Develop Reference

Rewind button with picasso

I am making an application that generates a random image by a url when touching the button and presents it in the imageview and I use picasso and to change the image you have to clear the cache and I would like someone to tell me how I could go back to the previous image, like a back button
Any help is appreciated from the heart
My code to generate a new image:
nextButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String quest1 = "https://proxxcraft.com/";
Picasso.get().load(quest1).memoryPolicy(MemoryPolicy.NO_CACHE).into(memeRandomView);
Picasso.get().isLoggingEnabled();
}
});

you should save the image as a bitmap, save it in an array or some other data structure. I know how to do it with glide but you should check for how to set callbacks to know when the image is loaded.
private void loadImage() {
Picasso.with(this)
.load("https://proxxcraft.com/")
.into(mContentTarget);
}
private Target mContentTarget = new Target() {
#Override
public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
//save the bitmap in an array so you can use it later.
Imageview.setImageBitmap(bitmap);
}
#Override
public void onBitmapFailed(Drawable errorDrawable) {
}
#Override
public void onPrepareLoad(Drawable placeHolderDrawable) {
}
};

two onclick on activity convert into fragment

I am new to the fragment.
in Activity, I have two onClick methods which are:
click that override the method
normal onclick
how can I change the onclick that override the method to fragment?
private void searchMobileNumber() {
mRecyclerView.addOnItemTouchListener(new SelectExistingOrNewNoFragment.RecyclerTouchListener(PostpaidRegistrationActivity.this, mRecyclerView, new SelectExistingOrNewNoFragment.ClickListener() {
#Override
public void onClick(View view, int position) {
selectedPostion = position;
mob_number_detail_lyt.setVisibility(View.GONE);
mobile_no_head_lyt.setVisibility(View.VISIBLE);
mobile_number_success.setImageDrawable(getResources().getDrawable(R.drawable.validation_correct));
if (simCardFirstTime) {
simCardFirstTime = false;
final Intent intent = new Intent(PostpaidRegistrationActivity.this, MyScanActivity.class);
intent.putExtra("ocrType", "Barcode");
intent.putExtra("message", "Please scan your SIM card");
startActivityForResult(intent, MposConstants.SIMCARD_FIRST_TIME);
}
}
}

If I get this clear, you have two buttons. One of which is to start a fragment or do something with it.. You just need a switch case. Also, use the R class for the cases.
Use view.getId()
Code:
#Override
public void onClick(View view, int position) {
switch(view.getId()){
case R.id.fragment_button:
// do something with fragment
break;
default: break;
}
}

While using the IntentIntegrator from the ZXing library, can I add a flash button to the barcode scanner via the Intent?

I am scanning barcodes and QR codes from an Android app via Intent using the ZXing Library and its port of the Android Application. I added the following two lines in my Gradle dependencies to use the android-integration code without modification:
compile 'com.journeyapps:zxing-android-embedded:3.2.0#aar'
compile 'com.google.zxing:core:3.2.1'
And I am using IntentIntegrator in my Activity to scan a barcode in the onCreate() like this:
integrator = new IntentIntegrator(this);
integrator.setOrientationLocked(false);
integrator.setPrompt(getString(R.string.scanner_text)); // Set the text of the scanner
integrator.setCameraId(0); // Use a specific camera of the device
integrator.setBeepEnabled(true); // Enable beep in the scanner
integrator.setBarcodeImageEnabled(false); // Do not fetch image from the camera
integrator.initiateScan();
Everything works and I get correct scanned result, but I want a flash button in the lower right corner of the scanner like this:
I can already control the flash using the volume up and down keys because I override the CaptureActivity.
Is a flash button like the one above already there in the barcode scanner which can switch between AUTO, ON and OFF mode? If there is, can I use the addExtra() method of the IntentIntegrator to activate it? Or is the only way to implement this would be to modify the entire code according to my needs?

