How notify user when my application is not running in qt? - qt

I have a qt quick 2 application that I run it in android.Now I want to show message to my users ,For example I want to send a get Request to my server to find out "Is this user has any message from another user or not?" and if has new message show a notification to my user.This should be run when my application is not runnng.
But I didn't see any Class that i can do this in qt?
How can I Do this?

Qt for Android lists what you can do with Qt. Qt Android Extras includes classes that wrap the most important functions of few Android package methods, but is not intended to provide out of the box methods for everything in Android.
You can write Java Classes to implement detailed or specialized Android functions, those then can easily be implemented with Qt using the rich Android Extras JNI APIs.
In Qt Examples, Qt Notifier, serves very similar or same functionality you asking for.
You can run Android services (long running apps hiding user interface) , by Creating Android Services And QAndroidService Class

Related

How To Setup Google Firebase Dynamic Links in Xamarin Forms - Android Edition

How do you setup google firebase dynamic links, deep linking, in a xamarin forms app?
This is how I setup Firebase Dynamic Links in Android project of my Xamarin Forms App, so most of this will apply directly to android. I will work on finishing and documenting the iOS implementation in the future.
Disclaimer: I'm not an expert, any or all of this could be wrong. It's just what worked for me and my basic understanding. Please let me know if there are any errors and let's improve our collective intelligence of the Xamarin Community
If you don't already know what Dynamic Links are, watch the 2 min video, it's a great overview. https://firebase.google.com/docs/dynamic-links/
The Setup
Setup is broken up into 2 parts.
Part 1 - Configure the Dynamic Links in the Firebase Console (Easy)
Part 2 - Configure your app to be able to receive and process the Deep Links (Not as Easy)
Part 1 - Configure the Dynamic Links in the Firebase Console (Easy)
1- Setup a free firebase account at https://firebase.google.com/
2- Create a project.
3- Create a new dynamic link, the tab is at the bottom of the 'Grow' section.
It will generate a static domain name for you based off of your project name. Ex. 'https://myproject.page.link'
Short Link url is what users will click on to navigate to your appstore or launch your app.
Deep Link url is what actually gets sent into your app for you to work with. Ex 'https://myproject.com/MainPage'
iOS behavior. Currently set mine to open the link in a url browser, as my app is not connected to it yet.
Android behavior Very Important but not as hard as my explanation makes it look.
Here is where you register your app with firebase. The package name should be easy, use the same one as defined in your
apps Android properties. Ex 'com.mycompany.appname'
Adding the signing certs SHA-1 and SHA-256 are required for Dynamic Links, which is what we are doing here.
Microsoft has a great guide on this, better than I can explain. here
Download the google-services.json file - You will need it later. Also, you will need the one that has incorporated the SHA cert details in it.
Ignore the instructions for adding the firebase SDK, we will add these to our project later using Nuget packages.
When this is all done your app should be selectable in a dropdown for the android behavior.
Finally, add any extra tags to your dynamic link url if you want, its optional.
And that's it! Now you should have a working short link. When used on an android device it should already be able to determine if the app is already installed or not, and then either direct the user to the play store or open the app. However, it won't do anything with that deep link url that you set. That brings us to the next part.
Part 2 - Configure your app to be able to receive and process the Deep Links (Not as Easy)
1- Versions, might be important.
2- Nuget Packages - Hopefully this goes smoother for you than it did for me.
3- The Code
3a- Intent Filters
3b- Handling the Deep Link
1- Versions.
I was having a lot of issues trying to get dynamic/deep linking to work. So I went back and updated everything to the newest versions available at the time.
Visual Studio Professional 2017 - 15.7.5
.NET Framework 4.7.03056
Xamarin 4.10.10.2
Xamarin.Android SDK 8.3.3.2
Android SDK Manager - Got the latest. Android 8.1 API 27 and Android 8.0 API 26 (Targeting 8.1 might be required)
Android Properties -
-Application - Compile using Android Version(Target Framework): Android 8.1 Oreo
-Android Manifest: Target Android Version: Use Compile SDK Version(haven't tried targetting 8.1 directly, might work). My min target is still Android 4.4 API 19 Kit Kat
2- Nuget Packages. These are just for the Android project. MyApp.Android
You shouldn't have to add anything into the .NET Standard Project, just make sure the Xamarin.Forms Versions match
Below is what I did
Update:
Xamarin.Forms - updated to 3.0.0.482510
Install:
This is where it immediately got annoying for me. Issues here are what lead me to go back and update my Android API Levels to the most recent, 8.1
Xamarin.Firebase.Dynamic.Links by Xamarin Inc v60.1142.1 is what you want to install.
The other dependencies should automatically install. In my case, they did not.
Dependency MonoAndroid,Version=v8.0 is important here. That should be the SDK API version that your app is set to compile against.
However, the other dependencies like Xamarin.GooglePlayServices.Basement (= 60.1142.1) have nested dependencies of their own that require MonoAndroid,Version=v8.1
So if you run into issues installing the Dynamic Links Package, thats where I would recommend looking first.
For my purposes, the nested dependencies were not automatically getting installed, so I went down through each of them and their lists and did them all manually. Even the ones that said not to do manually. It's only 20 or so, but my guess would be if I had my project SDK's set to 8.1 before all of this that it would have gone smoothly.
The CODE
Intent Filters
These are defined in your AndroidManifest.xml file
What do they do? They listen for instructions while your app starts.
When an app start matches a pre-defined filter(short link), they it stores your intended action or data on the Intent Class. That is where we pull the deep link from.
For us, this is what let's the android app receive and begin to process the deep link url that you set all the way back in Part 1.
The firebase dynamic link docs have a good breakdown and example of what to do. here
The android developer docs have a good example and breakdown of this also. here
NOTE Focus on whats between the activity tags. I've just included the other tags to show general structure, in case you haven't edited these before.
That is about the minimum of what you need.
The highlighted line should match the Short Dynamic Link you setup in the established in the Firebase Console.
I'd recommend using a Wildcard like I did in the path prefix.
That way you can make new Dynamic Links and your app can handle them without having to release new versions.
Handling the Deep Link
At this point if your app is launched by the short link, you should be able to catch the deep link during the android startup process and handle it how you want.
All I will cover here is a basic example of how to get the Deep Link as a string.
I pass mine to the main app project (.NET Standard Library) using a simple dependency service.
You can use it however you want though, there's actions it can take in either the App or the App.Android project.
The important thing is getting the deep link.
The firebase docs have good examples, but written in java or whatever language native android uses. here
I'll be showing mostly the same, just in C# examples
Get The Intent.
What is the intent you want to get? The deep link you are sending into your app Ex. "https://mycoolapp.com/mainpage"
You want to get it in the MainActivity. Below is an extremely simplified example, but it's just about that easy. Now you should be able to do what you want with that link inside of your app.
TIPS
Be careful if you have something that interrupts your startup procedures.
My Application uses a splash screen. Part of that is a line of code that creates a new Intent, overwriting the one sent in from the dynamic link
So I have my DeepLinkHandler fire off before that operation, and store the deep link in a static string.
Once it's in a static string I can use a dependency service from the Main App(.NET Standard Library) to call the GetDynamicLinkString method and return the deep link as a string.
How to Test Using an Emulator and Debugger
I have a simple settings page on my app. I added a field that would print the deep link, if it has one.
Fire off the emulator like normal using the debugger. The deep link field should be empty.
With the emulator still running, minimize the app.
Open a browser and enter in the short link url.
This should re-launch your app, but this time the deep link field has the url that you set on the firebase console.
Hope this is able to save someone some headaches.
-Tim

