Ninjacrab

  • XamarinForms – Overriding a ContentPage with a custom PageRenderer on Android

    The short version:

    If you want to have default behavior on all platforms except for Android. Do the following

    • Create your content page with all of it’s goodies
    • Create a custom PageRenderer
    • In the OnElementChanged function
      • Cast the Context property of the renderer to the Activity type associated
      • Take that value and execute the SetContentView method while passing in your new view!

    The awesome story version:

    I’m building a Xamarin Forms application which has a default implementation in most platforms and a special snowflake behavior on Android. While working through the Xamarin documentation I realized that custom renderers were the way to go.

    The default behavior for all platforms is performed through a WebView, which has some custom logic when pages are navigated. While the functionality still works, it doesn’t feel seamless. However, in Android there is already native functionality that really improves the user experience, so I wanted to make sure that if I was on the Android platform, … Read the rest

  • C# – How the Null Conditional Operator works with Nullable types

    The short answer:

    The null conditional operator also unwraps the nullable variable. So after the operator, the “Value” property is no longer needed.

    ex:

    DateTimeOffset? startAt;
...
System.Writeline(startAt?.TimeOfDay);

    The longer story:

    I had a scenario with a Nullable DateTimeOffset and I was trying to perform something like the following.

    DateTimeOffset? startAt;
...
public DateTime? StartDate { get { return startAt.Value.DateTime; } }

    As I tested, I immediately ran into a situation where that date was null, the program threw an exception and I needed to null check it. So I thought I wanted to use that latest, hottest stuff that Microsoft had to offer in C#.

    The null conditional operator. 

    I changed my code to the following

    public DateTime? StartDate { get { return startAt?.Value.DateTime; } }

    But instead it just got angry with me and for whatever reason I wasn’t looking at the obvious clues. I immediately ran off to search the interwebs on how to use this operator … Read the rest

  • Jenkins & Git & Windows Server – oh my!

    Got a weird freezing issue in Jenkins when attempting to pull the tags from a git repository. Turns out that the credential manager was the interactive windows popup and it just locked the build process. The fix was as simple as going into the following location and removing the credential helper

    [Git Install Folder]\mingw64\etc\gitconfig

    Example from this
    [credential]
    helper = manager

    to this
    [credential]
    # helper = manager    … Read the rest

  • libfdt is missing, please install it – Error

    In case anyone is trying to build a Dragonboard 410C boot image in Ubuntu/Debian distro. Although the docs says to install “device-tree-compiler” as a pre-requisite for skales, you also need “libfdt-dev”. Hope that helps anyone else!… Read the rest

  • Much respect to all inventors of #QUALCOMM #WhyWait Invent-off!

    WhyWait - Contestants

    The last episode of the invent-off is available to view!

    Regardless of the results, I feel privileged to have had an opportunity to work with all of those incredibly talented and passionate inventors. The competition was really fun and I finally got to dip my toes into IOT/IOE.

    http://whywait.kinja.com/and-we-have-a-winner-the-invent-off-finale-is-here-1723341729

    As promised, I created a video tutorial on preparing your own Arduino Yun’s to run AllJoynJS and I plan on creating more content for other aspiring inventors to build amazing things.

    http://www.ninjacrab.com/alljoyning/setting-up-an-arduino-yun-for-alljoynjs/… Read the rest

  • Success!! Ok and some failures with AllJoynJS #WhyWait #QuallComm #AllJoyn

    DSC_0019

    The third episode of the hackathon has been published. As the deadline of the contest is looming, I’m definitely creating synthetic stress upon myself. There are awesome advantages to using AllJoyn in our project, but also a few problems created by friction of complexity. Regardless, we’ll push through!

    http://whywait.kinja.com/what-bright-idea-will-the-teams-create-in-the-whywait-1718090122

    I know the episodes are short, but I hope you guys enjoy them!

    In the meantime, I wanted to share this post with those who run into the nefarious message while working with AllJoynJS, the Arduino Yun and any input output pins. If you see the following message

    ALERT: Error: Failed to configure digital output pin: 022
    ajs_io.c:211
    light_00409bf0_0002 light strict preventsyield
    global .js:10 preventsyield

    It’s possible that you just need to run the following script

    /usr/bin/lininoio start

    To get things going again.

    The comprehensive setup will come real soon, I promise! In the meantime, enjoy!… Read the rest

  • Shocking surprise in the 2nd Episode of the #WhyWait #Qualcomm challenge!

    Episode two has been released and this “voted” component thing truly is a shocker! I’m already losing sleep without any additional features, but I suppose you play with the hand that you are dealt with.

    More things to read up on and in the end, that means more content to create tutorials for!

    Enjoy all!

    http://whywait.kinja.com/meet-the-innovators-competing-to-win-the-whywait-inven-1717554111… Read the rest

  • Episode 1 of the #WhyWait Hackathon is available to watch!

    The first episode of the hackathon is out. I’m not entirely aware of how much of the build it will show as the episodes are brief, but fear not! Once it’s all done, I will create tutorials and walkthroughs!

    http://whywait.kinja.com/watch-two-teams-of-innovators-compete-in-the-whywait-i-1716856087

    Otherwise, enjoy!… Read the rest

  • Selected to be part of the #Qualcomm #WhyWait Hackathon!

    WhyWait Medium

    Recently I was selected to be a contestant of a hackathon sponsored by Qualcomm to build basically any green fielded idea pairing an Arduino Yun and an Android phone. The first episode will be aired online in the next week or so. Please support me by spreading the word, to any nerd!

    I’m super excited for this opportunity to play mad scientist with some IOT/IOE devices and hope we win!

    Following the series, I plan on making various tutorials on how we accomplished what we did and frameworks involved from the coding side. I’ll try to do my best to explain the fabrication side, but that’s what I’m leaning on my team mates for!… Read the rest

  • Resurrecting Persistent Windows

    Well, my amazing Wife gave me the green light on ordering 3x Dell P2415Q 4K monitors. So I enthusiastically connected them all via DisplayPort on my NVidia 970GTX card on my desktop and low and behold the windows are exhibiting the crazy re-arranging behavior!

    Thus, I’m reviving the project and now since I’ll be able to test it immediately(Instead of building it at home, running it on my work desktop, shipping log files home back home to diagnose), I should be able to improve it even more.

    Stay tuned for updates!… Read the rest