My Android app creates a folder on the users device's external storage on launch:
File images = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + File.separator + "rapical" + File.separator);
images.mkdirs();
I have around 16 image icons (.png) that I would like to place in this folder the first time the user opens the app.
What is the best practice to do this? Should I place them in the drawable folder initially and then copy them over to the newly created images folder? Not sure what approach to take!
There are two separate issues here:
What to do with images that the user adds to your app?
What to do with your starter images, for your default foods?
Using external storage for the user-added images has some implications:
Your app can survive that image no longer existing, since the user, or other apps, can delete that file at any point
Your user does not mind that the image will get picked up by other apps, such as photo galleries
Unless you specifically want these images to be user-manipulable outside of your app, I suggest that you use internal storage for the "re-sized, compressed and stored" user-supplied images. The original image might be on external storage (I assume that you are using ACTION_GET_CONTENT and/or ACTION_OPEN_DOCUMENT to get the image), but your modified copy would be private to your app.
I sincerely hope that you are using an image-loading library, like Picasso, for loading these images, since they will handle things like background threads and ListView/RecyclerView image recycling and stuff for you.
In that case, what you store in the SQLite database for your default foods needs to be something that the image-loading library can interpret, to bring in the image that you want.
In that case, I would suggest using assets/ to ship the images and file:///android_asset/... values in the database. file:///android_asset/ points to what amounts to assets/ in your project, so if you have assets/chicken_pad_thai.jpg in the project, Picasso (and any decent image-loading library) would be able to interpret file:///android_asset/chicken_pad_thai.jpg) and load the image.
This saves you from making duplicate copies of the images, saving the user disk space and time on first launch. It also means that if you replace the images in your app (e.g., you get a better photo representing chicken pad thai), the user will start seeing the updated image, without you having to do some extra work to realize that you shipped a new image and have to copy that image out to a file somewhere.
Now, suppose that you really do want the user-supplied images to be on external storage. In that case:
Probably rather than the directory that you chose, I would go with getExternalFilesDir() (a method on Context), as on API Level 19+, you do not need WRITE_EXTERNAL_STORAGE as a permission
If you want the user to be able to manipulate the images of the default foods, then copy those out to that location on first run
Related
I have a gallery which is maintained through app and didn't want to give images a jpg extension since I didn't want images to display in phone gallery so users cannot accidentally delete them. Filenames are something like "gall.22", "gall.381", etc. In fact, there are jpeg files.
When I share one or multiple images, they are shared with their filename which is not ending with .jpg and therefore cannot be opened regularly if shared to email, Viber, etc.
Is there a way to share files with a custom name, not the original one (to add just .jpg at the end of filename) and to avoid copying file to another file with wanted name prior sharing?
I didn't want images to display in phone gallery
I think you can try another way instead of rename extension, you can create the folder to store images and create file .nomedia inside this folder. MediaScaner will ignore this folder when scan and you can share image in normal way.
to avoid copying file to another file with wanted name prior sharing
When you share a file by Uri to another app can handle directly by Uri or copy, it depends on another app handle
I have to do some stuff. I'm downloading images using web-service, after successful download of each image, I'm using "AES" encryption algorithm to encrypt that images. I'have done encryption successfully. But whenever I'm going to open Gallery of device, I am able to seen that downloaded images encrypted by me. I don't want that. I wanna secure that images that can prevent access from Gallery.
I understood the whole process here.When I am storing each image after download Gallery capture that image and store into its cache so before my encryption process may be Gallery populate that images.
-> My Encryption process : Download Image - > Store into SDCARD - > Encrypting Image - > Delete the real Image
But this is not deleting from Gallery also.
So in short I wanna secure that images that can prevent access from Gallery. Let me know your best suggestion about my process is right or wrong? May I have to do a few changes on it? or have you nice idea instead of my process ?
Thanks for your best suggestions.
You must add an empty file to your images folder called .nomedia. This will prevent the MediaScanner from indexes images in that folder.
