The camera is used after calling Camera.release (). So, looking at the life cycle of an activity, you need to open the camera in onStart () or in onRestart (). So maybe this code will work fine ...
package com.example.gkvxm.materiallight;
import android.animation.ValueAnimator;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.widget.Toast;
import com.dd.CircularProgressButton;
import java.io.IOException;
public class FlashLightActivity extends Activity implements SurfaceHolder.Callback {
private boolean isLigtOn = false;
private Camera camera;
@Override
protected void onStart(){
super.onStart();
camera = Camera.open();
final Camera.Parameters p = camera.getParameters();
SurfaceView preview = (SurfaceView)findViewById(R.id.PREVIEW);
SurfaceHolder mHolder = preview.getHolder();
mHolder.addCallback(this);
}
@Override
protected void onStop(){
super.onStop();
if(camera!=null){
camera.release();
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_flash_light);
Context context = this;
PackageManager pm = context.getPackageManager();
if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Toast.makeText(FlashLightActivity.this, "Your Device is not supported", Toast.LENGTH_SHORT).show();
Log.e("err", "Device is not supported");
return;
}
camera = Camera.open();
final Camera.Parameters p = camera.getParameters();
final CircularProgressButton circularButton1 = (CircularProgressButton) findViewById(R.id.btnWithText);
circularButton1.setIndeterminateProgressMode(true);
circularButton1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (isLigtOn) {
turnOffFlash(p);
Toast.makeText(FlashLightActivity.this, "Lights Off!", Toast.LENGTH_SHORT).show();
} else {
turnOnFlash(p);
Toast.makeText(FlashLightActivity.this, "Lights On!", Toast.LENGTH_SHORT).show();
}
if (circularButton1.getProgress() == 0) {
simulateSuccessProgress(circularButton1);
} else {
circularButton1.setProgress(0);
}
}
});
}
private void turnOnFlash(Camera.Parameters p){
p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
camera.startPreview();
isLigtOn = true;
}
private void turnOffFlash(Camera.Parameters p){
p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
isLigtOn = false;
}
@Override
public void surfaceChanged(SurfaceHolder holder,int format,int width,int height){
}
@Override
public void surfaceCreated(SurfaceHolder holder){
try{
Log.i("SurfaceHolder","Setting preview");
camera.setPreviewDisplay(holder);
} catch (IOException e){
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder){
Log.i("SurfaceHOlder", "stopping preview");
camera.stopPreview();
holder = null;
}
private void simulateSuccessProgress(final CircularProgressButton button) {
ValueAnimator widthAnimation = ValueAnimator.ofInt(1, 100);
widthAnimation.setDuration(1500);
widthAnimation.setInterpolator(new AccelerateDecelerateInterpolator());
widthAnimation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
Integer value = (Integer) animation.getAnimatedValue();
button.setProgress(value);
}
});
widthAnimation.start();
}
private void simulateErrorProgress(final CircularProgressButton button) {
ValueAnimator widthAnimation = ValueAnimator.ofInt(1, 99);
widthAnimation.setDuration(1500);
widthAnimation.setInterpolator(new AccelerateDecelerateInterpolator());
widthAnimation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
Integer value = (Integer) animation.getAnimatedValue();
button.setProgress(value);
if (value == 99) {
button.setProgress(-1);
}
}
});
widthAnimation.start();
}
}