Tutorial by Examples: w

Adding/Removing an Observer with a Block

Instead of adding an observer with a selector, a block can be used: id testObserver = [[NSNotificationCenter defaultCenter] addObserverForName:@"TestNotification" object:nil ...

iOS • NSNotificationCenter

What is POSIX?

POSIX stands for "Portable Operating System Interface" and defines a set of standards to provide compatibility between different computing platforms. The current version of the standard is IEEE 1003.1 2016 and can be accessed from the OpenGroup POSIX specification. Previous versions incl...

POSIX • Getting started with POSIX

Binding WebUI to localhost or disabling

When deploying RethinkDB in production, you want to either turn off or lock down the WebUI. This will only respond to localhost to access the WebUI allowing you to SSH Tunnel to the host machine and access it for diagnostics and troubleshooting. docker run -d \ -v host_data_path:/data \ ret...

rethinkdb • Using RethinkDB with Docker

Show Toast Message Above Soft Keyboard

By default, Android will display Toast messages at the bottom of the screen even if the keyboard is showing. This will show a Toast message just above the keyboard. public void showMessage(final String message, final int length) { View root = findViewById(android.R.id.content); Toast toas...

Android • Toast

How to use a makefile other than Android.mk

ndk-build NDK_PROJECT_PATH=PROJECT_PATH APP_BUILD_SCRIPT=MyAndroid.mk

Android • Android NDK

Rules for some of the widely used Libraries

Currently it contains rules for following libraries:- ButterKnife RxJava Android Support Library Android Design Support Library Retrofit Gson and Jackson Otto Crashlitycs Picasso Volley OkHttp3 Parcelable #Butterknife -keep class butterknife.** { *; } -keepnames class * { @butterk...

Android • ProGuard - Obfuscating and Shrinking your code

Initial Setup with Android Studio

To setup for using Android Gradle Plugin you need many things: java gradle the Android project folder structure an Android Manifest initial plugin setup The easiest way to get all of them is to follow these steps: Donwload and Install Java OpenJDK version 6 or 7 (you can use 8 with addi...

android-gradle • Getting started with android-gradle

Simple Thread without Arguments

This basic example counts at different rates on two threads that we name sync (main) and async (new thread). The main thread counts to 15 at 1Hz (1s) while the second counts to 10 at 0.5Hz (2s). Because the main thread finishes earlier, we use pthread_join to make it wait async to finish. #include ...

POSIX • Threads

R in Latex with Knitr and Inline Code Chunks

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is inline code chunks. This apporach is demonstrated below. # r-noweb-file.Rnw \documentclass{article} \begin{document} This is an Rnw file (R noweb). It contains a combination of LateX and ...

R Language • R in LaTeX with knitr

R in LaTex with Knitr and Internal Code Chunks

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is internal code chunks. This apporach is demonstrated below. # r-noweb-file.Rnw \documentclass{article} \begin{document} This is an Rnw file (R noweb). It contains a combination of LateX a...

R Language • R in LaTeX with knitr

Start using ES6/7 with Babel

Browser support for ES6 is growing, but to be sure your code will work on environments that dont fully support it, you can use Babel, the ES6/7 to ES5 transpiler, try it out! If you would like to use ES6/7 in your projects without having to worry about compatibility, you can use Node and Babel CLI ...

JavaScript • Transpiling

D3js with Angular

Using D3js with Angular can open up new fronts of possibilities such as live updation of charts as soon as data is updated. We can encapsulate complete chart functionality within an Angular directive, which makes it easily reusable. index.html >> <!DOCTYPE html> <html ng-app="...

d3.js • Using D3 with other frameworks

Hello World in ABAP Objects

PROGRAM zhello_world. CLASS main DEFINITION FINAL CREATE PRIVATE. PUBLIC SECTION. CLASS-METHODS: start. ENDCLASS. CLASS main IMPLEMENTATION. METHOD start. cl_demo_output=>display( 'Hello World!' ). ENDMETHOD. ENDCLASS. START-OF-SELECTION. main=>start( ).

ABAP • Getting started with ABAP

Raise a number to a power (POW)

To raise a number x to a power y, use either the POW() or POWER() functions SELECT POW(2,2); => 4 SELECT POW(4,2); => 16

MySQL • Arithmetic

How to install and run ggplot2

To install and load the current stable version of ggplot2 for your R installation use: # install from CRAN install.packages("ggplot2") To install the development version from github use # install.packages("devtools") devtools::install_github("hadley/ggplot2") ...

ggplot2 • Getting started with ggplot2

Write to socket a simple http get request, and dump response

/** * we reuse a class written in example: * http://stackoverflow.com/documentation/sockets/2876/introduction-to-sockets#t=201607262114505531351 * pleas to familiar with it first to continue with this one **/ public class WriteToSocketExample extends ConnectSocketExample { private ...

sockets • Getting started with sockets

What is a macro?

A macro is a series of keystrokes meant to be "played back" by Vim without any delay. Macros can be stored in registers or variables, bound to keys, or executed on the command line. Here is a simple macro that uppercases the third word on a line: 0wwgUiw That macro could be recorded i...

vim • Macros

Customising the CMS / White Labeling

The SilverStripe CMS can be customised to change the CMS logo, link and application name. This can be achieved with the following config.yml settings LeftAndMain: application_name: 'My Application' application_link: 'http://www.example.com/' extra_requirements_css: - mysite/css/cms.c...

silverstripe • Getting started with silverstripe

Create an SKScene that Fills the SKView

A simple use case it to create an SKScene that exactly fills the SKView. This avoids the need to consider scaling the view to fit or setting a camera to show a part of the scene. The following code assumes an SKView called skView already exists (e.g. as defined in Create a Full Screen SKView using ...

sprite-kit • SKScene

Create an SKScene that Scales to fit the SKView

An SKScene has a scaleMode parameter that defines how it will change its size to fit within the SKView it is presented into the SKView if it is not the same size and/or shape. There are four options for scaleMode: AspectFit: the scene is scaled (but not stretched) until it fits within the view. ...

sprite-kit • SKScene