#!/usr/bin/env python
 
 
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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## This file is part of the examples of PyQt.
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from PyQt5.QtCore import (QAbstractTableModel, QDir, QModelIndex, QRect,
        QRectF, QSize, Qt)
from PyQt5.QtGui import QBrush, qGray, QImage, QPainter
from PyQt5.QtPrintSupport import QPrinter
from PyQt5.QtWidgets import (QAbstractItemDelegate, QApplication, QDialog,
        QFileDialog, QHBoxLayout, QLabel, QMainWindow, QMessageBox, QMenu,
        QProgressDialog, QSpinBox, QStyle, QStyleOptionViewItem, QTableView,
        QVBoxLayout, QWidget)
 
import pixelator_rc
 
 
ItemSize = 256
 
 
class PixelDelegate(QAbstractItemDelegate):
    def __init__(self, parent=None):
        super(PixelDelegate, self).__init__(parent)
 
        self.pixelSize = 12
 
    def paint(self, painter, option, index):
        if option.state & QStyle.State_Selected:
            painter.fillRect(option.rect, option.palette.highlight())
 
        size = min(option.rect.width(), option.rect.height())
        brightness = index.model().data(index, Qt.DisplayRole)
        radius = (size/2.0) - (brightness/255.0 * size/2.0)
        if radius == 0.0:
            return
 
        painter.save()
        painter.setRenderHint(QPainter.Antialiasing)
        painter.setPen(Qt.NoPen)
 
        if option.state & QStyle.State_Selected:
            painter.setBrush(option.palette.highlightedText())
        else:
            painter.setBrush(QBrush(Qt.black))
 
        painter.drawEllipse(QRectF(
                            option.rect.x() + option.rect.width()/2 - radius,
                            option.rect.y() + option.rect.height()/2 - radius,
                            2*radius, 2*radius))
 
        painter.restore()
 
    def sizeHint(self, option, index):
        return QSize(self.pixelSize, self.pixelSize)
 
    def setPixelSize(self, size):
        self.pixelSize = size
 
 
class ImageModel(QAbstractTableModel):
    def __init__(self, parent=None):
        super(ImageModel, self).__init__(parent)
 
        self.modelImage = QImage()
 
    def setImage(self, image):
        self.beginResetModel()
        self.modelImage = QImage(image)
        self.endResetModel()
 
    def rowCount(self, parent):
        return self.modelImage.height()
 
    def columnCount(self, parent):
        return self.modelImage.width()
 
    def data(self, index, role):
        if not index.isValid() or role != Qt.DisplayRole:
            return None
 
        return qGray(self.modelImage.pixel(index.column(), index.row()))
 
    def headerData(self, section, orientation, role):
        if role == Qt.SizeHintRole:
            return QSize(1, 1)
 
        return None
 
 
class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
 
        self.currentPath = QDir.homePath()
        self.model = ImageModel(self)
 
        centralWidget = QWidget()
 
        self.view = QTableView()
        self.view.setShowGrid(False)
        self.view.horizontalHeader().hide()
        self.view.verticalHeader().hide()
        self.view.horizontalHeader().setMinimumSectionSize(1)
        self.view.verticalHeader().setMinimumSectionSize(1)
        self.view.setModel(self.model)
 
        delegate = PixelDelegate(self)
        self.view.setItemDelegate(delegate)
 
        pixelSizeLabel = QLabel("Pixel size:")
        pixelSizeSpinBox = QSpinBox()
        pixelSizeSpinBox.setMinimum(4)
        pixelSizeSpinBox.setMaximum(32)
        pixelSizeSpinBox.setValue(12)
 
        fileMenu = QMenu("&File", self)
        openAction = fileMenu.addAction("&Open...")
        openAction.setShortcut("Ctrl+O")
 
        self.printAction = fileMenu.addAction("&Print...")
        self.printAction.setEnabled(False)
        self.printAction.setShortcut("Ctrl+P")
 
        quitAction = fileMenu.addAction("E&xit")
        quitAction.setShortcut("Ctrl+Q")
 
        helpMenu = QMenu("&Help", self)
        aboutAction = helpMenu.addAction("&About")
 
