I want to preview, and then print, a report through a printer using PyQt. I tried the following code :
printer = QtGui.QPrinter()
doc = QtGui.QTextDocument("testing")
dialog = QtGui.QPrintDialog(printer)
dialog.setModal(True)
dialog.setWindowTitle("printerrr")
pdialog = QtGui.QPrintPreviewDialog(printer)
pdialog.setWindowFlags(QtCore.Qt.Window)
pdialog.exec_()
How I can preview my report then print it?
Basic demo of Qt's print dialogs:
UPDATE:
An alternative solution to the ones given below is to use Qt WebEngine to render and print the documents. This allows a much greater range of document types to be supported in addition to HTML, such as PDFs, images, plain text, etc. The Printer class in the following example is based on the WebEngine Widgets PrintMe Example from the Qt docs.
PyQt6:
from PyQt6 import QtCore, QtGui, QtWidgets
from PyQt6 import QtPrintSupport, QtWebEngineWidgets
from PyQt6.QtWebEngineCore import QWebEngineSettings
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = QtWebEngineWidgets.QWebEngineView(self)
self.viewer.settings().setAttribute(
QWebEngineSettings.WebAttribute.PluginsEnabled, True)
self.viewer.settings().setAttribute(
QWebEngineSettings.WebAttribute.PdfViewerEnabled, True)
self.buttonOpen = QtWidgets.QPushButton('Open', self)
self.buttonOpen.clicked.connect(self.handleOpen)
self.buttonPrint = QtWidgets.QPushButton('Print', self)
self.buttonPrint.clicked.connect(self.handlePrint)
self.buttonPreview = QtWidgets.QPushButton('Preview', self)
self.buttonPreview.clicked.connect(self.handlePreview)
layout = QtWidgets.QGridLayout(self)
layout.addWidget(self.viewer, 0, 0, 1, 3)
layout.addWidget(self.buttonOpen, 1, 0)
layout.addWidget(self.buttonPrint, 1, 1)
layout.addWidget(self.buttonPreview, 1, 2)
self.printer = Printer(self.viewer, self)
def handleOpen(self):
if path := QtWidgets.QFileDialog.getOpenFileName(self)[0]:
self.viewer.load(QtCore.QUrl.fromLocalFile(path))
def handlePrint(self):
if self.viewer.url().isValid():
self.printer.print()
def handlePreview(self):
if self.viewer.url().isValid():
self.printer.preview()
class Printer(QtCore.QObject):
def __init__(self, view, parent=None):
super().__init__()
self._view = view
self._view.printRequested.connect(self.preview)
self._view.printFinished.connect(self.handleFinished)
self._printing = False
self._loop = QtCore.QEventLoop(self)
def print(self):
printer = QtPrintSupport.QPrinter(
QtPrintSupport.QPrinter.PrinterMode.HighResolution)
dialog = QtPrintSupport.QPrintDialog(printer, self._view)
if dialog.exec() == QtWidgets.QDialog.DialogCode.Accepted:
self.render(printer)
dialog.deleteLater()
def preview(self):
if not self._printing:
self._printing = True
printer = QtPrintSupport.QPrinter()
printer.setResolution(300)
dialog = QtPrintSupport.QPrintPreviewDialog(printer, self._view)
dialog.paintRequested.connect(self.render)
dialog.exec()
dialog.deleteLater()
self._printing = False
def render(self, printer):
QtWidgets.QApplication.setOverrideCursor(
QtCore.Qt.CursorShape.WaitCursor)
self._view.print(printer)
self._loop.exec(
QtCore.QEventLoop.ProcessEventsFlag.ExcludeUserInputEvents)
def handleFinished(self, success):
if not success:
painter = QtGui.QPainter()
if painter.begin(self._printer):
font = QtGui.QFont(painter.font())
font.setPixelSize(20)
painter.setFont(font)
painter.drawText(
QtCore.QPointF(10, 25),
'Could not generate print preview')
