PY-61639 Move PyKeywordTypeHandler to python.syntax

GitOrigin-RevId: 3e0e70f5868b0fc09c35e571db0d0e553902eb6d

python/python-syntax-core/src/com/jetbrains/python/codeInsight/PyUnindentUtil.java

@@ -0,0 +1,99 @@
+package com.jetbrains.python.codeInsight;
+
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.editor.EditorCoreUtil;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.PsiDocumentManager;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.jetbrains.python.PyNames;
+import com.jetbrains.python.ast.PyAstStatementWithElse;
+import com.jetbrains.python.ast.PyAstTryExceptStatement;
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+public final class PyUnindentUtil {
+  /**
+   * Unindent current line to be flush with a starting part, detecting the part if necessary.
+   *
+   * @return true if unindenting succeeded
+   */
+  public static boolean unindentAsNeeded(Project project, Editor editor, PsiFile file) {
+    // TODO: handle things other than "else"
+    final Document document = editor.getDocument();
+    int offset = editor.getCaretModel().getOffset();
+    CharSequence text = document.getCharsSequence();
+    if (offset >= text.length()) {
+      offset = text.length() - 1;
+    }
+
+    int line_start_offset = document.getLineStartOffset(document.getLineNumber(offset));
+    int nonspace_offset = findBeginning(line_start_offset, text);
+
+
+    Class<? extends PsiElement> parentClass = null;
+
+    int last_offset = nonspace_offset + PyNames.FINALLY.length(); // the longest of all
+    if (last_offset > offset) last_offset = offset;
+    int local_length = last_offset - nonspace_offset + 1;
+    if (local_length > 0) {
+      String piece = text.subSequence(nonspace_offset, last_offset + 1).toString();
+      final int else_len = PyNames.ELSE.length();
+      if (local_length >= else_len) {
+        if ((piece.startsWith(PyNames.ELSE) || piece.startsWith(PyNames.ELIF)) &&
+            (else_len == piece.length() || piece.charAt(else_len) < 'a' || piece.charAt(else_len) > 'z')) {
+          parentClass = PyAstStatementWithElse.class;
+        }
+      }
+      final int except_len = PyNames.EXCEPT.length();
+      if (local_length >= except_len) {
+        if (piece.startsWith(PyNames.EXCEPT) &&
+            (except_len == piece.length() || piece.charAt(except_len) < 'a' || piece.charAt(except_len) > 'z')) {
+          parentClass = PyAstTryExceptStatement.class;
+        }
+      }
+      final int finally_len = PyNames.FINALLY.length();
+      if (local_length >= finally_len) {
+        if (piece.startsWith(PyNames.FINALLY) &&
+            (finally_len == piece.length() || piece.charAt(finally_len) < 'a' || piece.charAt(finally_len) > 'z')) {
+          parentClass = PyAstTryExceptStatement.class;
+        }
+      }
+    }
+
+
+    if (parentClass == null) return false; // failed
+
+    PsiDocumentManager.getInstance(project).commitDocument(document); // reparse
+
+    PsiElement token = file.findElementAt(offset - 2); // -1 is our ':'; -2 is even safer.
+    PsiElement outer = PsiTreeUtil.getParentOfType(token, parentClass);
+    if (outer != null) {
+      int outer_offset = outer.getTextOffset();
+      int outer_indent = outer_offset - document.getLineStartOffset(document.getLineNumber(outer_offset));
+      assert outer_indent >= 0;
+      int current_indent = nonspace_offset - line_start_offset;
+      int indent = outer_indent - current_indent;
+      EditorCoreUtil.indentLine(project, editor, document.getLineNumber(offset), editor.getSettings().isUseTabCharacter(project)
+                                                                                   ? indent * editor.getSettings().getTabSize(project)
+                                                                                   : indent, false);
+      //TODO!!!: shouldUseSmartTabs! is it applicable?
+      return true;
+    }
+    return false;
+  }
+
+  // finds offset of first non-space in the line
+  private static int findBeginning(int start_offset, CharSequence text) {
+    int current_offset = start_offset;
+    int text_length = text.length();
+    while (current_offset < text_length) {
+      char current_char = text.charAt(current_offset);
+      if (current_char != ' ' && current_char != '\t' && current_char != '\n') break;
+      current_offset += 1;
+    }
+    return current_offset;
+  }
+}