I had overlooked this page on Embedding BarcodeView and these sample activities which show how to customise the Barcode Scanner according to your needs. The example activity that helped me was CustomScannerActivity.
There isn't a option in the IntentIntegrator class to implement a flash button natively. Instead I should make a custom layout for the Barcode Scanner, use it in a custom activity and call this activity from the IntentIntegrator.
I have two activities. One is the ScannerActivity and other one is the CallingActivity. A mistake that confused me for a while was that I created an instance of IntentIntegrator in the onCreate() method of ScannerActivity. It should be in the CallingActivity.
In the example given a Button is used and the text of the Button is changed according to the flash. I created a new Android Layout called activity_custom_scanner where I replaced the Button with a ToggleButton and used images for the button instead to get my desired Flash On/Off Button.
So my ScannerActivity looks like this:
public class CustomScannerActivity extends Activity implements
CompoundBarcodeView.TorchListener {
private static final int BarCodeScannerViewControllerUserCanceledErrorCode = 99991;
private static final String TAG = CustomScannerActivity.class.getSimpleName();
private CaptureManager capture;
private CompoundBarcodeView barcodeScannerView;
private ToggleButton switchFlashlightButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_custom_scanner);
barcodeScannerView = (CompoundBarcodeView)findViewById(R.id.zxing_barcode_scanner);
barcodeScannerView.setTorchListener(this);
switchFlashlightButton = (ToggleButton)findViewById(R.id.switch_flashlight);
switchFlashlightButton.setText(null);
switchFlashlightButton.setTextOn(null);
switchFlashlightButton.setTextOff(null);
// if the device does not have flashlight in its camera,
// then remove the switch flashlight button...
if (!hasFlash()) {
switchFlashlightButton.setVisibility(View.GONE);
}
switchFlashlightButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// Save the state here
if (isChecked) {
barcodeScannerView.setTorchOn();
} else {
barcodeScannerView.setTorchOff();
}
}
});
capture = new CaptureManager(this, barcodeScannerView);
capture.initializeFromIntent(getIntent(), savedInstanceState);
capture.decode();
}
#Override
protected void onResume() {
super.onResume();
capture.onResume();
}
#Override
protected void onPause() {
super.onPause();
capture.onPause();
}
#Override
protected void onDestroy() {
super.onDestroy();
capture.onDestroy();
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
capture.onSaveInstanceState(outState);
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
return barcodeScannerView.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event);
}
/**
* Check if the device's camera has a Flashlight.
* #return true if there is Flashlight, otherwise false.
*/
private boolean hasFlash() {
return getApplicationContext().getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
}
#Override
public void onTorchOn() {
// necessary override..
}
#Override
public void onTorchOff() {
// necessary override..
}
}
And the CallingActivity looks like this:
public class CallingActivity extends Activity {
private static final String TAG = CallingActivity.class.getSimpleName();
private static final int BarCodeScannerViewControllerUserCanceledErrorCode = 99991;
String uuid;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
uuid = getIntent().getStringExtra("uuid");
new IntentIntegrator(this).setOrientationLocked(false).setCaptureActivity(CustomScannerActivity.class).initiateScan();
}
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
if (resultCode == RESULT_OK) {
if (scanResult != null) {
// handle scan result
Log.i(TAG, "Text from Barcode Scanner: " + scanResult.getContents());
getIntent().putExtra("data", scanResult.getContents());
getIntent().putExtra("uuid", uuid);
}
}
else if (resultCode == RESULT_CANCELED) {
getIntent().putExtra("error", "User canceled");
getIntent().putExtra("error_code", BarCodeScannerViewControllerUserCanceledErrorCode);
}
else
{
getIntent().putExtra("error", getString(R.string.scanner_error));
getIntent().putExtra("error_code", BarCodeScannerViewControllerUserCanceledErrorCode);
}
setResult(resultCode, this.getIntent());
this.finish();
}
}
I am not sure if it's the perfect way, but that's how I did it.
Hope it helps someone!

There is a setTorchOn method in CompoundBarcodeView so you can check that method out and try to implement it for your needs. Hope it helps.

This question is probably too old, but you can use the Volume buttons to turn on/off the torch while scanning.

App crashes when using bitmap and mat with OpenCV

So I would like to start developing apps using OpenCV. I want try something simple, read an image, convert it to grayscale and then display it.
When I read it and convert it using Mat, the app works fine. When I read it and display it using Bitmaps it works fine as well. When I combine both, read the image using mat, convert it to bitmap it crashes. I don't have a logcat because I can't play the app straight away from the computer so I have to send the .apk every time ...
I downloaded LogcatBrowser and took a screenshot of what I obtained ...
MainAcvitity.Java code:
public class MainActivity extends Activity {
private Bitmap mBitmap;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
#Override
public void onManagerConnected(int status) {
if (status == LoaderCallbackInterface.SUCCESS ) {
ImageView img = (ImageView)findViewById(R.id.image_view_camera);
Mat m = Highgui.imread("gph.jpg");
//Imgproc.cvtColor(m, m, Imgproc.COLOR_BGR2GRAY);
Bitmap resultBitmap = Bitmap.createBitmap(m.cols(), m.rows(),Bitmap.Config.ARGB_8888);
Utils.matToBitmap(m, mBitmap);
img.setImageBitmap(mBitmap);
} else {
super.onManagerConnected(status);
}
}
};
#Override
public void onResume() {;
super.onResume();
OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_5,this, mLoaderCallback);
}
}

How to stop textureview listener and display an image before closing app

I have a simple xml layout as follow with just a TextureView inside a FrameLayout.
And the following main activity:
public class MainActivity extends Activity
implements TextureView.SurfaceTextureListener {
private static final String TAG = "MainActivity";
// Local references to layout components
private TextureView mTxvCameraPreview;
// Camera manager
private CameraManager mCameraManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Initialize layout and components
setContentView(R.layout.activity_main);
mTxvCameraPreview = (TextureView)findViewById(R.id.txv_camera_preview);
// Camera managing
mCameraManager = new CameraManager(this);
mTxvCameraPreview.setSurfaceTextureListener(this);
}
#Override
protected void onResume() {
super.onResume();
if (mTxvCameraPreview.isAvailable())
mCameraManager.startPreview(mTxvCameraPreview.getSurfaceTexture());
}
#Override
protected void onPause() {
super.onPause();
mCameraManager.stopPreview();
}
#Override
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
mCameraManager.startPreview(surface);
}
#Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
mCameraManager.stopPreview();
return true;
}
#Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {} // Unused
#Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {} // Unused
}
For every frame I do some elaboration and it is OK.
What I want is to add a button which stops the camera and display in the TextureView a file load from sdcard.
A pseudo-code of this can be something like this:
public void onButtonClicked(View view) {
// stop the surface listener (it is needed?)
File imgFile = new File(“/sdcard/Images/elaboration_result.jpg”);
Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
// show myBitmap on TextureView (if possible)
}
It is possible to do this without modifying the xml layout?
Thanks in advance!

You cannot set the content of a TextureView manually, I'm afraid. Your best bet is to make a new ImageView on top of your TextureView and set its image when you need to.
public void onButtonClicked(View view) {
// if we don't need to keep previewing new frames, stop the preview
mCameraManager.stopPreview();
// now, show our ImageView (which should be in front of the TextureView)
Bitmap myBitmap = BitmapFactory.decodeFile(file_path_here);
myImageView.setImageBitmap(myBitmap);
myImageView.setVisibility(View.VISIBLE);
}

No need to create another Image. Just use
textureView.getBitmap(file.getAbsolutePath);