im trying to make bluetooth connection from android to NXT LeJos Droid. It works fine in other project, but when i need it for another project , it doesnt want to resolved the getSingleton()
public void onConnectionClicked(View view) {
boolean on = ((ToggleButton) view).isChecked();
// turning it on just sets the flag
if(on) {
conn = MainActivity.connect(CASE_TYPE.LEGO_LCP);
NXTCommand.getSingleton().setNXTComm(conn.getNXTComm());
NXTInfo info = conn.getNXTInfo();
if (info.connectionState== NXTConnectionState.LCP_CONNECTED)
{
isConnected = true;
}
}
// turning it off captures one more frame and starts processing
if(!on) {
try {
conn.getNXTComm().close();
} catch (Exception e) {} finally {
conn = null;
}
}
}
it said unresolved
i tried to fix it by checking the permission and library. I even change attached source inside lejos.nxt.remote.NXTCommand to the path where pccomm.jar located , but it doesnt work. I'd tried clean project .
is there any other way to fix this?
Related
I am trying to turn on hardware acceleration for my application
but I never seem to get a 'true' result from this function.
I tried all the methods in the Android Developers blog post about the
the tag android:hardwareAccelerated=true to the application
and even called
getWindow().setFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED,
WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
You should always call isHardwareAccelearted() after the view is attached to the window. I am not sure about your case as I can't see where actually you are calling it.
Also, the support level of various operations across API levels are mentioned here. I hope this helps.
You can also try this method to verify hardwareAcceleration.
public static boolean hasHardwareAcceleration(Activity activity) {
// Has HW acceleration been enabled manually in the current window?
Window window = activity.getWindow();
if (window != null) {
if ((window.getAttributes().flags
& WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED) != 0) {
return true;
}
}
// Has HW acceleration been enabled in the manifest?
try {
ActivityInfo info = activity.getPackageManager().getActivityInfo(
activity.getComponentName(), 0);
if ((info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0) {
return true;
}
} catch (PackageManager.NameNotFoundException e) {
Log.e("Chrome", "getActivityInfo(self) should not fail");
}
return false;
}
For checking for View try this.
chat_wv.post(new Runnable() {
#Override
public void run() {
Log.e("isHardwareAccelerated", ""+chat_wv.isHardwareAccelerated());
}
});
I am trying billow Code from this answer to check if the permission is enabled. but it is returning false even when the permission is enabled from the settings.
public static boolean canDrawOverlayViews(Context con){
if(Build.VERSION.SDK_INT< Build.VERSION_CODES.LOLLIPOP){return true;}
try {
return Settings.canDrawOverlays(con);
}
catch(NoSuchMethodError e){
return canDrawOverlaysUsingReflection(con);
}
}
public static boolean canDrawOverlaysUsingReflection(Context context) {
try {
AppOpsManager manager = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
Class clazz = AppOpsManager.class;
Method dispatchMethod = clazz.getMethod("checkOp", new Class[] { int.class, int.class, String.class });
//AppOpsManager.OP_SYSTEM_ALERT_WINDOW = 24
int mode = (Integer) dispatchMethod.invoke(manager, new Object[] { 24, Binder.getCallingUid(), context.getApplicationContext().getPackageName() });
return AppOpsManager.MODE_ALLOWED == mode;
} catch (Exception e) { return false; }
}
Recently I've also faced the same issue and got the following workaround .
Referenced from
https://code.google.com/p/android/issues/detail?id=198671#c7
public boolean getWindoOverLayAddedOrNot2() {
String sClassName = "android.provider.Settings";
try {
Class classToInvestigate = Class.forName(sClassName);
if (context == null)
context = activity;
Method method = classToInvestigate.getDeclaredMethod("isCallingPackageAllowedToDrawOverlays", Context.class, int.class, String.class, boolean.class);
Object value = method.invoke(null, context, Process.myUid(), context.getPackageName(), false);
Log.i("Tag", value.toString());
// Dynamically do stuff with this class
// List constructors, fields, methods, etc.
} catch (ClassNotFoundException e) {
// Class not found!
} catch (Exception e) {
// Unknown exception
e.printStackTrace();
}
return false;
}
does the check involves the device admin?
I have encountered this problem when disabling device admin, I have checked this permission in the DeviceAdminReceiver->onDisabled() and on some devices, and canDrawOverlays returned false, despite the fact i had the permission.
The above answer helped sometimes but not all the time. the thing that did work is Thread.sleep before the check.
try {
Thread.sleep(20);
} catch (InterruptedException e) {
// some exception here
}
The minimal time that worked for me was 20 millis. than canDrawOverlays returned true
Note: this is not a good practice however this is the only thing that worked for me
Based on BennyP's answer, I've made a Runnable run the required code after 500ms and that worked very well. The feedback is a bit delayed, but the user won't even notice the delay.
