workspace/libs/plasma/shadowitem.cpp

   1 /*
   2  *   Copyright 2007 by Zack Rusin <zack@kde.org>
   3  *
   4  *   This program is free software; you can redistribute it and/or modify
   5  *   it under the terms of the GNU Library General Public License as
   6  *   published by the Free Software Foundation; either version 2, or
   7  *   (at your option) any later version.
   8  *
   9  *   This program is distributed in the hope that it will be useful,
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *   GNU General Public License for more details
  13  *
  14  *   You should have received a copy of the GNU Library General Public
  15  *   License along with this program; if not, write to the
  16  *   Free Software Foundation, Inc.,
  17  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  */
  19
  20 #include "shadowitem_p.h"
  21
  22 #include "effects/blur.cpp"
  23
  24 #include <QPainter>
  25 #include <QImage>
  26 #include <QDebug>
  27
  28 ShadowItem::ShadowItem(QGraphicsItem *item)
  29 {
  30     setZValue(20);
  31     m_shadowParent = 0;
  32     m_offset = QPointF(12, 12);
  33     setShadowParent(item);
  34 }
  35
  36 void ShadowItem::setShadowParent(QGraphicsItem *item)
  37 {
  38     m_shadowParent = item;
  39     adjustPosition();
  40     generate();
  41 }
  42
  43
  44 QGraphicsItem * ShadowItem::shadowParent() const
  45 {
  46     return m_shadowParent;
  47 }
  48
  49 QSize ShadowItem::shadowedSize() const
  50 {
  51     QSize s = boundingRect().size().toSize();
  52     return s - QSize(32, 32);
  53 }
  54
  55 void ShadowItem::generate()
  56 {
  57     if (!m_shadowParent) {
  58         return;
  59     }
  60
  61     QPainterPath path = m_shadowParent->shape();
  62     QRectF rect = path.boundingRect();
  63     QSize s = rect.size().toSize() + QSize(30, 30);
  64     QImage img(s, QImage::Format_ARGB32_Premultiplied);
  65     img.fill(0);
  66     QPainter p(&img);
  67     p.translate(15, 15);
  68     p.setRenderHint(QPainter::Antialiasing);
  69     p.setCompositionMode(QPainter::CompositionMode_Source);
  70     p.fillPath(path, Qt::gray);
  71     p.end();
  72 #ifdef DO_GLOW
  73     QImage blurred = img;
  74     expblur<16, 7>(img, 7);
  75     p.begin(&img);
  76     p.setCompositionMode(QPainter::CompositionMode_Plus);
  77     p.drawImage(0, 0, blurred);
  78     p.end();
  79 #else
  80     expblur<16, 7>(img, 7);
  81 #endif
  82
  83     setPixmap(QPixmap::fromImage(img));
  84 }
  85
  86
  87 void ShadowItem::adjustPosition()
  88 {
  89     if (!m_shadowParent) {
  90         return;
  91     }
  92
  93     setPos(m_shadowParent->pos() - m_offset);
  94 }
  95
  96 void ShadowItem::setOffset(const QPointF &offset)
  97 {
  98     m_offset = offset;
  99 }
 100
 101 QPointF ShadowItem::offset() const
 102 {
 103     return m_offset;
 104 }