feat(usage): enable to search for usage

src/main/kotlin/com/feakin/intellij/highlight/FeakinSyntaxHighlighter.kt

@@ -1,6 +1,6 @@
 package com.feakin.intellij.highlight
 
-import com.feakin.intellij.lexer.FeakinLexerAdapter
+import com.feakin.intellij.lexer.FkLexer
 import com.feakin.intellij.lexer.FeakinElementTypes
 import com.intellij.lexer.Lexer
 import com.intellij.openapi.editor.DefaultLanguageHighlighterColors
@@ -10,7 +10,7 @@ import com.intellij.psi.tree.IElementType
 
 class FeakinSyntaxHighlighter : SyntaxHighlighterBase() {
     override fun getHighlightingLexer(): Lexer {
-        return FeakinLexerAdapter()
+        return FkLexer()
     }
 
     override fun getTokenHighlights(tokenType: IElementType): Array<TextAttributesKey> {

src/main/kotlin/com/feakin/intellij/ide/FeakinBraceMatcher.java → src/main/kotlin/com/feakin/intellij/ide/FkBraceMatcher.java

@@ -8,7 +8,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-public class FeakinBraceMatcher implements PairedBraceMatcher {
+public class FkBraceMatcher implements PairedBraceMatcher {
     private static final BracePair[] BRACE_PAIRS = {
             new BracePair(FeakinElementTypes.LBRACE, FeakinElementTypes.RBRACE, true),
     };

src/main/kotlin/com/feakin/intellij/ide/search/FkFindUsagesHandler.kt

@@ -0,0 +1,8 @@
+package com.feakin.intellij.ide.search
+
+import com.intellij.find.findUsages.FindUsagesHandler
+import com.intellij.psi.PsiElement
+
+class FkFindUsagesHandler(psiElement: PsiElement, private val secondaryElements: Array<PsiElement>) : FindUsagesHandler(psiElement) {
+    override fun getSecondaryElements(): Array<PsiElement> = secondaryElements
+}

src/main/kotlin/com/feakin/intellij/ide/search/FkFindUsagesHandlerFactory.kt

@@ -0,0 +1,19 @@
+package com.feakin.intellij.ide.search
+
+import com.feakin.intellij.psi.FeakinNamedElement
+import com.intellij.find.findUsages.FindUsagesHandler
+import com.intellij.find.findUsages.FindUsagesHandlerFactory
+import com.intellij.psi.PsiElement
+
+class FkFindUsagesHandlerFactory : FindUsagesHandlerFactory() {
+    override fun canFindUsages(element: PsiElement): Boolean = element is FeakinNamedElement
+
+    override fun createFindUsagesHandler(element: PsiElement, forHighlightUsages: Boolean): FindUsagesHandler {
+        val secondaryElements = if (!forHighlightUsages) findSecondaryElements(element) else emptyList()
+        return FkFindUsagesHandler(element, secondaryElements.toTypedArray())
+    }
+
+    private fun findSecondaryElements(element: PsiElement): List<PsiElement> {
+        return emptyList()
+    }
+}

src/main/kotlin/com/feakin/intellij/ide/search/FkFindUsagesProvider.kt

@@ -0,0 +1,21 @@
+package com.feakin.intellij.ide.search
+
+import com.feakin.intellij.psi.FeakinNamedElement
+import com.intellij.lang.HelpID
+import com.intellij.lang.findUsages.FindUsagesProvider
+import com.intellij.psi.PsiElement
+
+class FkFindUsagesProvider : FindUsagesProvider {
+    override fun getWordsScanner() = FkWordScanner()
+
+    override fun canFindUsagesFor(psiElement: PsiElement): Boolean = psiElement is FeakinNamedElement
+
+    override fun getHelpId(psiElement: PsiElement): String = HelpID.FIND_OTHER_USAGES
+
+    override fun getType(element: PsiElement): String = ""
+
+    override fun getDescriptiveName(element: PsiElement): String = (element as? FeakinNamedElement)?.name.orEmpty()
+
+    override fun getNodeText(element: PsiElement, useFullName: Boolean): String = ""
+
+}