This is the code I've added to my onResume()
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
if(!Settings.canDrawOverlays(ControllerActivity.this)){
//Handle overlay permission not given here
}
else{
//Handle overlay permission given here
}
}
}, 500);
Hope it helps!
I tried restarting the activity after the user accessed the setting . This is code :
public static void restartActivity(Activity act){
Intent intent = getIntent();
finish();
startActivity(intent);
}
First of all, I am really very surprised with this strange behaviour of
Settings.canDrawOverlays(this);
I also faced the same issue with its usage, it was returning false even if the permission is already assigned.
What I noticed that, I was using this check in my onStart() method, where it was creating this wired behavior. To resolve this, I searched over internet and no result was there that can satisfy me and the one I can use.
Solution
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
Log.e("Overlay Permission", "" + Settings.canDrawOverlays(this));
if (!Settings.canDrawOverlays(this)) {
MyPreferences.saveBoolean(HomeScreen.this, "showOverlayPermissionDialog", true);
} else {
MyPreferences.saveBoolean(HomeScreen.this, "showOverlayPermissionDialog", false);
}
}
I did something lake this, in my onCreate(). Here I saved the values accordingly in my SharedPreferences, and according to these Shared Preference values, I created a check for showing an overlay dialog in my onStart(). This worked fine!
You can try this solution, and mark this answer useful if your problem is solved.
Thanks
i'm trying to make an app by using calimero library for KNX. In my app, i use some buttons, switches, togglebuttons, etc to switch on/off the lights.
With 'Button', everything works well. I can switch on/off a light or open/close curtains.
private class button9OnClickListener implements View.OnClickListener {
public void onClick(View view){
try {
falseTask dt = new falseTask();
String adr = "5/1/0";
dt.execute(adr);
} catch (Exception e) {
}
}
}
But when i use 'Switch' with either OnClickListener or OnCheckedChangeListenser, it crash.
private class switch1OnCheckedChangeListener implements CompoundButton.OnCheckedChangeListener {
public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
if(compoundButton.isChecked()) {
try {
trueTask dt = new trueTask();
String adr = "5/4/6";
dt.execute(adr);
} catch (Exception e) {
e.printStackTrace();
}
} else {
try {
falseTask dt = new falseTask();
String adr = "5/4/6";
dt.execute(adr);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
the problem is below:
uncaughtException java.lang.RuntimeException: An error occured while executing doInBackground()
and here's my doInBackground
protected String doInBackground(String...strings){
String adr = strings[0];
try {
final InetSocketAddress localEP = new InetSocketAddress(InetAddress.getByName(hostip), 0);
final InetSocketAddress remoteEP = new InetSocketAddress(remoteip, knxServerPort);
knxLink = new KNXNetworkLinkIP(KNXNetworkLinkIP.TUNNEL, localEP, remoteEP, true, TPSettings.TP1);
pc = new ProcessCommunicatorImpl(knxLink);
pc.write(new GroupAddress(adr), true);
knxLink.close();
}
catch (final KNXException e) {
}
catch (final UnknownHostException e) {
}
return null;
}
i'm new to java and android programming. Can you help with this problem? i can't understand why this work for 'button' but not for 'switch'.
Thank you in advance
UPDATE
I copy my code and try with eclipse. Everything work fine. I can switch on/off the light i want and there is no error.
With android studio, it did not work. Someone know the reason?
I tried with ToggleButton and Switch in Eclipse. All work good. I put exactly what I used in android studio. I copy all the code without any change. Can't understand the problem.
Finally I find the problem. I use 2 Bundle in the MainActivity and I use these 2 Bundle in doInBackground for my AsyncTask in the SecondActivity. But I just pass on the first Bundle to the SecondActivity and I forget to pass on the second Bundle. So I got error while executing doInBackground() What foolish mistake I have made...
I have a DropboxHelper Class that is handling downloading and uploading from dropbox.
Downloading works fine but when I try to upload from dropbox the first time the code is called. The following Line is false
if (dropboxFileSystem.isFile(dropboxPath)) {
}
It returns false. Tell the app to try again and this time it sees the file and uploads it to the app. Below is some of the code I am using for the class. Debug seems to incdicate the dropbox api has not completing started / synced the first time
public class DropBoxHelper {
public DropBoxHelper(Context pContext) {
context = pContext;
defineVariables();
}
private void defineVariables() {
dropboxAccountManager = DbxAccountManager.getInstance(context.getApplicationContext(), DROPBOX_APP_KEY, DROPBOX_APP_SECRET);
dropboxPath = new DbxPath(DbxPath.ROOT, DROPBOX_FILE_NAME);
}
public boolean importFromDropbox() {
try {
dropboxFileSystem = DbxFileSystem.forAccount(dropboxAccountManager.getLinkedAccount());
if (dropboxFileSystem.isFile(dropboxPath)) {
DbxFile databaseFileonDropbox = dropboxFileSystem.open(dropboxPath);
try {
// Do Copy
} finally {
Log.i(DEBUG_TAG, "Closing File");
databaseFileonDropbox.close();
}
}
Any ideas on why the copy fails first time.
