Using a maya gradient control with PySide

pyside_gradient.py

from PySide import QtCore, QtGui
from shiboken import wrapInstance
import maya.OpenMayaUI as omui
from functools import partial
import pymel.core as pm


def maya_main_window():
    main_window_ptr = omui.MQtUtil.mainWindow()
    return wrapInstance(long(main_window_ptr), QtGui.QWidget)

         
class CreateCurveWidget(QtGui.QWidget):
 
    def __init__(self, parent=None):
 
        super(CreateCurveWidget, self).__init__(parent)
        self.setWindowFlags(QtCore.Qt.Tool)
                
        self.resize(300,100)
        self.setWindowTitle("Create curve")
        
        # layout
        self.main_layout = QtGui.QVBoxLayout()
        self.setLayout(self.main_layout)
        
        # Create a gradient control
        self.gc = pm.gradientControlNoAttr(h=100, changeCommand=self.key_changed)
        ptr = omui.MQtUtil.findControl(self.gc.name())
        self.gradient_control_widget = wrapInstance(long(ptr), QtGui.QWidget)
        self.main_layout.addWidget(self.gradient_control_widget)
        
        # value (y), pos (x), interpolation
        self.gc.setAsString('.1,.25,1, .9,.75,1')
        
        
        # button 
        button = QtGui.QPushButton('Button')
        button.clicked.connect(self.button_clicked)
        self.main_layout.addWidget(button)
        
        
        # button 
        doit_button = QtGui.QPushButton('doit')
        doit_button.clicked.connect(self.doit_button_clicked)
        self.main_layout.addWidget(doit_button)    
    
    def key_changed(self, val):
        print(val)
          
    def button_clicked(self):
        
        # set the interpolation of the current key        
        #pm.gradientControlNoAttr(self.gc, e=True, currentKeyInterpValue=3)
                
        # get the current key
        print(self.gc.getCurrentKey())
        print(self.gc.getAsString())
        
        
    
    def doit_button_clicked(self):
        
        num = 40
        inc = 1.0 / (num-1)
        spacing = 40

        
        for n in range(num):
            
            u = inc * n
            # Query for the value on the curve at a given position.
            val = pm.gradientControlNoAttr(self.gc, q=True, valueAtPoint=u)
            
            sp = pm.polySphere(r=.5)[0]
            sp.translate.set(u*spacing, val*spacing, 0)
            
        
        


def show():
    win = CreateCurveWidget(parent=maya_main_window())
    win.show()
    return win


try:
    win.close()
    
except NameError:
    pass
    
win = show()
win.move(100,150)