Pyqt5 rapid development and practice 4.13 menu bar, toolbar and status bar and 4.14 qprinter

PyQt5 Rapid development and actual combat

4. The first 4 Chapter PyQt5 Basic window control

4.13 menu bar 、 Toolbar and status bar

4.13.1 menu bar

stay QMainWindow Under the title bar of the object , Horizontal QMenuBar Reserved display QMenu object .

QMenu Class provides a widget that can be added to the menu bar , It is also used to create context menus and pop-up menus . Every QMenu Objects can contain one or more QAction Object or cascading QMenu object .·
To create a pop-up menu ,PyQt API Provides createPopupMenu() function ;menuBar() The function returns the of the main window QMenuBar object ;addMenu() Function to add a menu to the menu bar ; adopt addAction() Functions can be added in the menu .

Some important methods in designing menu system ：

Method	describe
menuBar()	Return to the main window QMenuBar object
addMenu()	Add a new... In the menu bar QMenu object
addAction()	towards QMenu Add an action button to the widget , It contains text or icons
setEnabled()	Set the operation button status to enabled / Ban
addSeperator()	Add a split line to the menu
clear()	Delete menu / Contents of the menu bar
setShortcut()	Associate shortcut keys to action buttons
setText()	Set the text of the menu item
setTitle()	Set up QMenu The title of the widget
text()	Return and QAction Object associated text
title()	return QMenu The title of the widget

Click any QAction Button ,QMenu Objects emit triggered The signal .

Case study ——QMenuBar Use

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

class MenuDemo(QMainWindow):
    def __init__(self,parent = None):
        super(MenuDemo, self).__init__(parent)
        layout = QHBoxLayout()
        bar = self.menuBar()
        file = bar.addMenu("File")
        file.addAction("New")
        save = QAction("Save",self)
        save.setShortcut("Ctrl+S")
        file.addAction(save)
        edit = file.addMenu("Edit")
        edit.addAction("copy")
        edit.addAction("paste")
        quit = QAction("Quit",self)
        file.addAction(quit)
        file.triggered[QAction].connect(self.processtrigger)
        self.setLayout(layout)
        self.setWindowTitle("Menu Case study ")

    def processtrigger(self , q):
        print(q.text() + "is triggered")

if __name__ == '__main__':
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = MenuDemo()
    win.show()
    sys.exit(app.exec_())

4.13.2 QToolBar

QToolBar Control consists of a text button 、 A movable panel composed of icons or other gizmo buttons , Usually located below the menu bar .

QToolBar Common methods in class

Method	describe
addAction()	Add a tool button with text or icon
addSeperator()	Group display tool buttons
addWidget()	Add controls other than buttons in the toolbar
addToolBar()	Use QMainWindow Class to add a new toolbar
setMovable()	The toolbar becomes movable
setOrientation()	The direction of the toolbar can be set to Qt.Horizaontal or Qt.vertical

Whenever you click a button in the toolbar , Will launch actionTriggered The signal . in addition , This signal will be associated with QAction Object is sent to the connected slot function .

Case study ——QToolBar Use

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

class ToolBarDemo(QMainWindow):
    def __init__(self,parent = None):
        super(ToolBarDemo, self).__init__(parent)
        self.setWindowTitle(" Toolbar case ")
        self.resize(300 , 200)

        layout = QVBoxLayout()
        tb = self.addToolBar("File")
        new = QAction(QIcon("new.png"),"new",self)
        tb.addAction(new)
        open = QAction(QIcon("open.png"),"open",self)
        tb.addAction(open)
        save = QAction(QIcon("save.png"),"save",self)
        tb.addAction(save)
        tb.actionTriggered[QAction].connect(self.toolbtnpressed)
        self.setLayout(layout)

    def toolbtnpressed(self,a):
        print("Pressed tool button is " , a.text())

if __name__ == '__main__':
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = ToolBarDemo()
    win.show()
    sys.exit(app.exec_())

4.13.3 QStatusBar

MainWindow The object has a horizontal bar at the bottom , As a status bar (QStatusBar), Used to display permanent or temporary status information . Through the main window QMainWindow Of setStatusBar() Function setting status bar ：

self.statusBar = QStatusBar()
self.setStatusBar(self.statusBar)

