How To drag an image object in WxPython GUI? - python-3.x

Question

In below code, I have image shaped transparent window and a image inside of it, I would like to move the image(screw photo)by mouse. I wrote a bind function for that screw image but it does not move? what might be the problem?
As it can be seen I added images and bind functions. Is there a missing logic?
import wx
from wx import *
import wx.lib.statbmp as sb
from io import StringIO
# Create a .png image with something drawn on a white background
# and put the path to it here.
IMAGE_PATH = './wood.png'
class ShapedFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, -1, "Shaped Window",
style = wx.FRAME_SHAPED | wx.SIMPLE_BORDER | wx.STAY_ON_TOP)
self.hasShape = False
self.delta = wx.Point(0,0)
# Load the image
image = wx.Image(IMAGE_PATH, wx.BITMAP_TYPE_PNG)
image.SetMaskColour(255,255,255)
image.SetMask(True)
self.bmp = wx.Bitmap(image)
self.SetClientSize((self.bmp.GetWidth(), self.bmp.GetHeight()))
dc = wx.ClientDC(self)
dc.DrawBitmap(self.bmp, 0,0, True)
self.SetWindowShape()
self.Bind(wx.EVT_RIGHT_UP, self.OnExit)
self.Bind(wx.EVT_PAINT, self.OnPaint)
self.Bind(wx.EVT_WINDOW_CREATE, self.SetWindowShape)
panel = MyPanel(parent=self)
def SetWindowShape(self, evt=None):
r = wx.Region(self.bmp)
self.hasShape = self.SetShape(r)
def OnDoubleClick(self, evt):
if self.hasShape:
self.SetShape(wx.Region())
self.hasShape = False
else:
self.SetWindowShape()
def OnPaint(self, evt):
dc = wx.PaintDC(self)
dc.DrawBitmap(self.bmp, 0,0, True)
def OnExit(self, evt):
self.Close()
def OnLeftDown(self, evt):
self.CaptureMouse()
pos = self.ClientToScreen(evt.GetPosition())
origin = self.GetPosition()
self.delta = wx.Point(pos.x - origin.x, pos.y - origin.y)
def OnMouseMove(self, evt):
if evt.Dragging() and evt.LeftIsDown():
pos = self.ClientToScreen(evt.GetPosition())
newPos = (pos.x - self.delta.x, pos.y - self.delta.y)
self.Move(newPos)
def OnLeftUp(self, evt):
if self.HasCapture():
self.ReleaseMouse()
class MyPanel(wx.Panel):
# A panel is a window on which controls are placed. (e.g. buttons and text boxes)
# wx.Panel class is usually put inside a wxFrame object. This class is also inherited from wxWindow class.
def __init__(self,parent):
super().__init__(parent=parent)
MyImage(self)
class MyImage(wx.StaticBitmap):
def __init__(self,parent):
super().__init__(parent=parent)
jpg1 = wx.Image('./Images/screwsmall.png', wx.BITMAP_TYPE_ANY).ConvertToBitmap()
# bitmap upper left corner is in the position tuple (x, y) = (5, 5)
self.myImage = wx.StaticBitmap(parent, -1, jpg1, (10 + jpg1.GetWidth(), 5), (jpg1.GetWidth(), jpg1.GetHeight()))
self.myImage.Bind(wx.EVT_MOTION, self.OnMouseMove)
self.myImage.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)
def OnMouseMove(self, evt):
if evt.Dragging() and evt.LeftIsDown():
pos = self.ClientToScreen(evt.GetPosition())
newPos = (pos.x - self.delta.x, pos.y - self.delta.y)
self.Move(newPos)
def OnLeftUp(self, evt):
if self.HasCapture():
self.ReleaseMouse()
def OnLeftDown(self, evt):
self.CaptureMouse()
pos = self.ClientToScreen(evt.GetPosition())
origin = self.GetPosition()
self.delta = wx.Point(pos.x - origin.x, pos.y - origin.y)
if __name__ == '__main__':
app = wx.App()
ShapedFrame().Show()
app.MainLoop()
Visual output of my code you can use different shapes in local directory. To install wxpython for 3.x you can check this link https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ubuntu-16.04/ download your version for ubuntu and use pip install command.

