[Java. Code Formatting] Add better whitespace detection for AdjustWhitespaceLineTextBlockReformatPostProcessor

IDEA-271085

GitOrigin-RevId: 9b77c8be1713797b705fe5860b826a9d36dcb2d9

java/java-frontback-psi-api/src/com/intellij/psi/BasicLiteralUtil.java

@@ -8,6 +8,19 @@ public final class BasicLiteralUtil {
   private BasicLiteralUtil() {
   }
 
+  /**
+   * Returns the indent string for a text block expression. The indent string is calculated based on the indentation
+   * of the text block lines.
+   *
+   * @param expression the text block expression to calculate indent for
+   * @return The indent string of the text block, or null if it is impossible to determine indent string.
+   */
+  public static @Nullable String getTextBlockIndentString(@NotNull PsiElement expression) {
+    String[] lines = getTextBlockLines(expression.getText(), true);
+    if (lines == null) return null;
+    return getTextBlockIndentString(lines);
+  }
+
   /**
    * @param expression text block expression to calculate indent for
    * @return the indent of text block lines; may return -1 if text block is heavily malformed
@@ -18,7 +31,6 @@ public final class BasicLiteralUtil {
     return getTextBlockIndent(lines);
   }
 
-
   /**
    * Returns the lines of text inside the quotes of a text block. No further processing is performed.
    * Any escaped characters will remain escaped. Indent is not stripped.
@@ -65,17 +77,48 @@ public final class BasicLiteralUtil {
   }
 
   public static int getTextBlockIndent(String @NotNull [] lines, boolean preserveContent, boolean ignoreLastLine) {
+    return getTextBlockIndentInner(lines, preserveContent, ignoreLastLine).indentSize;
+  }
+
+  private static @NotNull IndentResult getTextBlockIndentInner(String @NotNull[] lines, boolean preserveContent, boolean ignoreLastLine) {
     int prefix = Integer.MAX_VALUE;
+    int position = -1;
     for (int i = 0; i < lines.length && prefix != 0; i++) {
       String line = lines[i];
       int indent = 0;
       while (indent < line.length() && Character.isWhitespace(line.charAt(indent))) indent++;
       if (indent == line.length() && (i < lines.length - 1 || ignoreLastLine)) {
         if (!preserveContent) lines[i] = "";
-        if (lines.length == 1) prefix = indent;
+        if (lines.length == 1) {
+          prefix = indent;
+          position = i;
+        }
+      }
+      else if (indent < prefix) {
+        prefix = indent;
+        position = i;
       }
-      else if (indent < prefix) prefix = indent;
     }
-    return prefix;
+    return new IndentResult(prefix, position);
+  }
+
+  private static @NotNull String getTextBlockIndentString(String @NotNull [] lines) {
+    IndentResult result = getTextBlockIndentInner(lines, true, false);
+    String restorationLine = lines[result.indentLineNumber];
+    StringBuilder builder = new StringBuilder();
+    for (int i = 0; i < result.indentSize; ++i) {
+      builder.append(restorationLine.charAt(i));
+    }
+    return builder.toString();
+  }
+
+  private static class IndentResult {
+    private final int indentSize;
+    private final int indentLineNumber;
+
+    private IndentResult(int indentSize, int indentLineNumber) {
+      this.indentSize = indentSize;
+      this.indentLineNumber = indentLineNumber;
+    }
   }
 }

java/java-impl/src/com/intellij/psi/formatter/java/AdjustWhitespaceLineTextBlockReformatPostProcessor.kt

@@ -1,7 +1,6 @@
 // Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.psi.formatter.java
 
-import com.intellij.openapi.fileTypes.FileType
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.*
 import com.intellij.psi.codeStyle.CodeStyleSettings
@@ -12,15 +11,15 @@ import com.intellij.util.text.CharArrayUtil
 
 class AdjustWhitespaceLineTextBlockReformatPostProcessor : PostFormatProcessor {
   override fun processElement(source: PsiElement, settings: CodeStyleSettings): PsiElement {
-    processFile(source.containingFile, source.textRange, settings)
+    processFile(source.containingFile, source.textRange)
     return source
   }
 
   override fun processText(source: PsiFile, rangeToReformat: TextRange, settings: CodeStyleSettings): TextRange {
-    return processFile(source, rangeToReformat, settings)
+    return processFile(source, rangeToReformat)
   }
 
-  private fun processFile(source: PsiFile, rangeToReformat: TextRange, settings: CodeStyleSettings): TextRange {
+  private fun processFile(source: PsiFile, rangeToReformat: TextRange): TextRange {
     val documentManager = PsiDocumentManager.getInstance(source.project)
     val document = documentManager.getDocument(source) ?: return rangeToReformat
 