How to get mobile app lifecycle events on QtApp

I am programming an app in Qt 5.9.4 commercial license. My app runs on Android and iOS.
Question:
Is there a way in Qt to detect usual mobile device events like:
- Device display switched off
- Device went to background after user presses home button on iOS/Android
- back button pressed on Android etc
There are a bunch of these events that each of the platform Android and iOS trigger.
If there is class/module in Qt that is relaying these events back then I wouldn't have to do the extra work of writing native(java and objective-c) classes to get these events inside my QtApp.
Most of these events are handeled by Qt itself and you can get them through classical means. Qt tries to hide android specific stuff as good as possible and delivers those though events etc. as you would get them on a desktop application.
The back button press triggers a QCloseEvent that is sent to the primary window. You can install an event filter on the object from C++ it to intercept it. For qml it's the Window::closing signal.
Since Qt does not support background execution of activities, the background press is propably reported as close event as well - or it quits the application directly.
For the DIsplay switch of I don't now for sure, but maybe the QGuiApplication::applicationStateChanged signal does report it as Qt::ApplicationSuspended or another of those states - simply try it out! (this might be the case for other events as well)
Short Hint for Android: If you however want something Qt does not handle, you can always just create a custom Java activity that extends the QtActivity and use it in the manifest. From there on you can use the JNI to interact with Java from C++ and vice versa. If you need to do so, have a look at the Qt Android Extras - They make using the JNI much easier and provide a bunch of nice wrapper classes and utility methods in the QtAndroid namespace that can come in very handy.

