Silverlight CaptureDeviceConfiguration.RequestDeviceAccess() - how does it know? - silverlight

CaptureDeviceConfiguration.RequestDeviceAccess() method must be invoked by user interaction, otherwise it fails. My question is how does Silverlight know the invocation came from user (i.e. via Button.Click())?

Have a look at this: http://liviutrifoi.wordpress.com/2011/05/18/silverlight-isolatedstoragefile-increasequotato/
Quote:
I was curios though how exactly does silverlight know what a user
initiated event is, but after digging through .net framework source
code I’ve got to a dead end:
if ((browserService == null) || !browserService.InPrivateMode())
{
//..
}
return false; //means that IncreaseQuota will fail
where browser.IsInPrivateMode is:
[SecuritySafeCritical]
public bool InPrivateMode()
{
bool privateMode = false;
return (NativeMethods.SUCCEEDED(UnsafeNativeMethods.DOM_InPrivateMode(this._browserServiceHandle, out privateMode)) && privateMode);
}
where DOM_InPrivateMode is in a DllImport["agcore"], which according
to microsoft is confidential :( So it looks like I won’t find out soon
how they’re detecting user initiated events, although I’m guessing
they have some centralized private method that detects clicks for
example, and then probably sets a flag that this was indeed “a user
initiated event”, and since you can’t forge clicks or keypresses using
javascript and since you can’t call those private methods using
reflection, it’s “safe”.

Related

GetNetworkType in Android 11

Following the changes posted here, the getNetworkType method is deprecated from Android R and onwards.
When trying to use this method in a R compiled application, results in the following exception being thrown:
java.lang.SecurityException: getDataNetworkTypeForSubscriber: uid 10225 does not have android.permission.READ_PHONE_STATE.
at android.os.Parcel.createExceptionOrNull(Parcel.java:2285)
at android.os.Parcel.createException(Parcel.java:2269)
at android.os.Parcel.readException(Parcel.java:2252)
at android.os.Parcel.readException(Parcel.java:2194)
at com.android.internal.telephony.ITelephony$Stub$Proxy.getNetworkTypeForSubscriber(ITelephony.java:7565)
at android.telephony.TelephonyManager.getNetworkType(TelephonyManager.java:2964)
at android.telephony.TelephonyManager.getNetworkType(TelephonyManager.java:2928)
at com.ironsource.environment.ConnectivityService.getCellularNetworkType(ConnectivityService.java:197)
at com.ironsource.sdk.service.DeviceData.updateWithConnectionInfo(DeviceData.java:98)
at com.ironsource.sdk.service.DeviceData.fetchMutableData(DeviceData.java:54)
at com.ironsource.sdk.service.TokenService.collectDataFromDevice(TokenService.java:120)
at com.ironsource.sdk.service.TokenService.getRawToken(TokenService.java:177)
at com.ironsource.sdk.service.TokenService.getToken(TokenService.java:166)
at com.ironsource.sdk.IronSourceNetwork.getToken(IronSourceNetwork.java:183)
This is fine and is expected according to the documentation. If I compile the application to any version before Android R, the exception doesn't show.
This exception indicates that I need to request the android.permission.READ_PHONE_STATE permission.
I wanted to know if there is a way to get the network type with any other API that does NOT require this permission (as this permission's level is dangerous and I would rather not ask the user for it).
Take runtime permission for READ_PHONE_STATE to ignore crash of getDataNetworkTypeForSubscriber
#Override
protected void onStart() {
super.onStart();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
int res = checkSelfPermission(android.Manifest.permission.READ_PHONE_STATE);
if (res != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{android.Manifest.permission.READ_PHONE_STATE}, 123);
}
}
}
private final static int REQUEST_CODE_ASK_PERMISSIONS = 1002;
#Override
public void onRequestPermissionsResult(int requestCode,
#NonNull String[] permissions, #NonNull int[] grantResults) {
switch (requestCode) {
case REQUEST_CODE_ASK_PERMISSIONS:
if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getApplicationContext(), "READ_PHONE_STATE Denied", Toast.LENGTH_SHORT)
.show();
} else {
}
stepAfterSplash();
break;
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
You can still use getDataNetworkType(); This method does not necessarily need READ_PHONE_STATE, as stated in his Doc, but that it's sufficient "that the calling app has carrier privileges".
https://developer.android.com/reference/android/telephony/TelephonyManager#getDataNetworkType()
For what I know about getting those privigileges, it could be tricky/really hard, you may look into getting carrier privileges and using this method, which is also the suggested substitution for getNetworkType().
This method necessarily need READ_PHONE_STATE by this way in your activity not just manifest >>>
// Check if the READ_PHONE_STATE permission is already available.
if(ActivityCompat.checkSelfPermission(this,Manifest.permission.READ_PHONE_STATE)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_PHONE_STATE)) {
//here >> use getNetworkType() method
// like this example
mStationInfo.set_networkType(mTelephonyManager.getNetworkType());
}
else {}
We can use ConnectivityManager#getNetworkCapabilities and NetworkCapablities#hasTransport like this
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkCapabilities caps = cm.getNetworkCapabilities(cm.getActivityNetwork());
boolean isMobile = caps.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR);
boolean isWifi = caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI);
Reference:
android.net.NetworkInfo
This class was deprecated in API level 29. Callers should instead use the ConnectivityManager.NetworkCallback API
to learn about connectivity changes, or switch to use
ConnectivityManager#getNetworkCapabilities or
ConnectivityManager#getLinkProperties to get information
synchronously. Keep in mind that while callbacks are guaranteed to be
called for every event in order, synchronous calls have no such
constraints, and as such it is unadvisable to use the synchronous
methods inside the callbacks as they will often not offer a view of
networking that is consistent (that is: they may return a past or a
future state with respect to the event being processed by the
callback). Instead, callers are advised to only use the arguments of
the callbacks, possibly memorizing the specific bits of information
they need to keep from one callback to another.
So my friend I have the same trouble as you but so far I came with a temporary fix I use the compileSdkVersion 29 not 30 as well as the targetSdkVersion 29 and my buildToolsVersion 28.0.3 and my app is loading fine.
Since this problem by me its coming due a third party library so till the fix the error I can not fix it alone, but I think with this temporary solution for now is quite well.

