I'm trying to figure out if it's possible to track when Safari is done loading a page request. I call Safari to open using this code:
// Open Safari
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:#"http://www.example.com/" description]]];
But, since my app goes to the background, it may be suspended (and not able to execute code). Is this even possible to do within Xcode 4?
EDIT
The reason why I am doing this is because the UIWebView and Safari are not running at the same level and I want to do some performance related testing on some websites.
So, if you'd like to see how I did it for jailbroken iOS (instead of the quite boring "Not possible"): I basically hooked safari to get access to the particular method that is called when the page has finished loaing. Using MobileSubstrate (filter for com.apple.mobilesafari when injecting your dynamic library):
#import <substrate.h>
#import <UIKit/UIKit.h>
/* Some globals */
static IMP _orig_1, _orig_2;
static id tabController;
id _mod_1(id __self, SEL __cmd, CGRect frame, id tabDocument);
void _mod_2(id __self, SEL __cmd, id doc, BOOL error);
/* The library constructor */
__attribute__((constructor))
static void init()
{
Class tabClass;
tabClass = objc_getClass("TabController");
MSHookMessageEx(tabClass, #selector(initWithFrame:tabDocument:),
(IMP)_mod_1, &_orig_1);
MSHookMessageEx(tabClass, #selector(tabDocument:didFinishLoadingWithError:),
(IMP)_mod_2, &_orig_2);
}
/* This hook merely captures the TabController of Safari. */
id _mod_1(id __self, SEL __cmd, CGRect frame, id tabDocument)
{
__self = _orig_1(__self, __cmd, frame, tabDocument);
tabController = __self;
return __self;
}
/* This is called when the page loading is done */
void _mod_2(id __self, SEL __cmd, id doc, BOOL error)
{
/* Make sure you always call the original method */
_orig_2(__self, __cmd, doc, error);
/* then do what you want */
}
This is not possible in general.
One thing you could do is from the page to be loaded, do a redirect to your application's URL scheme, which will launch your app. For more information on this matter, look at the -[UIApplicationDelegate application:openURL:sourceApplication:annotation:] method.
I don't think your application can reject the activation through such an URL scheme, so this means that your application will become active. Maybe the return value of the above method (which is a boolean) can be used, you'll have to test that.
This method also assumes that you have access to the page you're opening, so that you can add the redirect.
No, this is not possible. You can do this if you open the link in a UIWebView within your own application, however.
Related
The desired output looks like this,
how to show this on click event programmatically using flutter(even with native code if possible), it's really appreciated if anyone could show an example.
If there is no direct approach to this then a platform specific example using MethodChannel is also very welcome. Native code example must be in Objective C.
Additionally I have tried to use flutter_to_airplay but project fails to run and also has other functionalities that are not needed in this context, what is needed is showing Airplay panel only.
(Answer by M123 native code completely not working)
Here is a example how to open the AirPlayPanel in objective c.
Setup flutter
First you have to create a channel. To start communicating to the native code.
All channel names used in a single app must be unique; prefix the
channel name with a unique ‘domain prefix
static const platform = const MethodChannel('stack.M123.dev/airplay');
Then you have to invoke a method on the method channel.
Future<void> _openAirPlay() async {
try {
await platform.invokeMethod('openAirPlay');
} on PlatformException catch (e) {
print('error');
}
}
Native part
Now the flutter part is done.
First you have to add suppport for swift. For this open the ios folder in the flutter root with XCode.
Expand Runner > Runner in the Project navigator.
Open the AppDelegate.m located under Runner > Runner in the Project navigator.
Create a FlutterMethodChannel and add a handler inside the application didFinishLaunchingWithOptions: method. Make sure to use the same channel name as was used on the Flutter client side.
#import <Flutter/Flutter.h>
#import "GeneratedPluginRegistrant.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions {
FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;
FlutterMethodChannel* airPlayChannel= [FlutterMethodChannel
methodChannelWithName:#"stack.M123.dev/airplay"
binaryMessenger:controller.binaryMessenger];
[airPlayChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
// Note: this method is invoked on the UI thread.
if ([#"getBatteryLevel" isEqualToString:call.method]) {
int returnValue = [weakSelf openAirPlay];
result(#(returnValue));
}];
[GeneratedPluginRegistrant registerWithRegistry:self];
return [super application:application didFinishLaunchingWithOptions:launchOptions];
}
Add the method in the AppDelegate class, just before #end
- (int)openAirPlay {
//Open air play
return (int)(100);
}
Discalimer: I am not a IOS developer so the steps are mostly theoretical.
