bug 330693: Improve suggested variable name in Extract Local Variable

https://bugs.eclipse.org/bugs/show_bug.cgi?id=330693 Improved handling of long names

core/org.eclipse.cdt.ui.tests/resources/refactoring/ExtractLocalVariable.rts

@@ -546,3 +546,53 @@ int main() {
     return 0;
 }
 
+//!Bug 330693 Improve suggested variable name in Extract Local Variable
+//#org.eclipse.cdt.ui.tests.refactoring.extractlocalvariable.ExtractLocalVariableRefactoringTest
+//@A.cpp
+
+struct Foo{
+	int getVarWithLongName();
+};
+
+void bar(){
+	Foo f;
+	/*$*/f.getVarWithLongName()/*$$*/;
+}
+
+//=
+
+struct Foo{
+	int getVarWithLongName();
+};
+
+void bar(){
+	Foo f;
+    int varWithLongName = f.getVarWithLongName();
+    varWithLongName;
+}
+
+//!Bug 330693 Improve suggested variable name in Extract Local Variable: name == prefix
+//#org.eclipse.cdt.ui.tests.refactoring.extractlocalvariable.ExtractLocalVariableRefactoringTest
+//@A.cpp
+
+struct Foo{
+	int get();
+};
+
+void bar(){
+	Foo f;
+	/*$*/f.get()/*$$*/;
+}
+
+//=
+
+struct Foo{
+	int get();
+};
+
+void bar(){
+	Foo f;
+    int get = f.get();
+    get;
+}
+

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/refactoring/extractlocalvariable/ExtractLocalVariableRefactoring.java

@@ -320,21 +320,15 @@ public class ExtractLocalVariableRefactoring extends CRefactoring {
 		if (proposals.length == 0) {
 			return info.getName();
 		} else {
-			String name = getLastCamelCasePart(proposals[proposals.length - 1]);
+			String name = proposals[proposals.length - 1];
 			return name;
 		}
 	}
 
-	private String getLastCamelCasePart(String string) {
+	private String[] getPrefixes() {
-		if (string.length() == 0) {
+		// In Future we could use user preferences to define the prefixes
-			return string;
+		String[] prefixes = { "get", "is" }; //$NON-NLS-1$//$NON-NLS-2$
-		}
+		return prefixes;
-		int index = string.length() - 1;
-		while (index > 0
-				&& (Character.isLowerCase(string.charAt(index)) || Character.isDigit(string.charAt(index)))) {
-			--index;
-		}
-		return string.substring(index).toLowerCase();
 	}
 
 	/**
@@ -408,7 +402,7 @@ public class ExtractLocalVariableRefactoring extends CRefactoring {
 							tmpName[len++] = c;
 						}
 					}
-					name = getLastCamelCasePart(new String(tmpName, 0, len));
+					name = trimPrefixes(new String(tmpName, 0, len));
 					if (name.length() > 0) {
 						if (nameAvailable(name, guessedTempNames, scope)) {
 							guessedTempNames.add(name);
@@ -417,6 +411,7 @@ public class ExtractLocalVariableRefactoring extends CRefactoring {
 						}
 					}
 				}
+
 			});
 		}
 		if (guessedTempNames.isEmpty()) {
@@ -428,6 +423,40 @@ public class ExtractLocalVariableRefactoring extends CRefactoring {
 		return guessedTempNames.toArray(new String[0]);
 	}
 
+	private String trimPrefixes(String name) {
+		String lower = name.toLowerCase();
+		int start = 0;
+		for (String prefix : getPrefixes()) {
+			if(lower.startsWith(prefix)) {
+				if (name.length() > prefix.length()) {
+					start = prefix.length();
+				}
+			}
+			prefix = prefix + "_"; //$NON-NLS-1$
+			if(lower.startsWith(prefix)) {
+				if (name.length() > prefix.length()) {
+					start = prefix.length();
+				}
+			}
+		}
+
+		if (start > 0) {
+
+			String nameWithoutPrefix = name.substring(start);
+			if (Character.isUpperCase(nameWithoutPrefix.charAt(0))) {
+				nameWithoutPrefix = nameWithoutPrefix.substring(0, 1).toLowerCase()
+						+ nameWithoutPrefix.substring(1);
+			}
+
+			if (!Character.isJavaIdentifierStart(nameWithoutPrefix.charAt(0))) {
+				nameWithoutPrefix = "_" + nameWithoutPrefix; //$NON-NLS-1$
+			}
+			return nameWithoutPrefix;
+		} else {
+			return name;
+		}
+	}
+
 	private boolean nameAvailable(String name, List<String> guessedNames, IScope scope) {
 		if (guessedNames.contains(name) || info.getUsedNames().contains(name)) {
 			return false;