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Implement AsyncTask for heavy computation to unblock UI thread #55

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143 changes: 94 additions & 49 deletions android/src/main/java/com/eguma/barcodescanner/BarcodeScannerView.java
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
package com.eguma.barcodescanner;


import android.os.AsyncTask;
import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Color;
Expand Down Expand Up @@ -56,61 +58,104 @@ public void stopCamera() {
mPreview.stopCamera();
}

@Override
public void onPreviewFrame(byte[] data, Camera camera) {
try {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
int width = size.width;
int height = size.height;

if (DisplayUtils.getScreenOrientation(getContext()) == Configuration.ORIENTATION_PORTRAIT) {
byte[] rotatedData = new byte[data.length];
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++)
rotatedData[x * height + height - y - 1] = data[x + y * width];
}

int tmp = width;
width = height;
height = tmp;
data = rotatedData;
}

Result rawResult = null;
PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(data, width, height, 0, 0, width, height, false);
public class ProcessFrameData {
public byte[] data;
public Camera camera;

public ProcessFrameData(byte[] data, Camera camera) {
this.data = data;
this.camera = camera;
}
}

private class ProcessFrameTask extends AsyncTask<ProcessFrameData, Void, Void> {
protected Void doInBackground(ProcessFrameData... objArr) {

byte[] data = objArr[0].data;
Camera camera = objArr[0].camera;

if (source != null) {
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

try {
rawResult = mMultiFormatReader.decodeWithState(bitmap);
} catch (ReaderException re) {
// continue
} catch (NullPointerException npe) {
// This is terrible
} catch (ArrayIndexOutOfBoundsException aoe) {

} finally {
mMultiFormatReader.reset();
}
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
int width = size.width;
int height = size.height;

if (DisplayUtils.getScreenOrientation(getContext()) == Configuration.ORIENTATION_PORTRAIT) {
byte[] rotatedData = new byte[data.length];
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++)
rotatedData[x * height + height - y - 1] = data[x + y * width];
}

int tmp = width;
width = height;
height = tmp;
data = rotatedData;
}

Result rawResult = null;
PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(data, width, height, 0, 0, width, height, false);

if (source != null) {
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
try {
rawResult = mMultiFormatReader.decodeWithState(bitmap);
} catch (ReaderException re) {
// continue
} catch (NullPointerException npe) {
// This is terrible
} catch (ArrayIndexOutOfBoundsException aoe) {

} finally {
mMultiFormatReader.reset();
}
}

final Result finalRawResult = rawResult;

if (finalRawResult != null) {
Log.i(TAG, finalRawResult.getText());
WritableMap event = Arguments.createMap();
event.putString("data", finalRawResult.getText());
event.putString("type", finalRawResult.getBarcodeFormat().toString());
ReactContext reactContext = (ReactContext)getContext();
reactContext.getJSModule(RCTEventEmitter.class).receiveEvent(
getId(),
"topChange",
event);
}
} catch(Exception e) {
// TODO: Terrible hack. It is possible that this method is invoked after camera is released.
Log.e(TAG, e.toString(), e);
}

return null;
}

final Result finalRawResult = rawResult;

if (finalRawResult != null) {
Log.i(TAG, finalRawResult.getText());
WritableMap event = Arguments.createMap();
event.putString("data", finalRawResult.getText());
event.putString("type", finalRawResult.getBarcodeFormat().toString());
ReactContext reactContext = (ReactContext)getContext();
reactContext.getJSModule(RCTEventEmitter.class).receiveEvent(
getId(),
"topChange",
event);
protected void onProgressUpdate(Integer... progress) {

}
} catch(Exception e) {
// TODO: Terrible hack. It is possible that this method is invoked after camera is released.
Log.e(TAG, e.toString(), e);

protected void onPostExecute() {

}
}


public ProcessFrameTask CURRENT_TASK;
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
// only allow one running task
if(CURRENT_TASK == null || CURRENT_TASK.getStatus() == AsyncTask.Status.FINISHED ) {
if(camera != null) {
// AsyncTask expects one parameter, so I wrap data and camera in a class
ProcessFrameData frameDataHeloer = new ProcessFrameData(data, camera);
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@grunch grunch Oct 2, 2016 •
edited
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@AlexSchwabauer Maybe you want to change "frameDataHeloer" for "frameDataHelper" :)

CURRENT_TASK = new ProcessFrameTask();
CURRENT_TASK.execute(frameDataHeloer);
}

}
}
}