painter.end()
self._loop.quit()
QtWidgets.QApplication.restoreOverrideCursor()
if __name__ == '__main__':
app = QtWidgets.QApplication(['Printing Demo'])
window = Window()
window.setGeometry(600, 100, 800, 600)
window.show()
app.exec()
PyQt5:
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5 import QtPrintSupport, QtWebEngineWidgets
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = QtWebEngineWidgets.QWebEngineView(self)
self.viewer.settings().setAttribute(
QtWebEngineWidgets.QWebEngineSettings.PluginsEnabled, True)
self.viewer.settings().setAttribute(
QtWebEngineWidgets.QWebEngineSettings.PdfViewerEnabled, True)
self.buttonOpen = QtWidgets.QPushButton('Open', self)
self.buttonOpen.clicked.connect(self.handleOpen)
self.buttonPrint = QtWidgets.QPushButton('Print', self)
self.buttonPrint.clicked.connect(self.handlePrint)
self.buttonPreview = QtWidgets.QPushButton('Preview', self)
self.buttonPreview.clicked.connect(self.handlePreview)
layout = QtWidgets.QGridLayout(self)
layout.addWidget(self.viewer, 0, 0, 1, 3)
layout.addWidget(self.buttonOpen, 1, 0)
layout.addWidget(self.buttonPrint, 1, 1)
layout.addWidget(self.buttonPreview, 1, 2)
self.printer = Printer(self.viewer.page(), self)
def handleOpen(self):
if path := QtWidgets.QFileDialog.getOpenFileName(self)[0]:
self.viewer.load(QtCore.QUrl.fromLocalFile(path))
def handlePrint(self):
if self.viewer.url().isValid():
self.printer.print()
def handlePreview(self):
if self.viewer.url().isValid():
self.printer.preview()
class Printer(QtCore.QObject):
def __init__(self, page, parent=None):
super().__init__(parent)
self._page = page
self._printing = False
def render(self, printer):
loop = QtCore.QEventLoop()
failed = False
QtWidgets.QApplication.setOverrideCursor(QtCore.Qt.WaitCursor)
def callback(result):
nonlocal failed
failed = not result
QtWidgets.QApplication.restoreOverrideCursor()
loop.quit()
self._page.print(printer, callback)
loop.exec()
if failed:
painter = QtGui.QPainter()
if painter.begin(printer):
font = painter.font()
font.setPixelSize(20)
painter.setFont(font)
painter.drawText(QtCore.QPointF(10, 25),
'Could not generate print preview')
painter.end()
def preview(self):
if not self._printing:
self._printing = True
printer = QtPrintSupport.QPrinter()
printer.setResolution(300)
dialog = QtPrintSupport.QPrintPreviewDialog(
printer, self._page.view())
dialog.paintRequested.connect(self.render)
dialog.exec()
dialog.deleteLater()
self._printing = False
def print(self):
printer = QtPrintSupport.QPrinter(
QtPrintSupport.QPrinter.HighResolution)
dialog = QtPrintSupport.QPrintDialog(printer, self._page.view())
if dialog.exec() == QtWidgets.QDialog.Accepted:
self.render(printer)
dialog.deleteLater()
if __name__ == '__main__':
QtWidgets.QApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
app = QtWidgets.QApplication(['Printing Demo'])
window = Window()
window.setGeometry(600, 100, 800, 600)
window.show()
app.exec()
Previous examples:
PyQt4:
import sys, os
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
def __init__(self):
super(Window, self).__init__()
self.setWindowTitle('Document Printer')
self.editor = QtGui.QTextEdit(self)
self.editor.textChanged.connect(self.handleTextChanged)
self.buttonOpen = QtGui.QPushButton('Open', self)
self.buttonOpen.clicked.connect(self.handleOpen)
self.buttonPrint = QtGui.QPushButton('Print', self)