I am following the official guide from Flutter. It can be found in full length here.
I am developing a network monitor app that runs in background as a service. Is it possible to get a notification/call when the screen is turned on or off?
It exists in Android by using the following code:
private void registerScreenOnOffReceiver()
{
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
registerReceiver(screenOnOffReceiver, filter);
}
screenOnOffReceiver is then called when screen is turned on/off. Is there a similar solution for iOS?
Edit:
The best I've found so far is UIApplicationProtectedDataWillBecomeUnavailable ( Detect if iPhone screen is on/off ) but it require the user to enable Data Protection (password protection) on the device.
You can use Darwin notifications, to listen for the events. I'm not 100% sure, but it looks to me, from running on a jailbroken iOS 5.0.1 iPhone 4, that one of these events might be what you need:
com.apple.iokit.hid.displayStatus
com.apple.springboard.hasBlankedScreen
com.apple.springboard.lockstate
Update: also, the following notification is posted when the phone locks (but not when it unlocks):
com.apple.springboard.lockcomplete
To use this, register for the event like this (this registers for just one event, but if that doesn't work for you, try the others):
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
NULL, // observer
displayStatusChanged, // callback
CFSTR("com.apple.iokit.hid.displayStatus"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
where displayStatusChanged is your event callback:
static void displayStatusChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo) {
NSLog(#"event received!");
// you might try inspecting the `userInfo` dictionary, to see
// if it contains any useful info
if (userInfo != nil) {
CFShow(userInfo);
}
}
If you really want this code to run in the background as a service, and you're jailbroken, I would recommend looking into iOS Launch Daemons. As opposed to an app that you simply let run in the background, a launch daemon can start automatically after a reboot, and you don't have to worry about iOS rules for apps running tasks in the background.
Let us know how this works!
Using the lower-level notify API you can query the lockstate when a notification is received:
#import <notify.h>
int notify_token;
notify_register_dispatch("com.apple.springboard.lockstate", ¬ify_token, dispatch_get_main_queue(), ^(int token) {
uint64_t state = UINT64_MAX;
notify_get_state(token, &state);
NSLog(#"com.apple.springboard.lockstate = %llu", state);
});
Of course your app will have to start a UIBackgroundTask in order to get the notifications, which limits the usefulness of this technique due to the limited runtime allowed by iOS.
While iPhone screen is locked appdelegate method
"- (void)applicationWillResignActive:(UIApplication *)application"
will be called you can check that. Hope it may help you.
The problem: I'm crashing when I want to render my incoming data which was retrieved asynchronously.
The app starts and displays some dialog boxes using XAML. Once the user fills in their data and clicks the login button, the XAML class has in instance of a worker class that does the HTTP stuff for me (asynchronously using IXMLHTTPRequest2). When the app has successfully logged in to the web server, my .then() block fires and I make a callback to my main xaml class to do some rendering of the assets.
I am always getting crashes in the delegate though (the main XAML class), which leads me to believe that I cannot use this approach (pure virtual class and callbacks) to update my UI. I think I am inadvertently trying to do something illegal from an incorrect thread which is a byproduct of the async calls.
Is there a better or different way that I should be notifying the main XAML class that it is time for it to update it's UI? I am coming from an iOS world where I could use NotificationCenter.
Now, I saw that Microsoft has it's own Delegate type of thing here: http://msdn.microsoft.com/en-us/library/windows/apps/hh755798.aspx
Do you think that if I used this approach instead of my own callbacks that it would no longer crash?
Let me know if you need more clarification or what not.
Here is the jist of the code:
public interface class ISmileServiceEvents
{
public: // required methods
virtual void UpdateUI(bool isValid) abstract;
};
// In main XAML.cpp which inherits from an ISmileServiceEvents
void buttonClick(...){
_myUser->LoginAndGetAssets(txtEmail->Text, txtPass->Password);
}
void UpdateUI(String^ data) // implements ISmileServiceEvents
{
// This is where I would render my assets if I could.
