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Window.h #include <QWidget> class Window : public QWidget { Q_OBJECT public: Window(QWidget *parent = Q_NULLPTR) : QWidget(parent) {} } main.cpp #include <QApplication> #include "Window.h" int main() { QApplication app; Window window; wi...

The SUBDIRS ability of qmake can be used to compile a set of libraries, each of which depend on another. The example below is slightly convoluted to show variations with the SUBDIRS ability. Directory Structure Some of the following files will be omitted in the interest of brevity. They can be a...

A simple example to make a library (rather than an executable, which is the default). TEMPLATE variable specifies type of the project you are making. lib option allows makefile to build a library. library.pro HEADERS += library.h SOURCES += library.cpp TEMPLATE = lib # By default, qmake wil...

var syntaxTree = CSharpSyntaxTree.ParseText( @"using System; using System.Collections; using System.Linq; using System.Text; namespace HelloWorldApplication { class Program { static void Main(string[] args) { Console.WriteLine(""Hello World""); } } }"); ...

The following example is a sample Less file which shows how variables are declared and used, how mixins are defined and called in Less. /* Variables */ @color-base: #87ceeb; /* Simple mixin to set border */ .set-border(@width; @style; @color) { border: @width @style darken(@color, 10%); ...

Install symfony correctly as guided above. Start symfony server if you are not installed in www directory. Ensure http://localhost:8000 is working if symfony server is used. Now it is ready to play with simplest example. Add following code in a new file /src/AppBundle/Controller/MyController.p...

#demo-element { background: @theme-color; color: contrast(@theme-color, black, white, 50%); } @theme-color: red; The above example will set the text color of the element as white if the background-color is dark and vice-versa. This is achieved using the contrast() color operation functi...

In Object oriented programming language, a mixin is a class that contains methods for use by other classes without having to be the parent class of those other classes. How those other classes gain access to the mixin's methods depends on the language. It provides a mechanism for multiple inheritan...

To create mixins, simply declare lightweight classes that can be used as "behaviours". class Flies { fly() { alert('Is it a bird? Is it a plane?'); } } class Climbs { climb() { alert('My spider-sense is tingling.'); } } class Bulletproof { ...

For most GNU/Linux distributions, a version of GnuCOBOL is available in the repositories. GnuCOBOL was originally OpenCOBOL, rebranded when the project became an official GNU project. Many repositories are still using open-cobol as the package name (as of August 2016). For Fedora, and other RPM b...

com.android.dex.DexException: Multiple dex files define Lcom/example/lib/Class; This error occurs because the app, when packaging, finds two .dex files that define the same set of methods. Usually this happens because the app has accidentally acquired 2 separate dependencies on the same library....

Find meaningful names for computation units. Use for comprehensions or map to combine computations together. Let's say you have something like this: if (userAuthorized.nonEmtpy) { makeRequest().map { case Success(respone) => someProcessing(..) if (resendToUser) { ...

A Haskell project can either use the system wide packages or use a sandbox. A sandbox is an isolated package database and can prevent dependency conflicts, e. g. if multiple Haskell projects use different versions of a package. To initialize a sandbox for a Haskell package go to its directory and r...

A SIGABRT or an EXC_BAD_INSTRUCTION usually means the app crashed itself intentionally because some check failed. These should log a message to the debugger console with more information; check there for more information. Many SIGABRTs are caused by uncaught Objective-C exceptions. There are a lo...

EXC_BAD_ACCESS means the process tried to access memory in an invalid way, like dereferencing a NULL pointer or writing to read-only memory. This is the hardest kind of crash to debug, because it usually does not have an error message, and some crashes can be very difficult to reproduce and/or occu...

Firstly you have to add Xamarin.Android.Support.V7.AppCompat library for NuGet: https://www.nuget.org/packages/Xamarin.Android.Support.v7.AppCompat/ In the "values" folder under "Resources" add new xml file called "styles.xml": "styles.xml" file should co...

Sometimes it's useful to check if a field is present or absent on your JSON to avoid some JSONException on your code. To achieve that, use the JSONObject#has(String) or the method, like on the following example: Sample JSON { "name":"James" } Java code String jsonStr...

Basic Text Email <?php $mail = new PHPMailer(); $mail->From = "[email protected]"; $mail->FromName = "Full Name"; $mail->addReplyTo("[email protected]", "Reply Address"); $mail->Subject = "Subject Text"; $mail->Body ...

Basic Text Email <?php $sendgrid = new SendGrid("YOUR_SENDGRID_API_KEY"); $email = new SendGrid\Email(); $email->addTo("[email protected]") ->setFrom("[email protected]") ->setSubject("Subject Text") ->setTex...

package com.example.xml.adapters; import javax.xml.bind.annotation.adapters.XmlAdapter; public class StringTrimAdapter extends XmlAdapter<String, String> { @Override public String unmarshal(String v) throws Exception { if (v == null) return null; ...