b>won't</b> be scaled.
	 */
	IN_SAMPLE_INT,
	/**
	 * Image will scaled-down exactly to target size (scaled width or height or
	 * both will be equal to target size; depends on
	 * {@linkplain android.widget.ImageView.ScaleType ImageView's scale type}).
	 * Use it if memory economy is critically important.<br />
	 * <b>Note:</b> If original image size is smaller than target size then
	 * original image <b>won't</b> be scaled.<br />
	 * <br />
	 * <b>NOTE:</b> For creating result Bitmap (of exact size) additional Bitmap
	 * will be created with
	 * {@link android.graphics.Bitmap#createBitmap(android.graphics.Bitmap, int, int, int, int, android.graphics.Matrix, boolean)
	 * Bitmap.createBitmap(...)}.<br />
	 * <b>Cons:</b> Saves memory by keeping smaller Bitmap in memory cache
	 * (comparing with IN_SAMPLE... scale types)<br />
	 * <b>Pros:</b> Requires more memory in one time for creation of result
	 * Bitmap.
	 */
	EXACTLY,
	/**
	 * Image will scaled exactly to target size (scaled width or height or both
	 * will be equal to target size; depends on
	 * {@linkplain android.widget.ImageView.ScaleType ImageView's scale type}).
	 * Use it if memory economy is critically important.<br />
	 * <b>Note:</b> If original image size is smaller than target size then
	 * original image <b>will be stretched</b> to target size.<br />
	 * <br />
	 * <b>NOTE:</b> For creating result Bitmap (of exact size) additional Bitmap
	 * will be created with
	 * {@link android.graphics.Bitmap#createBitmap(android.graphics.Bitmap, int, int, int, int, android.graphics.Matrix, boolean)
	 * Bitmap.createBitmap(...)}.<br />
	 * <b>Cons:</b> Saves memory by keeping smaller Bitmap in memory cache
	 * (comparing with IN_SAMPLE... scale types)<br />
	 * <b>Pros:</b> Requires more memory in one time for creation of result
	 * Bitmap.
	 */
	EXACTLY_STRETCHED
}