        self.menuBar().addMenu(fileMenu)
        self.menuBar().addSeparator()
        self.menuBar().addMenu(helpMenu)
 
        openAction.triggered.connect(self.chooseImage)
        self.printAction.triggered.connect(self.printImage)
        quitAction.triggered.connect(QApplication.instance().quit)
        aboutAction.triggered.connect(self.showAboutBox)
        pixelSizeSpinBox.valueChanged.connect(delegate.setPixelSize)
        pixelSizeSpinBox.valueChanged.connect(self.updateView)
 
        controlsLayout = QHBoxLayout()
        controlsLayout.addWidget(pixelSizeLabel)
        controlsLayout.addWidget(pixelSizeSpinBox)
        controlsLayout.addStretch(1)
 
        mainLayout = QVBoxLayout()
        mainLayout.addWidget(self.view)
        mainLayout.addLayout(controlsLayout)
        centralWidget.setLayout(mainLayout)
 
        self.setCentralWidget(centralWidget)
 
        self.setWindowTitle("Pixelator")
        self.resize(640, 480)
 
    def chooseImage(self):
        fileName, _ = QFileDialog.getOpenFileName(self, "Choose an Image",
                self.currentPath, '*')
 
        if fileName:
            self.openImage(fileName)
 
    def openImage(self, fileName):
        image = QImage()
 
        if image.load(fileName):
            self.model.setImage(image)
 
            if not fileName.startswith(':/'):
                self.currentPath = fileName
                self.setWindowTitle("%s - Pixelator" % self.currentPath)
 
            self.printAction.setEnabled(True)
            self.updateView()
 
    def printImage(self):
        if self.model.rowCount(QModelIndex()) * self.model.columnCount(QModelIndex()) > 90000:
            answer = QMessageBox.question(self, "Large Image Size",
                    "The printed image may be very large. Are you sure that "
                    "you want to print it?",
                    QMessageBox.Yes | QMessageBox.No)
            if answer == QMessageBox.No:
                return
 
        printer = QPrinter(QPrinter.HighResolution)
 
        dlg = QPrintDialog(printer, self)
        dlg.setWindowTitle("Print Image")
 
        if dlg.exec_() != QDialog.Accepted:
            return
 
        painter = QPainter()
        painter.begin(printer)
 
        rows = self.model.rowCount(QModelIndex())
        columns = self.model.columnCount(QModelIndex())
        sourceWidth = (columns+1) * ItemSize
        sourceHeight = (rows+1) * ItemSize
 
        painter.save()
 
        xscale = printer.pageRect().width() / float(sourceWidth)
        yscale = printer.pageRect().height() / float(sourceHeight)
        scale = min(xscale, yscale)
 
        painter.translate(printer.pageRect().x()+printer.pageRect().width()/2,
                          printer.pageRect().y()+printer.pageRect().height()/2)
        painter.scale(scale, scale)
        painter.translate(-sourceWidth/2, -sourceHeight/2)
 
        option = QStyleOptionViewItem()
        parent = QModelIndex()
 
        progress = QProgressDialog("Printing...", "Cancel", 0, rows, self)
        y = ItemSize / 2.0
 
        for row in range(rows):
            progress.setValue(row)
            QApplication.processEvents()
            if progress.wasCanceled():
                break
 
            x = ItemSize / 2.0
 
            for column in range(columns):
                option.rect = QRect(x, y, ItemSize, ItemSize)
                self.view.itemDelegate.paint(painter, option,
                        self.model.index(row, column, parent))
                x = x + ItemSize
 
            y = y + ItemSize
 
        progress.setValue(rows)
 
        painter.restore()
        painter.end()
 
        if progress.wasCanceled():
            QMessageBox.information(self, "Printing canceled",
                    "The printing process was canceled.", QMessageBox.Cancel)
 
    def showAboutBox(self):
        QMessageBox.about(self, "About the Pixelator example",
                "This example demonstrates how a standard view and a custom\n"
                "delegate can be used to produce a specialized "
                "representation\nof data in a simple custom model.")
 
    def updateView(self):
        self.view.resizeColumnsToContents()
        self.view.resizeRowsToContents()
 
 
if __name__ == '__main__':
 
    import sys
 
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    window.openImage(':/images/qt.png')
    sys.exit(app.exec_())