package neal.http.ui;
import android.content.Context;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.ViewGroup;
import neal.http.Http;
import neal.http.base.HttpError;
import neal.http.process.ImageLoader;
import neal.http.utils.RecyclingBitmapDrawable;
/**
* Created by Neal on 2014/10/30.
*/
/**
* Handles fetching an image from a URL as well as the life-cycle of the
* associated request.automatically notifies the drawable when it is
* being displayed. It is a combination of NetworkImageView and RecyclingImageView
*/
public class RecyclingNetImageView extends RecyclingImageView{
/** The URL of the network image to load */
private String mUrl;
/**
* Resource ID of the image to be used as a placeholder until the network image is loaded.
*/
private int mDefaultImageId;
private Drawable mDefaultDrawable;
/**
* Resource ID of the image to be used if the network response fails.
*/
private int mErrorImageId;
private Drawable mErrorDrawable;
/** Local copy of the ImageLoader. */
private ImageLoader mImageLoader;
/** Current ImageContainer. (either in-flight or finished) */
private ImageLoader.ImageContainer mImageContainer;
private Context mContext;
public RecyclingNetImageView(Context context) {
this(context, null);
mContext=context;
}
public RecyclingNetImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public RecyclingNetImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mContext=context;
}
/**
* Sets URL of the image that should be loaded into this view. Note that calling this will
* immediately either set the cached image (if available) or the default image specified by
* {@link RecyclingNetImageView#setDefaultImageResId(int)} on the view.
*
* NOTE: If applicable, {@link RecyclingNetImageView#setDefaultImageResId(int)} and
* {@link RecyclingNetImageView#setErrorImageResId(int)} should be called prior to calling
* this function.
*
* @param url The URL that should be loaded into this ImageView.
* @param imageLoader ImageLoader that will be used to make the request.
*/
public void setImageUrl(String url, ImageLoader imageLoader,int defaultImage, int errorImage) {
mUrl = url;
if(null==imageLoader){
imageLoader= Http.getImageLoader(mContext.getApplicationContext());
}
mImageLoader = imageLoader;
setDefaultImageResId(defaultImage);
setErrorImageResId(errorImage);
// The URL has potentially changed. See if we need to load it.
loadImageIfNecessary(false);
}
public void setImageUrl(String url,int defaultImage, int errorImage){
setImageUrl(url,null,defaultImage,errorImage);
}
/* public void setImageUrl(String url, ImageLoader imageLoader) {
mUrl = url;
mImageLoader = imageLoader;
// The URL has potentially changed. See if we need to load it.
loadImageIfNecessary(false);
}*/
/**
* Sets the default image resource ID to be used for this view until the attempt to load it
* completes.
*/
public void setDefaultImageResId(int defaultImage) {
mDefaultImageId = defaultImage;
//资源的drawable，系统会提供缓存机制，不做缓存，recycle等处理
mDefaultDrawable=getResources().getDrawable(defaultImage);
}
/**
* Sets the error image resource ID to be used for this view in the event that the image
* requested fails to load.
*/
public void setErrorImageResId(int errorImage) {
mErrorImageId = errorImage;
mErrorDrawable=getResources().getDrawable(errorImage);
}
/**
* Loads the image for the view if it isn't already loaded.
* @param isInLayoutPass True if this was invoked from a layout pass, false otherwise.
*/
void loadImageIfNecessary(final boolean isInLayoutPass) {
int width = getWidth();
int height = getHeight();
boolean wrapWidth = false, wrapHeight = false;
if (getLayoutParams() != null) {
wrapWidth = getLayoutParams().width == ViewGroup.LayoutParams.WRAP_CONTENT;
wrapHeight = getLayoutParams().height == ViewGroup.LayoutParams.WRAP_CONTENT;
}
// if the view's bounds aren't known yet, and this is not a wrap-content/wrap-content
// view, hold off on loading the image.
boolean isFullyWrapContent = wrapWidth && wrapHeight;
if (width == 0 && height == 0 && !isFullyWrapContent) {
return;
}
// if the URL to be loaded in this view is empty, cancel any old requests and clear the
// currently loaded image.
if (TextUtils.isEmpty(mUrl)) {
if (mImageContainer != null) {
mImageContainer.cancelRequest();
mImageContainer = null;
}
setDefaultImageOrNull();
return;
}
// if there was an old request in this view, check if it needs to be canceled.
if (mImageContainer != null && mImageContainer.getRequestUrl() != null) {
if (mImageContainer.getRequestUrl().equals(mUrl)) {
// if the request is from the same URL, return.
return;
} else {
// if there is a pre-existing request, cancel it if it's fetching a different URL.
mImageContainer.cancelRequest();
setDefaultImageOrNull();
}
}
// Calculate the max image width / height to use while ignoring WRAP_CONTENT dimens.
int maxWidth = wrapWidth ? 0 : width;
int maxHeight = wrapHeight ? 0 : height;
// The pre-existing content of this view didn't match the current URL. Load the new image
// from the network.
ImageLoader.ImageContainer newContainer = mImageLoader.get(mUrl,
new ImageLoader.ImageListener() {
@Override
public void onErrorResponse(HttpError error) {
if (mErrorDrawable != null) {
setImageDrawable(mErrorDrawable);
}
}
@Override
public void onResponse(final ImageLoader.ImageContainer response, boolean isImmediate) {
// If this was an immediate response that was delivered inside of a layout
// pass do not set the image immediately as it will trigger a requestLayout
// inside of a layout. Instead, defer setting the image by posting back to
// the main thread.
if (isImmediate && isInLayoutPass) {
post(new Runnable() {
@Override
public void run() {
onResponse(response, false);
}
});
return;
}
if (response.getBitmapDrawable() != null) {
setImageDrawable(response.getBitmapDrawable());
} else if (mDefaultDrawable != null) {
setImageDrawable(mDefaultDrawable);
}
}
}, maxWidth, maxHeight);
// update the ImageContainer to be the new bitmap container.
mImageContainer = newContainer;
}
private void setDefaultImageOrNull() {
if(mDefaultDrawable != null) {
//此处统一使用setImageDrawable，否则影响recycle。因为使用setImageResource也会改变getDrawable的值。
setImageDrawable(mDefaultDrawable);
}
else {
setImageDrawable(null);
}
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
loadImageIfNecessary(true);
}
@Override
protected void onDetachedFromWindow() {
if (mImageContainer != null) {
// If the view was bound to an image request, cancel it and clear
// out the image from the view.
mImageContainer.cancelRequest();
setImageDrawable(null);
// also clear out the container so we can reload the image if necessary.
mImageContainer = null;
}
super.onDetachedFromWindow();
}
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
invalidate();
}
}