Android Open Source - AUIL-for-volley Image Size Utils

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License

The source code is released under:

Apache License

Java Source Code

/*******************************************************************************
 * Copyright 2013 Sergey Tarasevich/*from   w w  w . java 2s. c o  m*/
 *
 * 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.nostra13.universalimageloader.utils;

import android.util.DisplayMetrics;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;
import com.nostra13.universalimageloader.core.assist.ImageSize;

import java.lang.reflect.Field;

/**
 * Provides calculations with image sizes, scales
 *
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.8.3
 */
public final class ImageSizeUtils {

  private ImageSizeUtils() {
  }

  /**
   * Defines target size for image. Size is defined by target {@link android.widget.ImageView view} parameters, configuration
   * parameters or device display dimensions.<br />
   * Size computing algorithm:<br />
   * 1) Get the actual drawn <b>getWidth()</b> and <b>getHeight()</b> of the View. If view haven't drawn yet then go
   * to step #2.<br />
   * 2) Get <b>layout_width</b> and <b>layout_height</b>. If both of them haven't exact value then go to step #3.<br />
   * 3) Get <b>maxWidth</b> and <b>maxHeight</b>. If both of them are not set then go to step #4.<br />
   * 4) Get <b>maxImageWidth</b> param (<b>maxImageWidthForMemoryCache</b>) and <b>maxImageHeight</b> param
   * (<b>maxImageHeightForMemoryCache</b>). If both of them are not set (equal 0) then go to step #5.<br />
   * 5) Get device screen dimensions.
   */
  public static ImageSize defineTargetSizeForView(ImageView imageView, int maxImageWidth, int maxImageHeight) {
    final DisplayMetrics displayMetrics = imageView.getContext().getResources().getDisplayMetrics();

    final LayoutParams params = imageView.getLayoutParams();
    int width = (params != null && params.width == LayoutParams.WRAP_CONTENT) ? 0 : imageView.getWidth(); // Get actual image width
    if (width <= 0 && params != null) width = params.width; // Get layout width parameter
    if (width <= 0) width = getImageViewFieldValue(imageView, "mMaxWidth"); // Check maxWidth parameter
    if (width <= 0) width = maxImageWidth;
    if (width <= 0) width = displayMetrics.widthPixels;

    int height = (params != null && params.height == LayoutParams.WRAP_CONTENT) ? 0 : imageView.getHeight(); // Get actual image height
    if (height <= 0 && params != null) height = params.height; // Get layout height parameter
    if (height <= 0) height = getImageViewFieldValue(imageView, "mMaxHeight"); // Check maxHeight parameter
    if (height <= 0) height = maxImageHeight;
    if (height <= 0) height = displayMetrics.heightPixels;

    return new ImageSize(width, height);
  }

  private static int getImageViewFieldValue(Object object, String fieldName) {
    int value = 0;
    try {
      Field field = ImageView.class.getDeclaredField(fieldName);
      field.setAccessible(true);
      int fieldValue = (Integer) field.get(object);
      if (fieldValue > 0 && fieldValue < Integer.MAX_VALUE) {
        value = fieldValue;
      }
    } catch (Exception e) {
      L.e(e);
    }
    return value;
  }
}

Java Source Code List

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