1 # A very simple Drag and Drop Example
   2 # provided with no warranty whatsoever for any purpose, ever
   3 
   4 # This code creates a Text Control from which Text can be dragged,
   5 # a Text Control to which Text can be dragged (from the first Text Control or from other applications),
   6 # and a Text Control to which Files can be dragged from outside this application.
   7 # While the later two windows can receive data from outside the application, the first window
   8 # does not appear to be able to provide text to other applications.  Please feel free to fix
   9 # this if you know how, as I think that would be more useful as an example.
  10 
  11 # It is designed to demonstrate the fundamentals of very simple drag-and-drop operations.
  12 
  13 """ This mini-ap is designed to demonstrate simple Drag and Drop functioning in wxPython """
  14 
  15 __author__ = 'David Woods, Wisconsin Center for Education Research <dwoods@wcer.wisc.edu>'
  16 
  17 # Import wxPython
  18 from wxPython.wx import *
  19 
  20 # Declare GUI Constants
  21 MENU_FILE_EXIT = 101
  22 DRAG_SOURCE    = 201
  23 
  24 # Define Text Drop Target class
  25 class TextDropTarget(wxTextDropTarget):
  26    """ This object implements Drop Target functionality for Text """
  27    def __init__(self, obj):
  28       """ Initialize the Drop Target, passing in the Object Reference to
  29           indicate what should receive the dropped text """
  30       # Initialize the wxTextDropTarget Object
  31       wxTextDropTarget.__init__(self)
  32       # Store the Object Reference for dropped text
  33       self.obj = obj
  34 
  35    def OnDropText(self, x, y, data):
  36       """ Implement Text Drop """
  37       # When text is dropped, write it into the object specified
  38       self.obj.WriteText(data + '\n\n')
  39 
  40 # Define File Drop Target class
  41 class FileDropTarget(wxFileDropTarget):
  42    """ This object implements Drop Target functionality for Files """
  43    def __init__(self, obj):
  44       """ Initialize the Drop Target, passing in the Object Reference to
  45           indicate what should receive the dropped files """
  46       # Initialize the wsFileDropTarget Object
  47       wxFileDropTarget.__init__(self)
  48       # Store the Object Reference for dropped files
  49       self.obj = obj
  50 
  51    def OnDropFiles(self, x, y, filenames):
  52       """ Implement File Drop """
  53       # For Demo purposes, this function appends a list of the files dropped at the end of the widget's text
  54       # Move Insertion Point to the end of the widget's text
  55       self.obj.SetInsertionPointEnd()
  56       # append a list of the file names dropped
  57       self.obj.WriteText("%d file(s) dropped at %d, %d:\n" % (len(filenames), x, y))
  58       for file in filenames:
  59          self.obj.WriteText(file + '\n')
  60       self.obj.WriteText('\n')
  61 
  62 
  63 
  64 class MainWindow(wxFrame):
  65    """ This window displays the GUI Widgets. """
  66    def __init__(self,parent,id,title):
  67        wxFrame.__init__(self,parent,-4, title, size = (800,600), style=wxDEFAULT_FRAME_STYLE|wxNO_FULL_REPAINT_ON_RESIZE)
  68        self.SetBackgroundColour(wxWHITE)
  69 
  70        # Menu Bar
  71        # Create a MenuBar
  72        menuBar = wxMenuBar()
  73        # Build a Menu Object to go into the Menu Bar
  74        menu1 = wxMenu()
  75        menu1.Append(MENU_FILE_EXIT, "E&xit", "Quit Application")
  76        # Place the Menu Item in the Menu Bar
  77        menuBar.Append(menu1, "&File")
  78        # Place the Menu Bar on the ap
  79        self.SetMenuBar(menuBar)
  80        #Define Events for the Menu Items
  81        EVT_MENU(self, MENU_FILE_EXIT, self.CloseWindow)
  82 
  83        # GUI Widgets
  84        # Define a Text Control from which Text can be dragged for dropping
  85        # Label the control
  86        wxStaticText(self, -1, "Text Drag Source  (left-click to select, right-click to drag)", (10, 1))
  87        # Create a Text Control
  88        self.text = wxTextCtrl(self, DRAG_SOURCE, "", pos=(10,15), size=(350,500), style = wxTE_MULTILINE|wxHSCROLL)
  89        # Make this control a Text Drop Target
  90        # Create a Text Drop Target object
  91        dt1 = TextDropTarget(self.text)
  92        # Link the Drop Target Object to the Text Control
  93        self.text.SetDropTarget(dt1)
  94        # Put some text in the control as a starting place to have something to copy
  95        for x in range(20):
  96           self.text.WriteText("This is line %d of some text to drag.\n" % x)
  97        # Define Right-Click as start of Drag
  98        EVT_RIGHT_DOWN(self.text, self.OnDragInit)
  99 
 100        # Define a Text Control to recieve Dropped Text
 101        # Label the control
 102        wxStaticText(self, -1, "Text Drop Target", (370, 1))
 103        # Create a read-only Text Control
 104        self.text2 = wxTextCtrl(self, -1, "", pos=(370,15), size=(410,235), style = wxTE_MULTILINE|wxHSCROLL|wxTE_READONLY)
 105        # Make this control a Text Drop Target
 106        # Create a Text Drop Target object
 107        dt2 = TextDropTarget(self.text2)
 108        # Link the Drop Target Object to the Text Control
 109        self.text2.SetDropTarget(dt2)
 110 
 111        # Define a Text Control to recieve Dropped Files
 112        # Label the control
 113        wxStaticText(self, -1, "File Drop Target (from off application only)", (370, 261))
 114        # Create a read-only Text Control
 115        self.text3 = wxTextCtrl(self, -1, "", pos=(370,275), size=(410,235), style = wxTE_MULTILINE|wxHSCROLL|wxTE_READONLY)
 116        # Make this control a File Drop Target
 117        # Create a File Drop Target object
 118        dt3 = FileDropTarget(self.text3)
 119        # Link the Drop Target Object to the Text Control
 120        self.text3.SetDropTarget(dt3)
 121 
 122        # Display the Window
 123        self.Show(true)
 124 
 125 
 126    def CloseWindow(self, event):
 127        """ Close the Window """
 128        self.Close()
 129 
 130    def OnDragInit(self, event):
 131        """ Begin a Drag Operation """
 132        # Create a Text Data Object, which holds the text that is to be dragged
 133        tdo = wxPyTextDataObject(self.text.GetStringSelection())
 134        # Create a Drop Source Object, which enables the Drag operation
 135        tds = wxDropSource(self.text)
 136        # Associate the Data to be dragged with the Drop Source Object
 137        tds.SetData(tdo)
 138        # Intiate the Drag Operation
 139        tds.DoDragDrop(True)
 140 
 141 
 142 
 143 class MyApp(wxApp):
 144    """ Define the Drag and Drop Example Application """
 145    def OnInit(self):
 146       """ Initialize the Application """
 147       # Declare the Main Application Window
 148       frame = MainWindow(None, -1, "Drag and Drop Example")
 149       # Show the Application as the top window
 150       self.SetTopWindow(frame)
 151       return true
 152       
 153 
 154 # Declare the Application and start the Main Loop
 155 app = MyApp(0)
 156 app.MainLoop()