Can someone tell me if creating barcode scanner app (for Android) is difficult? Is OpenCV library good start? Where can I find algorithm which clearly explains how to read barcodes? I will appreciate all good materials about this topic!
Thanks in advance!
The ZXing project provides a standalone barcode reader application which — via Android's intent mechanism — can be called by other applications who wish to integrate barcode scanning.
The easiest way to do this is to call the ZXing SCAN Intent from your application, like this:
public Button.OnClickListener mScan = new Button.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
startActivityForResult(intent, 0);
}
};
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == 0) {
if (resultCode == RESULT_OK) {
String contents = intent.getStringExtra("SCAN_RESULT");
String format = intent.getStringExtra("SCAN_RESULT_FORMAT");
// Handle successful scan
} else if (resultCode == RESULT_CANCELED) {
// Handle cancel
}
}
}
Pressing the button linked to mScan would launch directly into the ZXing barcode scanner screen (or crash if ZXing isn't installed). Once a barcode has been recognised, you'll receive the result in your Activity, here in the contents variable.
To avoid the crashing and simplify things for you, ZXing have provided a utility class which you could integrate into your application to make the installation of ZXing smoother, by redirecting the user to the Android Market if they don't have it installed already.
Finally, if you want to integrate barcode scanning directly into your application without relying on having the separate ZXing application installed, well then it's an open source project and you can do so! :)
You can use the existing Zebra Crossing barcode scanner for Android, available at: http://code.google.com/p/zxing/. Typically the idea is that you would invoke it via intents, like in the example here: http://code.google.com/p/zxing/wiki/ScanningViaIntent.
Zebra Crossing is the best documented java 1D or 2D barcode decoder or encoder around. Lots of people use it, and it's become the de facto standard for android. There's a healthy buzz about it on here too.
RedLaser has an api, but you'll have to pay if you use it in production. When I tried it out, I didn't find it to be a spectacular improvement over Zebra Crossing. Certainly not for the price.
jjil does barcodes but there are only 3 committers on the project, and I've never used it myself so I don't know what to tell you about it. Its source is certainly readable.
Once you start reading, you'll find readers are tricky things to implement due to blurry images, noise, distortion, weird angles, and so forth. So if you want something reliable, you probably want to go with a community-maintained library.
You can use zbar library. Download it from:
http://sourceforge.net/projects/zbar/files/AndroidSDK/
I think this is more fast and accurate than zxing.
Related
I'm currently working on making an Android app, but have been having some trouble. I want to be able to push a button with the title of the document as it's TextView and then have that document open to be read. I've looked around for guides but everything I've found is either out of date or doesn't explain any of the code shown. Does anyone know how I can put such a thing in my app? At this point, I'm not even sure where to start with the process.
Note, I'm working in Java not Kotlin.
UPDATE: I was directed to a solution using intents. Now there seems to be an issue loading the file. My code is this:
public class atotf_pdf extends literature {
File file = new File("/storage/emulated/0/AToTF Preview.pdf");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
Uri pdfURI = FileProvider.getUriForFile(atotf_pdf.this, "net.whispwriting.whispwriting.provider", file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(pdfURI, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
startActivity(intent);
}
Is it something here that's causing the error?
It looks like the file is somehow not being stored in the filesystem when the app is installed.
Just like #ruben said, you could use a WebView for such a task: https://developer.android.com/reference/android/webkit/WebView. For more information about using WebView to display content, you can take a look at this post: How can I display a pdf document into a Webview?
Another potential solution could be using intents, which has also been discussed before: How to open a PDF via Intent from SD card
Hopefully this helps!
I have implemented Google Maps in my App and doing reverse geocoding when clicking on map.Im using This API. but it gives me more than one result on Single tap. I know why Google behave like this.
Then I look into PlacePicker widget for Android, but Im unable to use that widget without opening another Map screen to pick place.
What I want is that I want to use my Google Map screen to get tapped place instead of opening PlacePicker screen. I just want PlacePicker work with my implemented Map i.e want PlacePicker to respond map click and give place without opening widget if this is not possible then inform me about other solution to get exactly one and correct place on Map tap? Thank you in advance
Updated
Why Im getting closed vote for question? it is not too broad? Simply,I want to know whether is it possible to use Google Map (MapView|SuportFragment) as PlacePicker's main screen. Have look code below
int PLACE_PICKER_REQUEST = 1;
PlacePicker.IntentBuilder builder = new PlacePicker.IntentBuilder();
// I don't want this line, Don't want PlacePicker to open another Map Screen to allow user to pick place.
startActivityForResult(builder.build(this), PLACE_PICKER_REQUEST);
now look at below code
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == PLACE_PICKER_REQUEST) {
if (resultCode == RESULT_OK) {
Place place = PlacePicker.getPlace(data, this);
String toastMsg = String.format("Place: %s", place.getName());
Toast.makeText(this, toastMsg, Toast.LENGTH_LONG).show();
}
}
}
above code is executed when user pick a place from PlacePicker screen and that screen returns a Intent with picked place. Is there any way to make that type of 'Intent' on Google Map tap with lat,lng? so that I could get Place detail. I don't want to user reverse geocoding as it gives me many results.
