ExpandBracketsIntention: cr fixes (IDEA-CR-43518):

1. changed division expansion to non-integer types only
2. enabled start in write action when only one expansion is possible

plugins/IntentionPowerPak/src/com/siyeh/ipp/expression/expand/DistributiveExpression.java

@@ -5,6 +5,7 @@ import com.intellij.psi.*;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.util.PsiPrecedenceUtil;
 import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.psi.util.TypeConversionUtil;
 import com.intellij.util.ObjectUtils;
 import com.intellij.util.containers.hash.HashMap;
 import org.jetbrains.annotations.Contract;
@@ -146,6 +147,7 @@ class DistributiveExpression extends ExpandableExpression {
     if (polyadicExpression == null || !JavaTokenType.DIV.equals(polyadicExpression.getOperationTokenType())) return expression;
     PsiExpression operand = expression.getOperand();
     if (polyadicExpression.getTokenBeforeOperand(operand) != null) return null;
+    if (TypeConversionUtil.isIntegralNumberType(polyadicExpression.getType())) return null;
     return expression;
   }
 }

plugins/IntentionPowerPak/src/com/siyeh/ipp/expression/expand/ExpandBracketsIntention.java

@@ -24,10 +24,13 @@ import java.util.List;
 
 public class ExpandBracketsIntention extends BaseElementAtCaretIntentionAction {
 
+  private boolean myStartInWriteAction = false;
+
   private static final Pass<PsiParenthesizedExpression> EXPAND_CALLBACK = new Pass<PsiParenthesizedExpression>() {
     @Override
     public void pass(@NotNull PsiParenthesizedExpression expression) {
       WriteCommandAction.writeCommandAction(expression.getProject(), expression.getContainingFile())
+        .withName(getName())
         .run(() -> replaceExpression(expression));
     }
   };
@@ -36,24 +39,30 @@ public class ExpandBracketsIntention extends BaseElementAtCaretIntentionAction {
   @NotNull
   @Override
   public String getFamilyName() {
-    return getText();
+    return getName();
   }
 
   @NotNull
   @Override
   public String getText() {
+    return getName();
+  }
+
+  private static String getName() {
     return IntentionPowerPackBundle.defaultableMessage("expand.brackets.intention.name");
   }
 
   @Override
   public boolean startInWriteAction() {
-    return false;
+    return myStartInWriteAction;
   }
 
   @Override
   public boolean isAvailable(@NotNull Project project, Editor editor, @NotNull PsiElement element) {
     List<PsiParenthesizedExpression> possibleInnerExpressions = getPossibleInnerExpressions(element);
-    return possibleInnerExpressions != null && possibleInnerExpressions.size() > 0;
+    if (possibleInnerExpressions == null || possibleInnerExpressions.isEmpty()) return false;
+    myStartInWriteAction = possibleInnerExpressions.size() == 1;
+    return true;
   }
 
   @Override
@@ -65,7 +74,7 @@ public class ExpandBracketsIntention extends BaseElementAtCaretIntentionAction {
 
   private static void processInnerExpression(@Nullable Editor editor, @NotNull List<PsiParenthesizedExpression> expressions) {
     if (expressions.size() == 1) {
-      EXPAND_CALLBACK.pass(expressions.get(0));
+      replaceExpression(expressions.get(0));
       return;
     }
     if (expressions.isEmpty() || editor == null) return;

plugins/IntentionPowerPak/test/com/siyeh/ipp/expression/expand_brackets/Distributive.java

@@ -1,5 +1,5 @@
 class Test {
-  void distributiveTest(int a, int b, int c, int d) {
+  void distributiveTest(int a, int b, int c, int d, double cc) {
     int e = /*1*/a * (b /*2*/<caret>+ c);
     int f = -/*1*/a * -/*2*/(b - -/*3*/c<caret>);
     int g = /*1*/a * (b +<caret> c) * d;
@@ -11,7 +11,7 @@ class Test {
     int m = a | (-c & <caret>b);
     int n = a & (c | <caret>b);
     int o = 2 * (3 - -a <caret>/ -/*1*/b * -/*2*/c);
-    int p = (a <caret>+/*1*/ b) /*2*// c;
+    double p = (a <caret>+/*1*/ b) /*2*// cc;
   }
 
   void distributiveBooleanTest(boolean a, boolean b, boolean c, boolean d) {

plugins/IntentionPowerPak/test/com/siyeh/ipp/expression/expand_brackets/Distributive_after.java

@@ -1,5 +1,5 @@
 class Test {
-  void distributiveTest(int a, int b, int c, int d) {
+  void distributiveTest(int a, int b, int c, int d, double cc) {
       /*2*/
       int e = /*1*/a * b + a * c;
       /*1*/
@@ -21,7 +21,7 @@ class Test {
       int o = 2 * 3 + 2 * a / b * c;
       /*1*/
       /*2*/
-      int p = a / c + b / c;
+      double p = a / cc + b / cc;
   }
 
   void distributiveBooleanTest(boolean a, boolean b, boolean c, boolean d) {