@@ -30,12 +29,11 @@ class AdjustWhitespaceLineTextBlockReformatPostProcessor : PostFormatProcessor {
     var deltaLength = 0
     textBlockVisitor.whiteSpaceRangesWithIndentList.sortedByDescending {
       it.whiteSpaceRange.startOffset
-    }.forEach { (range, indent) ->
+    }.forEach { (range, indentString) ->
-      val newSpaces = buildWhitespaceString(settings, source.fileType, indent)
+      deltaLength += indentString.length
-      deltaLength += newSpaces.length
       deltaLength -= range.length
       document.deleteString(range.startOffset, range.endOffset)
-      document.insertString(range.startOffset, newSpaces)
+      document.insertString(range.startOffset, indentString)
     }
 
     documentManager.commitDocument(document)
@@ -44,11 +42,6 @@ class AdjustWhitespaceLineTextBlockReformatPostProcessor : PostFormatProcessor {
 
   override fun isWhitespaceOnly(): Boolean = true
 
-  private fun buildWhitespaceString(settings: CodeStyleSettings, fileType: FileType, indent: Int): String {
-    val whitespaceSymbol = if (settings.useTabCharacter(fileType)) "\t" else " "
-    return whitespaceSymbol.repeat(indent)
-  }
-
   private class TextBlockVisitor(private val rangeToReformat: TextRange) : JavaRecursiveElementVisitor() {
     val whiteSpaceRangesWithIndentList: List<WhiteSpaceRangeWithIndent>
       get() = _whiteSpaceRangesWithIndentList
@@ -60,13 +53,13 @@ class AdjustWhitespaceLineTextBlockReformatPostProcessor : PostFormatProcessor {
         return
       }
 
-      val indent = PsiLiteralUtil.getTextBlockIndent(literal)
+      val indentString = PsiLiteralUtil.getTextBlockIndentString(literal)
-      if (indent == -1) {
+      if (indentString == null) {
         return
       }
       val text = literal.text
 
-      JavaFormatterUtil.extractTextRangesFromLiteralText(text, indent, true)
+      JavaFormatterUtil.extractTextRangesFromLiteralText(text, indentString.length, true)
         .filter { textRange ->
           rangeToReformat.contains(textRange.shiftRight(literal.startOffset)) &&
           CharArrayUtil.isEmptyOrSpaces(literal.text, textRange.startOffset, textRange.endOffset)
@@ -74,11 +67,11 @@ class AdjustWhitespaceLineTextBlockReformatPostProcessor : PostFormatProcessor {
         .map { it.shiftRight(literal.startOffset) }
         .reversed()
         .forEach {
-          _whiteSpaceRangesWithIndentList.add(WhiteSpaceRangeWithIndent(it, indent))
+          _whiteSpaceRangesWithIndentList.add(WhiteSpaceRangeWithIndent(it, indentString))
         }
 
     }
   }
 
-  private data class WhiteSpaceRangeWithIndent(val whiteSpaceRange: TextRange, val indent: Int)
+  private data class WhiteSpaceRangeWithIndent(val whiteSpaceRange: TextRange, val indentString: String)
 }

java/java-psi-api/src/com/intellij/psi/util/PsiLiteralUtil.java

@@ -418,6 +418,16 @@ public final class PsiLiteralUtil {
     return BasicLiteralUtil.getTextBlockIndent(expression);
   }
 
+  /**
+   * Retrieves the indent string of a text block literal expression.
+   * @param expression The text block literal expression.
+   * @return The indent string of the text block, or null if it is impossible to determine indent string.
+   * @see #getTextBlockIndent(PsiLiteralExpression)
+   */
+  public static @Nullable String getTextBlockIndentString(@NotNull PsiLiteralExpression expression) {
+    return BasicLiteralUtil.getTextBlockIndentString(expression);
+  }
+
   /**
    * @see #getTextBlockIndent(PsiLiteralExpression)
    */

java/java-tests/testData/psi/formatter/java/textBlock/NonIntegerNumberOfTabs.java

@@ -0,0 +1,8 @@
+public class Formatter {
+	void foo() {
+		String sss = """
+		    		
+					   
+					    foo""";
+	}
+}

java/java-tests/testData/psi/formatter/java/textBlock/NonIntegerNumberOfTabs_after.java

@@ -0,0 +1,8 @@
+public class Formatter {
+	void foo() {
+		String sss = """
+					 
+					 
+					 foo""";
+	}
+}

java/java-tests/testSrc/com/intellij/java/psi/formatter/java/AdjustWhitespaceLineTextBlockReformatPostProcessorTest.kt

@@ -30,6 +30,11 @@ class AdjustWhitespaceLineTextBlockReformatPostProcessorTest : LightPlatformCode
     doTest()
   }
 
+  fun testNonIntegerNumberOfTabs() {
+    getCommonSettings().indentOptions?.USE_TAB_CHARACTER = true
+    getJavaSettings().ALIGN_MULTILINE_TEXT_BLOCKS = true
+    doTest()
+  }
 
   fun testAlignTextBlockWhitespacesLessThanAlignment() {
     getJavaSettings().ALIGN_MULTILINE_TEXT_BLOCKS = true