Develop Reference

what should callerContext param be for Fresco's prefetchToBitmapCache?

In order to implement image pre-fetching, we get the ImagePipeline and call prefetchToBitmapCache on it. however, both the API Javadoc (http://frescolib.org/javadoc/reference/com/facebook/imagepipeline/core/ImagePipeline.html#prefetchToBitmapCache(com.facebook.imagepipeline.request.ImageRequest, java.lang.Object) and the plain doc (http://frescolib.org/docs/using-image-pipeline.html#) are incorrect. specifically , they leave out the description and example for what the second method parameter is. I am talking about the Object callerContext . which since its an object isn't an android Context. I'm guessing that because the type is an object, not a Context. Could the documentation be updated and/or someone explain what the caller context is supposed to be?
Thank you!

So I posted this question a while back on the fresco github (https://github.com/facebook/fresco/issues/609) and I was told the documentation would be updated. I'm posting my results here since it is likely others might look here. I still haven't seen any updates to frescolib.org or anywhere else. I decided to figure it out myself. Basically, if you're using SimpleDraweeView and its respective ImageRequest (which the prefetch call needs) , then you would notice that setting the uri on the view creates a DraweeController with a null callerContext. I figured that might be what is needed here. Sure enough, I made the call to prefetchToBitmapCache(draweeController, null) and its prefetched! I know that because I waited for a bit and turned off the data. also this call was only active on a select imageview. the other did not load. I can't be sure this is the right way to do it, ntil they come out with the right documentation. but like i said it works.

what is relation between android WebView and WebViewClassic

I am having a problem in copy-paste on long click on text inside my class extending Android WebView.
I'm able to copy, but paste is not working.
While investigating, somewhere on net got suggestion to look into android.webkit.WebViewClassic.
In WebViewClassic, there's a method named pasteFromClipboard().
I think actual pasting of code happens in that method, but not sure.
So can anyone please tell me Am I right, i.e. whether investigating in WebViewClassic is worth for me?
If yes, please tell me what is relation between WebView and WebViewClassic, i.e. how long click in WebView goes to WebViewClassic.
And sorry, I cant expose my code or log.

WebViewClassic is the default WebViewProvider for WebView. From the implementation notes:
The WebView is a thin API class that delegates its public API to a backend WebViewProvider
class instance. WebView extends {#link AbsoluteLayout} for backward compatibility reasons.
Methods are delegated to the provider implementation: all public API methods introduced in this
file are fully delegated, whereas public and protected methods from the View base classes are
only delegated where a specific need exists for them to do so.
Basically, touch handling is forwarded from the WebView to a WebViewClassic instance. If you read through it's onTouchEvent implementation, and its inner WebViewInputDispatcher implementation PrivateHandler you can trace where the touch handling will lead to a call to pasteFromClipboard() on the WebViewClassic instance.
So yes, you are correct. When you tap the paste button on the PastePopupWindow, there will be a call to WebViewClassic's pasteFromClipboard(); method.

Unittesting AsyncTaskLoader with getLoaderResultSynchronously

I am trying to create unit tests for a REST client that does some API calls. The client works fine in the live application, but I can't get it to run in the test case.
Apparantly, LoaderTestCase.getLoaderResultSynchronously() could be used here (at least according to Android reference, but it will not accept my loader. The code:
public void testGetEventInfo() {
// Init some vars
...
// Create & execute loader
RESTLoader loader = new RESTLoader(getContext(),
RESTLoader.HTTPVerb.GET, action, params, LOADER_GET_NEWS);
getLoaderResultSynchronously(loader);
}
This yields the error getLoaderResultSynchronously(Loader) in the type LoaderTestCase is not applicable for the arguments (RESTLoader).
RESTLoader extends AsyncLoader. Note that I'm using the supportlibrary, maybe the Loader in there is incompatible? The documentation gives no information on this.
I've tried to solve this in several ways, though none seem to work:
Registered a listener to loader. However, the callback never triggers
Using CountdownLatch (also with a listener). Again, no trigger/countdown timeout.
Playing around with the type template (), without success.
Similar solutions on SO, though again failing to reach the listener.
Does anybody know why getLoaderResultSynchronously will not accept the loader? Or another clean way of testing the Loader, including a way to test return data? I can test handling the return data in a separate case, but I would also like to test the actual data.
Sincerely,

