package com.aptana.editor.php.internal.ui.editor.contentassist;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.contentassist.IContextInformationExtension;
import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
import org.eclipse.jface.text.contentassist.IContextInformationValidator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
/**
* PHP content assist validator. <br>
* This validator checks whether the editor should display argument assistance when typing in arguments into a function
* or a constructor.
*/
public class PHPContextInformationValidator implements IContextInformationValidator, IContextInformationPresenter
{
private IContextInformation fContextInformation;
private int fInitialOffset;
private ITextViewer fViewer;
private int fCurrentParameter;
/**
*
*/
public PHPContextInformationValidator()
{
}
/**
* @see org.eclipse.jface.text.contentassist.IContextInformationValidator#install(org.eclipse.jface.text.contentassist.IContextInformation,
* org.eclipse.jface.text.ITextViewer, int)
*/
public void install(IContextInformation info, ITextViewer viewer, int offset)
{
fContextInformation = info;
fViewer = viewer;
if (info instanceof IContextInformationExtension)
{
fInitialOffset = ((IContextInformationExtension) info).getContextInformationPosition();
}
else
{
fInitialOffset = offset - 1;
}
fInitialOffset++;
fCurrentParameter = -1;
}
/**
* @see IContextInformationValidator#isContextInformationValid(int)
*/
public boolean isContextInformationValid(int offset)
{
try
{
if (offset < fInitialOffset)
return false;
IDocument document = fViewer.getDocument();
IRegion line = document.getLineInformationOfOffset(fInitialOffset);
if (offset < line.getOffset() || offset >= document.getLength())
return false;
return getCharCount(document, fInitialOffset, offset, "(", ")", false) >= 0; //$NON-NLS-1$ //$NON-NLS-2$
}
catch (BadLocationException x)
{
return false;
}
}
/**
* @see org.eclipse.jface.text.contentassist.IContextInformationPresenter#updatePresentation(int,
* org.eclipse.jface.text.TextPresentation)
*/
public boolean updatePresentation(int offset, TextPresentation presentation)
{
int currentParameter = -1;
try
{
currentParameter = getCharCount(fViewer.getDocument(), fInitialOffset, offset, ",", "", true); //$NON-NLS-1$//$NON-NLS-2$
}
catch (BadLocationException x)
{
return false;
}
if (fCurrentParameter != -1)
{
if (currentParameter == fCurrentParameter)
return false;
}
presentation.clear();
fCurrentParameter = currentParameter;
String s = fContextInformation.getInformationDisplayString();
int[] commas = computeCommaPositions(s);
if (commas.length - 2 < fCurrentParameter)
{
presentation.addStyleRange(new StyleRange(0, s.length(), null, null, SWT.NORMAL));
return true;
}
int start = commas[fCurrentParameter] + 1;
int end = commas[fCurrentParameter + 1];
if (start > 0)
presentation.addStyleRange(new StyleRange(0, start, null, null, SWT.NORMAL));
if (end > start)
presentation.addStyleRange(new StyleRange(start, end - start, null, null, SWT.BOLD));
if (end < s.length())
presentation.addStyleRange(new StyleRange(end, s.length() - end, null, null, SWT.NORMAL));
return true;
}
private int getCharCount(IDocument document, int start, final int end, String increments, String decrements,
boolean considerNesting) throws BadLocationException
{
Assert.isTrue((increments.length() != 0 || decrements.length() != 0) && !increments.equals(decrements));
// The given offset that we get here for PHP is for the function name end. We'll need to
// scan for the open bracket and fix the offset to be inside the function arguments.
while (start < end)
{
char c = document.getChar(start);
if (Character.isWhitespace(c))
{
start++;
}
else if (c == '(')
{
start++;
break;
} else {
// Avoid an infinite loop
break;
}
}
final int NONE = 0;
final int BRACKET = 1;
final int BRACE = 2;
final int PAREN = 3;
final int ANGLE = 4;
int nestingMode = NONE;
int nestingLevel = 0;
int charCount = 0;
int offset = start;
while (offset < end)
{
char curr = document.getChar(offset++);
switch (curr)
{
case '/':
if (offset < end)
{
char next = document.getChar(offset);
if (next == '*')
{
// a comment starts, advance to the comment end
offset = getCommentEnd(document, offset + 1, end);
}
else if (next == '/')
{
// '//'-comment: nothing to do anymore on this line
int nextLine = document.getLineOfOffset(offset) + 1;
if (nextLine == document.getNumberOfLines())
offset = end;
else
offset = document.getLineOffset(nextLine);
}
}
break;
case '*':
if (offset < end)
{
char next = document.getChar(offset);
if (next == '/')
{
// we have been in a comment: forget what we read before
charCount = 0;
++offset;
}
}
break;
case '"':
case '\'':
offset = getStringEnd(document, offset, end, curr);
break;
case '[':
if (considerNesting)
{
if (nestingMode == BRACKET || nestingMode == NONE)
{
nestingMode = BRACKET;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case ']':
if (considerNesting)
{
if (nestingMode == BRACKET)
if (--nestingLevel == 0)
nestingMode = NONE;
break;
}
//$FALL-THROUGH$
case '(':
if (considerNesting)
{
if (nestingMode == ANGLE)
{
// generics heuristic failed
nestingMode = PAREN;
nestingLevel = 1;
}
if (nestingMode == PAREN || nestingMode == NONE)
{
nestingMode = PAREN;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case ')':
if (considerNesting)
{
if (nestingMode == PAREN)
if (--nestingLevel == 0)
nestingMode = NONE;
break;
}
//$FALL-THROUGH$
case '{':
if (considerNesting)
{
if (nestingMode == ANGLE)
{
nestingMode = BRACE;
nestingLevel = 1;
}
if (nestingMode == BRACE || nestingMode == NONE)
{
nestingMode = BRACE;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case '}':
if (considerNesting)
{
if (nestingMode == BRACE)
if (--nestingLevel == 0)
nestingMode = NONE;
break;
}
//$FALL-THROUGH$
default:
if (nestingLevel != 0)
continue;
if (increments.indexOf(curr) >= 0)
{
++charCount;
}
if (decrements.indexOf(curr) >= 0)
{
--charCount;
}
}
}
return charCount;
}
private int[] computeCommaPositions(String code)
{
final int length = code.length();
int pos = 0;
List<Integer> positions = new ArrayList<Integer>();
positions.add(new Integer(-1));
while (pos < length && pos != -1)
{
char ch = code.charAt(pos);
switch (ch)
{
case ',':
positions.add(new Integer(pos));
break;
case '[':
pos = code.indexOf(']', pos);
break;
default:
break;
}
if (pos != -1)
pos++;
}
positions.add(new Integer(length));
int[] fields = new int[positions.size()];
for (int i = 0; i < fields.length; i++)
fields[i] = ((Integer) positions.get(i)).intValue();
return fields;
}
private int getCommentEnd(IDocument d, int pos, int end) throws BadLocationException
{
while (pos < end)
{
char curr = d.getChar(pos);
pos++;
if (curr == '*')
{
if (pos < end && d.getChar(pos) == '/')
{
return pos + 1;
}
}
}
return end;
}
private int getStringEnd(IDocument d, int pos, int end, char ch) throws BadLocationException
{
while (pos < end)
{
char curr = d.getChar(pos);
pos++;
if (curr == '\\')
{
// ignore escaped characters
pos++;
}
else if (curr == ch)
{
return pos;
}
}
return end;
}
}