The purpose of the file containing export directives - flutter

What is the purpose of the dart file containing the content like this? The file is located right in the lib folder and contains nothing more.
export 'src/admob.dart';
export 'src/admob_banner.dart';
export 'src/admob_banner_size.dart';
export 'src/admob_banner_controller.dart';
export 'src/admob_interstitial.dart';
export 'src/admob_reward.dart';
export 'src/admob_events.dart';

The user of the library will be able to import just the single file and get all the classes and methods exported in it. Also, it's considered a bad practice to import anything from src/* directories, as they are considered to contain implementation details.
You can find more info in the documentation, specifically this point:
Create a “main” library file directly under lib, lib/.dart, that exports all of the public APIs. This allows the user to get all of a library’s functionality by importing a single file.

Related

Can I stored class based DSC resource in separate file from PSM file?

Currently, for my modules, I store actual code in a separate file from PSM1 file, then dot source it and use Export-ModuleMember to export Functions, this way it allows me easily debug/test individual functions.
I assume it's not possible since Export-ModuleMember does not give the option to export DSCResource but is it possible to have a similar setup for class based DSC Resources?
Bug filed against WMF 5.0. Please upvote.
https://windowsserver.uservoice.com/forums/301869-powershell/suggestions/14288805-nested-modules-does-not-work-invoke-dscresource
You can have a module containing many DSC class based resources.
In that module you can have 1 class per file but you can't split it further (like Test method in one file Set method in another).
Powershell does not support partial classes.

Rename references at the same time in Eclipse

I have the following situation:
Consider that I have a class nested in a folder structure like for example /fol/der/exam/ple.java . Of course, the class ple.java contains package or import instuctions referencing to some sources. Now, when I choose Use as a source folder for /fol/der/exam/ple.java then, of course, the references used in package, import or function parameters are not the same anymore. I need to adjust them. Is there an elegant how to do that automatically in eclipse?
So, let´s assume that I have the following line in ple.java:
package fol.der.exam;
and that I have this line also in other files like a.java, b.java, etc. and I want to change the line, let´s say to package der.exam;
How can I do that automatically for all java files in eclipse?
best regards,

Issues with reading xml file after creating jar

We are building an application using ScalaFX. When I run the project in IntelliJIDEA, everything works fine. However, when I create jar file and try to execute it, I am getting errors in reading some xml file.
I tried various solutions posted in SO, but with no use.
package com.app.adt
import scalafx.application.JFXApp
import scalafx.Includes._
import scalafx.scene.Scene
import scala.reflect.runtime.universe.typeOf
import scalafxml.core.{FXMLView, DependenciesByType}
object App extends JFXApp {
val root = FXMLView(getClass.getResource("/com/app/adt/Home.fxml"),
new DependenciesByType(Map(
typeOf[TestDependency] -> new TestDependency("ADT"))))
stage = new JFXApp.PrimaryStage() {
title = "ADT"
scene = new Scene(root)
}
}
The xml file(Home.fxml) is placed in com/app/adt package. I am creating the jar file using sbt-one-jar.
I have tried different combinations of path, but alwasys gives the same error.
Error Stack:
Caused by: javafx.fxml.LoadException:
file:/adt-app_2.11-1.3-SNAPSHOT-one-jar.jar!/main/adt-app_2.11-1.3-S
NAPSHOT.jar!/com/app/adt/Home.fxml
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2611)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2589)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2403)
at scalafxml.core.FXMLView$.apply(FXMLView.scala:17)
Jar Structure:
adt-app_2.11-1.3-SNAPSHOT-one-jar.jar
|
main
|
adt-app_2.11-1.3-SNAPSHOT.jar
|
com\app\adt
|
App.scala
Home.fxml
Also, I have tried with sbt-assembly instead of sbt-one-jar. But , still getting the same error. :(
Tried with below answers in SO:
Q1
Q2
The real problem is rather tricky. Firstly, one needs to realize that JAR is an archive (e.g. similar to ZIP) and archives are regular files. Thus the archive itself is located somewhere in the file system, hence, it is accessible via URL.
On the contrary, the "subfiles" (entries) are just data-block within the archive. Neither the operating system nor the JVM knows that this particular file is an archive therefore they treat is as a regular file.
If you're interested in deeper archive handling, try to figure out how ZipFile works. JAR is basically ZIP so you're able to apply this class to it.
Java provides Class.getResourceAsStream methods that enables the programmer to read files as streams. This solution is obviously useless in this particular example since the ScalaFX method expects the File instead.
So basically you have three options
Use the stream API in order to duplicate the XML into temporary file, than pass this file to the method.
Deploy your resources separately in a way they remain regular files.
Re-implement JavaFX in order to accept streams (this should probably happen anyway)

Automatically import properties file?