self.buttonPrint.clicked.connect(self.handlePrint)
self.buttonPreview = QtGui.QPushButton('Preview', self)
self.buttonPreview.clicked.connect(self.handlePreview)
layout = QtGui.QGridLayout(self)
layout.addWidget(self.editor, 0, 0, 1, 3)
layout.addWidget(self.buttonOpen, 1, 0)
layout.addWidget(self.buttonPrint, 1, 1)
layout.addWidget(self.buttonPreview, 1, 2)
self.handleTextChanged()
def handleOpen(self):
path = QtGui.QFileDialog.getOpenFileName(
self, 'Open file', '',
'HTML files (*.html);;Text files (*.txt)')
if path:
file = QtCore.QFile(path)
if file.open(QtCore.QIODevice.ReadOnly):
stream = QtCore.QTextStream(file)
text = stream.readAll()
info = QtCore.QFileInfo(path)
if info.completeSuffix() == 'html':
self.editor.setHtml(text)
else:
self.editor.setPlainText(text)
file.close()
def handlePrint(self):
dialog = QtGui.QPrintDialog()
if dialog.exec_() == QtGui.QDialog.Accepted:
self.editor.document().print_(dialog.printer())
def handlePreview(self):
dialog = QtGui.QPrintPreviewDialog()
dialog.paintRequested.connect(self.editor.print_)
dialog.exec_()
def handleTextChanged(self):
enable = not self.editor.document().isEmpty()
self.buttonPrint.setEnabled(enable)
self.buttonPreview.setEnabled(enable)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = Window()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
PyQt5:
import sys, os
from PyQt5 import QtCore, QtWidgets, QtPrintSupport
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.setWindowTitle('Document Printer')
self.editor = QtWidgets.QTextEdit(self)
self.editor.textChanged.connect(self.handleTextChanged)
self.buttonOpen = QtWidgets.QPushButton('Open', self)
self.buttonOpen.clicked.connect(self.handleOpen)
self.buttonPrint = QtWidgets.QPushButton('Print', self)
self.buttonPrint.clicked.connect(self.handlePrint)
self.buttonPreview = QtWidgets.QPushButton('Preview', self)
self.buttonPreview.clicked.connect(self.handlePreview)
layout = QtWidgets.QGridLayout(self)
layout.addWidget(self.editor, 0, 0, 1, 3)
layout.addWidget(self.buttonOpen, 1, 0)
layout.addWidget(self.buttonPrint, 1, 1)
layout.addWidget(self.buttonPreview, 1, 2)
self.handleTextChanged()
def handleOpen(self):
path = QtWidgets.QFileDialog.getOpenFileName(
self, 'Open file', '',
'HTML files (*.html);;Text files (*.txt)')[0]
if path:
file = QtCore.QFile(path)
if file.open(QtCore.QIODevice.ReadOnly):
stream = QtCore.QTextStream(file)
text = stream.readAll()
info = QtCore.QFileInfo(path)
if info.completeSuffix() == 'html':
self.editor.setHtml(text)
else:
self.editor.setPlainText(text)
file.close()
def handlePrint(self):
dialog = QtPrintSupport.QPrintDialog()
if dialog.exec_() == QtWidgets.QDialog.Accepted:
self.editor.document().print_(dialog.printer())
def handlePreview(self):
dialog = QtPrintSupport.QPrintPreviewDialog()
dialog.paintRequested.connect(self.editor.print_)
dialog.exec_()
def handleTextChanged(self):
enable = not self.editor.document().isEmpty()
self.buttonPrint.setEnabled(enable)
self.buttonPreview.setEnabled(enable)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
To print-preview a graphics view, use its render method:
def handlePreview(self):
# dialog = QtPrintSupport.QPrintPreviewDialog() # PyQt5
dialog = QtGui.QPrintPreviewDialog()
dialog.paintRequested.connect(self.handlePaintRequest)
dialog.exec_()
def handlePaintRequest(self, printer):
self.view.render(QtGui.QPainter(printer))