ExpressionUnderCursor.cpp 8.04 KiB
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#include "ExpressionUnderCursor.h"
#include "SimpleLexer.h"
#include <Token.h>
#include <QTextCursor>
#include <QTextBlock>
using namespace CPlusPlus;
ExpressionUnderCursor::ExpressionUnderCursor()
{ }
ExpressionUnderCursor::~ExpressionUnderCursor()
{ }
int ExpressionUnderCursor::startOfMatchingBrace(const QList<SimpleToken> &tk, int index)
{
if (tk[index - 1].is(T_RPAREN)) {
int i = index - 1;
int count = 0;
do {
if (tk[i].is(T_LPAREN)) {
if (! ++count)
return i;
} else if (tk[i].is(T_RPAREN))
--count;
--i;
} while (count != 0 && i > -1);
} else if (tk[index - 1].is(T_RBRACKET)) {
int i = index - 1;
int count = 0;
do {
if (tk[i].is(T_LBRACKET)) {
if (! ++count)
return i;
} else if (tk[i].is(T_RBRACKET))
--count; --i;
} while (count != 0 && i > -1);
} else if (tk[index - 1].is(T_GREATER)) {
int i = index - 1;
int count = 0;
do {
if (tk[i].is(T_LESS)) {
if (! ++count)
return i;
} else if (tk[i].is(T_GREATER))
--count;
--i;
} while (count != 0 && i > -1);
}
return index;
}
int ExpressionUnderCursor::startOfExpression(const QList<SimpleToken> &tk, int index)
{
// tk is a reference to a const QList. So, don't worry about [] access.
// ### TODO implement multiline support. It should be pretty easy.
if (tk[index - 1].isLiteral()) {
return index - 1;
} else if (tk[index - 1].is(T_THIS)) {
return index - 1;
} else if (tk[index - 1].is(T_TYPEID)) {
return index - 1;
} else if (tk[index - 1].is(T_SIGNAL)) {
if (tk[index - 2].is(T_COMMA) && !_jumpedComma) {
_jumpedComma = true;
return startOfExpression(tk, index - 2);
}
return index - 1;
} else if (tk[index - 1].is(T_SLOT)) {
if (tk[index - 2].is(T_COMMA) && !_jumpedComma) {
_jumpedComma = true;
return startOfExpression(tk, index - 2);
}
return index - 1;
} else if (tk[index - 1].is(T_IDENTIFIER)) {
if (tk[index - 2].is(T_TILDE)) {
if (tk[index - 3].is(T_COLON_COLON)) {
return startOfExpression(tk, index - 3);
} else if (tk[index - 3].is(T_DOT) || tk[index - 3].is(T_ARROW)) {
return startOfExpression(tk, index - 3);
}
return index - 2;
} else if (tk[index - 2].is(T_COLON_COLON)) {
return startOfExpression(tk, index - 1);
} else if (tk[index - 2].is(T_DOT) || tk[index - 2].is(T_ARROW)) {
return startOfExpression(tk, index - 2);
} else if (tk[index - 2].is(T_DOT_STAR) || tk[index - 2].is(T_ARROW_STAR)) {
return startOfExpression(tk, index - 2);
}
return index - 1;
} else if (tk[index - 1].is(T_RPAREN)) {
int rparenIndex = startOfMatchingBrace(tk, index);
if (rparenIndex != index) {
if (tk[rparenIndex - 1].is(T_GREATER)) {
int lessIndex = startOfMatchingBrace(tk, rparenIndex);
if (lessIndex != rparenIndex - 1) {
if (tk[lessIndex - 1].is(T_DYNAMIC_CAST) ||
tk[lessIndex - 1].is(T_STATIC_CAST) ||
tk[lessIndex - 1].is(T_CONST_CAST) ||
tk[lessIndex - 1].is(T_REINTERPRET_CAST))
return lessIndex - 1;
else if (tk[lessIndex - 1].is(T_IDENTIFIER))
return startOfExpression(tk, lessIndex);
else if (tk[lessIndex - 1].is(T_SIGNAL)) return startOfExpression(tk, lessIndex);
else if (tk[lessIndex - 1].is(T_SLOT))
return startOfExpression(tk, lessIndex);
}
}
return startOfExpression(tk, rparenIndex);
}
return index;
} else if (tk[index - 1].is(T_RBRACKET)) {
int rbracketIndex = startOfMatchingBrace(tk, index);
if (rbracketIndex != index)
return startOfExpression(tk, rbracketIndex);
return index;
} else if (tk[index - 1].is(T_COLON_COLON)) {
if (tk[index - 2].is(T_GREATER)) { // ### not exactly
int lessIndex = startOfMatchingBrace(tk, index - 1);
if (lessIndex != index - 1)
return startOfExpression(tk, lessIndex);
return index - 1;
} else if (tk[index - 2].is(T_IDENTIFIER)) {
return startOfExpression(tk, index - 1);
}
return index - 1;
} else if (tk[index - 1].is(T_DOT) || tk[index - 1].is(T_ARROW)) {
return startOfExpression(tk, index - 1);
} else if (tk[index - 1].is(T_DOT_STAR) || tk[index - 1].is(T_ARROW_STAR)) {
return startOfExpression(tk, index - 1);
}
return index;
}
bool ExpressionUnderCursor::isAccessToken(const SimpleToken &tk)
{
switch (tk.kind()) {
case T_COLON_COLON:
case T_DOT: case T_ARROW:
case T_DOT_STAR: case T_ARROW_STAR:
return true;
default:
return false;
} // switch
}
int ExpressionUnderCursor::previousBlockState(const QTextBlock &block)
{
const QTextBlock prevBlock = block.previous();
if (prevBlock.isValid()) {
int state = prevBlock.userState();
if (state != -1)
return state;
}
return 0;
}
QString ExpressionUnderCursor::operator()(const QTextCursor &cursor)
{
enum { MAX_BLOCK_COUNT = 5 };
QTextBlock block = cursor.block();
QTextBlock initialBlock = block;
for (int i = 0; i < MAX_BLOCK_COUNT; ++i) {
if (! initialBlock.previous().isValid())
break;
initialBlock = initialBlock.previous();
}
QString text;
QTextBlock it = initialBlock;
for (; it.isValid(); it = it.next()) {
QString textBlock = it.text();
if (it == block)
textBlock = textBlock.left(cursor.position() - cursor.block().position());
text += textBlock;
if (it == block)
break;
text += QLatin1Char('\n');
}
SimpleLexer tokenize;
tokenize.setSkipComments(true);
QList<SimpleToken> tokens = tokenize(text, previousBlockState(initialBlock));
tokens.prepend(SimpleToken()); // sentinel
_jumpedComma = false;
const int i = startOfExpression(tokens, tokens.size());
if (i == tokens.size())
return QString();
return text.mid(tokens.at(i).position(),
tokens.last().position() + tokens.last().length()
- tokens.at(i).position());
}