Tomsondev Blog

Fairly everything in e(fx)clipse is done with DS-Services when you run in an OSGi-Environment.

Still many of them don’t have any dependency on OSGi at all so most components we have can also run/get used in an ordinary Java-Environment (see the blog post about the code editor framework as an example). Since the beginning we published some of them through the ServiceLoader-API (and we’ll still keep it for those) but that has the draw back that you can not express relations between services.

Tonight I had a crazy idea: Could I read the DS-Component-Registration files in an none-OSGi environment and wire services together without using the ServiceLoader-API.

The result is JavaDSServiceProcessor. Our public service lookup API has been retrovited to use this internal service instead of ServiceLoader so if one now eg looks up our AdapterService like this:

import org.eclipse.fx.core.Util;
import org.eclipse.fx.core.adapter.AdapterService;

public class Test {
  public static void main(String[] args) {
    AdapterService adapterService = Util.getService(AdapterService.class).get();
  }
}

will get a fully configured AdapterService. We currently don’t support everything from the DS-Spec (eg Properties are not yet support) but I’ll fill this gap soon.

If you happen to be at JavaOne this week.

I’ll do a talk today (Tuesday Oct 27th at 16:00) on How to Build an IDE/Code Editor with JavaFX – CON3123. I’ll explain how one can build cool and lightweight code editors – who can be embedded ANYWHERE – with JavaFX and e(fx)clipse.

Hope to see you there!

In last blog post I talked about the problem that people (including me!) often forget to set the contributorURI of the MApplicationElement instance which could lead to problems.

So with the next release of e(fx)clipse there’s a new service called ModelElementFactory who does the initialization for you and has some other nice features.

Let’s see how we can create model instances:

import org.eclipse.fx.ui.workbench.services.ModelService;
import org.eclipse.fx.ui.workbench.services.ModelService.ModelElementFactory;
import org.eclipse.e4.ui.workbench.modeling.EModelService;

class Handler {
   @Execute
   public void createPart(EModelService eModelService, ModelService modelService) {
     ModelElementFactory factory = modelService.createModelElementFactory(getClass(),eModelService);
     MPart part = factory.createModelElement(MPart.class); // Creates the instance and sets the contributorURI
     // ...
   }
}

You might ask why does one have to create the service instance through the ModelService as the factory and the problem is that:

1. we need the EModelService-Instance
2. we need access to the owner of the final element which we can only extract from the caller-class

While 1. can be worked around with the an IContextFunction the 2nd problem is not easy to solve (although it can be solved and I’ll introduce the solution in an upcoming blog post)

So the first API provided solves our basic usecase of creating application model elements but there’s more

• Post processing of created instances

  
  MPart part = factory.createModelElement(MPart.class, this::fillPart);
  
  private MPart fillPart(MPart part) {
    // initialize the part
  }
  

• Creation of Supplier instances you can pass around

  
  class Handler {
     @Execute
     public void createPart(EModelService eModelService, ModelService modelService) {
       ModelElementFactory factory = modelService.createModelElementFactory(getClass(),eModelService);
       Supplier<MPart> part = factory.createModelElementCreator(MPart.class, this::fillPart)
       // ...
     }
  }
  
  public class EditorOpener {
      public void createOrSelectPart(MPartStack stack, String elementId, Supplier<MPart> partCreator) {
        // do some logic eg detecting of the elementId already exists
  
        MPart part = partCreator.get();
        partStack.getChildren().add(part);
        return part;
      }
  }
  

Yesterday I worked on a cool addition required to develop syntax highlighting for things like Asciidoc.

Suppose you want to define lexical highlighting for Asciidoc you very likely have a rule like this:

lexical_highlighting {
  // ...
  rule __dftl_partition_content_type whitespace javawhitespace {
    // ...
    adoc_section_0 {
      single_line "= "
    }
    // ...
  }
  // ...
}

But now suppose your asciidoc-File looks like this:

= This is a head line
if a = b you're doing something wrong

the above rule would produce the following highlighting

which obivously is wrong. What our rule really has to express is

if a line starts with = (equal-sign) followed by a space

So the new addition I added the the ldef-DSL is that you can now define at which column in a line the rule has to start

lexical_highlighting {
  // ...
  rule __dftl_partition_content_type whitespace javawhitespace {
    // ...
    adoc_section_0 {
      single_line "= " col eq 0
    }
    // ...
  }
  // ...
}

and now the result looks ok

In my last few blogs (here, here and here) I started implementing a smart dart editor with syntax highlighting, auto complete, … for google dart.

While the first posts have been dedicated to getting syntax highlighting working we’ll now start with the higher level features you are used to from full blown IDEs.

In this first blog post we’ll look how we can interface with the Dart Analysis Server which is the reason I’ve chose dart as the example language.

The communication with the Dart Analysis is done through the input and output stream. An example will probably help.

Let’s suppose we have a /home/tomschindl/dart-samples/test.dart with the following content:

class Rectangle {
  num left;   
  num top;
  num width; 
  num height;          
  
  num get right             => left + width;
      set right(num value)  => left = value - width;
  num get bottom            => top + height;
      set bottom(num value) => top = value - height;
}

// This is where the app starts executing.
main() {
  var r = new Rectangle();
  r.
}

If you now want to get all auto completetion proposals after r. you issue the following commands/requests to the server:

• You launch the dart analysis server eg on my workstation it is:

  /Users/tomschindl/Downloads/dart-sdk/bin/dart \
   bin/snapshots/analysis_server.dart.snapshot

• You inform the server about the root directory:

  { 
    "id" : "default_1", 
    "method" : "analysis.setAnalysisRoots" , 
    "params" :  {
       "included":["/Users/tomschindl/dart-samples/"],
       "excluded":[]
    }
  }
  

• Which will synchronously return the following result

  {
    "id":"default_1"
  }
  

• Requesting all auto completetions at offset 367 which is directly after r.

