I am in the middle of writing an android app while teaching myself java all at the same time and my project is a bit cumbersome for a first time app. NOTE:
I am not a newbie to programming, I know several languages with the exception of java and writing code for mobile devices. With this all said and done, I don't want to have to force my users to have to update the app every time there is a new image.
Is there a way, I am assuming there is, to check on startup if all the images are up to date and if not download the new ones to the drawable resource folder for use in the app?
I have searched and found ways to remotely fetch items but nothing specifically for updating app images. For example: Splash Screen Image, or background image etc.
Thanks for your time and apologize if this does not conform to stackoverflow form of asking a question.
Shawn Mulligan
Based on my knowledges, there is no way to do why you're asking for. Resources are static contents and there no way to modify or update them programatically.
To achieve a kind of feature that you describe, it should be through a distant server, eventually with a local cache of your images on disc, associate to a download date.
But you won't be able to use them in the exact same way that you can use drawable resources.
Also depends of what you really mean by "if images are up to date".
Related
I am developing an app which is a graphical book. Every week, a new chapter is being released and the app will be updated. There are basically images that are going to be shown to the user as slides. The user can subscribe and all chapters will be visible to the user (the image sources are offline and embedded inside the APK file). The images are not saved into the internal SD card (like they are not shown in the phone gallery after installing the app).
I am afraid that it is not a safe way to show the content to the users. What if someone just extracts all the images? I am thinking of the solutions below. Please give me the best option to keep my image files secured.
Obfuscating the app (I'm not sure if this works in this case. I know obfuscating helps to change the codes but I'm not sure if it helps to encrypt the images)
Using an online server and let subscribed users download the images (I think this way it might be saved inside the external storage. Anyway after the download the images must be available offline)
Should I encrypt the images by an encryption method?
Let's explore your options one by one
If you obfuscate the app, it can be deobfuscated
If you use an online server, the images will be downloaded, you can manage to store the downloaded images into the memory instead of the disk and then show directly from memory.
If you encrypt the images, you need to have some decryption method/key implemented in the app, which can be retrieved and bingo,
the user can have decrypted images.
So if downloading the images from an online service will not break your business requirement, then go ahead with that.
Remember that, in any of the cases, if one is determined to save the images, he/she can.
You may need to have multiple methods in place to make it harder for those, seeking to save it.
I have an app that has an activity which allow users to download PDF files by selecting a PDF and clicking the download button.
The issue is: I don't want to always ask users to update the app when there's a new material available.
Is there a way I can update the .java code without always asking users to update the app?
Wrong design point.
You have probably hardcoded the PDF / file names in your Java application.
When these values are supposed to change, then well: don't hardcode them.
Instead you create a server side service that lists the available PDFs. And then your app uses that service in order to acquire that information.
Anything that is "dynamic" must not be hardcoded in your app itself. Instead your app knows how to fetch that piece of information from somewhere.
When the source code of your application changes, your users have to upgrade the app. It is that simple. The other way round: if you know about "changes" to your app that need to work without upgrading the app, then well: you have to design the whole app around that requirement.
A first starting point / further reading: see here.
Is it possible to get the user behavior on the phone (for example Alpesh has an Android phone and he uses multiple apps, browser YouTube etc). Whatever he is doing on the phone I want to get all those things from behind (which apps he has installed, which app he opens and what he search on the phone, All these data I want to get programmatically so what all can be get in android).
For now I am aware that installed apps list can be get easily but I want to get usage history and what he do all on mobile.
This is not a code solution, but an answer to your question, so you can get start some where.
In my opinion your question title are asking about two things.
(part 1) Getting User Behavior on the Android Phone (part 2)(App History, Browse
History etc)
1- First part Getting User Behavior on the Android Phone:
There is a concept called context awareness. Short described; it is about gathering different information from the phone, like light sensor, motion sensor, sound, location or even user behavior etc. and depending on your app requirement and the gathered information:
You could send these information over cloud data store for statically usage
You could make your phone doing (behavior) different things depending on location, motion or what ever.
etc.
For context awareness it is an open area for pervasive computing research. And it is not just few lines of code to write, it is typically a complete solution depending on requirement. Example I have built a context awareness application to gather noise collected by phones from different locations for research purpose inspired from this framework, but I am pretty sure you can find other frameworks or even build your own, as I did in my case.
The mentioned framework has some examples.