src/main/kotlin/com/feakin/intellij/ide/search/FkWordScanner.kt

@@ -0,0 +1,13 @@
+package com.feakin.intellij.ide.search
+
+import com.feakin.intellij.lexer.FeakinElementTypes.*
+import com.feakin.intellij.lexer.FkLexer
+import com.intellij.lang.cacheBuilder.DefaultWordsScanner
+import com.intellij.psi.tree.TokenSet
+
+class FkWordScanner : DefaultWordsScanner(
+    FkLexer(),
+    TokenSet.create(IDENTIFIER),
+    TokenSet.create(BLOCK_COMMENT, COMMENT),
+    TokenSet.create(STRING_LITERAL)
+)

src/main/kotlin/com/feakin/intellij/lexer/FkLexer.kt

@@ -0,0 +1,5 @@
+package com.feakin.intellij.lexer
+
+import com.intellij.lexer.FlexAdapter
+
+class FkLexer : FlexAdapter(com.feakin.intellij.lexer._FeakinLexer(null))

src/main/kotlin/com/feakin/intellij/parser/FeakinParserDefinition.kt

@@ -3,7 +3,7 @@ package com.feakin.intellij.parser
 import com.feakin.intellij.FkFile
 import com.feakin.intellij.FkLanguage
 import com.feakin.intellij.lexer.FeakinElementTypes
-import com.feakin.intellij.lexer.FeakinLexerAdapter
+import com.feakin.intellij.lexer.FkLexer
 import com.intellij.lang.ASTNode
 import com.intellij.lang.ParserDefinition
 import com.intellij.lang.PsiParser
@@ -18,13 +18,12 @@ import com.intellij.psi.tree.TokenSet
 
 class FeakinParserDefinition : ParserDefinition {
     companion object {
-        val WHITE_SPACES = TokenSet.create(TokenType.WHITE_SPACE)
         val COMMENTS = TokenSet.create(FeakinElementTypes.COMMENT)
         val FILE = IFileElementType(FkLanguage)
     }
 
     override fun createLexer(project: Project): Lexer {
-        return FeakinLexerAdapter()
+        return FkLexer()
     }
 
     override fun createParser(project: Project): PsiParser {

src/main/resources/META-INF/plugin.xml

@@ -27,14 +27,15 @@
         <lang.psiStructureViewFactory language="Feakin"
                                       implementationClass="com.feakin.intellij.structure.FkStructureViewFactory"/>
 
+        <!-- Editor -->
+        <extendWordSelectionHandler implementation="com.feakin.intellij.ide.editor.FeakinBlockSelectionHandler"/>
         <lang.foldingBuilder language="Feakin"
                              implementationClass="com.feakin.intellij.edit.FeakinFoldingBuilder"/>
 
         <lang.commenter language="Feakin" implementationClass="com.feakin.intellij.completion.FeakinCommenter"/>
-        <lang.braceMatcher language="Feakin" implementationClass="com.feakin.intellij.ide.FeakinBraceMatcher"/>
+        <lang.braceMatcher language="Feakin" implementationClass="com.feakin.intellij.ide.FkBraceMatcher"/>
+
 
-        <!-- Editor -->
-        <extendWordSelectionHandler implementation="com.feakin.intellij.ide.editor.FeakinBlockSelectionHandler"/>
         <!-- Navigate between useDomainObject and DomainObjectDecl -->
         <stubIndex implementation="com.feakin.intellij.psi.stubs.FkNamedElementIndex"/>
         <!-- TODO: add support for goto -->
@@ -66,6 +67,10 @@
 
         <!-- Formatter -->
         <lang.formatter language="Feakin" implementationClass="com.feakin.intellij.formatter.FkFormattingModelBuilder"/>
+
+        <!-- Usages Provider -->
+        <lang.findUsagesProvider language="Feakin" implementationClass="com.feakin.intellij.ide.search.FkFindUsagesProvider"/>
+        <findUsagesHandlerFactory implementation="com.feakin.intellij.ide.search.FkFindUsagesHandlerFactory"/>
     </extensions>
 
     <actions>