Enable multiple checker and add dropdown list for checkers

feature/.project

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>lsp_checkerframework.feature</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.pde.FeatureBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.pde.FeatureNature</nature>
+	</natures>
+</projectDescription>

feature/build.properties

@@ -0,0 +1,8 @@
+bin.includes = feature.xml,\
+               bin/,\
+               plugin/,\
+               feature/
+src.includes = feature.xml,\
+               build.properties,\
+               .project 
+

plugin/src/org/checkerframework/languageserver/eclipse/LSPCheckerFrameworkPreferencePage.java

@@ -1,5 +1,10 @@
 package org.checkerframework.languageserver.eclipse;
 
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.PreferencePage;
 import org.eclipse.swt.SWT;
@@ -12,6 +17,7 @@
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
+import org.eclipse.swt.widgets.List;
 import org.eclipse.swt.widgets.Text;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.IWorkbenchPreferencePage;
@@ -23,10 +29,24 @@
  */
 public class LSPCheckerFrameworkPreferencePage extends PreferencePage
     implements IWorkbenchPreferencePage, SelectionListener, ModifyListener {
+
+  /**
+   * Creates built in checker map.
+   *
+   * @key Checkers' display names in the drop down list
+   * @value Checkers' full name to initialize the server
+   */
+  final private Map<String, String> builtinCheckers = new HashMap<String, String>() {{
+    put("Nullness Checker", "org.checkerframework.checker.nullness.NullnessChecker");
+	put("Optional Checker", "org.checkerframework.checker.optional.OptionalChecker");
+	put("Regex Checker", "org.checkerframework.checker.regex");
+	put("Interning Checker", "org.checkerframework.checker.interning.InterningChecker");
+  }};
 
   private Text textFieldTypeChecker;
   private Text textFieldCheckerPath;
   private Text textFieldCommandLineOptions;
+  private List multiSelectCheckerOptions;
 
   /**
    * Creates composite control and sets the default layout data.
@@ -62,6 +82,11 @@ protected Control createContents(Composite parent) {
     createLabel(
         composite_textField_typeChecker,
         MessageUtil.getString("Text_Field_Type_Checker")); // $NON-NLS-1$
+
+    Composite composite_multiSelectDropdown_checker_options = createComposite(parent, 2);
+    createLabel(
+    		composite_multiSelectDropdown_checker_options,
+        MessageUtil.getString("Dropdown_Checker_Options"));
 
     Composite composite_textField_checkerPath = createComposite(parent, 2);
     createLabel(
@@ -74,6 +99,7 @@ protected Control createContents(Composite parent) {
         MessageUtil.getString("Text_Field_Command_Options")); // $NON-NLS-1$
 
     textFieldTypeChecker = createTextField(composite_textField_typeChecker);
+    multiSelectCheckerOptions = createMultiSelectDropdown(composite_multiSelectDropdown_checker_options);
     textFieldCheckerPath = createTextField(composite_textField_checkerPath);
     textFieldCommandLineOptions = createTextField(composite_textField_commandOptions);
 
@@ -117,6 +143,22 @@ private Text createTextField(Composite parent) {
     text.setLayoutData(data);
     return text;
   }
+
+  /**
+   * Create a multi-select list specific for this application
+   *
+   * @param parent the parent of the new text field
+   * @return the new multi-select list
+   */
+  private List createMultiSelectDropdown(Composite parent) {
+	// Create a multiple-selection list
+	List multi = new List(parent, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL);
+	for (String item : builtinCheckers.keySet()) {
+	    multi.add(item);
+	}
+	multi.addSelectionListener(this);
+	return multi;
+  }
 
