2 // imagedelegate.cpp - Qt Model/View rendering class
5 // (C) 2010 Underground Software
7 // JLH = James L. Hammons <jlhamm@acm.org>
10 // --- ---------- -------------------------------------------------------------
11 // JLH 02/04/2010 Created this file
14 // This class takes care of rendering items in our custom model in the ListView
15 // class utilized in FilePicker.
17 #include "imagedelegate.h"
20 #include "filelistmodel.h"
22 //ImageDelegate::ImageDelegate(QObject * parent): QAbstractItemDelegate(parent)//, pixelSize(12)
26 ImageDelegate::ImageDelegate()
28 QImage cartImg(":/res/cart-blank.png");
29 QPainter painter(&cartImg);
30 painter.drawPixmap(23, 87, QPixmap(":/res/label-blank.png"));
32 cartSmall = cartImg.scaled(488/4, 395/4, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
36 Each item is rendered by the delegate's paint() function. The view calls this function with a ready-to-use QPainter object, style information that the delegate should use to correctly draw the item, and an index to the item in the model:
39 void ImageDelegate::paint(QPainter * painter, const QStyleOptionViewItem & option, const QModelIndex & index) const
41 if (option.state & QStyle::State_Selected)
42 painter->fillRect(option.rect, option.palette.highlight());
45 The first task the delegate has to perform is to draw the item's background correctly. Usually, selected items appear differently to non-selected items, so we begin by testing the state passed in the style option and filling the background if necessary.
47 The radius of each circle is calculated in the following lines of code:
51 int size = qMin(option.rect.width(), option.rect.height());
52 int brightness = index.model()->data(index, Qt::DisplayRole).toInt();
53 double radius = (size/2.0) - (brightness/255.0 * size/2.0);
59 First, the largest possible radius of the circle is determined by taking the smallest dimension of the style option's rect attribute. Using the model index supplied, we obtain a value for the brightness of the relevant pixel in the image. The radius of the circle is calculated by scaling the brightness to fit within the item and subtracting it from the largest possible radius.
64 painter->setRenderHint(QPainter::Antialiasing, true);
65 painter->setPen(Qt::NoPen);
68 We save the painter's state, turn on antialiasing (to obtain smoother curves), and turn off the pen.
71 if (option.state & QStyle::State_Selected)
72 painter->setBrush(option.palette.highlightedText());
74 painter->setBrush(QBrush(Qt::black));
77 The foreground of the item (the circle representing a pixel) must be rendered using an appropriate brush. For unselected items, we will use a solid black brush; selected items are drawn using a predefined brush from the style option's palette.
80 painter->drawEllipse(QRectF(option.rect.x() + option.rect.width()/2 - radius,
81 option.rect.y() + option.rect.height()/2 - radius, 2*radius, 2*radius));
83 // painter->drawPixmap(option.rect.x()+8, option.rect.y()+8, 200, 94, QPixmap(":/res/labels/rayman.jpg"));
84 // painter->drawPixmap(option.rect.x()+13, option.rect.y()+51, 433/2, 203/2, QPixmap(":/res/labels/rayman.jpg"));
85 // painter->drawPixmap(option.rect.x(), option.rect.y(), 488/2, 395/2, QPixmap(":/res/cart-blank.png"));
88 // This is crappy. We really should have a properly scaled image ready to go so we
89 // don't get Qt's default ugly looking fast scaling...
90 #warning "!!! FIX !!! Need to create properly scaled down cart/label images!"
91 // unsigned long i = index.model()->data(index, Qt::DisplayRole).toUInt();
93 unsigned long i = index.model()->data(index, Qt::DisplayRole).toUInt();
94 QString filename = index.model()->data(index, Qt::EditRole).toString();
95 QImage label = index.model()->data(index, Qt::DecorationRole).value<QImage>();
97 unsigned long i = index.model()->data(index, FLM_INDEX).toUInt();
98 QString filename = index.model()->data(index, FLM_FILENAME).toString();
99 QImage label = index.model()->data(index, FLM_LABEL).value<QImage>();
103 if (i == 0xFFFFFFFF) // Not found...
105 int lastSlashPos = filename.lastIndexOf('/');
106 nameToDraw = "\"" + filename.mid(lastSlashPos + 1) + "\"";
109 nameToDraw = romList[i].name;
111 if (role == Qt::DecorationRole)
112 return list.at(index.row()).label;
113 else if (role == Qt::DisplayRole)
114 return (uint)list.at(index.row()).dbIndex;
115 else if (role == Qt::EditRole)
116 return list.at(index.row()).filename;
119 // if (romList[i].file[0] == 0)
122 // painter->drawPixmap(option.rect.x()+14, option.rect.y()+50, 433/2, 203/2, QPixmap(":/res/label-blank.png"));
123 // painter->drawPixmap(option.rect.x()+7, option.rect.y()+25, 433/4, 203/4, QPixmap(":/res/label-blank.png"));
124 painter->drawImage(option.rect.x() + 2, option.rect.y() + 2, cartSmall);
125 //Need to query the model for the data we're supposed to draw here...
126 // painter->drawText(17, 73, QString(romList[i].name));
127 // painter->setPen(Qt::white);
128 painter->setPen(QColor(255, 128, 0, 255));
129 // painter->drawText(QRect(option.rect.x()+20, option.rect.y()+73, 196, 70), Qt::TextWordWrap | Qt::AlignHCenter, QString(romList[i].name));
130 painter->drawText(QRect(option.rect.x()+10, option.rect.y()+36, 196/2, 70/2),
131 Qt::TextWordWrap | Qt::AlignHCenter, nameToDraw);
136 QString filename(romList[i].file);
137 filename.prepend("./label/");
138 QImage img(filename);
139 painter->drawImage(QRect(option.rect.x()+7, option.rect.y()+25, 433/4, 203/4), img);
141 painter->drawPixmap(option.rect.x() + 2, option.rect.y() + 2, 488/4, 395/4, QPixmap(":/res/cart-blank.png"));
142 painter->drawImage(QRect(option.rect.x()+2+7, option.rect.y()+2+25, 433/4, 203/4), label);
151 Finally, we paint the circle within the rectangle specified by the style option and we call restore() on the painter.
153 The paint() function does not have to be particularly complicated; it is only necessary to ensure that the state of the painter when the function returns is the same as it was when it was called. This usually means that any transformations applied to the painter must be preceded by a call to QPainter::save() and followed by a call to QPainter::restore().
155 The delegate's sizeHint() function returns a size for the item based on the predefined pixel size, initially set up in the constructor:
158 QSize ImageDelegate::sizeHint(const QStyleOptionViewItem & /* option */, const QModelIndex & /* index */) const
160 // 488x395 --> blank cart (full size)
161 // 400x188 --> label (full size) 433x203 <-- (actually, it's this)
163 // 200x94 is shrunk dimension...
164 // return QSize(100, 47);
165 // return QSize(216, 110);
166 // return QSize(488/2, 395/2);
167 return QSize((488/4) + 4, (395/4) + 4);
171 The delegate's size is updated whenever the pixel size is changed. We provide a custom slot to do this:
174 //void ImageDelegate::setPixelSize(int size)