com.nostra13.universalimageloader.core.imageaware.ImageViewAware Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright 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.nostra13.universalimageloader.core.imageaware;

import android.graphics.Bitmap;
import android.graphics.drawable.Drawable;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.nostra13.universalimageloader.core.assist.ViewScaleType;
import com.nostra13.universalimageloader.utils.L;

import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;

/**
 * Wrapper for Android {@link android.widget.ImageView ImageView}. Keeps weak reference of ImageView to prevent memory
 * leaks.
 *
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.9.0
 */
public class ImageViewAware implements ImageAware {

	protected Reference imageViewRef;
	protected boolean checkActualViewSize;

	/**
	 * Constructor.
	 * References {@link #ImageViewAware(android.widget.ImageView, boolean) ImageViewAware(imageView, true)}.
	 *
	 * @param imageView {@link android.widget.ImageView ImageView} to work with
	 */
	public ImageViewAware(ImageView imageView) {
		this(imageView, true);
	}

	/**
	 * Constructor
	 *
	 * @param imageView           {@link android.widget.ImageView ImageView} to work with
	 * @param checkActualViewSize true - then {@link #getWidth()} and {@link #getHeight()} will check actual
	 *                            size of ImageView. It can cause known issues like
	 *                            this.
	 *                            But it helps to save memory because memory cache keeps bitmaps of actual (less in
	 *                            general) size.
	 *                            
	 *                            false - then {@link #getWidth()} and {@link #getHeight()} will NOT
	 *                            consider actual size of ImageView, just layout parameters.
	 */
	public ImageViewAware(ImageView imageView, boolean checkActualViewSize) {
		this.imageViewRef = new WeakReference(imageView);
		this.checkActualViewSize = checkActualViewSize;
	}

	/**
	 * {@inheritDoc}
	 * 

	 * Width is defined by target {@link ImageView view} parameters, configuration
	 * parameters or device display dimensions.

	 * Size computing algorithm:

	 * 1) Get the actual drawn getWidth() of the View. If view haven't drawn yet then go
	 * to step #2.

	 * 2) Get layout_width. If it hasn't exact value then go to step #3.

	 * 3) Get maxWidth.
	 */
	@Override
	public int getWidth() {
		ImageView imageView = imageViewRef.get();
		if (imageView != null) {
			final ViewGroup.LayoutParams params = imageView.getLayoutParams();
			int width = 0;
			if (checkActualViewSize && params != null && params.width != ViewGroup.LayoutParams.WRAP_CONTENT) {
				width = 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
			L.w("width = " + width);
			return width;
		}
		return 0;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * Height is defined by target {@link ImageView view} parameters, configuration
	 * parameters or device display dimensions.

	 * Size computing algorithm:

	 * 1) Get the actual drawn getHeight() of the View. If view haven't drawn yet then go
	 * to step #2.

	 * 2) Get layout_height. If it hasn't exact value then go to step #3.

	 * 3) Get maxHeight.
	 */
	@Override
	public int getHeight() {
		ImageView imageView = imageViewRef.get();
		if (imageView != null) {
			final ViewGroup.LayoutParams params = imageView.getLayoutParams();
			int height = 0;
			if (checkActualViewSize && params != null && params.height != ViewGroup.LayoutParams.WRAP_CONTENT) {
				height = 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
			L.w("height = " + height);
			return height;
		}
		return 0;
	}

	@Override
	public ViewScaleType getScaleType() {
		ImageView imageView = imageViewRef.get();
		if (imageView != null) {
			return ViewScaleType.fromImageView(imageView);
		}
		return null;
	}

	@Override
	public ImageView getWrappedView() {
		return imageViewRef.get();
	}

	@Override
	public boolean isCollected() {
		return imageViewRef.get() == null;
	}

	@Override
	public int getId() {
		ImageView imageView = imageViewRef.get();
		return imageView == null ? super.hashCode() : imageView.hashCode();
	}

	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;
	}

	@Override
	public boolean setImageDrawable(Drawable drawable) {
		ImageView imageView = imageViewRef.get();
		if (imageView != null) {
			imageView.setImageDrawable(drawable);
			return true;
		}
		return false;
	}

	@Override
	public boolean setImageBitmap(Bitmap bitmap) {
		ImageView imageView = imageViewRef.get();
		if (imageView != null) {
			imageView.setImageBitmap(bitmap);
			return true;
		}
		return false;
	}
}