composeim.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

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**
** This file is part of the Qtopia Environment.
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** under the terms of the GNU General Public License as published by the
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** option) any later version.
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** LICENSE.GPL.
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** See the GNU General Public License for more details.
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** the code of this program with Qtopia applications copyrighted, developed
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#include "composeim.h"

/*
   If the last 4 characters of s form a hex digit replaces them
   with the unicode character they describe.
*/
static void compose( QString &s )
{
    if ( s.length() < 4 )
	return;
    QString hex = s.right(4);
    for ( int i=0; i < 4; i++ ) {
	if ( hex[i].isSpace() )
	    return;
    }
    bool ok;
    unsigned short int unicode = hex.toUShort( &ok, 16 );
    if ( ok && unicode >= ' ' && unicode < 0xffff ) {
	s.truncate( s.length() - 4 );
	s += QChar( unicode );
    }
}

/*
   Constructs the ComposeIM and sets initial state to Off
*/
ComposeIM::ComposeIM()
{
    state = Off;
}
/*
   Destorys the ComposeIM
*/
ComposeIM::~ComposeIM() { }


/*
   Confirms current input, then resets ComposeIM and sets state to Off
*/
void ComposeIM::reset()
{
    if ( state == On ) {
	state = Off;
	sendIMEvent( QWSServer::IMEnd, composed, 0 );
	composed = "";
    }
}

/*
   Filters key events from qwsServer.  Returns FALSE if event should be
   sent on as is, otherwise returns FALSE.

   \a unicode is the text of the event. \a keycode is the Qt Key for the event
   as described in qnamespace.h. \a modifiers is a combination of zero or
   more of the following OR'ed together: Qt::ShiftButton, Qt::ControlButton
   and Qt::AltButton. If used, \a autoRepeat would be FALSE if the event
   comes from the intial press of the button, and TRUE if it comes from event
   generated from holding the button down for a period of time.
*/
bool ComposeIM::filter(int unicode, int keycode, int modifiers, 
  bool isPress, bool /*autoRepeat*/)
{
    if ( isPress && keycode == Qt::Key_Space && 
	 modifiers & Qt::ShiftButton ) {
	//switch to opposite state
	if ( state == On ) {
	    sendIMEvent( QWSServer::IMEnd, QString::null, 0 );
	    composed = "";
	    state = Off; //reset and remove text
	} else {
	    state = On;
	}
	return TRUE; //block event
    } else if ( state == On ) {
	if ( isPress ) {
	    if ( keycode == Qt::Key_Return ) {
		//accept text and remain active
		sendIMEvent( QWSServer::IMEnd, composed, composed.length() );
		composed = "";
	    } else if ( keycode == Qt::Key_Backspace ) {
		if ( composed.length() > 0 )
		    composed = composed.left( composed.length() - 1 );
		sendIMEvent( QWSServer::IMCompose, composed, composed.length(), 0 );
	    } else if ( unicode > 0 && unicode < 0xffff) {
		composed += QChar( unicode );
		compose( composed );
		sendIMEvent( QWSServer::IMCompose, composed, composed.length(), 0 );
	    }
	}
	return TRUE; //block event
    }  
    return FALSE; //pass keystroke normally.
}