View source for User:Axiom

[[User:Axiom/KDE4]]

==Axiom's sandbox==

I am just putting some stuff here right now, because you have such nice color coding in your wiki.  Maybe I'll turn it into a tutorial if I figure out what I am doing.

==Dynamically Loading a .ui file==
I found this snippet [http://kib2.free.fr/pyqt4/pyqt4.html here] (french).
I don't know if this is the right way to do it, but it seems to work.
===loadui.py===
<code python>
import sys
from PyQt4 import QtGui, uic

app = QtGui.QApplication(sys.argv)
widget = uic.loadUi("demo.ui")
widget.show()

# La boucle principale
app.exec_()
</code>
Of course you will need to make a ui file called demo.ui for this to work.

==Connecting Buttons From Dynamically loaded .ui File==

This code really works.

===callMainWindow.py===
<code python>
import sys
from PyQt4 import QtGui
from PyQt4 import uic
from PyQt4 import QtCore

# the class has to have the same base class as your UI
class DemoImpl(QtGui.QMainWindow):
    def __init__(self, *args):
        QtGui.QMainWindow.__init__(self, *args)
	# just pass self
	uic.loadUi("mainWindow.ui", self)
    #this line makes sure that we are only looking for a string
    #if we want a bool as well we can add 	@QtCore.pyqtSignature("bool")
    @QtCore.pyqtSignature("")   
    def on_button1_clicked(self):
        print "You Clicked the button!"
    @QtCore.pyqtSignature("")
    def on_button2_clicked(self):
        print "You Clicked the button2!"	
	

app = QtGui.QApplication(sys.argv)
widget = DemoImpl()
widget.show()
app.exec_()


</code>

You will need [[User:Axiom/demo.ui|this file]] too.




==Getting user input into a variable==
Once you have it in a variable, you can throw the whole power of python at it.
I have tried to show how to do this in the simplest way possible.
''Note: This code shamelessly stolen from [http://www.apaku.de/linux/xpathevaluator/index.php xpathevaluator].  Lots of good pyqt4 sample code in there.  Also might be helpful if you want to evaluate an xpath.  But I'm not sure why you would want to do that.


===readinput.py===
<code python>
import sys
  #Load the widget
from PyQt4.QtGui import QWidget  #This is a widget, not a window, and that makes a difference
from PyQt4.uic import loadUiType  #We need this to dynamically load the .ui file we created in qt designer
from PyQt4.QtCore import pyqtSignature, Qt #Not sure what this signature thing is, but apparently it is great for buttons (signals/slots?)
import sys

(form, formbase) = loadUiType('readinput.ui') #this is the .ui file we want to show

class readInputWidget(QWidget, form):  #in this class, we load the window, and assign actions to the buttons
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        self.setAttribute(Qt.WA_DeleteOnClose) #This doesn't seem to change anything if you delete it, but may be usefull for housekeeping
        self.setupUi(self)
       
    @pyqtSignature("on_exitButton_clicked()")
    def on_exitButton_clicked(self):
        self.close()
    
    @pyqtSignature("on_evalButton_clicked()")
    def on_evalButton_clicked(self):
        print 'This should echo our text:'
        userinput =  self.inputBox1.text() #This is the fantastic line of code we were waiting for!  Make sure you have an input box by that name, and specify that it is text
        print userinput

def main():
  from PyQt4.QtGui import QApplication
  from PyQt4.QtCore import Qt
  app = QApplication(sys.argv)
  widget = readInputWidget()
  widget.show()
  return app.exec_()

if __name__ == "__main__":
  sys.exit(main())        
</code>
You will also need the [[User:Axiom/readinput.ui|ui file]] that goes along with that.




==Writing input to a file, and bringing it back==
This snippet does the same as above, except it saves whatever you type as config.txt, and the next time you run it, it loads the text back into the input field.  I got this code from [http://www.daniweb.com/code/snippet389.html here], and [http://www.devshed.com/c/a/Python/PyQT-Input-Widgets/ here].

===readinput.py===
<code python>

import sys
  #Load the widget
from PyQt4.QtGui import QWidget  #This is a widget, not a window, and that makes a difference
from PyQt4.uic import loadUiType  #We need this to dynamically load the .ui file we created in qt designer
from PyQt4.QtCore import pyqtSignature, Qt #Not sure what this signature thing is, but apparently it is great for buttons (signals/slots?)
import sys

(form, formbase) = loadUiType('readinput.ui') #this is the .ui file we want to show

class readInputWidget(QWidget, form):  #in this class, we load the window, and assign actions to the buttons
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        self.setAttribute(Qt.WA_DeleteOnClose) #This doesn't seem to change anything if you delete it, but may be usefull for housekeeping
        self.setupUi(self)

	# read back the entire test string as a string with read()
	filename = "config.txt"
	try:
	    fin = open(filename, "r")
	    str3 = fin.read()
	    fin.close()
	    print "Contents of file %s:" % filename
	    print str3
	    self.inputBox1.setText(str3) #This is the line where we set the input box to display whatever was written to the config file last time
	
	except IOError:
	    print "File %s does not exist!" % filename


    @pyqtSignature("on_exitButton_clicked()")
    def on_exitButton_clicked(self):
        self.close()
    
    @pyqtSignature("on_evalButton_clicked()")
    def on_evalButton_clicked(self):
        print 'This should echo our text:'
        userinput =  self.inputBox1.text() #This is the fantastic line of code we were waiting for!  Make sure you have an input box by that name, and specify that it is text
        print userinput
        # a look at file handling in Python
        # tested with Python24    vegaseat   29sep2005

	# set up a test string
	str1 =userinput
	
	# let's create our test file by writing the test string to the working folder/directory with write()
	# modifier "w" is for writing text, use "wb" for binary data like images
	fout = open("config.txt", "w")
	fout.write(str1)
	fout.close()








def main():
  from PyQt4.QtGui import QApplication
  from PyQt4.QtCore import Qt
  app = QApplication(sys.argv)
  widget = readInputWidget()
  widget.show()
  return app.exec_()

if __name__ == "__main__":
  sys.exit(main())        

  
</code>
This uses the exact same [[User:Axiom/readinput.ui|ui file]] as above.