I Donot know anything about the google geo api or PlacePicker api.
The google independent android standard way would be to use "ACTION_PICK" with a geo uri.
For more infos see https://github.com/k3b/k3b-geoHelper/wiki/Android-Geo-howto.
This only works if you have installed a geo-pick-aware app that supports geo-pick.
Note: you do not have to use the lib. All you need to do is to decode the geo-uri returned by activity result
I have found solution to my problem, To get rid of reverse geocoding to many results and to get clicked place I use following code
googleMap.setOnPoiClickListener(new GoogleMap.OnPoiClickListener() {
#Override
public void onPoiClick(PointOfInterest pointOfInterest) {
String SS="";
isPOI=true;
poiPlaceID=pointOfInterest.placeId;
// Then using Google PlaceDetail API with placeId, It gives me exact Location click
}
});
I am trying to add a button in my application that starts Google Voice Typing (or the default speech recognition). I have tried following this tutorial. This tutorial is incredibly confusing to me. I imported the .jar, and added the necessary permissions, services, and activities to my Manifest. But I can't seem to figure out how to "put it all together". I'm wondering:
Am I supposed to call the inputMethodService from my button click in my Main Activity? Or does my inputMethodService essentially become my Main Activity?
What does IME mean? I tried to Google it, but the definitions it gave me didn't help my understanding.
When I try to copy and paste the whole DemoInputMethodService code into my current activity, I get an error saying I cannot extend InputMethodService inside of this activity. (Which leads back to to ask question one.)
How can I get this to work?
If you want to follow the tutorial that you mention then you need to implement an IME (input method editor) first, see http://developer.android.com/guide/topics/text/creating-input-method.html
This IME can have a regular keyboard look-and-feel or contain just a microphone button.
The user of your app will first have to click on a text field to launch the IME. (Note that there can be several IMEs installed on the device and they have to be explicitly enabled in the Settings.) Then the user will have to click on the microphone button to trigger the speech recognition.
The tutorial provides a jar that lets you directly call Google's recognizer. It would be nicer if instead you called the recognizer via the SpeechRecognizer-interface (http://developer.android.com/reference/android/speech/SpeechRecognizer.html), this way the user can decide whether to use Google's or something else.
The SpeechRecognizer is given a listener which supports the method onPartialResults, which allows you to monitor the recognition hypotheses while the user is speaking. It's up to you how you display them. Note however that the specification of SpeechRecognizer does not promise that this method gets called. This depends on the implementation of the recognizer service. Regarding Google's implementation: what it supports keeps changing unannounced, it does not have a public API nor even release notes.
You might be able to reuse my project Kõnele (http://kaljurand.github.io/K6nele/about/), which contains two implementations of SpeechRecognizer and an IME that uses them. One of the implementations offers continuous recognition of arbitrarily long audio input, using the Kaldi GStreamer server (https://github.com/alumae/kaldi-gstreamer-server). You would need to set up your own instance of the server porting it to the language that you want to recognize (unless you want to use the Estonian server that Kõnele uses by default).
Voice recognition samples are found where you have the android SDK..
example:
$ find $SDK_ROOT/samples -name *recogni*
./android-19/legacy/VoiceRecognitionService/res/xml/recognizer.xml
./android-19/legacy/VoiceRecognitionService/src/com/example/android/voicerecognitionservice
./android-19/legacy/ApiDemos/res/layout/voice_recognition.xml
./android-18/legacy/VoiceRecognitionService/res/xml/recognizer.xml
./android-18/legacy/VoiceRecognitionService/src/com/example/android/voicerecognitionservice
./android-18/legacy/ApiDemos/res/layout/voice_recognition.xml
./android-21/legacy/VoiceRecognitionService/res/xml/recognizer.xml
./android-21/legacy/VoiceRecognitionService/src/com/example/android/voicerecognitionservice
./android-21/legacy/ApiDemos/res/layout/voice_recognition.xml
any one of the services should help show how to do a RecognizerIntent
The "APIDemo" seems to include use of a RecognizerIntent. check the source for that one. Otherwise look into the services and carve them up into an intent.
I had the same issue, but after a long time looking for continuous voice dictation on an activity, I solved that problem using pocketsphinx.