I have a properties file used for building in Ant containing variables that I want to add to Eclipse classpath. Is there a way to do this automatically?
Ideally I'd like to be able to add an argument to the command line and automatically import the values in the file.
Acceptable solutions also include the usage of a plugin that adds this functionality.
Example:
test.propeties
MW_HOME=C:\\Program\\Oracle\\
TEST_HOME=C:\\temp\\

What is the correct way to embed a resource in a reusable MFC class?

I am writing a C++ (MFC in particular) class which uses an external .gif image file and produces another image file after some processing. It would be nice if the initial image could be embedded in the code somehow. I have read in MSDN about using multiple .rc files and the whole thing seems quite complicated.
I would like to know from people who have gone through this before how to handle this problem.
EDIT : Sorry I was not clear. The class I am writing should be standalone, so I could use it again. If I put the image in a resource file, then the class will not compile if used in a fresh project.
You cannot embedd MFC resources inside a class or similar C++ container. They can only be embedded in DLL or EXE files - in a separate section of the produced binary. Since you want your class to be reusable, you must put it in a DLL. Hence, you must tag your class with the AFX_EXT_CLASS keyword.
There are two solutions.
Solution #1:
Create an MFC DLL project (MFC Extension DLL). Call it MyLibrary or whatever.
Put all your standalone classes in this DLL.
Embed all necessary resources.
Let your classes load resources from the HINSTANCE of your DLL as described below.
There are several ways to retrieve the HINSTANCE of your DLL. If you ask me, the best solution is to grab it in DllMain. This is done automatically if you choose the MFC Extension DLL configuration:
static AFX_EXTENSION_MODULE MyLibDLL = { NULL, NULL }; // Make this variable global!
// Then access the hInstance as follows:
LoadResource(MyLibDLL.hModule, ...)
Solution #2:
Store your resource as a byte buffer. Or better, convert it to Base64 and store it as an ASCII string. But remember not to blow the stack! Keep your resources small or increase the stack size in your project settings. Example:
const char *encodedResource = "SGVsbG8gd29ybGQh";
char *data = decode(encodedResource);
foo(data);
In the solution explorer go to resource view, Right click and click Add Resource then click Import and add the gif file. Now you can use your Resource ID to access the gif file in your code.
Just adding the file to a resource doesn't embed the file in the actual resource file it just links to the file. If you open your .rc file you'll see it says something like:
IDB_GIF_MYIMAGE GIF "artwork\\mygif.gif"
During the compilation face the resource will be included in the EXE, which you reference using the resource id IDB_GIF_MYIMAGE. You can reference the same file in other projects without having to duplicate the file.
To embed an image (or any other type of binary data) into your class without using resource files, use the bin2c utility, for example you can download it from here: http://www.opensource.apple.com/source/libpcap/libpcap-16/libpcap/msdos/bin2c.c . Running this on a file will produce what is basically a static array with the bytes of the file as members of that array. Stuff this array into a .h file (or put it in the header of your class, or make it a static member...) and then you will have that file available in-memory without having to use LoadResource() and its brethren.
If you want to use this with CImage::Load(), you will have to write your own class that derives from IStream, and implement a few of the methods in a way so that they 'read' from memory. I don't know of any ways to let CImage decode an image from an in-memory representation of a gif file.
I think the best solution is just to document that to use the class you must also import to your project a certain .gif file and give it a certain expected identifier (e.g. IDB_MYCLASS_MYGIF). You can then use the preprocessor to detect if the resource has been correctly added, e.g.:
#ifndef IDB_MYCLASS_MYGIF
#error Make sure you import mygif.gif to the project. See docs for more info.
#endif
This will prevent the class compiling until the user imports the image properly. Alternatively you could just use #ifdefs to fall back to code which does not use the default image if it is not provided.
Have a look at the CRuntimeDialog class presented in http://www.codeproject.com/Articles/5371/ToDoList-6-5-4-Feature-Release-An-effective-and-fl . It provides a way to create a dialog from the string that makes up the resource definition.