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roslaunch is an important tool that manages the start and stop of ROS nodes. It takes one or more "*.launch" files as arguments. For this example, I will refer to the following (as asked in this question), so how can we execute those commands consecutively & automatically : roscd ste...

Objective-C //Checking for 3-D Touch availability if ([self.traitCollection respondsToSelector:@selector(forceTouchCapability)] && (self.traitCollection.forceTouchCapability == UIForceTouchCapabilityAvailable)) { [self registerForPreviewingWithDelegate:self sourceVie...

Passing ByRef or ByVal indicates whether the actual value of an argument is passed to the CalledProcedure by the CallingProcedure, or whether a reference (called a pointer in some other languages) is passed to the CalledProcedure. If an argument is passed ByRef, the memory address of the argument i...

let bodies = (contact.bodyA.categoryBitMask <= contact.bodyB.categoryBitMask) ? (A:contact.bodyA,B:contact.bodyB) : (A:contact.bodyB,B:contact.bodyA) switch (bodies.A.categoryBitMask,bodies.B.categoryBitMask) { case let (a, _) where (a && superPower): //All we care about is i...

Objective-C First add the Social Framework to the XCode project. Import the #import "Social/Social.h" class to the required ViewController Twitter with text, image and link //- - To Share text on twitter - - if([SLComposeViewController isAvailableForServiceType:SLServiceTypeTwitter]) ...

Given a money system, is it possible to give an amount of coins and how to find a minimal set of coins corresponding to this amount. Canonical money systems. For some money system, like the ones we use in the real life, the "intuitive" solution works perfectly. For example, if the diffe...

The module keyword can be used to begin a module, which allows code to be organized and namespaced. Modules can define an external interface, typically consisting of exported symbols. To support this external interface, modules can have unexported internal functions and types not intended for public...

Typically, packages consist of one or more modules. As packages grow, it may be useful to organize the main module of the package into smaller modules. A common idiom is to define those modules as submodules of the main module: module RootModule module SubModule1 ... end module SubModul...

Quite often within mobile applications, there will be a reason to deal with dates. When working with dates, you will probably need some sort of user input to select a date. This could occur when working with a scheduling or calendar app. In this case, it is best to provide users with a specialized c...

External Maps Plugin Open external maps to navigate to a specific geolocation or address. Option to launch with navigation option on iOS as well. Available on NuGet :[https://www.nuget.org/packages/Xam.Plugin.ExternalMaps/][1] XAML <StackLayout Spacing="10" Padding="10"&...

Easly access geolocation across Xamarin.iOS, Xamarin.Android and Windows. Available Nuget: [https://www.nuget.org/packages/Xam.Plugin.Geolocator/][1] XAML <StackLayout Spacing="10" Padding="10"> <Button x:Name="buttonGetGPS" Text="Get GPS"/...

Take or pick photos and videos from a cross platform API. Available Nuget : [https://www.nuget.org/packages/Xam.Plugin.Media/][1] XAML <StackLayout Spacing="10" Padding="10"> <Button x:Name="takePhoto" Text="Take Photo"/> <Butto...

Messaging plugin for Xamarin and Windows to make a phone call, send a sms or send an e-mail using the default messaging applications on the different mobile platforms. Available Nuget : [https://www.nuget.org/packages/Xam.Plugins.Messaging/][1] XAML <StackLayout Spacing="10" Padding...

Check to see if your users have granted or denied permissions for common permission groups on iOS and Android. Additionally, you can request permissions with a simple cross-platform async/awaitified API. Available Nuget : https://www.nuget.org/packages/Plugin.Permissions enter link description he...

There are many reasons a write operation may fail. A frequent one is because your security rules reject the operation, for example because you're not authenticated (by default a database can only be accessed by an authenticated user). You can see these security rule violations in the console output...

This document details the steps to obtain the facebook access tokens and the using the tokens to fetch FB feeds. Example: A live example is available in https://newtonjoshua.com Introduction to Graph API: The Graph API is the primary way to get data in and out of Facebook's platform. It's a...

ContentPage: Displays a single View. XAML <?xml version="1.0" encoding="utf-8" ?> <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="XamlBasics.SampleXaml"> &lt...

MasterDetailPage: Manages two separate Pages (panes) of information. XAML <?xml version="1.0" encoding="utf-8" ?> <MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class=&quot...

With the 2.x versions of typescript, typings are now available from the npm @types repository. These are automatically resolved by the typescript compiler and are much simpler to use. To install a type definition you simply install it as a dev dependency in your projects package.json e.g. npm i -...

It is important to read the error response that is returned by the Google Analytics API server. In a lot of cases they can tell you exactly what is wrong. 400 invalidParameter { "error": { "errors": [ { "domain": "global", "reason&...