Hi @blastframe,
so, this thread has not been forgotten by me :) Yesterday I finally got around to taking a closer look on that problem. I am still not quite sure yet if this a bug or not (I have reached out to the devs for now). There are two problems here at play:
GeDialog.GetItemDim(ID_SOME_SCROLLGROUP) takes the scroll bars of a scroll group into account, GeDialog.SetVisibleArea(ID_SOME_SCROLLGROUP) does not.GeDialog.SetVisibleArea(ID_SOME_SCROLLGROUP) is behaving differently than advertised in the documentation and will do nothing for frames larger than the scroll group it is being called on.
I did provide a working example for your problem at the end which wiggles itself around these problems. I also reached out to the devs if we want to consider this a bug or not. If we don't, we will update the documentation of at least SetVisibleArea to make this need for being precise about the passed frame more clear. For now the little work around should work fine in your case, it is only that the code might look a bit cryptic.
Cheers,
Ferdinand
"""Example for centering a scroll group.
I have added the method ExampleDialog._centerAlignScrollGroup() and two
lines calling that method. For details read _centerAlignScrollGroup().
As discussed in:
plugincafe.maxon.net/topic/13205
"""
import c4d
import random
from c4d import gui
GADGET_ID_GEUSERAREA = 10000
SCROLL_ID = 10001
SLIDER_ID = 10002
class ExampleGeUserArea(c4d.gui.GeUserArea):
width = 400
height = 500
bmp_cache = None
def GetBitmap(self):
bmp = c4d.bitmaps.BaseBitmap()
bmp.Init(self.width, self.height)
for h in range(self.height):
for w in range(self.width):
r = random.randint(0, 70)
bmp.SetPixel(w, h, r, r, r)
return bmp
def DrawMsg(self, x1, y1, x2, y2, msg):
# print("DrawMsg: x1: %d, y1: %d, x2: %d, y2: %s" % (x1, y1, x2, y2))
self.OffScreenOn()
self.SetClippingRegion(x1, y1, x2, y2)
self.DrawSetPen(c4d.Vector(1, 0, 0))
self.DrawRectangle(x1, y1, x2, y2)
if self.bmp_cache == None:
self.bmp_cache = self.GetBitmap()
self.DrawBitmap(self.bmp_cache, x1, y1, x2, y2, 0, 0,
w=self.bmp_cache.GetBw(),
h=self.bmp_cache.GetBh(),
mode=c4d.BMP_NORMAL)
def Message(self, msg, result):
# Catch the draw message to cancel it (return True)
# and call ourself the DrawMsg with the dimension we expect
if msg.GetId() == c4d.BFM_DRAW:
self.DrawMsg(0, 0, self.width, self.height, c4d.BaseContainer())
return True
return c4d.gui.GeUserArea.Message(self, msg, result)
def GetMinSize(self):
# print("GetMinSize: self.width: %d, self.height: %d" %
# (self.width, self.height))
return self.width, self.height
class ExampleDialog(c4d.gui.GeDialog):
geUserArea = ExampleGeUserArea()
def _centerAlignScrollGroup(self):
"""Centers the scroll group.
There are two problems/bugs here at play which we have to deal with:
1. GeDialog.GetItemDim(SCROLL_ID) takes the scroll bars of a
scroll group into account, GeDialog.SetVisibleArea(SCROLL_ID)
does not.
2. GeDialog.SetVisibleArea(SCROLL_ID) is behaving differently
than advertised in the documentation frames and does nothing
for frames larger than the scroll group it is being called upon.
My workaround here simply computes the deltas for the unaccounted
scrollbars.
"""
# The width and height of the scroll group and user area gadgets.
_, _, sgw, sgh = self.GetItemDim(SCROLL_ID).values()
_, _, uaw, uah = self.GetItemDim(GADGET_ID_GEUSERAREA).values()
# These are the magic numbers we have to apply for now after querying
# a scroll group for its dimensions. These are the scroll bars which
# are being accounted for in the total values. Which get in the way
# when we do not deal with them, due to Get/SetVisibleArea not taking
# them into account.
# sgw -= 16
# sgh -= 15
# To take the safe route, i.e., to make this OS and somewhat version
# agnostic, we should compute these deltas ourselves.
sax1, say1, sax2, say2 = self.GetVisibleArea(SCROLL_ID).values()
dx, dy = sgw - (sax2 - sax1), sgh - (say2 - say1) # 16, 15
sgw -= dx
sgh -= dy
# When we do not do this, .SetVisibleArea() will fail due not working
# as advertised. It cannot handle frames larger than the gadget and
# will carry out something different than instructed with such a too
# large frame (which in most cases will seem as if it did not do
# anything).
# The top left corner of the centered scroll bar frame.
x, y = int((uaw - sgw) * .5), int((uah - sgh) * .5)
self.SetVisibleArea(SCROLL_ID, x, y, x + sgw, y + sgh)
def DrawUA(self, scale):
# print("DrawUserArea", int(400*scale), int(500*scale))
self.geUserArea.width = int(400*scale)
self.geUserArea.height = int(500*scale)
self.LayoutChanged(SCROLL_ID)
def CreateLayout(self):
self.SetTitle("GeUserArea")
if self.ScrollGroupBegin(SCROLL_ID, c4d.BFH_SCALEFIT | c4d.BFV_SCALEFIT, c4d.SCROLLGROUP_HORIZ | c4d.SCROLLGROUP_VERT):
self.AddUserArea(GADGET_ID_GEUSERAREA, c4d.BFH_CENTER | c4d.BFH_SCALE |
c4d.BFV_CENTER | c4d.BFV_SCALE, initw=gui.SizePix(400), inith=gui.SizePix(500))
self.AttachUserArea(self.geUserArea, GADGET_ID_GEUSERAREA)
self.GroupEnd()
self.AddEditSlider(SLIDER_ID, c4d.BFH_SCALEFIT | c4d.BFV_CENTER)
return True
def InitValues(self):
self.SetFloat(SLIDER_ID, 1.0, min=0.01, max=2, step=0.01)
# Center the scroll group.
self._centerAlignScrollGroup()
return True
def Command(self, id, msg):
if id == SLIDER_ID:
self.DrawUA(msg[c4d.BFM_ACTION_VALUE])
# Center the scroll group.
self._centerAlignScrollGroup()
return True
def main():
global dlg
dlg = ExampleDialog()
dlg.Open(c4d.DLG_TYPE_ASYNC, pluginid=1234567, defaultw=300, defaulth=300)
if __name__ == "__main__":
main()