// Cannot legally do much here. Always crashes.
// Follow the rest of the code to get here.
}
// In MyUser.cpp
void LoginAndGetAssets(String^ email, String^ password){
Uri^ uri = ref new URI(MY_SERVER + "login.json");
String^ inJSON = "some json input data here"; // serialized email and password with other data
// make the HTTP request to login, then notify XAML that it has data to render.
_myService->HTTPPostAsync(uri, json).then([](String^ outputJson){
String^ assets = MyParser::Parse(outputJSON);
// The Login has returned and we have our json output data
if(_delegate)
{
_delegate->UpdateUI(assets);
}
});
}
// In MyService.cpp
task<String^> MyService::HTTPPostAsync(Uri^ uri, String^ json)
{
return _httpRequest.PostAsync(uri,
json->Data(),
_cancellationTokenSource.get_token()).then([this](task<std::wstring> response)
{
try
{
if(_httpRequest.GetStatusCode() != 200) SM_LOG_WARNING("Status code=", _httpRequest.GetStatusCode());
String^ j = ref new String(response.get().c_str());
return j;
}
catch (Exception^ ex) .......;
return ref new String(L"");
}, task_continuation_context::use_current());
}
Edit: BTW, the error I get when I go to update the UI is:
"An invalid parameter was passed to a function that considers invalid parameters fatal."
In this case I am just trying to execute in my callback is
txtBox->Text = data;
It appears you are updating the UI thread from the wrong context. You can use task_continuation_context::use_arbitrary() to allow you to update the UI. See the "Controlling the Execution Thread" example in this document (the discussion of marshaling is at the bottom).
So, it turns out that when you have a continuation, if you don't specify a context after the lambda function, that it defaults to use_arbitrary(). This is in contradiction to what I learned in an MS video.
However by adding use_currrent() to all of the .then blocks that have anything to do with the GUI, my error goes away and everything is able to render properly.
My GUI calls a service which generates some tasks and then calls to an HTTP class that does asynchronous stuff too. Way back in the HTTP classes I use use_arbitrary() so that it can run on secondary threads. This works fine. Just be sure to use use_current() on anything that has to do with the GUI.
Now that you have my answer, if you look at the original code you will see that it already contains use_current(). This is true, but I left out a wrapping function for simplicity of the example. That is where I needed to add use_current().
I am trying to write some code that interacts with an USB device in Objective C, and I got stuck on setting the callback function for incoming reports. In my case it's an IOKIT function but I think the problem is more general as I (apparently) don't know how to correctly set a C callback function in Objective-C. I've got a Class "USBController" that handles the io functions
USBController.m:
#include <CoreFoundation/CoreFoundation.h>
#include <Carbon/Carbon.h>
#include <IOKit/hid/IOHIDLib.h>
#import "USBController.h"
static void Handle_IOHIDDeviceIOHIDReportCallback(
void * inContext, // context from IOHIDDeviceRegisterInputReportCallback
IOReturn inResult, // completion result for the input report operation
void * inSender, // IOHIDDeviceRef of the device this report is from
IOHIDReportType inType, // the report type
uint32_t inReportID, // the report ID
uint8_t * inReport, // pointer to the report data
CFIndex InReportLength) // the actual size of the input report
{
printf("hello"); //just to see if the function is called
}
#implementation USBController
- (void)ConnectToDevice {
...
IOHIDDeviceRegisterInputReportCallback(tIOHIDDeviceRefs[0], report, reportSize,
Handle_IOHIDDeviceIOHIDReportCallback,(void*)self);
...
}
...
#end
All the functions are also declared in the header file.
I think I did pretty much the same as what I've found here, but it doesn't work. The project compiles nicely and everything works up till the moment there is input and the callback function is to be called. Then I get an "EXC_BAD_ACCESS" error. The first three arguments of the function are correct. I'm not so sure about the context..
What did I do wrong?
I am not sure at all that your EXEC_BAD_ACCESS depends on your callback. Indeed, if you say that it is called (I suppose you see the log) and since it only logs a message, there should be no problem with this.