QStatusBar Common methods in class

Method	describe
addWidget()	Add the given widget object to the status bar
addPermanentWidget()	Permanently add the given widget object in the status bar
showMessage()	Display a temporary message in the status bar to specify the time interval
clearMessage()	Delete the temporary information being displayed
removeWidget()	Delete the specified gizmo from the status bar

Case study ——QStatusBar Use

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

class StatusDemo(QMainWindow):
    def __init__(self,parent = None):
        super(StatusDemo, self).__init__(parent)
        bar = self.menuBar()
        file = bar.addMenu("File")
        file.addAction("show")
        file.triggered[QAction].connect(self.processTrigger)
        self.setCentralWidget(QTextEdit())
        self.statusBar=  QStatusBar()
        self.setWindowTitle(" Status bar case ")
        self.setStatusBar(self.statusBar)

    def processTrigger(self , q):
        if(q.text() == "show"):
            self.statusBar.showMessage(q.text() + " The menu option was clicked ",5000)

if __name__ == '__main__':
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = StatusDemo()
    win.show()
    sys.exit(app.exec_())

4.14 QPrinter

Printing image is a common function in image processing software . Printing an image is actually QPaintDevice Chinese painting , As usual QWidget、QPixmap and QImage It's the same as drawing in , Is to create a QPainter Object for drawing , Just print using QPrinter, It is also essentially a QPaintDevice（ Drawing equipment ).

4.14.1 QPrinter Use

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QImage, QIcon, QPixmap, QPainter
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QSizePolicy, QAction
from PyQt5.QtPrintSupport import QPrinter, QPrintDialog
import sys


class MainWindow(QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setWindowTitle(self.tr(" Print pictures "))
        #  Create a place for the image QLabel object imageLabel, And put the QLabel Object as the central form .
        self.imageLabel = QLabel()
        self.imageLabel.setSizePolicy(QSizePolicy.Ignored, QSizePolicy.Ignored)
        self.setCentralWidget(self.imageLabel)

        self.image = QImage()

        #  Create a menu , Toolbar and other parts 
        self.createActions()
        self.createMenus()
        self.createToolBars()

        #  stay imageLabel Object 
        if self.image.load("./images/screen.png"):
            self.imageLabel.setPixmap(QPixmap.fromImage(self.image))
            self.resize(self.image.width(), self.image.height())

    def createActions(self):
        self.PrintAction = QAction(QIcon("images/screen.png"), self.tr(" Print "), self)
        self.PrintAction.setShortcut("Ctrl+P")
        self.PrintAction.setStatusTip(self.tr(" Print "))
        self.PrintAction.triggered.connect(self.slotPrint)

    def createMenus(self):
        PrintMenu = self.menuBar().addMenu(self.tr(" Print "))
        PrintMenu.addAction(self.PrintAction)

    def createToolBars(self):
        fileToolBar = self.addToolBar("Print")
        fileToolBar.addAction(self.PrintAction)

    def slotPrint(self):
        #  Create a new one QPrinter object 
        printer = QPrinter()
        #  Create a QPrintDialog object , Parameter is QPrinter object 
        printDialog = QPrintDialog(printer, self)

        '''  Judge whether the user clicks... After the print dialog box is displayed “ Print ” Button , If you click “ Print ” Button ,  Then the related print attributes can be created by QPrintDialog Object QPrinter Object to obtain ,  If the user clicks “ Cancel ” Button , Then no subsequent printing operation will be performed . '''
        if printDialog.exec_():
            #  Create a QPainter object , And specify the drawing device as a QPrinter object .
            painter = QPainter(printer)
            #  get QPainter The viewport rectangle of the object 
            rect = painter.viewport()
            #  Get the size of the image 
            size = self.image.size()
            #  Resets the viewport rectangle to the scale of the drawing 
            size.scale(rect.size(), Qt.KeepAspectRatio)
            painter.setViewport(rect.x(), rect.y(), size.width(), size.height())
            #  Set up QPainter The window size is the size of the image 
            painter.setWindow(self.image.rect())
            #  Print 
            painter.drawImage(0, 0, self.image)

if __name__ == '__main__':
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
    app = QApplication(sys.argv)
    win = MainWindow()
    win.show()
    sys.exit(app.exec_())