Tutorial by Examples: e

Sometimes you need to create your own Event, one that other plugins can listen to (Vault, among other plugins, does this) and even cancel. Bukkit's Event API allows this to be possible. All you need to do is make a new class, have it extend Event, add the handlers and the attributes your event needs...

#include <mutex> #include <condition_variable> class Semaphore { public: Semaphore (int count_ = 0) : count(count_) { } inline void notify( int tid ) { std::unique_lock<std::mutex> lock(mtx); count++; cout <...

So first we will create rails project and setup device create a rails application rails new devise_example now add devise to gem list you can find a file named 'Gemfile' at the root of rails project Then run bundle install Next, you need to run the generator: rails generate devise:insta...

MultiTrigger is not needed frequently but there are some situations where it is very handy. MultiTrigger behaves similarly to Trigger or DataTrigger but it has multiple conditions. All the conditions must be true for a Setters to fire. Here is a simple example: <!-- Text field needs to be initia...

The following function adds four threads. Three threads compete for the semaphore, which is set to a count of one. A slower thread calls notify_one(), allowing one of the waiting threads to proceed. The result is that s1 immediately starts spinning, causing the Semaphore's usage count to remain be...

Introduction Julia uses the following syntax for dictionaries: Dict({k₁ => v₁, k₂ => v₂, …, kₙ₋₁ => vₙ₋₁, kₙ => vₙ) While Python and JSON looks like this: {k₁: v₁, k₂: v₂, …, kₙ₋₁: vₙ₋₁, kₙ: vₙ} For illustrative purposes we could also use this syntax in Julia and add new seman...

JavaScript uses reference counting technique to detect unused objects. When reference count to an object is zero, that object will be released by the garbage collector. Weakmap uses weak reference that does not contribute to reference count of an object, therefore it is very useful to solve memory l...

To create our own MessageBox control simply follow the guide below... Open up your instance of Visual Studio (VS 2008/2010/2012/2015/2017) Go to the toolbar at the top and click File -> New Project --> Windows Forms Application --> Give the project a name and then click ok. O...

public FontFamily Maneteke = GetResourceFontFamily(Properties.Resources.manteka);

public static FontFamily GetResourceFontFamily(byte[] fontbytes) { PrivateFontCollection pfc = new PrivateFontCollection(); IntPtr fontMemPointer = Marshal.AllocCoTaskMem(fontbytes.Length); Marshal.Copy(fontbytes, 0, fontMemPointer, fontbytes.Length); pfc.AddMemoryFont(fontMemPo...

public static class Res { /// <summary> /// URL: https://www.behance.net/gallery/2846011/Manteka /// </summary> public static FontFamily Maneteke = GetResourceFontFamily(Properties.Resources.manteka); public static FontFamily GetRes...

You can write detailed signals with the [Signal (detailed = true)] attribute. public class Emitter : Object { [Signal (detailed = true)] public signal void detailed_signal (); public void emit_with_detail (string detail) { this.detailed_signal[detail] (); } } void...

Signals can have a default handler. All you need to do is to give it a body when you declare it. public class Emitter : Object { public signal void my_signal () { print ("Hello from the default handler!\n"); } } This handler will always be called after the connected...

You can declare a UIFont as follows: var font: UIFont! UIFont has more init() methods: UIFont.init(descriptor: UIFontDescriptor, size: CGFloat) UIFont.init(name: String, size: CGFloat) Therefore, you can initialize a UIFont like this: let font = UIFont(name: "Helvetica Neue", s...

To change a label's text font, you need to access its font property: label.font = UIFont(name:"Helvetica Neue", size: 15) The code above will change the font of the label to Helvetica Neue, size 15. Beware that you must spell the font name correctly, otherwise it will throw this error,...

Coercion happens with data types in R, often implicitly, so that the data can accommodate all the values. For example, x = 1:3 x [1] 1 2 3 typeof(x) #[1] "integer" x[2] = "hi" x #[1] "1" "hi" "3" typeof(x) #[1] "character" ...

The Builder Pattern decouples the creation of the object from the object itself. The main idea behind is that an object does not have to be responsible for its own creation. The correct and valid assembly of a complex object may be a complicated task in itself, so this task can be delegated to anoth...

Used for the RAII style acquiring of try locks, timed try locks and recursive locks. std::unique_lock allows for exclusive ownership of mutexes. std::shared_lock allows for shared ownership of mutexes. Several threads can hold std::shared_locks on a std::shared_mutex. Available from C++ 14. std:...

A shared_lock can be used in conjunction with a unique lock to allow multiple readers and exclusive writers. #include <unordered_map> #include <mutex> #include <shared_mutex> #include <thread> #include <string> #include <iostream> class PhoneBook { ...

std::call_once ensures execution of a function exactly once by competing threads. It throws std::system_error in case it cannot complete its task. Used in conjunction with std::once_flag. #include <mutex> #include <iostream> std::once_flag flag; void do_something(){ std::ca...