How to submit crash report to Microsoft App Center for Xamarin.Forms?

I want to submit crash report to Microsoft App Center for my project which is created in Xamarin.Forms.
Can anybody please suggest a link or steps where I can follow and integrate required steps in my project? I also want to test.
Please guide.
Whenever you login to the App Center portal all the information you need is right there. Create an app in the portal, one for Android and one for iOS if you have these platforms.
From there, basically you have to install the NuGet packages and add one initialisation line in your code. Note that you will be provided with the ID for this specific app under step 2. If you have multiple platforms, add the line once and replace the different IDs for each platform.
You will then have basic crash reporting and analytics (if you install both packages). You do not need to do anything extra for it, start your app, start using it and watch data come back to the portal.
Since a little while you can now also track handled exceptions and custom events.
For more information, check out the extensive documentation here: https://learn.microsoft.com/en-us/appcenter/
Please refer the detailed information here:
App center for Xamarin
Steps are:
You need to create 3 apps in App Center – one for each OS.You need to select Xamarin as the platform for Android and iOS applications and obtain App secret
Install Microsoft.AppCenter.Analytics and Microsoft.AppCenter.Crashes packages.
Open your App.xaml.cs and write this in OnStart() method:
AppCenter.Start("ios={Your App Secret};android={Your App Secret}", typeof(Analytics), typeof(Crashes));

Using Qt classes natively in an Android application

The Android application I am about to work on has the UI in Java and the non-UI functionality in C++ that would be accessed via JNI. The C++ code uses some non-UI Qt classes. I am thinking I will spawn a thread in JNI_OnLoadthat essentially will instantiate and run QCoreApplication. Any subsequent JNI call will simply post an event to this thread. Is this possible? Regards.
What you want to do is definitely possible but a bit more difficult than it seems initially.
If you build your app end to end in Qt there's a lot of functionality you get for free from their framework that allows it to run on Android and a lot of that functionality/plumbing is wrapped up in their UI. So if you're not using their UI there's extra work that you need to do.
On Android their UI framework basically creates a native Activity and then uses that activity as a wrapper for the app. If you look at the low-level source for their UI thats what's happening on Android and it's what allows the Qt app to access local resources, the network, OS facilities, etc.
Without the Activity wrapper, your app will only be able to do simple, in-memory operations that require no OS, file system, or network access and also won't be able to make use of other Qt libraries(eg Qt5Sql, Qt5Core, etc).
Here's what we had to do to make this work in our java app:
Create a proxy wrapper Activity for Qt to use that shares the base
context of your app.
Create a QtActivityDelegate.
Set the proxy activity and delegate using the native Qt android
libraries. eg QtNavite.setActivity.
Instantiate and set a DexClassLoader using the same native Qt android libraries.
Load any Qt libraries using System.loadLibrary(..). Please note that the libraries need to be present on the file system already. This part was a big pain for us.
For your Qt Code, make sure you have proper wrappers written so that they can be used via jni. We ended up using swig to auto-generate java wrappers for our code.
You can find out more about swig here: http://swig.org/
After all that you should be able to use your Qt class/library from within a native Android app.
Painful but definitely possible!

How to access the QObject of a Qt UI from another QT application?

I am intending to implement a simple test QT application in linux which launch a QT UI application running on an Embedded linux platform to verify it. I want to be able to send signals from the test application to the UI, for instance to press a button on the GUI, then check if the signal has made the expected change on the QT UI application. I know there are some tools like Squish, Testability Driver that can hook a running QT application and access the properties of each graphical element (e.g. button).
I have searched a lot, but I could not find any suitable solution. If somebody can introduce a suitable solution?
On Unix platforms you can use dbus. Otherwise you have to roll your own mechanism, or use a third party tool.

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