Thanks
I'm not 100% sure, but I believe you need to use dropboxFileSystem.awaitFirstSync() to make sure at least one sync with the server has happened before you try to find the file.
An alternative might be to just call dropboxFileSystem.open(...) directly and handle the exception that's raised if the file doesn't exist.
There is any way I can enable Android NFC reader using API?
So apparently there is no way to enable the NFC from the API, even though Google does so within their source code (see below).
If you look at a line from the API for NfcAdapter.isEnabled():
Return true if this NFC Adapter has
any features enabled.
Application may use this as a helper
to suggest that the user should turn
on NFC in Settings.
If this method returns false, the NFC
hardware is guaranteed not to generate
or respond to any NFC transactions.
It looks like there is no way to do it within the API. Bummer. Your best bet is a dialog to inform the user they need to enable it in the settings, and perhaps launch a settings intent.
EDIT: The following is from the source, but it looks like they didn't allow the user to implement the methods in the API (I'm confused about this).
I found this from the android source code to help enable and disable the adapter.
Relevant source:
public boolean onPreferenceChange(Preference preference,
Object value) {
// Turn NFC on/off
final boolean desiredState = (Boolean) value;
mCheckbox.setEnabled(false);
// Start async update of the NFC adapter state, as the API is
// unfortunately blocking...
new Thread("toggleNFC") {
public void run() {
Log.d(TAG, "Setting NFC enabled state to: "
+ desiredState);
boolean success = false;
if (desiredState) {
success = mNfcAdapter.enable();
} else {
success = mNfcAdapter.disable();
}
if (success) {
Log.d(TAG,
"Successfully changed NFC enabled state to "
+ desiredState);
mHandler.post(new Runnable() {
public void run() {
handleNfcStateChanged(desiredState);
}
});
} else {
Log.w(TAG, "Error setting NFC enabled state to "
+ desiredState);
mHandler.post(new Runnable() {
public void run() {
mCheckbox.setEnabled(true);
mCheckbox
.setSummary(R.string.nfc_toggle_error);
}
});
}
}
}.start();
return false;
}
I got it working through reflection
This code works on API 15, haven't checked it against other verions yet
public boolean changeNfcEnabled(Context context, boolean enabled) {
// Turn NFC on/off
final boolean desiredState = enabled;
mNfcAdapter = NfcAdapter.getDefaultAdapter(context);
if (mNfcAdapter == null) {
// NFC is not supported
return false;
}
new Thread("toggleNFC") {
public void run() {
Log.d(TAG, "Setting NFC enabled state to: " + desiredState);
boolean success = false;
Class<?> NfcManagerClass;
Method setNfcEnabled, setNfcDisabled;
boolean Nfc;
if (desiredState) {
try {
NfcManagerClass = Class.forName(mNfcAdapter.getClass().getName());
setNfcEnabled = NfcManagerClass.getDeclaredMethod("enable");
setNfcEnabled.setAccessible(true);
Nfc = (Boolean) setNfcEnabled.invoke(mNfcAdapter);
success = Nfc;
} catch (ClassNotFoundException e) {
} catch (NoSuchMethodException e) {
} catch (IllegalArgumentException e) {
} catch (IllegalAccessException e) {
} catch (InvocationTargetException e) {
}
} else {
try {
NfcManagerClass = Class.forName(mNfcAdapter.getClass().getName());
setNfcDisabled = NfcManagerClass.getDeclaredMethod("disable");
setNfcDisabled.setAccessible(true);
Nfc = (Boolean) setNfcDisabled.invoke(mNfcAdapter);
success = Nfc;
} catch (ClassNotFoundException e) {
} catch (NoSuchMethodException e) {
} catch (IllegalArgumentException e) {
} catch (IllegalAccessException e) {
} catch (InvocationTargetException e) {
}
}
if (success) {
Log.d(TAG, "Successfully changed NFC enabled state to "+ desiredState);
} else {
Log.w(TAG, "Error setting NFC enabled state to "+ desiredState);
}
}
}.start();
return false;
}//end method
This requires 2 permissions though, put them in the manifest:
<!-- change NFC status toggle -->
<uses-permission android:name="android.permission.NFC" />
<uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS" />
The NFC button's state switches accordingly when the code is used, so there are no issues when doing it manually in the seetings menu.
If you can see the NfcService Application Source Code, there is a Interface file INfcAdapter.aidl. In the file two API's are there namely "boolean enable()" and "boolean disable()". You can directly use this API's to enable and disable NfcService through an android application. But the trick over here is that you can not compile the code using SDK provided by the Android. You have to compile the application using the a makefile. I have successfully build a application.
I hope this forum would be help you to resolve this issue as well to get the clear understanding on the NFC power on/off API barries.
http://ranjithdroid.blogspot.com/2015/11/turn-onoff-android-nfc-by.html