I couldn't find the way to integrate Google Voice Typing on an activity, just on an input method by following that tutorial. If it confuse you, just download this demo and modify it.
Good Luck!
You can trigger an intent from a button listener
Intent checkIntent = new Intent();
checkIntent.setAction(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
startActivityForResult(checkIntent, MY_DATA_CHECK_CODE);
And the result can be get from
private TextToSpeech mTts;
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == MY_DATA_CHECK_CODE) {
if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS) {
// success, create the TTS instance
mTts = new TextToSpeech(this, this);
} else {
// missing data, install it
Intent installIntent = new Intent();
installIntent.setAction(
TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
startActivity(installIntent);
}
}
}
Refer this link for more info.
I am working on application that will record the voice of the user and save the file on the SD card and then allow the user to listen to the audio again.
I am able to allow the user to record his voice using the RecognizerIntent, but I cant figure out how to save the audio file and allow the user to hear the audio. I would appreciate it if someone could help me out. I have displayed my code below:
// Setting up the onClickListener for Audio Button
attachVoice = (Button) findViewById(R.id.AttachVoice_questionandanswer);
attachVoice.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent voiceIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
voiceIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
voiceIntent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Please Speak");
startActivityForResult(voiceIntent, VOICE_REQUEST);
}
});
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == VOICE_REQUEST && resultCode == RESULT_OK){
}
There is an example of how to do audio capture using MediaRecorder in the Android Developer Documentation.
I would recommend saving the files on the SD Card and then have your gallery code check the SD card to see which files to display. You can get the directory of the SD Card using the Environment.getExternalStorageDirectory() method. It would be best to save your files in a subdirectory of the SD Card root directory.
Make sure you give your applications the Permissions it will need. At the very least it will need RECORD_AUDIO and WRITE_EXTERNAL_STORAGE.
Also you have to see these tutorials:
http://www.androiddevblog.net/android/android-audio-recording-part-1
http://www.androiddevblog.net/android/android-audio-recording-part-2
If you really want to record audio via the speech recognition API then you could use the RecognitionService.Callback which has a method
void bufferReceived(byte[] buffer)
This gives you access to the recorded audio buffer as speech is being recorded and recognized. (No information is provided about the sample rate though.) You can then save the obtained buffers into a file for a later playback. I think keyboard apps use this call to display the waveform of the recorded speech. You have to implement the UI yourself.
The bare RecognizerIntent.ACTION_RECOGNIZE_SPEECH just returns a set of words/phrases without any audio.
I have just made application using BarCode scanner (ZXing 1.7). User doesn't use bar code scanner on his phone, therefore I can't add external Bar Code scanner into my application. I have added ZXing sources for into my project, but I don't know how I can execute it without intents. Please, help me.
Update: or how can I make that external bar code scanner will be installed automatically with my application?
You can't install the external barcode scanner to be installed automatically. What you could do is to check if it is installed, and if not show a dialog asking the user wether they want to install it (this will take the user to the app market link).
If you want to avoid this, you can integrate directly the ZXing library but it requires more work. The barcode scanner app is open source so you can see how to do it from there.
If the zxing barcode scanner is installed in the mobile, its very easy:
Intent intent = new Intent(
"com.google.zxing.client.android.SCAN");
intent.putExtra("SCAN_MODE", "PRODUCT_MODE");//for Qr code, its "QR_CODE_MODE" instead of "PRODUCT_MODE"
intent.putExtra("SAVE_HISTORY", false);//this stops saving ur barcode in barcode scanner app's history
startActivityForResult(intent, 0);
and in OnActivityResult:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 0) {
if (resultCode == RESULT_OK) {
String contents =
data.getStringExtra("SCAN_RESULT"); //this is the result
}
else if (resultCode == RESULT_CANCELED) {
// Handle cancel
}
If its not installed: u can put this code in try-catch block and catching the exception, u can do this:
Uri marketUri = Uri
.parse("market://details?id=com.google.zxing.client.android");
Intent marketIntent = new Intent(Intent.ACTION_VIEW,
marketUri);
startActivity(marketIntent);
So it redirects the app to android market and ur app continues running once if the barcode scanner is installed.
If u dont want to use the other app in ur app, U have to download zxing library and try using the classes from core.jar file(it is created using apache ant). Follow this tutorial to do that: http://code.google.com/p/zxing/wiki/GettingStarted
Just use the provided Intent-based integration code. It's very easy. It will send the user to Market to download the app. This is much better than trying to automatically install it for at least three reasons. First, I do not think users expect apps to install other apps and probably don't like it. Second it will only possibly work if the user has set the device to allow third-party apps from outside Market. Finally, you will be installing a potentially old version.