Click anywhere on/in Frame to drag/move it, how to minimize flicker/choppiness (or how to draw Frame outline until MouseUp?)

wxPython Users
1

I’d like my busy/progress modal to be draggable, not just via the title bar, but by clicking anywhere on the Frame. Just so users can quickly get it out of the way if they want, since it has no interaction ability. It has a few widgets in it:
Panel

BoxSizer

AnimationCtrl

Gauge

Currently I’ve got it working by Bind[ing] self (the Frame) the Panel and each widget with EVT_LEFT_DOWN and EVT_LEFT_UP, and also EVT_IDLE (but just on self, the Frame).

My problem is that it looks a bit ‘choppy’. Windows gets around this by only displaying the Frame’s border while dragging. I’m not sure how I’d go about this… I could imagine doing something in OnPaint, manually drawing a square and setting it’s position until MouseUp when I move the actual Frame to the final position. But I feel like that might not work since the drawn item would be outside the Frame.

Any ideas? Here’s the relevant Frame init code:

class (wx.Frame)

def __init__:

	self.Show()

	self.MouseLeftIsDown = False

            #bind all the widgets

	self.Bind(wx.EVT_LEFT_UP, self.MouseUp)

	self.TestPanel.Bind(wx.EVT_LEFT_DOWN, self.MouseDown)

	self.TestPanel.Bind(wx.EVT_LEFT_UP, self.MouseUp)

	self.progressGauge.Bind(wx.EVT_LEFT_DOWN, self.MouseDown)

	self.progressGauge.Bind(wx.EVT_LEFT_UP, self.MouseUp)

	self.beachBall.Bind(wx.EVT_LEFT_DOWN, self.MouseDown)

	self.beachBall.Bind(wx.EVT_LEFT_UP, self.MouseUp)

	self.Bind(wx.EVT_IDLE, self.OnIdle)

def MouseDown(self, event):

	self.posInFrame = event.GetPosition()

	self.MouseLeftIsDown = True

def MouseUp(self, event):

	self.MouseLeftIsDown = False

def OnIdle(self, event):

	if self.MouseLeftIsDown and wx.GetMouseState().LeftIsDown():

		topLeftInScreen = wx.GetMousePosition()

		topLeftInScreen = topLeftInScreen - self.posInFrame

		self.SetPosition(topLeftInScreen)
2

I slightly improved the mouse position offset calculation… still not drawing just the border though:

def MouseDown(self, event):

	#figure out how thick the Title and Frame border are

	#subtract the panel size from the overall frame

	sizeDiff = self.GetSize() -  self.GetClientSize()

	#these get the system specific thicknesses, 

	#since this works I believe Windows is showing a 3D border next to the normal border

	borderAdjust = wx.SystemSettings.GetMetric(wx.SYS_BORDER_Y) + wx.SystemSettings.GetMetric(wx.SYS_EDGE_Y)

	#the left and right side border is identical, so we can divide by 2

	#since the upper border isn't the same as the bottom, adjust only for the top

	sizeDiff = wx.Point(sizeDiff[0]/2, sizeDiff[1]-borderAdjust)

	#use the global mouse position, since event.GetPosition() can come from a widget,

	# and this will give non-Panel referenced coordinates

	self.posInFrame = self.ScreenToClient(wx.GetMousePosition()) + sizeDiff

	self.MouseLeftIsDown = True