IDEA-52305 condensed code formatting for "flying geese" braces

Initial

diff --git a/java/java-impl/src/com/intellij/psi/formatter/java/spacing/JavaBraceSpacingProcessor.java b/java/java-impl/src/com/intellij/psi/formatter/java/spacing/JavaBraceSpacingProcessor.java
new file mode 100644 (file)
index 0000000..8548c25
--- /dev/null
+++ b/java/java-impl/src/com/intellij/psi/formatter/java/spacing/JavaBraceSpacingProcessor.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi.formatter.java.spacing;
+
+import com.intellij.formatting.Spacing;
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.JavaTokenType;
+import com.intellij.psi.codeStyle.CodeStyleSettings;
+import com.intellij.psi.formatter.java.FormattingAstUtil;
+
+/**
+ * Utility class that encapsulates algorithm of defining {@link Spacing} to use for the target code block containing brace.
+ * <p/>
+ * This class is not singleton but it's thread-safe and provides single-point-of-usage field {@link #INSTANCE}.
+ * <p/>
+ * Thread-safe.
+ *
+ * @author Denis Zhdanov
+ * @since Apr 26, 2010 1:52:52 PM
+ */
+public class JavaBraceSpacingProcessor {
+
+  /** Single-point-of-usage field. */
+  public static final JavaBraceSpacingProcessor INSTANCE = new JavaBraceSpacingProcessor();
+
+  /**
+   * Allows to get {@link Spacing} to use for the given AST node that is assumed to be right sibling of left curly brace and that brace.
+   *
+   * @param settings      code formatting settings to use
+   * @param rightNode     right sibling of target left curly brace
+   * @return              spacing to use for the left curly brace and it's given right sibling
+   */
+  @SuppressWarnings({"MethodMayBeStatic"})
+  public Spacing getLBraceSpacing(CodeStyleSettings settings, ASTNode rightNode) {
+    if (shouldUseFlyingGeeseStyleForLeftBrace(settings, rightNode)) {
+      return getFlyingGeesSpacing(settings);
+    }
+    return Spacing.createSpacing(
+      0, 0, settings.BLANK_LINES_AFTER_CLASS_HEADER + 1, settings.KEEP_LINE_BREAKS, settings.KEEP_BLANK_LINES_IN_DECLARATIONS
+    );
+  }
+
+  /**
+   * Allows to get {@link Spacing} to use for the given AST node that is assumed to be left sibling of right curly brace and that brace.
+   *
+   * @param settings      code formatting settings to use
+   * @param leftNode      left sibling of target right curly brace
+   * @return              spacing to use for the right curly brace and it's given left sibling
+   */
+  @SuppressWarnings({"MethodMayBeStatic"})
+  public Spacing getRBraceSpacing(CodeStyleSettings settings, ASTNode leftNode, boolean insideAnonymousClass) {
+    if (shouldUseFlyingGeeseStyleForRightBrace(settings, leftNode)) {
+      return getFlyingGeesSpacing(settings);
+    }
+    return Spacing.createSpacing(
+      0, Integer.MAX_VALUE, insideAnonymousClass ? 0 : 1, settings.KEEP_LINE_BREAKS, settings.KEEP_BLANK_LINES_BEFORE_RBRACE
+    );
+  }
+
+  private static boolean shouldUseFlyingGeeseStyleForLeftBrace(CodeStyleSettings settings, ASTNode rightNode) {
+    if (!settings.USE_FLYING_GEESE_BRACES) {
+      return false;
+    }
+
+    ASTNode rightSibling = FormattingAstUtil.getNextNonWhiteSpaceNode(rightNode);
+    return rightSibling != null && rightSibling.getElementType() == JavaTokenType.RBRACE;
+  }
+
+  private static boolean shouldUseFlyingGeeseStyleForRightBrace(CodeStyleSettings settings, ASTNode leftNode) {
+    if (!settings.USE_FLYING_GEESE_BRACES) {
+      return false;
+    }
+
+    ASTNode leftSibling = FormattingAstUtil.getPrevNonWhiteSpaceNode(leftNode);
+    return leftSibling != null && leftSibling.getElementType() == JavaTokenType.LBRACE;
+  }
+
+  private static Spacing getFlyingGeesSpacing(CodeStyleSettings settings) {
+    return Spacing.createSpacing(settings.FLYING_GEESE_BRACES_GAP, settings.FLYING_GEESE_BRACES_GAP, 0, false, 0);
+  }
+}