| /** |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * 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.android.volley.toolbox; |
| |
| import android.content.Context; |
| import android.text.TextUtils; |
| import android.util.AttributeSet; |
| import android.view.ViewGroup.LayoutParams; |
| import android.widget.ImageView; |
| |
| import com.android.volley.VolleyError; |
| import com.android.volley.toolbox.ImageLoader.ImageContainer; |
| import com.android.volley.toolbox.ImageLoader.ImageListener; |
| |
| /** |
| * Handles fetching an image from a URL as well as the life-cycle of the |
| * associated request. |
| */ |
| public class NetworkImageView extends ImageView { |
| /** 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; |
| |
| /** |
| * Resource ID of the image to be used if the network response fails. |
| */ |
| private int mErrorImageId; |
| |
| /** Local copy of the ImageLoader. */ |
| private ImageLoader mImageLoader; |
| |
| /** Current ImageContainer. (either in-flight or finished) */ |
| private ImageContainer mImageContainer; |
| |
| public NetworkImageView(Context context) { |
| this(context, null); |
| } |
| |
| public NetworkImageView(Context context, AttributeSet attrs) { |
| this(context, attrs, 0); |
| } |
| |
| public NetworkImageView(Context context, AttributeSet attrs, int defStyle) { |
| super(context, attrs, defStyle); |
| } |
| |
| /** |
| * 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 NetworkImageView#setDefaultImageResId(int)} on the view. |
| * |
| * NOTE: If applicable, {@link NetworkImageView#setDefaultImageResId(int)} and |
| * {@link NetworkImageView#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) { |
| 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; |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * 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(); |
| ScaleType scaleType = getScaleType(); |
| |
| boolean wrapWidth = false, wrapHeight = false; |
| if (getLayoutParams() != null) { |
| wrapWidth = getLayoutParams().width == LayoutParams.WRAP_CONTENT; |
| wrapHeight = getLayoutParams().height == 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. |
| |
| // update the ImageContainer to be the new bitmap container. |
| mImageContainer = mImageLoader.get(mUrl, |
| new ImageListener() { |
| @Override |
| public void onErrorResponse(VolleyError error) { |
| if (mErrorImageId != 0) { |
| setImageResource(mErrorImageId); |
| } |
| } |
| |
| @Override |
| public void onResponse(final 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.getBitmap() != null) { |
| setImageBitmap(response.getBitmap()); |
| } else if (mDefaultImageId != 0) { |
| setImageResource(mDefaultImageId); |
| } |
| } |
| }, maxWidth, maxHeight, scaleType); |
| } |
| |
| private void setDefaultImageOrNull() { |
| if(mDefaultImageId != 0) { |
| setImageResource(mDefaultImageId); |
| } |
| else { |
| setImageBitmap(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(); |
| setImageBitmap(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(); |
| } |
| } |