2- The second part is about App History, Browse History etc.:
This is possible, but you still need to build a peace of software (App) to collect all these information (logs) from the phone. Hereafter you can make phone act on different conditions and/or again send it over a RESTful API over cloud service data store, there is no limit for it.
The problem is, there is no thing out of the box for your requirement. Even if you find frameworks you still need to research it and further work on it.
You can find different examples for your requirement, like to collect browser history, you can find SO question here:
Get browser history and search result in android
Or get list of installed application:
How to get a list of installed android applications and pick one to run
My point here is you need to solve small goals at a time and put your knowledge together at the end.
Both 1 and 2 can also be related to each other, depending on your achievement.
Conclusion
Make a goal to your project.
Define the main requirements and tasks of your project.
Research your options (Technology, Cost, Target Audience, What data I can or I should not collect, what is possible to collect, what is the limits, Privacy issues etc.).
Split your project in small assets and try to solve small problems/goals.
Finally you would be able to put the puzzles together and build your final application
but i want to get usage history and what he do all on mobile
This is not possible and shouldn't ever be possible. Each app is sandboxed by Android so apps cannot inspect what other apps are doing. Think about it, you wouldn't want apps to be able to intercept private information such as banking details.
Every app is isolated from the other ones. Unless you develop a system signed app, you will not be able to gather all that data.
What you could do is to develop your own Android Rom where you then develop your data collection the exact way you want. Then you need to distribute your rom, which is another story...
How would you approach this problem:
My app should download different packages of pictures (containing up to 300 pngs, each about 20 kb) and store the pictures on the phone, so i can display them.
I want to upload the pictures somewhere online, so I can change them every time and the user can enjoy the newest pictures. (I upload the pictures not with the app)
I read that storing them in a sqlite db isn't the best option.
At the moment I am storing the pictures in the app, but then I don't know how I can upload and replace pictures on all apps immediately without the need of updating the whole app.
I don't need code or stuff, so don't waste your precious time on that, just some general hints where and how you would store the pictures online, and how android can download the pictures easily.
Take a look at the Glide or Picasso libraries. Those are super easy to use for thread-safe downloading of images.
Personally, I just fetch/store the images on imgur.
If you want to upload a dedicated databse, you'll have to set one up. Some common ones are Amazon, Google, etc. There are tons.
Have a look at this answer. In this answer Picasso library is used to handle image download. Picasso gets rid of a lot of coding and testing to handle image download.
In a project that I am working on, we use Amazon S3 to store our pictures, it's very reliable and is one of the goto solutions right now.
From what I heard Snapchat and some other big firms use S3 to store their picture!
It's also very cheap, plus I believe they have free hosting to a certain degree.
This is their API guide for android.
We use a service called File Picker to handle upload and download from amazonS3, it reduces a lot of work, but I don't think it's a free service.
You can use Picasso for downloading images from network in Android. For storing images Amazon S3 or Google cloud storage can be your options.
Not sure if downloading packages is better than downloading individual pictures (archiving won't save you much space).
As for your question, you can make some kind of API you will query from your app, even a flat file hosted somewhere with changing content would work. Your app could check it periodically for the new address to download pictures from (assuming it will change).
another way is using push messages - sending out a push through GCM that your apps will receive that will notify them about new content available. It would even work when the app is closed.
I'm looking to build a companion photo capture app for my photo capture website. I was planning to do this with phone gap.
Upon triggering the camera I want to grab a frame (a still, really) up to five times a second and send it to the server (barring any surprises, The sending part should already be dealt with in code I have). I suppose the realtime video from the camera itself should be displayed to the user as well, though I could just use the stop motion frames for that part.
Unfortunately, according to the phone gap docs, one can only launch the phone's cam app, manually take a picture, then return the user to the app.
I am looking into plugins, but I don't see any massive phonegap plugin repository out there, so I am not sure where to begin. I am just rambling now, so here is a list of bulleted questions:
Is there a plugin out there that does something like this already?
Is there a giant repository of phone gap plugins that I am too foolish to find?
If I try to roll my own java plugin (this is for an android app), what am I really getting myself into? Will I need to know enough to just make the damned thing native? I am pretty exclusively in the JS world at the moment, and am trying to get this out the door asap.
Am I missing something and there is a way to to this with vanilla phone gap?
Any other suggestions?
Thanks!
The phonegap plugins are here:
https://github.com/phonegap/phonegap-plugins