I am still new to cloud and mit app inventor.But I would to ask some question regarding cloud and mit app inventor.
But firsty i would like to explain how project should work.
My project is about home security system. When a press button is pressed, it will capture the image of visitor and the home owner will receive picture of the visitor on android app. The android should be able to receive picture and unlock door by pressing button unlock. The camera used is VC0706 Camera connected to Arduino Mega.
My question is that can mit app inventor receive picture from cloud since all of the picture taken will be stored in cloud.
Accessing images and sounds in App Inventor 2
Applications built with App Inventor can access sound, image, and video sources from three different kinds of locations:
Application assets
The sources labeled Media shown in the designer — part of the application's assets — are packaged with the application. Anyone who installs your application will have them, as part of the application. You also specify them in the designer, which is convenient. You can also specify these in programs by their file name: just use the file name without any special prefix. For example, if you have an image asset named kitty.png, you can use it as an image: just set the Picture property of an image component to the text kitty.png. You can similarly use files names for sound (Sound or Player) or video (VideoPlayer).
Assets are the most convenient to use, but the space for them is limited to a few megabytes, because they must be packaged with the application. They are good for small images and short audio selections. Bit you would probably not use them for complete songs or videos.
The phone SD card
You can access files on your phone's SD (secure digital) card using file names that begin with /sdcard . You could play a song on your SDCard by setting the source of a Player component to
/sdcard/Music/Blondie/The Best of Blondie/Heart of Glass.mp3
and starting the Player (assuming of course, that the song file is on the SDCard). Make sure to specify the complete file name, including the "mp3".
The Android system also includes an alternative way to designe SDCard files as URLs. Here you prefix the file name with file:///sdcard and use "URL encoding" for special characters. For example, a space is "%20". So you could designate the same file by setting the player source to
file:///sdcard/Music/Blondie/The%20Best%20of%20Blondie/Heart%20of%20Glass.mp3
Note that you'll want to use a Player component for this, not Sound. A complete song like this is too large for Sound to handle.
Images and videos can be designated similarly.
App Inventor doesn't (yet) include any way to store files on the SD card. It also doesn't (yet) include a way to list the files on the SDCard. You'll have to use other applications or the Android phone file manager for that.
Using the SD Card provides a lot more space for media than trying to package things as assets. The drawback is that users won't automatically get them by installing your application.
URLs and the Web
You can access files on Web using URLs, starting with http:// , for example, setting the picture property of an image to
http://www.google.com/images/srpr/nav_logo14.png
and similarly for music and videos. Make sure you use the link that points to the actual file, not to players for the files, which is much more common on the Web, especially for music and videos.
Other content URLs
The Android system also uses URLs to access various places that media is stored on the phone. For example, the images in the photo gallery can be accessed with file names beginning content://media/external/images/media , as you can see by using the ImagePicker and examining the resulting image path.
App inventor 2 has built-in web storage TinywebDB which stores text strings only.
In your scenario, post the images to somewhere on the web, and then store the image URIs in TinyWebDB insdie App inventor.
Yes, using MIT App Inventor you can send and receive the picture not directly but indirectly. First, you have to convert that image to imagebase64 it means in text formate then decode this text to get the original image. It means you can store any images in clouddb or firebase. Here is the video about that
https://youtu.be/ySruxnxeJgM
Related
I'm not good at English, so I'm sorry if there are any mistakes in the expression.
I want to Object detection application on Android.
Here is how the app works:
Take some videos for which you want to perform object detection
Select a video from the taken videos
Detect specify object and get that coodinates
To develop avobe app,I have some videos for vertification.
Here is my question. Which folder should I put the vertification videos?
For now, I put the videos in raw folder.
But,I am creating an app assuming that the videos were taken with a camera. If so, should it be in the same place as if it were taken by the camera? and, which folder should the videos be placed in?
I'm new to android development.
Could anyone give me some advice? Thank you.
As you are new to Android development I am going to explain in detail.
First you have the videos for verification. You should put those videos in raw folder. But what if the size of those videos is too large? That means the size of your APK will also increase which is not a good thing if you want to upload your app on google play store. In this case, you can store those videos on your own server, and when user installs your app download those videos from the server.
Now let's come to the second question: Where should I put the videos taken with the camera?
You can put these videos in any of the following paths.
context.getFilesDir();
or
context.getExternalFilesDir(null);
These paths are on which you can store the camera-shooted videos and do any processing on them. If you want to know the difference between these two paths that's another topic. You can learn about them here.