Have you taken a look at the source code? You'll find the following import statements:
import android.content.Loader;
import android.content.Loader.OnLoadCompleteListener;
It doesn't look like Android offers a support version for LoaderTestCase. The easiest solution would be to temporarily change to the non-support LoaderManager (that is, have your class make use of the android.content.Loader instead), test your app, and then switch back to the support implementation. You might also consider copying the testing source code into your project, import the support LoaderManager, and execute it directly. I'm not familiar with the test libraries for Loaders but it doesn't seem outwardly obvious that this would cause any major issues.

You can get sources from LoaderTestCase here, create SupportLoaderTestCase class from that sources in your test project and modify all namespaces to support library namespaces (e.g. change android.content.Loader with android.support.v4.content.Loader). Than you can extend your test case from SupportLoaderTestCase (not from LoaderTestCase) and use it without problems

The method you are trying to call (getLoaderResultSynchronously) accepts an object of type android.content.Loader. If your RESTLoader class is not of that EXACT type then you will get this error. I suspect your class directly or indirectly extends android.support.v4.content.Loader, which would explain the error.
I am not aware of a back-port of LoaderTestCase that would support testing of this type of class.

Get neat content from Wiki page. (MediaWiki API)

I want to get a content page from Wiki in this format (the picture below) then show it in WebView. It means the content includes text and links.
I tried this but the output seems to be messy.
http://en.wikipedia.org/w/api.php?action=query&prop=revisions&rvprop=content&titles=Albert_Einstein&format=xmlfm

I stumbled across this answer a year later and would like to note that the ?action=render parameter has been depreciated as of this post.
The recommended method is to use the Mediawiki API to parse the wikitext.

You want index.php?action=render; an example. This returns the HTML of the page content with no sidebar/header/footer HTML. You'll have to match and remove infoboxes yourself.
Reference: MediaWiki — Manual:Parameters to index.php.

You can use HTML generated by mediawiki instead of wikicode.
BTW: look at this

Determine element of url from webview shouldOverRideUrlLoading

I am displaying a html in a custom activity with a webview. I am overriding
public boolean shouldOverrideUrlLoading(WebView view, String url) {
to intercept certain urls. Now I would like to be able to figure out some more details about the html around that url.
In my case I would like to get the html element that contains the url. E.g. if the url comes from
Manfred Moser
I would like to be able to somehow retrieve the value "Manfred Moser" from within the anchor tag. Is there a way to do that. I found that you do not have access to the DOM from Java.
One way I can think of would be to download the page separately and parse it all before even loading it in webview. However that is an ugly hack at best. Is there a better way?

There is a dirty hack:
Bind some Java object so that it can be called from Javascript with WebView:
addJavascriptInterface(javaObjectExposed, "JSname")
Force execute javascript within an existing page by
WebView.loadUrl("javascript:window.JSname.passData("some data");");
Described here: http://lexandera.com/2009/01/extracting-html-from-a-webview/
Note: this is a security risk - any JS code in this web page could access/call your binded Java object. Best to pass some one-time cookies to loadUrl() and pass them back your Java object to check that it's your code making the call.

In addition to #Peter Knego's approach, there is the inverse:
Use addJavascriptInterface(), per his step #1
For your link, use an onClick attribute on your <a> tag to call out some method on the Java object from step #1, where the Java object turns around and loads the URL into the WebView, and supplies whatever sort of identifying information you want.
Suffice it to say, there's no way to get the information you want from shouldOverrideUrlLoading().