EXEC_BAD_ACCESS is caused by an attempt to access an already deallocated object. You can get more information in two ways:
execute the program in debug mode, so when it crashes you will be able to see the stack content;
activate NSZombies or run the program using the performance tool Zombies; this will tell you exactly which object was accessed after its deallocation.
I know how to fix this. When calling this:
IOHIDDeviceRegisterInputReportCallback(tIOHIDDeviceRefs[0], report, reportSize,
Handle_IOHIDDeviceIOHIDReportCallback,(void*)self);
You don't include the code for the creation/type of the value called report. However the method name "Handle_IOHIDDeviceIOHIDReportCallback" comes from an Apple document where there is an error in the creation of the report value. https://developer.apple.com/library/archive/technotes/tn2187/_index.html
CFIndex reportSize = 64;
uint8_t report = malloc( reportSize ); // <---- WRONG
IOHIDDeviceRegisterInputReportCallback( deviceRef,
report,
reportSize,
Handle_IOHIDDeviceIOHIDReportCallback,
context );
Instead do this:
uint8_t *report = (uint8_t *)malloc(reportSize);
I'm putting together a Mac OS X Application and I'm trying to register to receive Display Reconfiguration notices, but I'm very lost right now. I've been reading Apple's documentation and some forums posts, etc., but everything seems to assume a better knowledge of things than I apparently possess. I understand that I have to request the callback inside a run loop for it to work properly. I don't know how to set up a basic run loop for it, though. I also feel like the example Apple has in their documentation is missing stuff they are expecting me to already know. To display my ignorance here is what I feel like things should look like.
NSRunLoop *rLoop = [NSRunLoop currentRunLoop];
codeToStartRunLoop
void MyDisplayReconfigurationCallBack (
CGDirectDisplayID display,
CGDisplayChangeSummaryFlags flags,
void *userInfo);
{
if (flags & kCGDisplayAddFlag) {
NSLog (#"Display Added");
}
else if (kCGDisplayRemoveFlag) {
NSLog (#"Display Removed");
}
}
CGDisplayRegisterReconfigurationCallback(MyDisplayReconfigurationCallBack, NULL);
The actual code I got was from Apple's Example, but it tells me that flags is an undeclared identifier at this point and won't compile. Not that it would work right since I don't have it in a run loop. I was hoping to find a tutorial somewhere that explains registering for system callback in a run loop but have not been successful. If anyone could point me in the right direction I'd super appreciate it.
(I'm sure that you'll be able to tell from my question that I'm very green. I taught myself Objective-C out of a book as my first programming language. I skipped C, so every once in a while I hit a snag somewhere that I can't figure out.)
If you're writing a Mac OS X application, the AppKit has already set up a run loop for you, so you don't need to worry about that part. You really only need to create your own run loop in Cocoa when you are also creating your own thread.
For the "undeclared identifier" part, it looks like it's due to a typo/syntax mistake:
void MyDisplayReconfigurationCallBack (CGDirectDisplayID display,
CGDisplayChangeSummaryFlags flags,
void *userInfo);
// Semicolon makes this an invalid function definition^^
{
// This is an anonymous block,* and flags wasn't declared in it
if (flags & kCGDisplayAddFlag) {
// etc.
}
Also, unlike some other languages, you can't declare or define functions inside of other functions, methods, or blocks* -- they have to be at the top level of the file. You can't put this in the same place where you call CGDisplayRegisterReconfigurationCallback.
Just as an sample (I have no idea what the rest of your code really looks like):
// MyClassThatIsInterestedInDisplayConfiguration.m
#import "MyClassThatIsInterestedInDisplayConfiguration.h"
// Define callback function at top level of file
void MyDisplayReconfigurationCallBack (
CGDirectDisplayID display,
CGDisplayChangeSummaryFlags flags,
void *userInfo)
{
if (flags & kCGDisplayAddFlag) {
NSLog (#"Display Added");
}
else if (kCGDisplayRemoveFlag) {
NSLog (#"Display Removed");
}
}
#implementation MyClassThatIsInterestedInDisplayConfiguration
- (void) comeOnBabyAndDoTheRegistrationWithMe {
// Register callback function inside a method
CGDisplayRegisterReconfigurationCallback(MyDisplayReconfigurationCallBack,
NULL);
}
#end
*The basic C curly-brace-delimited thing, not the new cool Obj-C ad hoc function thing.