Answer 1

I am going to put my answer. As it can be seen in the #RolfofSaxony comment, there is a drag image demo inside the WXPYTHON tar file. In that DragImage.py file there are two different classes do the dragging job. I modified those functions and wrote my own two class. You can use these classes in your code as a component. My code is working and tested.
class DragShape:
def __init__(self, bmp):
self.bmp = bmp
self.pos = (0,0)
self.shown = True
self.text = None
self.fullscreen = False
def HitTest(self, pt):
rect = self.GetRect()
return rect.Contains(pt)
def GetRect(self):
return wx.Rect(self.pos[0], self.pos[1],
self.bmp.GetWidth(), self.bmp.GetHeight())
def Draw(self, dc, op = wx.COPY):
if self.bmp.IsOk():
memDC = wx.MemoryDC()
memDC.SelectObject(self.bmp)
dc.Blit(self.pos[0], self.pos[1],
self.bmp.GetWidth(), self.bmp.GetHeight(),
memDC, 0, 0, op, True)
return True
else:
return False
#----------------------------------------------------------------------
class DragCanvas(wx.ScrolledWindow):
def __init__(self, parent, ID):
wx.ScrolledWindow.__init__(self, parent, ID)
self.shapes = []
self.dragImage = None
self.dragShape = None
self.hiliteShape = None
self.SetCursor(wx.Cursor(wx.CURSOR_ARROW))
bmp = images.TheKid.GetBitmap()
shape = DragShape(bmp)
shape.pos = (200, 5)
self.shapes.append(shape)
self.Bind(wx.EVT_PAINT, self.OnPaint)
self.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)
self.Bind(wx.EVT_LEFT_UP, self.OnLeftUp)
self.Bind(wx.EVT_MOTION, self.OnMotion)
self.Bind(wx.EVT_LEAVE_WINDOW, self.OnLeaveWindow)
# We're not doing anything here, but you might have reason to.
# for example, if you were dragging something, you might elect to
# 'drop it' when the cursor left the window.
def OnLeaveWindow(self, evt):
pass
# Go through our list of shapes and draw them in whatever place they are.
def DrawShapes(self, dc):
for shape in self.shapes:
if shape.shown:
shape.Draw(dc)
# This is actually a sophisticated 'hit test', but in this
# case we're also determining which shape, if any, was 'hit'.
def FindShape(self, pt):
for shape in self.shapes:
if shape.HitTest(pt):
return shape
return None
# Fired whenever a paint event occurs
def OnPaint(self, evt):
dc = wx.PaintDC(self)
self.PrepareDC(dc)
self.DrawShapes(dc)
# print('OnPaint')
# Left mouse button is down.
def OnLeftDown(self, evt):
# Did the mouse go down on one of our shapes?
shape = self.FindShape(evt.GetPosition())
# If a shape was 'hit', then set that as the shape we're going to
# drag around. Get our start position. Dragging has not yet started.
# That will happen once the mouse moves, OR the mouse is released.
if shape:
self.dragShape = shape
self.dragStartPos = evt.GetPosition()
# Left mouse button up.
def OnLeftUp(self, evt):
if not self.dragImage or not self.dragShape:
self.dragImage = None
self.dragShape = None
return
# Hide the image, end dragging, and nuke out the drag image.
self.dragImage.Hide()
self.dragImage.EndDrag()
self.dragImage = None
if self.hiliteShape:
self.RefreshRect(self.hiliteShape.GetRect())
self.hiliteShape = None
# reposition and draw the shape
# Note by jmg 11/28/03
# Here's the original:
#
# self.dragShape.pos = self.dragShape.pos + evt.GetPosition() - self.dragStartPos
#
# So if there are any problems associated with this, use that as
# a starting place in your investigation. I've tried to simulate the
# wx.Point __add__ method here -- it won't work for tuples as we
# have now from the various methods
#
# There must be a better way to do this :-)
#
self.dragShape.pos = (
self.dragShape.pos[0] + evt.GetPosition()[0] - self.dragStartPos[0],
self.dragShape.pos[1] + evt.GetPosition()[1] - self.dragStartPos[1]
)
self.dragShape.shown = True
self.RefreshRect(self.dragShape.GetRect())
self.dragShape = None
# The mouse is moving
def OnMotion(self, evt):
# Ignore mouse movement if we're not dragging.
if not self.dragShape or not evt.Dragging() or not evt.LeftIsDown():
return
# if we have a shape, but haven't started dragging yet
if self.dragShape and not self.dragImage:
# only start the drag after having moved a couple pixels
tolerance = 2
pt = evt.GetPosition()
dx = abs(pt.x - self.dragStartPos.x)
dy = abs(pt.y - self.dragStartPos.y)
if dx <= tolerance and dy <= tolerance:
return
# refresh the area of the window where the shape was so it
# will get erased.
self.dragShape.shown = False
self.RefreshRect(self.dragShape.GetRect(), True)
self.Update()
item = self.dragShape.text if self.dragShape.text else self.dragShape.bmp
self.dragImage = wx.DragImage(item,
wx.Cursor(wx.CURSOR_HAND))
hotspot = self.dragStartPos - self.dragShape.pos
self.dragImage.BeginDrag(hotspot, self, self.dragShape.fullscreen)
self.dragImage.Move(pt)
self.dragImage.Show()
# if we have shape and image then move it, posibly highlighting another shape.
elif self.dragShape and self.dragImage:
onShape = self.FindShape(evt.GetPosition())
unhiliteOld = False
hiliteNew = False
# figure out what to hilite and what to unhilite
if self.hiliteShape:
if onShape is None or self.hiliteShape is not onShape:
unhiliteOld = True
if onShape and onShape is not self.hiliteShape and onShape.shown:
hiliteNew = True
# if needed, hide the drag image so we can update the window
if unhiliteOld or hiliteNew:
self.dragImage.Hide()
if unhiliteOld:
dc = wx.ClientDC(self)
self.hiliteShape.Draw(dc)
self.hiliteShape = None
if hiliteNew:
dc = wx.ClientDC(self)
self.hiliteShape = onShape
self.hiliteShape.Draw(dc, wx.INVERT)
# now move it and show it again if needed
self.dragImage.Move(evt.GetPosition())
if unhiliteOld or hiliteNew:
self.dragImage.Show()