Which control codes have be implemented in the control handler of a service

The SERVICE_STATUS documentation says this structure has to filled out when calling the SetServiceStatus() function.
The third field is dwControlsAccepted.
Unfortunately I have not found any information about which control codes MUST ALWAYS be implemented/react to, at least.
The page says:
By default, all services accept the SERVICE_CONTROL_INTERROGATE value.
But, is there a problem when the service control handler does not react to the SERVICE_CONTROL_STOP control code? Is there a problem when the service control handler does not at least call SetServiceStatus() in this case?
As far as dwControlsAccepted is concerned, there are no mandatory control codes. You can set this value to zero if that meets your needs. Apart from SERVICE_CONTROL_INTERROGATE your code does not need to handle any control codes that you have not specified as acceptable.
For example, if you have not set SERVICE_ACCEPT_STOP then Windows will never send you the SERVICE_CONTROL_STOP control. Any attempt to stop the service will result in error 1052, "The requested control is not valid for this service."
Note that unless you have a specific need to perform a clean shutdown (for example, because you have a database file that has to be properly closed) you do not need to accept shutdown controls either. Such a service will continue to run until the computer is actually powered down.
If you always set dwControlsAccepted to zero, this is all you need for a control handler:
static DWORD WINAPI ServiceHandlerEx(DWORD control, DWORD eventtype, LPVOID lpEventData, LPVOID lpContext)
{
if (control == SERVICE_CONTROL_INTERROGATE)
{
return NO_ERROR;
}
else
{
return ERROR_CALL_NOT_IMPLEMENTED;
}
}

