Question about app data and storage


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  1. writhum

    writhum Well-Known Member This Topic's Starter

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    Recently I downloaded a home-makover app called 'Home++'. In the Home++ desktop gallery there is a background that I love, and I can't find anywhere online. I would like to do some HSB edits to the picture, but I can't seem to find it in the phone's filesystem. Does anyone know where the default place for an app to store data is? I've looked through the SD and ROM and can't seem to find it.
     

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  2. regulatre

    regulatre Well-Known Member

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    It's most likely stored as a resource in R.java belonging to that app. This is an interesting idea and if there is a way to extract files from R.java I'd be interested in learning about it too.

    This might sound crazy but I bet the APK files aren't compressed so you could potentially open the app (apk) in a hex editor, locate the JPG header (......JFIF) and then extract the image jpg manually. The size of the JPG is stored in the header (6 bytes in front of the JFIF tag I think) so you could also calculate how many bytes after the header you need to grab.

    Even apk are compressed, just find a way to decompress it and go after your picture.

    If none of this makes sense I might have time to take a whack at it if you send me the apk.

    I wrote a VB program that does this back in the day. I might be able to reuse some code.
     
  3. writhum

    writhum Well-Known Member This Topic's Starter

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    Sounds like really cool stuff. A little advanced for me, but I'll play around with it...seems like a good thing to know how to do. I'll hit you up with the apk in a few.


    http://hpp.intuitit.mobi/Launcher.apk?attredirects=0
     
  4. writhum

    writhum Well-Known Member This Topic's Starter

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    Update:
    Astro file manager has an extract feature...used it on the apk and nested in a folder were the original jpg files=)
     
  5. regulatre

    regulatre Well-Known Member

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    I just did a little experiment with one of my apps. I took the apk file and renamed it to .zip and then extracted it. All the drawable resources were neatly placed into res/drawable. Looks like that's all you have to do.
     
  6. writhum

    writhum Well-Known Member This Topic's Starter

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    Now here's the real question: once extracted, how can I convert back to .apk? Would it require the sdk?
     
  7. regulatre

    regulatre Well-Known Member

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    I suppose it depends. You can probably install it on your phone without much hassle (just re-zip the file structure into apk, get it on your phone, install it).

    What exactly are you up to? =)
     
  8. writhum

    writhum Well-Known Member This Topic's Starter

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    I use home++ as a home replacement
    In the apk file I found all of the graphics used for everything from shortcut to notification bar icons. I wanna make my own and re-pack it! (would that be possible?)
     
  9. wige

    wige Well-Known Member

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    Not entirely sure, but that might invalidate the signature. I think you can resign a package yourself though.
     

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