/*
* CppCompletionUtils.java
*
* Copyright (C) 2009-12 by RStudio, Inc.
*
* Unless you have received this program directly from RStudio pursuant
* to the terms of a commercial license agreement with RStudio, then
* this program is licensed to you under the terms of version 3 of the
* GNU Affero General Public License. This program is distributed WITHOUT
* ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
* AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
*
*/
package org.rstudio.studio.client.workbench.views.source.editors.text.cpp;
import org.rstudio.studio.client.workbench.views.source.editors.text.DocDisplay;
import org.rstudio.studio.client.workbench.views.source.editors.text.ace.Position;
import com.google.gwt.dom.client.NativeEvent;
public class CppCompletionUtils
{
public static boolean isCppIdentifierKey(NativeEvent event)
{
if (event.getAltKey() || event.getCtrlKey() || event.getMetaKey())
return false ;
int keyCode = event.getKeyCode() ;
if (keyCode >= 'a' && keyCode <= 'z')
return true ;
if (keyCode >= 'A' && keyCode <= 'Z')
return true ;
if (keyCode == 189 && event.getShiftKey()) // underscore
return true ;
if (event.getShiftKey())
return false ;
if (keyCode >= '0' && keyCode <= '9')
return true ;
return false ;
}
public static boolean isCppIdentifierChar(char c)
{
return ((c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '_');
}
public static CompletionPosition getCompletionPosition(DocDisplay docDisplay,
boolean explicit,
boolean alwaysComplete)
{
// get the current line of code
String line = docDisplay.getCurrentLine();
// get the cursor position
Position position = docDisplay.getCursorPosition();
// is there already a C++ identifier character at this position?
// if so then bail
if ((position.getColumn() < line.length()) &&
CppCompletionUtils.isCppIdentifierChar(
line.charAt(position.getColumn())))
{
return null;
}
// determine the column right before this one
int inputCol = position.getColumn() - 1;
// walk backwards across C++ identifer symbols
int col = inputCol;
while ((col >= 0) &&
CppCompletionUtils.isCppIdentifierChar(line.charAt(col)))
{
col--;
}
// record source position
Position startPos = Position.create(position.getRow(), col + 1);
// check for a completion triggering sequence
char ch = line.charAt(col);
char prefixCh = line.charAt(col - 1);
// member
if (ch == '.' || (prefixCh == '-' && ch == '>'))
{
return new CompletionPosition(startPos,
"", // no user text (get all completions)
CompletionPosition.Scope.Member);
}
// scope
else if (prefixCh == ':' && ch == ':')
{
return new CompletionPosition(startPos,
"", // no user text (get all completions)
CompletionPosition.Scope.Namespace);
}
// minimum character threshold
else if ((alwaysComplete || explicit) && // either always completing or explicit
((inputCol - col) >= (explicit ? 1 : 5)) && // meets the character threshold
(ch != '"')) // not a quote character
{
// calculate user text (up to two characters of additional
// server side filter)
String userText = line.substring(
col + 1, Math.min(col + 3, position.getColumn()));
return new CompletionPosition(startPos,
userText,
CompletionPosition.Scope.Global);
}
else
{
return null;
}
}
}