PyQt学习笔记(4)--Smart Dialog

   这里的 smart dialogs一般都是指的非模态对话框，就是用户想要实时的看到自己的操作对主窗口的影响，当然在某些模态对话框中，添加预览功能可以实现上面的需求，但是这 些在非模态对话框中是很容易做到的。

   我们在前面模态对话框的字体选择程序基础上加以修改。先写一个类，ModelessDialog.py,如下：

#!/usr/bin/env python
#coding=utf-8

from PyQt4.QtCore import *
from PyQt4.QtGui import *

class FontPropertiesDlg(QDialog):
    def __init__(self,parent=None):
        super(FontPropertiesDlg, self).__init__(parent)
        self.format=format
        FontStyleLabel = QLabel(u"中文字体:")
        self.FontstyleComboBox = QComboBox()
        self.FontstyleComboBox.addItems([u"宋体", u"黑体", u"仿宋",
                                         u"隶书", u"楷体"])
        self.FontEffectCheckBox =QCheckBox(u"使用特效")
        FontSizeLabel = QLabel(u"字体大小")
        self.FontSizeSpinBox = QSpinBox()
        self.FontSizeSpinBox.setRange(1, 90)
        applyButton = QPushButton(u"应用")
        cancelButton = QPushButton(u"取消")

        buttonLayout = QHBoxLayout()
        buttonLayout.addStretch()
        buttonLayout.addWidget(applyButton)
        buttonLayout.addWidget(cancelButton)
        layout = QGridLayout()
        layout.addWidget(FontStyleLabel, 0, 0)
        layout.addWidget(self.FontstyleComboBox, 0, 1)
        layout.addWidget(FontSizeLabel, 1, 0)
        layout.addWidget(self.FontSizeSpinBox, 1, 1)
        layout.addWidget(self.FontEffectCheckBox,1,2)
        layout.addLayout(buttonLayout, 2, 0)
        self.setLayout(layout)

        self.connect(applyButton,SIGNAL("clicked()"),self.apply)
        self.connect(cancelButton,SIGNAL("clicked()"),self,SLOT("reject()"))
        self.setWindowTitle(u"字体")

    def apply(self):
        self.format["fontstyle"] =unicode(self.FontstyleComboBox.currentText())
        self.format["fontsize"] = self.FontSizeSpinBox.value()
        self.format["fonteffect"] =self.FontEffectCheckBox.isChecked()
        self.emit(SIGNAL("changed"))

   编写主程序：

#!/usr/bin/env python
#coding=utf-8

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import ModelessDialog

class FontPropertiesDlg(QDialog):
    def __init__(self,parent=None):
        super(FontPropertiesDlg, self).__init__(parent)
        FontStyleLabel = QLabel(u"中文字体:")
        self.FontstyleComboBox = QComboBox()
        self.FontstyleComboBox.addItems([u"宋体",u"黑体", u"仿宋",
                                         u"隶书", u"楷体"])
        self.FontEffectCheckBox =QCheckBox(u"使用特效")
        FontSizeLabel = QLabel(u"字体大小")
        self.FontSizeSpinBox = QSpinBox()
        self.FontSizeSpinBox.setRange(1, 90)
        okButton = QPushButton(u"确定")
        cancelButton = QPushButton(u"取消")
        
        buttonLayout = QHBoxLayout()
        buttonLayout.addStretch()
        buttonLayout.addWidget(okButton)
        buttonLayout.addWidget(cancelButton)
        layout = QGridLayout()
        layout.addWidget(FontStyleLabel, 0, 0)
        layout.addWidget(self.FontstyleComboBox, 0, 1)
        layout.addWidget(FontSizeLabel, 1, 0)
        layout.addWidget(self.FontSizeSpinBox, 1, 1)
        layout.addWidget(self.FontEffectCheckBox,1,2)
        layout.addLayout(buttonLayout, 2, 0)
        self.setLayout(layout)
        #为okButton与cancelButton部件的点击信号添加槽函数
        self.connect(okButton,SIGNAL("clicked()"),self,SLOT("accept()"))
        self.connect(cancelButton,SIGNAL("clicked()"),self,SLOT("reject()"))
        self.setWindowTitle(u"字体")
        
class MainDialog(QDialog):
    def __init__(self,parent=None):
        super(MainDialog,self).__init__(parent)
        #创建一个FontPropertiesDlg对象
        self.FontPropertiesDlg=None
        #定义一个字典
        self.format=dict(fontstyle="宋体",fontsize=1,fonteffect=False)
        #创建两个按钮部件
        FontButton1 = QPushButton(u"设置字体(模态)")
        FontButton2 = QPushButton(u"设置字体(非模态)")
        self.label = QLabel(u"默认选择")
        #创建网格部件
        layout = QGridLayout()
        layout.addWidget(FontButton1,0,0)
        layout.addWidget(FontButton2,0,1)
        layout.addWidget(self.label)
        self.setLayout(layout)
        #信号与槽函数，槽函数为自身定义的函数
        self.connect(FontButton1,SIGNAL("clicked()"),self.FontModalDialog)
        self.connect(FontButton2,SIGNAL("clicked()"),self.FontModalessDialog)
        self.setWindowTitle(u"模态与非模态对话框")
        #实现updataData函数
        self.updataData()
    def updataData(self):
        #为上面创建的label部件添加内容
        self.label.setText(u"选择字体：%s
字体大小：%d
是否特效：%s"
        %(self.format["fontstyle"],self.format["fontsize"],self.format["fonteffect"]))
    def FontModalDialog(self):
        #创建一个FontPropertiesDlg类对象并且赋值
        dialog = FontPropertiesDlg(self)
        if dialog.exec_():
           self.format["fontstyle"] =dialog.FontstyleComboBox.currentText()
           self.format["fontsize"] = dialog.FontSizeSpinBox.value()
           self.format["fonteffect"] = dialog.FontEffectCheckBox.isChecked()
           self.updataData()
           print(self.format)
    def FontModalessDialog(self):
        dialog = ModelessDialog.FontPropertiesDlg(self)
        self.connect(dialog,SIGNAL("changed"),self.updataData)
        dialog.show()
app = QApplication(sys.argv)
app.aboutToQuit.connect(app.deleteLater)
font= MainDialog()
font.show()
app.exec_()

   运行结果如下：

   只要我们点击应用，左边对话框立刻更新用户选择，我们也可以看到程序中两个最重要的地方：

1.self.emit(SIGNAL("changed"))

2.self.connect(dialog,SIGNAL("changed"),self.updataData)

   可以看到只要用户点击“应用”，后程序发现填出对话框内容发生改变，则立刻产生消息“changed”，主程序消息循环得到这个消息，立刻运行updataData，所以主窗口更新了内容。