/**
* Internal draw request handler.
*
* @param gc Graphics context to update.
*/
private final void handleDrawRequest(final GC gc) {
if (mBracketPosition.isDeleted) {
return;
}
int length = mBracketPosition.getLength();
if (length < 1) {
return;
}
int offset = mBracketPosition.getOffset();
IRegion region = mSourceViewer.getVisibleRegion();
if (region.getOffset() <= offset
&& region.getOffset() + region.getLength() >= offset + length) {
offset -= region.getOffset();
draw(gc, offset, 1);
}
}
/** @see IPainter#paint(int) */
public final void paint(final int reason) {
Point selection = mSourceViewer.getSelectedRange();
if (selection.y > 0) {
deactivate(true);
return;
}
SexpNavigator explorer = mEditor.getExplorer();
boolean backward = true;
boolean closeToParen = false;
int offset = selection.x;
IDocument document = mEditor.getDocument();
try {
char previousChar = '\0';
char nextChar = '\0';
if (selection.x > 0) previousChar = document.getChar(selection.x - 1);
if (selection.x > 0
&& SchemeScannerUtilities.isClosingParenthesis(previousChar)
&& SchemeTextUtilities.getPartition(document, selection.x - 1).getType()
== IDocument.DEFAULT_CONTENT_TYPE) {
closeToParen = true;
} else {
nextChar = document.getChar(selection.x);
if (selection.x < document.getLength() - 1
&& SchemeScannerUtilities.isOpeningParenthesis(nextChar)
&& SchemeTextUtilities.getPartition(document, selection.x).getType()
== IDocument.DEFAULT_CONTENT_TYPE) {
closeToParen = true;
backward = false;
}
}
if (closeToParen && backward && explorer.backwardSexpression(selection.x)) {
offset = explorer.getListStart();
char matchingChar = document.getChar(offset);
mMismatch =
SchemeScannerUtilities.getParenthesisType(previousChar)
!= SchemeScannerUtilities.getParenthesisType(matchingChar);
} else {
if (closeToParen && !backward && explorer.forwardSexpression(selection.x)) {
offset = explorer.getSexpEnd() - 1;
char matchingChar = document.getChar(offset);
mMismatch =
SchemeScannerUtilities.getParenthesisType(nextChar)
!= SchemeScannerUtilities.getParenthesisType(matchingChar);
} else {
deactivate(true);
return;
}
}
} catch (BadLocationException exception) {
deactivate(true);
return;
}
if (mIsActive) {
// only if different
if (offset != mBracketPosition.getOffset()) {
// remove old highlighting
handleDrawRequest(null);
// update position
mBracketPosition.isDeleted = false;
mBracketPosition.offset = offset;
mBracketPosition.length = 1;
// apply new highlighting
handleDrawRequest(null);
}
} else {
mIsActive = true;
mBracketPosition.isDeleted = false;
mBracketPosition.offset = offset;
mBracketPosition.length = 1;
mTextWidget.addPaintListener(this);
mPositionManager.managePosition(mBracketPosition);
handleDrawRequest(null);
}
}