Houdini 18.5 Examples Python panel examples

Drag and Drop

How to implement drag and drop functionality in a Python Panel.

Example

This example demonstrates specifically how to enable dragging items from other parts in Houdini and dropping them into the Python Panel interface.

<?xml version="1.0" encoding="UTF-8"?>
<pythonPanelDocument>
  <!-- This file contains definitions of Python interfaces and the
 interfaces menu.  It should not be hand-edited when it is being
 used by the application.  Note, that two definitions of the
 same interface or of the interfaces menu are not allowed
 in a single file. -->
  <interface name="DragDropExample" label="Drag and Drop Example" icon="SOP_torus">
    <script><![CDATA[from hutil.Qt import QtCore, QtGui, QtWidgets
class DDTest(QtWidgets.QFrame):
    def __init__(self, parent=None):
        super(DDTest, self).__init__(parent)

        self.myList = QtWidgets.QListView(self)
        self.myModel = QtGui.QStandardItemModel(self.myList)
        self.myList.setModel(self.myModel)

        self.mySlider = QtWidgets.QSlider(QtCore.Qt.Horizontal, self)
        self.mySlider.setRange(1, 100)
        self.mySlider.setSliderPosition(20)
        self.mySlider.valueChanged.connect(self.sliderChange)

        list_label = QtWidgets.QLabel("Selected nodes (drag and drop to add):")
        slider_label = QtWidgets.QLabel("Uniform scale:")

        horiz_layout = QtWidgets.QHBoxLayout()
        horiz_layout.addWidget(slider_label)
        horiz_layout.addWidget(self.mySlider)

        layout = QtWidgets.QVBoxLayout()
        layout.addWidget(list_label)
        layout.addWidget(self.myList)
        layout.addLayout(horiz_layout)

        self.setLayout(layout)
        self.setAcceptDrops(True)

    def dragEnterEvent(self, event):
        event.acceptProposedAction()

    def dropEvent(self, event):
        str = event.mimeData().text()
        index = str.find(",")

        while index > 0:
            item = QtGui.QStandardItem()
            item.setText(str[0:index])
            item.setCheckable(True)
            item.setCheckState(QtCore.Qt.Checked)
            self.myModel.appendRow(item)

            str = str[index+1:]
            index = str.find(",")

        item = QtGui.QStandardItem()
        item.setText(str)
        item.setCheckable(True)
        item.setCheckState(QtCore.Qt.Checked)
        self.myModel.appendRow(item)

        event.acceptProposedAction()

    def sliderChange(self, value):
        scale = float(value) / 20
        for i in range(0, self.myModel.rowCount()):
            item = self.myModel.item(i)
            if item.checkState() is QtCore.Qt.Checked:
                node = hou.node(item.text())
                if node is not None:
                    node.setParms({"scale": scale})

def onCreateInterface():
    return DDTest()

]]></script>
  </interface>
</pythonPanelDocument>

Python panel examples

  • Custom Graphics

    Custom OpenGL drawing in a Python Panel.

  • Drag and Drop

    How to implement drag and drop functionality in a Python Panel.

  • Linked parameters

    How to link PySide parameter widgets (i.e. text fields and sliders) to Houdini node parameters and vice versa.

  • Node path

    How to listen for changes to the current node path.

  • Qt designer

    How to load user interface layout from a Qt Designer file.

  • Qt events

    How Python Panels can listen to Qt events.

  • Viewport color editor

    A PySide interface for editing viewport colors.