   /**
    * The <code>ReadmePreferencePage</code> implementation of this <code>PreferencePage</code> method
@@ -152,6 +194,57 @@ private void initializeValues() {
     textFieldCheckerPath.setText(store.getString(LSPCheckerFrameworkConstants.CHECKER_PATH));
     textFieldCommandLineOptions.setText(
         store.getString(LSPCheckerFrameworkConstants.COMMAND_OPTIONS));
+
+    /** Initializes states of the multi-select list from the preference store. */
+    String[] checkersStored = store.getString(LSPCheckerFrameworkConstants.TYPE_CHECKER).split("\\,");
+    synchronizeMultiSelectListWithTextField(checkersStored);
+
+    /** Adds a listener to the multi-select list to synchronize inputed checkers from the text field. */
+    ModifyListener checkerMultiSelectListener = new ModifyListener() {
+        /** {@inheritDoc} */
+        public void modifyText(ModifyEvent e) {
+            // Handle event
+        	String[] inputCheckers = textFieldTypeChecker.getText().split("\\,");
+        	synchronizeMultiSelectListWithTextField(inputCheckers);
+        }
+    };
+    textFieldTypeChecker.addModifyListener(checkerMultiSelectListener);
+
+    /** Adds a listener to the text field to synchronize inputed checkers from the multi-select list. */
+    SelectionListener checkerTextFieldListener = new SelectionListener() {
+		@Override
+		public void widgetSelected(SelectionEvent arg0) {
+			java.util.List<String> checkers = Arrays.asList(multiSelectCheckerOptions.getSelection());;
+		    String result = checkers.stream()
+		    		.map(i -> builtinCheckers.get(i))
+		    		.collect(Collectors.joining(","));
+		    textFieldTypeChecker.setText(result);
+		}
+
+		/** The multi-select list is initialized above in initializeValues() not need to set default again. */
+		@Override
+		public void widgetDefaultSelected(SelectionEvent arg0) {}
+
+    };
+    multiSelectCheckerOptions.addSelectionListener(checkerTextFieldListener);
+  }
+
+  private void synchronizeMultiSelectListWithTextField(String[] inputCheckersInTextField) {
+  	multiSelectCheckerOptions.deselectAll();
+  	/** Looping input checkers in text field */
+  	for (String checkerFullName : inputCheckersInTextField) {
+  		/** Looping built in checkers */
+  		for (String checkerName : builtinCheckers.keySet()) {
+      		if (checkerFullName.equals(builtinCheckers.get(checkerName))) {
+      			/** Looping multi-select list to select the checkers */
+      			for(int i = 0; i < multiSelectCheckerOptions.getItems().length; i++) {
+      				if(multiSelectCheckerOptions.getItems()[i].equals(checkerName)) {
+      	    			multiSelectCheckerOptions.select(i);
+      	        	}
+      			}
+      		}
+      	}
+    }
   }
 
   /** (non-Javadoc) Method declared on ModifyListener */
@@ -185,7 +278,7 @@ private void storeValues() {
     store.setValue(
         LSPCheckerFrameworkConstants.COMMAND_OPTIONS, textFieldCommandLineOptions.getText());
   }
-
+  
   /** (non-Javadoc) Method declared on SelectionListener */
   public void widgetDefaultSelected(SelectionEvent event) {
     // Handle a default selection. Do nothing in this example

plugin/src/org/checkerframework/languageserver/eclipse/LanguageServerStreamConnectionProvider.java

@@ -117,7 +117,7 @@ public LanguageServerStreamConnectionProvider() {
       commands.add("--commandLineOptions");
       commands.add(commandOptions);
     }
-
+    
     setCommands(commands);
     setWorkingDirectory(System.getProperty("user.dir"));
   }

plugin/src/org/checkerframework/languageserver/eclipse/messages.properties

@@ -4,3 +4,4 @@ Check_Box_Options=Check Box Options
 Text_Field_Type_Checker=Type Checker
 Text_Field_Checker_Path=Checker Path
 Text_Field_Command_Options=Command Line Options
+Dropdown_Checker_Options=Built-in Checkers:

update-site/.project

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>lsp_checkerframework.update_site</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.pde.UpdateSiteBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.pde.UpdateSiteNature</nature>
+	</natures>
+</projectDescription>

update-site/site.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<site>
+   <feature url="features/checker-framework-eclipse-feature_0.0.1.jar" id="checker-framework-eclipse-feature" version="0.0.1"/>
+      <category name="checker-framework-eclipse-update-site"/>
+   </feature>
+   <category-def name="checker-framework-eclipse-update-site" label="Pluggable Type-Checking"/>
+</site>
+