Part 1: add sections to breadcrumbs

src/nl/hannahsten/texifyidea/structure/latex/LatexBreadcrumbsInfo.kt

@@ -2,10 +2,14 @@ package nl.hannahsten.texifyidea.structure.latex
 
 import com.intellij.psi.PsiElement
 import com.intellij.ui.breadcrumbs.BreadcrumbsProvider
+import nl.hannahsten.texifyidea.editor.folding.LatexSectionFoldingBuilder
 import nl.hannahsten.texifyidea.grammar.LatexLanguage
 import nl.hannahsten.texifyidea.psi.LatexCommands
 import nl.hannahsten.texifyidea.psi.LatexEnvironment
+import nl.hannahsten.texifyidea.util.files.document
 import nl.hannahsten.texifyidea.util.parser.name
+import nl.hannahsten.texifyidea.util.parser.parents
+import nl.hannahsten.texifyidea.util.parser.requiredParameter
 
 /**
  * @author Hannah Schellekens
@@ -16,7 +20,7 @@ open class LatexBreadcrumbsInfo : BreadcrumbsProvider {
 
     override fun getElementInfo(element: PsiElement) = when (element) {
         is LatexEnvironment -> element.name()?.text
-        is LatexCommands -> element.commandToken.text
+        is LatexCommands -> if (element.name == "\\section") element.requiredParameter(0) else  element.name
         else -> ""
     } ?: ""
 
@@ -25,4 +29,17 @@ open class LatexBreadcrumbsInfo : BreadcrumbsProvider {
         is LatexCommands -> true
         else -> false
     }
+
+    override fun getParent(element: PsiElement): PsiElement? {
+        val document = element.containingFile.document() ?: return super.getParent(element)
+        val parent = LatexSectionFoldingBuilder().buildFoldRegions(element.containingFile, document, quick = true)
+            // Only top-level elements in the section should have the section as parents, other elements should keep their direct parent (e.g. an environment)
+            .filter { it.range.contains(element.textRange) }
+            .filterNot { it.range.contains(element.parent.textRange) }
+            .firstOrNull { it.element.psi != element }
+            ?.element?.psi
+        // Avoid creating a loop
+        if (parent?.parents()?.contains(element) == true) { return super.getParent(element) }
+        return parent ?: super.getParent(element)
+    }
 }