I am developing a digital media app using Google's flutter framework which contains songs, movies and etc. The main focus is, these media content should be accessible only through the app and not by outside methods (eg: media players, file browsers).
Eg: A music file which was downloaded through the app should only be played within the app and not by any media player. In that case, there should be an encryption method which should be used to lock these files from outside world.
In this case, bigger files such as Movies should also be taken into consideration. The size of a file can be anywhere between few kbs to 2-3 GBs.
What should be the better approach when solving this problem?
Is it to
Store everything in a database after encrypting the bytes?
Encrypt the entire file and still keep them in the form of "file"?
The downloaded data should also be able to be consumed quickly once the user requested for it. And once the consume is done, the file should be locked again from the rest of the world.
I am not sure if this topic is too broad but somehow I would appreciate it if anyone could provide me with something to start off.
Thank you.
The core part of my application is load PDF online and user have access to download it as per their given rights.
The problem I am facing is that I want to load pdf online. After many research I have found that,
There are likely two ways to show pdf online in android:
1) In Web view by loading simple hosted URL
2) By google doc.
But in our case, if we use way (1), the mobile web view does not redirect hosted url of PDF.
And if we use way (2), then there are certain limitations of the google docs regarding the file sizes. (Small pdf it will load like 5 to 10 with size of 1MB)
But after loading PDF with the size of 2 or 3 MB it's also giving me error as "No PREVIEW AVAILABLE" and its continuously giving me this error opening different urls.
So it seems there is still no easy solution for viewing a pdf from url (online without downloading pdf).
The other way to open pdf online is that we can open it in any other third party applications like browser, adobe pdf reader or any kind of pdf viewer application available in the device.
Cons: If we open pdf in browser then it will get downloaded automatically and if we open it in any third party application then they have options to download the pdf.
Please give me some solution to read the PDF online.
And if there are any paid pdf SDK availble which gives functionality of loading pdf online from URL, then please provide information of that too.
Please also suggest me some pdf viewer library for displaying pdf online.
I have used many of the library, but it increases my application's size to 8 to 10 MB.
Thanks in advance.
The suggested primary solution,
Download the file, store it in the app specific folder so users don't have access. For viewers who don't have access rights to download it, you will delete the file as they leave the view. For viewers who have access rights to download it, they will be given an option to copy the file to their SD card (an accessible location) and then you will delete the original file as they leave the view.
For storing in app specific directory to restrict user access,
http://www.grokkingandroid.com/how-to-correctly-store-app-specific-files-in-android/
Also use a library to view the pdf(MUCH SIMPLER), choose an appropriate one from here
https://android-arsenal.com/search?q=pdf
Alternate solution,
If security is a major concern, you can encrypt the pdf file and store it on the server. And decrypt the file when you download it to the device.
For added security, don't store the file as pdf, just store it as a file. Download it as a file. Set type as pdf when you want to access it.
Conclusion,
Data wise, Even if you load it online, the device will consume almost same data as downloading the pdf. (Infact for viewing something online, your device downloads the data and stores it in the cache and you can view it)
Security wise, only a rooted phone will be able to access the file but that too for as long as you have decided to store it.
I suggest you check out PDF.js, a Javascript library from Mozilla to render PDF's in a browser. You can adapt this into a WebView easily, and display PDF's without downloading them.
Here is an open source app which does something similar to what you're looking for
Working on an Android app that downloads images in JPEG format internally and then displays them within the app.
The issue is that the default Gallery App, shows those images as it scans entire storage for JPEG or PNG files. That causes confusion w/ some users as they do not expect to see internal app images next to their family photos.
My initial thoughts are to rename the extension. But before that, does anyone know if perhaps a simpler way exists by using permissions?
I have a large amount of online images stored on my server. I have created a small java server backend to provide album lists and images per album, including a small management console.
I want to use/view these images on my Android device, by using the standard photo/gallery application. Apps like Google Picasa and Facebook do the same thing.
Eg. When I open up the gallery app, there's a tab called "Albums" where a number of folders are visible, including Picasa/Facebook. Most of these folders can be found on my SD card, but the albums by Picasa/Facebook are only online. Entering these online albums clearly shows the "album structure" you have with that provider ("Profile Pictures" at Facebook for instance).
The question:
How did Picasa/Facebook end up there, and how can I recreate said functionality?
I am almost certain it is done using Content Providers, but I can't even find a simple example when used for images. And unfortunatly, most answers here are providing solutions to the wrong problem.
The secondary question: Would this also be possible with Android's Movie and Music players?