KeyPressEvent don't work with ibus?

[albuseer]

Here is my code:
@
#include <QApplication>
#include <QTextEdit>
#include <QKeyEvent>

class TextEdit : public QTextEdit {
void keyPressEvent(QKeyEvent *e) {
qDebug("pressed key %d", e->key());
}
void keyReleaseEvent(QKeyEvent *e) {
qDebug("released key %d", e->key());
}
};

int main(int argc, char *argv[]) {
QApplication a(argc, argv);
TextEdit e;
e.show();
return a.exec();
}
@

The problem is, all text input are not captured by keyPressEvent when any ibus input method is on.
I tested with ibus-pinyin and ibus-mozc and the only config it works is in mozc's direct input mode (not Latin mode, which buffers inputs inline and require a return to submit). ibus-pinyin's English mode also doesn't work.

But it's strange that ASCII inputs in both ibus-pinyin's English mode and ibus-mozc's Latin mode are captured by keyReleaseEvent.

-Is there any way to filter user input regardless of languages and input methods? How is Qt Creator's fakevim mode implemented?-

My environment is GNOME 3.6.3 in Gentoo, with Qt 4.8.5 in Gentoo repo and Qt 5.1.1 downloaded from this site.

Edit: I've found inputMethodEvent so the question is solved but it's still strange for text not captured in keyPressEvent being captured in keyReleaseEvent.