However, there is a bug on ICS that makes this slightly harder. On ICS, your folder must have the .nomedia present before you add images to it, or else the images will be indexed.
Another, slightly less compliant option is to begin your folder name with a dot (something like .foldername). As Android is UNIX based, this will make it a hidden folder, and hence not have the MediaScanner scan it.
I have got a proper solution. That will also work with higher versions.
You can keep it private with your application's private folder using following directory :
String mDirectory = getPackageManager().getPackageInfo("com.example.myapp", 0).applicationInfo.dataDir;
You can store your private data into this package. It will prevent access as well as prevent indexing from Gallery. So you don't need to worry about it's encryption process also :) . May be this folder will not provide much space. But atleast it will be help us.
Sounds like below solution might work for all versions -
(Storing videos, images and audio files that can not be accesses by others)
For this you have to store your data in External Storage with creating a folder name starting with the .(dot) then this folder is hidden from the FileExplorer.In this folder you need to create a .nomedia file and place your Images and video then images and videos are can not be visible to User in the Gallery.nomedia folder files can not be read by the gallery.
I'm writing an android application, which user can download some image files from server. There image files will be stored in android mobile.
Now I want to put some of image files inside the apk file, that user can start the application quickly after installing. I found I can put them into assets directory, but the directory is read only. When user download other image files, I need to store them into another directory.
So there will be two directories to store the image files, but they are the same type.
Is there any good solution for this case?
Check out http://developer.android.com/guide/topics/data/data-storage.html#filesInternal for a listing of different places you can put data on Android.
You should put downloaded image files into one of three places, depending on your needs.
If the images are meant to be viewable by the user (e.g. downloaded photos), put them on the external storage. If they are meant to be user-interface elements or other crucial (but not user-facing) images, put them on internal storage. If they are meant to be cached for quick access but downloaded if necessary (e.g. temporary images like those found on a website), put them in the internal cache directory (Context.getCacheDir()).
If you don't have a lot of assets, you can copy them to the target location when your program first runs (e.g. check for the existence of a certain file, and create that file when you are done setting up). Then you only have to check one place (unless it's the cache dir, in which case you can't guarantee that the files will stick around forever).
If you have a lot of asset files, I would use a two-stage lookup: consult your downloaded image directory first (so you can override builtin assets, for example), then consult your assets directory. This is also flexible enough to allow you to make use of multiple storage locations should you find the need.
I want to do this. my app has many screens and in each of them, on the top, I display an imageView as a logo. So I have 20 screens and that means (20*3) images in my drawable which makes my app be many Mb's. Because this image is static and never changes I want to do this: Getting it from the web (I know how to do it, I am not asking this) only for the first time this screen is ever launched, then this image be stored somewhere in user's device and then use that path as a source. (I mean not download it again, because it will be annoying for the user waiting every time). So is it possible? Will it make my app go slower (not the first time, but the rest) because I am retrieving data from SD?
Yes, you can do this fairly easily. You also do not have to store the data on the SD card necessarily. You can store the image in the internal storage.
Basically, set up a cache directory. When you need the image, check the cache directory, and if the file is not there, download it over http and store the file in the cache directory.
It will change how you get the resource (e.g., you won't be able to use R.drawable.imagename), but you can just load the drawable programmatically.
I want to store images locally, So which is efficient way , storing image in data base or storing image in internal memory. I have no option of external memory.
Best wud be to pre bundle the images in your apk itself. Else there is no way to do that.Also if you can save images on the sd card, you can make the folder names start with "." (dot) so that they wont be visible in normal condition (will be visible only if there is option checked of "show hidden files" in your file browser of phone).And if you want that your images dont show up in gallery then just add an empty file to the folder named ".nomedia".This will make your images not to shpw up in Android Gallery.
This page shows the various options you have for data storage. If you just need to save images, I can't see why you would use a database. Also, your database would be located in Internal memory.
Images stored in private internal memory do not show up in the gallery as they are only accessible to the app that created them.