WPF application continues even after explicit shutdown

I have a simple wpf application that continues to run even after I explicitly call it to shut down.
It integrates with a third party application and needs to check that a few documents of a certain type and with specific content are open as it initializes.
Here is a portion of the initialization code:
try
{
ActiveProductDoc = Automation.CATIA.ActiveDocument as ProductDocument;
}
catch
{
InvalidAssemblyShutdown("You must have an assembly open before you run the app");
}
if(ActiveProduct == null)
InvalidAssemblyShutdown("You must have one assembly open (not a part)");
ActiveProduct = ActiveProductDoc.Product;
And here is the InvalidAssemblyShutdown method:
private void InvalidAssemblyShutdown(string message)
{
MessageBox.Show(message);
Close();
Application.Current.Shutdown();
}
I have set the application's ShutdownMode property to OnMainWindowClose.
I am currently doing a use case test where the user has the wrong type of document open and so the ActiveProduct field is null. The InvalidAssemblyShutdown method is called as expected but despite this the line in the initialization method following the shutdown call still runs and throws an exception.
Any ideas what's going on?
Should I throw exceptions instead and use a global exception handler?
If you have a look at the source code for Application.Current.Shutdown (link to source), you'll see that it uses Dispatcher.BeginInvoke() to initiate the shutdown. In other words, the shutdown gets queued on the UI thread. It doesn't take effect during that precise method call, so the following code keeps executing.
You'll need to exit the code right after the call to Application.Current.Shutdown if you don't want some code to run while the shutdown request gets processed. Something like:
if(ActiveProduct == null)
{
InvalidAssemblyShutdown("You must have one assembly open (not a part)");
return; // prevent further code execution.
}
For what it's worth, this.Close() works in a similar way. So if you have proper flow control, you won't need to invoke Application.Current.Shutdown at all. Your call to this.Close() should be enough.

Validation in GWT+GAE-based application

Is there any standard approach to input data validation and error displaying in GWT+GAE-based application?
Eclipse plugin generates GWT project with shared.FieldVerifier class, which provides static method for values validation:
public static boolean isValidName(String name) {
if (name == null) {
return false;
}
return name.length() > 3;
}
isValidName() method is then called on input data in client-side code and server-side code, and if something is wrong, error logics is executed. BTW, I suppose, this approach (set of static validation methods, specific error displaying logics in each case) may be not very scalable.
Also, I found gwt-validation project on code.google.com, but I did not investigate it yet.
Could you please recommend any standard approaches / libraries, which can help to handle validation and error displaying? Is gwt-validation library a standard?
The standard is JSR303 and can be used to validate client side as well on the server side.
Please have a look at this topic:
GWT JSR 303 client validation