  { 
    "id" : "default_2", 
    "method" : "completion.getSuggestions" , 
    "params" :  {
      "file":"/Users/tomschindl/dart-samples/test.dart",
      "offset":367
    }
  }
  

• Which will synchronously return the following result

  {
    "id":"default_2",
    "result":{
      "id":"0"
    }
  }
  

• And asynchronously the following events will occur

  {
    "event":"completion.results",
    "params":{
      "id":"0",
      "replacementOffset":367,
      "replacementLength":0,
      "results":[],
      "isLast":false
    }
  }
  
  {
    "event":"completion.results",
     "params":{
       "id":"0",
       "replacementOffset":367,
       "replacementLength":0,
       "results": [
         {
           "kind":"INVOCATION",
           "relevance":1000,
           "completion":"left",
           "selectionOffset":4,
           "selectionLength":0,
           "isDeprecated":false,
           "isPotential":false,
           "declaringType":"Rectangle",
           "element":{
             "kind":"FIELD",
             "name":"left",
             "location":{
               "file":"/Users/tomschindl/dart-samples/test.dart",
               "offset":24,
               "length":4,
               "startLine":2,
               "startColumn":7
             },
             "flags":0,
             "returnType":"num"
           },"returnType":"num"
         },
         {
           "kind":"INVOCATION",
           "relevance":1000,
           "completion":"right",
           "selectionOffset":5,
           "selectionLength":0,
           "isDeprecated":false,
           "isPotential":false,
           "declaringType":"Rectangle",
           "element":{
             "kind":"GETTER",
             "name":"right",
             "location":{
               "file":"/Users/tomschindl/dart-samples/test.dart",
               "offset":95,
               "length":5,
               "startLine":7,
               "startColumn":11
             },
             "flags":0,
             "returnType":"num"
           },
           "returnType":"num"
         }
         // Many more
       ],
      "isLast":true
    }
  }
  

I guess you get the idea – not really rocket science but in java we don’t want to deal with this low-level stuff. So as part of the editor work we also developed a Java interface for the Dart Analysis Server available from maven-central.

If we want to issue the same commands as above through the Java-API.

Create a maven-project and make the pom.xml look like this:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>at.bestsolution</groupId>
	<artifactId>at.bestsolution.dart.server.sample</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<repositories>
		<repository>
			<id>sonatype-snapshots</id>
			<url>https://oss.sonatype.org/content/repositories/snapshots/</url>
		</repository>
	</repositories>
	<dependencies>
		<dependency>
			<groupId>at.bestsolution.eclipse</groupId>
			<artifactId>org.eclipse.fx.core</artifactId>
			<version>2.1.0-SNAPSHOT</version>
		</dependency>
		<dependency>
			<groupId>at.bestsolution</groupId>
			<artifactId>at.bestsolution.dart.server.api</artifactId>
			<version>1.0.0</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>1.8</source>
					<target>1.8</target>
				</configuration>
			</plugin>
		</plugins>
	</build>
</project>

And a java class with the following content:

package at.bestsolution.dart.server.sample;

import java.io.IOException;
import java.util.stream.Stream;

import org.eclipse.fx.core.Util;

import at.bestsolution.dart.server.api.DartServer;
import at.bestsolution.dart.server.api.DartServerFactory;
import at.bestsolution.dart.server.api.Registration;
import at.bestsolution.dart.server.api.model.CompletionResultsNotification;
import at.bestsolution.dart.server.api.services.ServiceAnalysis;
import at.bestsolution.dart.server.api.services.ServiceCompletion;

public class DartServerSample {
	public static void main(String[] args) {
		// Get the server factory from the service registry
		DartServerFactory serverFactory = Util.lookupService(DartServerFactory.class);
		// Create a server instance
		DartServer server = serverFactory.getServer("server");

		// Get the analysis and completion service
		ServiceAnalysis analysisService = server.getService(ServiceAnalysis.class);
		ServiceCompletion completionService = server.getService(ServiceCompletion.class);

		// set the root
		analysisService.setAnalysisRoots(new String[] {"/Users/tomschindl/dart-samples/"}, new String[0], null);
		// register for completion notifcations
		Registration proposalRegistration = completionService.results(DartServerSample::handleHandleResults);

		// Request completion at offset 367
		completionService.getSuggestions("/Users/tomschindl/dart-samples/test.dart", 367);

		// Wait for a key press
		try {
			System.in.read();
		} catch (IOException e) {
		}

		// unregister the notification listener
		proposalRegistration.dispose();
		// shutdown the server instance
		server.dispose();
	}

	private static void handleHandleResults(CompletionResultsNotification notification) {
		Stream.of(notification.getResults()).forEach( c -> System.err.println(c.getCompletion()));
	}
}

And then you have to launch the class with

java -Ddart.sdkdir=/Users/tomschindl/Downloads/dart-sdk at.bestsolution.dart.server.sample.DartServerSample

where you replace /Users/tomschindl/Downloads/dart-sdk with the path to your dart-sdk installation.