Bug 992 – Part of scrollbar not draggable

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Bug 992 - Part of scrollbar not draggable

Summary:

Part of scrollbar not draggable

Status:	CLOSED INVALID

Product:	PySide
Classification:	Unclassified
Component:	QtGui
Version:	1.0.6
Platform:	PC MS Windows XP/Vista/7

Importance:	P5 minor
Assigned To:	renato filho

URL:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2011-08-29 16:53 EEST by Robbert
Modified:	2011-10-25 15:14 EEST (History)
CC List:	9 users (show)

See Also:

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Description Robbert 2011-08-29 16:53:12 EEST

Python 2.6.4 (32bit, winxp)

The scrollbar on some widgets doesn't 'grip' on the whole scrollbar (only on
the right side). When your mouse doesn't 'grip', it is actually dragging inside
the widget. This effect is bigger (less area to drag) when the widget is larger
(horizontally).

I've seen this effect on QTextEdit and QTreeWidget, but not on QWebkit.

steps to reproduce (code below):
- Fill with text so a scrollbar is visable
- Try to scroll by dragging the scrollbar (on the left side of the scrollbar)

- make the window bigger (horizontally)
- Try to scroll by dragging the scrollbar (on the left side of the scrollbar)
    Note: when your note dragging the scrollbar, you are selecting text


<code>
import sys
from PySide.QtGui import *
app = QApplication(sys.argv)

text = QTextEdit()
text.show()

sys.exit(app.exec_())
</code>

Comment 1 Hugo Parente Lima 2011-08-29 17:00:54 EEST

Works for me on Linux, it may be a Qt bug on Windows.

Comment 2 Robbert 2011-08-29 17:01:41 EEST

I now notice it works for met too,
I think I oversimplified the example..

Comment 3 Robbert 2011-08-29 18:16:19 EEST

It is working, but with my regular mouse.
When using a Wacom Tablet (pen) (ET 0405a, graphire2) this bug manifests.
On another computer (winXP, python 2.6.4, PySide 1.0.?) and a wacom bamboo
(Mte450a) it works

The following results are reproducible by me using 3 programs (including the
demo code from the first post)

Logitech Mouse                     : works
Wacom Bamboo    (own driver      ) : works
Wacom Graphire2 (driver 6.1.4-3  ) : bug
Wacom Graphire  (driver 6.1.4-3  ) : works
(I tried all pen combination, but this doesn't change anything)
Wacom Bamboo    (Other PC        ) : works

Note: The Graphire and Graphire2 use the same driver
Updating the driver of the Graphire to 6.1.6-5 did not help

Other programs (and QWebkit) do not suffer from this problem

Comment 4 Hugo Parente Lima 2011-08-29 20:10:09 EEST

This may be a driver problem with Wacom Graphire2 or a Qt bug on tablet input
devices, but certain not a PySide bug, I can't reproduce it here because we
don't have the hardware, but I'm almost sure that if you rewrite your code in
C++ the bug will be there with the very same combination of Wacom Graphire2 and
driver version 6.1.4-3. Could you do it?

Comment 5 Robbert 2011-09-27 22:47:05 EEST

Python 2.6.4 (32bit, winxp), screen 1680x1050, Graphire-Driver: 6.1.6-5 

Let me reformulate the bug:
Sometimes a wrong position of the mouse is given to the application, when using
a graphire2.
This seems to be a scaling issue.

I searched for a similar qt bug report, but without result.

The following test results are made with the c Qt-Demos 
(qt-win-opensource-4.7.3-vs2008.exe). The bug still manifests, we can therefore
conclude that this is not a PySide bug.

Demo      : webkit -> Html-previewer
Graphire1 : Works
Graphire2 : Works
Test-Case : Create a large Html page (make it scrollable), try to scroll by
grabbing the scrollbar at left side of the scrollbar
Result    : It scrolls :P

Demo      : widgets -> tablet
Graphire1 : Works
Graphire2 : Doesn't work
Test-Case : Put the application in full-screen. Draw a line from top-left, to
bottom right.
Result    :
In both cases the pressure sensor works (e.g. thinner and thicker lines).
But when using the graphire2 the line is drawn at the wrong position on the
window (Not at the position of the cursor).
This effect bigger when the mouse is approaching the bottom-right corner of the
screen (not window) (dot and mouse are further apart). 
Note that it is inpossible to draw something in the bottom-right corner, since
the mouse-cursor is still blocked by windows.
I measured the offset when the mouse is at the bottom-right corner of the
screen. It's about 20 pixels horizontally, 10 pixels vertically.

Demo      : itemview -> Basic Sort/Filter
Graphire1 : Works
Graphire2 : Doesn't work
Test-Case :   Place the window in the bottom-right corner, try to scroll by
grabbing the scrollbar at left side of the scroll bar. Place the window in the
top-left corner, and try again.
Result    : 
When using the graphire2, instead of grabbing the scrollbar, you are
drag/selecting inside the list.
This effect is more noticable when the window is in the bottom right corner
(e.g. you can grab the scrollbar more to the right while still maintaining this
effect).

Comment 6 Hugo Parente Lima 2011-10-18 02:34:15 EEST

If it's reproducible in C++ it's definitely not a PySide bug, thanks for the
further investigation, I recommend you to file a bug report on Qt bug tracker.

Regards.

Comment 7 Hugo Parente Lima 2011-10-20 22:53:50 EEST

Released on 1.0.8.

Comment 8 Robbert 2011-10-25 15:14:15 EEST

Bug reported at QT: https://bugreports.qt.nokia.com/browse/QTBUG-22277