Windows Phone 7 close application

Is there any possibility to programatically close Silverlight application on Windows Phone 7?
If you write an XNA Game, you will have access to an explicit Exit() method. If you are writing traditional Silverlight project, then NO, there is no way to programatically close your app. See also Peter Torr's Blog entry on Exiting Silverlight Apps in Windows Phone 7. There he also mentions the option of throwing an unhandled exception, which IMO is a terrible programing style.
An option you may try, is using the WP7 Navigation Service to programatically navigate back out of the application. Not sure if that would work though. Why do you need to Exit?
You can always call an exit by doing this at your landing page use this code on click of your application back button:
if (NavigationService.CanGoBack)
{
while (NavigationService.RemoveBackEntry() != null)
{
NavigationService.RemoveBackEntry();
}
}
This will remove back entries from the stack, and you will press a back button it will close the application without any exception.
Short answer for Silverlight is No.
You should not provide a way to close the applicaiton. Closing the applicaiton should be the users choice and implemented by using the back button the appropriate number of times. This is also a marketplace requirement.
That said, a silverlight application will close if there is an unhandled exception. I have seen a few people try and create programmatic closing by throwing a custom error which is explicitly ignored in error handling. This can work but there is still the marketplace issue.
XNA applications can explictly call Exit().
Some good info here already. Adding to this..
The platform is fully capable of managing closure of apps. The more apps don't provide an exit, the quicker users will become accustomed to not thinking about app house keeping, and let the platform manage it.
The user will just navigate their device using start, back, etc.
If the user wants out of the current app to go do something else quickly - easy - they just hit start.
.Exit(), whilst available for xna, really isn't required anymore either. There was a cert requirement during CTP that games had to provide an exit button. This is now gone.
Non game apps never had the need to implement this.
The more this topic's discussed (and it really has been given a good run around the block), the more the indicators to me suggest there is no need to code an exit.
Update: For those thinking of an unhandled exception as a suitable way of closing an app intentionally or letting the app close due to subpar operating conditions, I would recommend reviewing the comments concerning Application Certification Requirements in this answer. Is there a way to programmatically quit my App? (Windows Phone 7)
Here is another solution.
If you have an error page that i.e. displays error to the end user you can use the
protected override void OnBackKeyPress(System.ComponentModel.CancelEventArgs e)
{
base.OnBackKeyPress(e);
e.Cancel = true;
}
And you can instruct user to press start button to exit application.
Add a reference to Microsoft.Xna.Framework.Game, then call:
new Microsoft.Xna.Framework.Game().Exit();
private void PhoneApplicationPage_BackKeyPress(object sender, System.ComponentModel.CancelEventArgs e)
{
while (NavigationService.CanGoBack)
NavigationService.RemoveBackEntry();
}
That works for me fine.
You can close the app using this statement
Application.Current.Terminate();
This worked perfectly on Windows phone 7
System.Reflection.Assembly asmb = System.Reflection.Assembly.Load("Microsoft.Xna.Framework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=842cf8be1de50553");
asmb = System.Reflection.Assembly.Load("Microsoft.Xna.Framework.Game, Version=4.0.0.0, Culture=neutral, PublicKeyToken=842cf8be1de50553");
Type type = asmb.GetType("Microsoft.Xna.Framework.Game");
object obj = type.GetConstructor(new Type[] { }).Invoke(new object[] { });
type.GetMethod("Exit").Invoke(obj, new object[] { });
Link - source
My 2 pence worth, reasons for an exit
1) there is no interent connection the first time it is run and it needs to create an account on a web service somewhere to run.
2) You need to force an upgrade for the user, again when tied to a web service, you may discover a bug in your app, or have web service changes that mean the user needs to be forced to upgrade, at that point you will want to inform the user that they must upgrade and then exit the app.
Currently in my app I am forced to take the user to a form that says "they" must exit, and if they click back they are again forced back to this page. not very nice.
In Silverlight, I throw an un-handled exception when I have to exit the application. I know that this isn't the graceful method to handle this but it is still the most convenient and easiest solution.
I know that according to the guidelines there shouldn't be any un-handled exceptions in the code but I write why I am explicitly throwing an un-handled exception in the Exception Request document at the time of submission.
Till now this method has always worked and never failed me.
Easiest way to do this is to add a reference to Microsoft.Xna.Framework.Game, then add
using Microsoft.Xna.Framework.GamerServices; before namespace. Then we have a button in our Example.xaml with Click="quit_button". In out Example.xaml.cs we put this code inside our page-class:
private void quit_Click(object sender, EventArgs e)
{
new Microsoft.Xna.Framework.Game().Exit();
//This will close our app
}
var buttonInfo = MessageBox.Show("Are you sure you want to exit?", "Exit", MessageBoxButton.OKCancel);
if (buttonInfo == MessageBoxResult.OK)
{
if (NavigationService.CanGoBack)
{
while (NavigationService.RemoveBackEntry() != null)
{
//
}
}
e.Cancel = false;
}
else
{
//Stop page from navigating
e.Cancel = true;
}
Navigate to App.xaml.cs in your solution explorer and
add a static method to the App class
public static void Exit()
{
App.Current.Terminate();
}
so that you can call it anywhere from your application , as below
App.Exit();

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