Mini-plugin for paragraph navigation V2 in IntelliJ IDEs (to be use with https://github.com/dkandalov/live-plugin)

plugin.kts

import com.intellij.openapi.command.executeCommand
import com.intellij.openapi.editor.Editor
import com.intellij.openapi.editor.EditorModificationUtil
import com.intellij.openapi.editor.IndentGuideDescriptor
import com.intellij.openapi.editor.LogicalPosition
import com.intellij.openapi.editor.ScrollType.CENTER_DOWN
import com.intellij.openapi.editor.impl.IndentsModelImpl
import com.intellij.openapi.fileEditor.ex.IdeDocumentHistory
import liveplugin.registerEditorAction

registerEditorAction("Next Paragraph", "alt PERIOD") { editor, _, _ ->
    val indents = (editor.indentsModel as? IndentsModelImpl)?.indents ?: return@registerEditorAction
    val lines = editor.document.text.lines()
    val lineIndex = editor.caretModel.logicalPosition.line
    val lineIndices = lineIndex..lines.lastIndex
    val indentByLine = lineIndices.associateWith { index ->
        indents.filter { index in (it.startLine until it.endLine) }.maxByOrNull { it.indentLevel }
    }//.let { show(it.toPrintableString(lines)) }

    val newLineIndex = lineIndices.zipWithNext().asSequence()
        .mapNotNull { (lastIndex, index) ->
            val lastIndent = indentByLine[lastIndex] ?: IndentGuideDescriptor(-1, -1, -1)
            val indent = indentByLine[index] ?: IndentGuideDescriptor(-1, -1, -1)
            val lastLine = lines[lastIndex]
            val line = lines[index]
            when {
                lastIndent != indent && lastIndent.indentLevel < indent.indentLevel -> index
                !lastLine.containsCode() && line.containsCode() -> index
                else -> null
            }
        }.firstOrNull()

    if (newLineIndex != null) {
        editor.moveCaretTo(newLineIndex, lines[newLineIndex].firstColumnIndex())
    }
}

registerEditorAction("Previous Paragraph", "alt COMMA") { editor, _, _ ->
    val indents = (editor.indentsModel as? IndentsModelImpl)?.indents ?: return@registerEditorAction
    val lines = editor.document.text.lines()
    val lineIndex = editor.caretModel.logicalPosition.line
    val lineIndices = lineIndex - 1 downTo 0
    val indentByLine = lines.indices.associateWith { index ->
        indents.filter { index in (it.startLine until it.endLine) }.maxByOrNull { it.indentLevel }
    }

    val newLineIndex = lineIndices.zipWithNext().asSequence()
        .mapNotNull { (lastIndex, index) ->
            val lastIndent = indentByLine[lastIndex] ?: IndentGuideDescriptor(-1, -1, -1)
            val indent = indentByLine[index] ?: IndentGuideDescriptor(-1, -1, -1)
            val lastLine = lines[lastIndex]
            val line = lines[index]
            when {
                lastIndent != indent && lastIndent.indentLevel > indent.indentLevel -> lastIndex
                lastLine.containsCode() && !line.containsCode() -> lastIndex
                else -> null
            }
        }.firstOrNull()

    if (newLineIndex != null) {
        editor.moveCaretTo(newLineIndex, lines[newLineIndex].firstColumnIndex())
    }
}

fun List<String>.containCodeAt(index: Int) =
    if (index !in indices) false
    else this[index].containsCode()

fun String.containsCode() =
    trim().trim(' ', '{', '}', ',', '(', ')', '/').isNotBlank()

fun Editor.moveCaretTo(newLineIndex: Int, columnIndex: Int) {
    caretModel.moveToLogicalPosition(LogicalPosition(newLineIndex, columnIndex))
    caretModel.removeSecondaryCarets()
    caretModel.currentCaret.removeSelection()
    scrollingModel.scrollToCaret(CENTER_DOWN)
    EditorModificationUtil.scrollToCaret(this)
    IdeDocumentHistory.getInstance(this@Plugin.project).includeCurrentCommandAsNavigation()
}

fun String.firstColumnIndex() =
    indexOfFirst { !it.isWhitespace() }
        .let { if (it == -1) 0 else it }

fun Map<Int, IndentGuideDescriptor?>.toPrintableString(lines: List<String>) =
    entries.joinToString("<br/>") {
        (it.value?.indentLevel ?: -1).toString() + " -- " + lines[it.key]
    }