java folding: use unicode right arrow for closures

java/java-psi-impl/src/com/intellij/codeInsight/folding/impl/JavaFoldingBuilderBase.java

@@ -26,6 +26,8 @@ import com.intellij.lang.folding.NamedFoldingDescriptor;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.FoldingGroup;
+import com.intellij.openapi.editor.colors.EditorColorsManager;
+import com.intellij.openapi.editor.colors.EditorFontType;
 import com.intellij.openapi.progress.ProgressIndicatorProvider;
 import com.intellij.openapi.project.DumbAware;
 import com.intellij.openapi.project.DumbService;
@@ -41,7 +43,11 @@ import com.intellij.psi.impl.source.tree.JavaDocElementType;
 import com.intellij.psi.impl.source.tree.JavaElementType;
 import com.intellij.psi.javadoc.PsiDocComment;
 import com.intellij.psi.tree.IElementType;
-import com.intellij.psi.util.*;
+import com.intellij.psi.util.PropertyUtil;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.psi.util.PsiUtil;
+import com.intellij.psi.util.PsiUtilCore;
+import com.intellij.util.FontUtil;
 import com.intellij.util.Function;
 import com.intellij.util.ObjectUtils;
 import com.intellij.util.text.CharArrayUtil;
@@ -49,6 +55,7 @@ import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.awt.*;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
@@ -830,7 +837,9 @@ public abstract class JavaFoldingBuilderBase extends CustomFoldingBuilder implem
                   return psiParameter.getName();
                 }
               }, ", ");
-              @NonNls final String lambdas = type + methodName + "(" + params + ") -> {";
+              Font font = EditorColorsManager.getInstance().getGlobalScheme().getFont(EditorFontType.PLAIN);
+              String arrow = FontUtil.rightArrow(font);
+              @NonNls final String lambdas = type + methodName + "(" + params + ") " + arrow + " {";
 
               final int closureStart = expression.getTextRange().getStartOffset();
               final int closureEnd = expression.getTextRange().getEndOffset();

java/java-tests/testSrc/com/intellij/codeInsight/folding/JavaFoldingTest.groovy

@@ -279,12 +279,12 @@ class Test {
     configure text
     def foldingModel = myFixture.editor.foldingModel as FoldingModelImpl
 
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable(")).placeholderText == '() -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable2(")).placeholderText == '(Runnable2) () -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable3(")).placeholderText == '(Runnable3) () -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable4(")).placeholderText == '() -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("MyAction(")).placeholderText == '(MyAction) () -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("MyAction2(")).placeholderText == '(MyAction2) () -> { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable(")).placeholderText == '() → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable2(")).placeholderText == '(Runnable2) () → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable3(")).placeholderText == '(Runnable3) () → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable4(")).placeholderText == '() → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("MyAction(")).placeholderText == '(MyAction) () → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("MyAction2(")).placeholderText == '(MyAction2) () → { '
   }
 
   public void "test closure folding after paste"() {
@@ -306,7 +306,7 @@ class Test {
 
     def foldingModel = myFixture.editor.foldingModel as FoldingModelImpl
 
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable(")).placeholderText == '() -> { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable(")).placeholderText == '() → { '
   }
 
   public void "test closure folding when overriding one method of many"() {
@@ -333,8 +333,8 @@ class Test {
     configure text
     def foldingModel = myFixture.editor.foldingModel as FoldingModelImpl
 
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable("))?.placeholderText == 'run() -> { '
-    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable2("))?.placeholderText == '(Runnable2) run2() -> { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable("))?.placeholderText == 'run() → { '
+    assert foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable2("))?.placeholderText == '(Runnable2) run2() → { '
   }
 
   public void "test no closure folding when the method throws an unresolved exception"() {

platform/util/src/com/intellij/util/FontUtil.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2000-2014 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.util;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.awt.*;
+
+public class FontUtil {
+  @NotNull
+  public static String rightArrow(@NotNull Font font) {
+    char rightArrow = '\u2192';
+    return font.canDisplay(rightArrow) ? String.valueOf(rightArrow) : "->";
+  }
+}

platform/util/src/com/intellij/util/ui/UIUtil.java

@@ -2973,8 +2973,7 @@ public class UIUtil {
 
   @NotNull
   public static String rightArrow() {
-    char rightArrow = '\u2192';
-    return getLabelFont().canDisplay(rightArrow) ? String.valueOf(rightArrow) : "->";
+    return FontUtil.rightArrow(getLabelFont());
   }
 
   public static EmptyBorder getTextAlignBorder(@NotNull JToggleButton alignSource) {