abakus/src/dragsupport.cpp

/*
 * dragsupport.cpp - part of abakus
 * Copyright (C) 2004, 2005 Michael Pyne <michael.pyne@kdemail.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <qstring.h>
#include <qpixmap.h>
#include <qimage.h>
#include <qpainter.h>
#include <qcolor.h>
#include <qfont.h>
#include <qbrush.h>
#include <qfontmetrics.h>

#include "dragsupport.h"

namespace DragSupport
{

QPixmap makePixmap(const QString &text, const QFont &font)
{
    QColor background(234, 178, 230);
    QFontMetrics fm(font);

    int height = 2 * fm.height();
    QSize bonusSize (height, 0);
    QSize size(fm.width(text), height);
    QImage image(size + bonusSize, 32);

    image.setAlphaBuffer(false);
    image.fill(0); // All transparent pixels
    image.setAlphaBuffer(true);

    QPixmap pix(size + bonusSize);
    pix.fill(Qt::magenta); // Watch for incoming hacks

    QPainter painter(&pix);
    painter.setFont(font);

    // Outline black, background white
    painter.setPen(Qt::black);
    painter.setBrush(background);

    // roundRect is annoying in that the four "pies" in each corner aren't
    // circular, they're elliptical.  Try to make the radii force it circular
    // again.
    painter.drawRoundRect(pix.rect(), 75 * pix.height() / pix.width(), 75);

    // Alias better names for some constants.
    int textLeft = height / 2;

    // Draw text
    painter.setPen(Qt::black);
    painter.drawText(textLeft, height / 4, size.width(), size.height(), 0, text);

    QImage overlay(pix.convertToImage());

    // The images should have the same size, copy pixels from overlay to the
    // bottom unless the pixel is called magenta.  The pixels we don't copy
    // are transparent in the QImage, and will remain transparent when
    // converted to a QPixmap.

    for(int i = 0; i < image.width(); ++i)
	for(int j = 0; j < image.height(); ++j) {
	    if(QColor(overlay.pixel(i, j)) != Qt::magenta)
		image.setPixel(i, j, overlay.pixel(i, j));
	}

    pix.convertFromImage(image);
    return pix;
}

} // DragSupport