Add brace matching/folding feature

README.md

@@ -20,6 +20,8 @@ _NOTE_: This plugin is in active development and features are still being implem
 ## Features
 
 - `.usd`/`.usda` filetype syntax highlighting & validation
+
+- Brace matching/folding
 
 TODO:
 
@@ -31,8 +33,6 @@ TODO:
 
 - Line markers for overrides, inheritance, etc
 
-- Brace matching
-
 - Python autocompletions for the `pxr.Usd` library
 
 ## License

build.gradle

@@ -3,7 +3,7 @@ plugins {
 }
 
 group 'com.justint'
-version '0.1.3'
+version '0.2'
 
 sourceSets.main.java.srcDirs = ['src/main/gen','src/main/java']
 

src/main/java/com/justint/usdidea/codeinsight/folding/USDFoldingBuilder.java

@@ -0,0 +1,68 @@
+package com.justint.usdidea.codeinsight.folding;
+
+import com.intellij.lang.ASTNode;
+import com.intellij.lang.folding.FoldingBuilder;
+import com.intellij.lang.folding.FoldingDescriptor;
+import com.intellij.lang.folding.NamedFoldingDescriptor;
+import com.intellij.openapi.editor.Document;
+import com.intellij.psi.tree.IElementType;
+import com.justint.usdidea.lang.psi.USDTypes;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class USDFoldingBuilder implements FoldingBuilder {
+
+    private static final IElementType[] BRACKET_TYPES = new IElementType[] {
+            USDTypes.BODY,
+            USDTypes.DICT,
+            USDTypes.TIME_SAMPLE
+    };
+
+    @NotNull
+    @Override
+    public FoldingDescriptor[] buildFoldRegions(@NotNull ASTNode astNode, @NotNull Document document) {
+        List<FoldingDescriptor> descriptors = new ArrayList<>();
+        collectRegionsRecursively(astNode, document, descriptors);
+        return descriptors.toArray(FoldingDescriptor.EMPTY);
+    }
+
+    private void collectRegionsRecursively(@NotNull final ASTNode astNode,
+                                           @NotNull final Document document,
+                                           @NotNull List<FoldingDescriptor> descriptors) {
+        final IElementType elementType = astNode.getElementType();
+
+        if (elementType == USDTypes.METADATA) {
+            descriptors.add(new NamedFoldingDescriptor(
+                    astNode,
+                    astNode.getTextRange(),
+                    null,
+                    "(...)"
+            ));
+        } else if (Arrays.asList(BRACKET_TYPES).contains(elementType)) {
+            descriptors.add(new NamedFoldingDescriptor(
+                    astNode,
+                    astNode.getTextRange(),
+                    null,
+                    "{...}"));
+        }
+
+        for (ASTNode child : astNode.getChildren(null)) {
+            collectRegionsRecursively(child, document, descriptors);
+        }
+    }
+
+    @Nullable
+    @Override
+    public String getPlaceholderText(@NotNull ASTNode astNode) {
+        return "...";
+    }
+
+    @Override
+    public boolean isCollapsedByDefault(@NotNull ASTNode astNode) {
+        return false;
+    }
+}

src/main/java/com/justint/usdidea/codeinsight/highlighting/USDBraceMatcher.java

@@ -0,0 +1,35 @@
+package com.justint.usdidea.codeinsight.highlighting;
+
+import com.intellij.lang.BracePair;
+import com.intellij.lang.PairedBraceMatcher;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.tree.IElementType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import static com.justint.usdidea.lang.psi.USDTypes.*;
+
+public class USDBraceMatcher implements PairedBraceMatcher {
+
+    private static final BracePair[] PAIRS = new BracePair[] {
+            new BracePair(LEFTBRACE, RIGHTBRACE, true),
+            new BracePair(LEFTPARENS, RIGHTPARENS, true),
+            new BracePair(LEFTBRACKET, RIGHTBRACKET, false)
+    };
+
+    @NotNull
+    @Override
+    public BracePair[] getPairs() {
+        return PAIRS;
+    }
+
+    @Override
+    public boolean isPairedBracesAllowedBeforeType(@NotNull IElementType lBraceType, @Nullable IElementType contextType) {
+        return true;
+    }
+
+    @Override
+    public int getCodeConstructStart(PsiFile file, int openingBraceOffset) {
+        return openingBraceOffset;
+    }
+}

src/main/java/com/justint/usdidea/lang/USD.bnf

@@ -174,7 +174,7 @@ Identifier ::= alpha (alpha | number)*
 NamespacedIdentifier ::= Identifier (colon Identifier)+
 
 
-PrimSpec ::= Specifier Metadata? Body {methods=[getPrimName getPrimType getName getPresentation]}
+PrimSpec ::= Specifier Metadata? Body
 
 Specifier ::= def [Typename] PrimName | over PrimName | class [Typename] PrimName
 

src/main/resources/META-INF/change-notes.html

@@ -1,6 +1,12 @@
 <!DOCTYPE html>
 <html lang="en">
 <body>
+<strong>Version 0.2:</strong>
+<ul>
+    <li>Added brace matching and block folding features</li>
+    <li>Improved syntax highlighting (Prim names, special metadata keywords)</li>
+    <li>Set a wider release version support for IDE versions 2016-2019 (builds 145-191.*)</li>
+</ul>
 <strong>Version 0.1:</strong>
 <ul>
     <li>Basic syntax highlighting</li>

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

@@ -12,12 +12,12 @@
 <ul>
     <li>Syntax highlighting</li>
     <li>Parser</li>
+    <li>Brace matching & block folding</li>
 </ul>
 <strong>Planned features:</strong>
 <ul>
     <li>Reference Contributor implementation (Go to declaration feature)</li>
     <li>Structure View</li>
-    <li>Brace matching</li>
     <li>Line markers for <i>overrides</i>, <i>inherits</i>, and more</li>
 </ul>
     ]]></description>
@@ -35,7 +35,9 @@
         <!-- TODO: re-add the color settings page once syntax highlighting is more complete -->
         <!--<colorSettingsPage implementation="com.justint.usdidea.codeinsight.highlighting.USDColorSettingsPage"/>-->
 
-        <lang.psiStructureViewFactory language="USD" implementationClass="com.justint.usdidea.codeinsight.structureview.USDStructureViewFactory"/>
+        <lang.foldingBuilder language="USD" implementationClass="com.justint.usdidea.codeinsight.folding.USDFoldingBuilder"/>
+        <lang.braceMatcher language="USD" implementationClass="com.justint.usdidea.codeinsight.highlighting.USDBraceMatcher"/>
+
     </extensions>
 
     <actions>