Double pointer after Drag and Drop Discussion

This seems to be the top issue with Elementary OS with well over 1000 messages from over 250 people in the bug tracker on launchpad. I have been obsessing over this recently to try and track down where the issue is in the hope of fixing it properly.

The Symptoms:


The image is not mine but the symptoms are identical across systems.

On first drag and drop, the pointer graphic seems to half in height in the vertical plane, but because of the problem with the redraw size, rather than redrawing over the entire image, it only does the top half, leaving the bottom half of the dragged icon. I think the cursor on the right side is a 'wrapped' every second pixel line of the full pointer. It does show the green plus sign when dragging. While both pointers do seem the same size, if you mouse over a text box the right pointer seems smaller.

I have successfully recorded the screen but the issue does not show in the recording. I'm going to investigate where in the process the video gets recorded from to see if I can track things down a bit.

If you try one of the temporary fixes like superkey + L, The drag drop effect changes.

Dragging now stretches the dragged item out vertically with a pixel line in between each pixel. Here you can see the wrapping in the horizontal direction too. The 'gap' seems to be caused by each line being stretched an wrapped around to the left and pushing the next pixel down.

Possible causes:
1.Problem with SNA acceleration in xorg trusty/utopic Hardware Enablement Stack
2.Problem with Intel driver
3.Problem in GTK/gnome drag and drop
4.Problem with video card.

My theory is that somewhere along the line, some information is getting concatenated before it gets rendered to screen. It seems to affect intel graphics. I suspect that the drag and drop routines in xserver or gnome are not matching what is being fed back from the Intel driver for certain cards.

My laptop is a Dell 1545 from 2008 and has a Mobile 4 Series Chipset Integrated Graphics Controller. The OpenGL acceleration is software rather than hardware based.

Fixes:

Lock & Unlock screen

Press Superkey + L to lock the screen, then log back in with a jiggle of the mouse. Alternatively, logging in and out or restarting will get the pointer back but your first drag and drop will get your double pointer back.

Reset the pointer

Run "gsettings set org.gnome.settings-daemon.plugins.cursor active false &&
gsettings set org.gnome.settings-daemon.plugins.cursor active true" from the terminal.

Force UXA acceleration

This is the most permanent fix at the moment.

You can do this by running the following in the terminal

Code (Text):

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

This will create a new empty file. Open the file in an editor that allows you to make changes as super user. Scratch won’t do this but sublime for example will.

Add the following to the file and save entering your admin password.

Code (Text):

Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "uxa"
EndSection

This should get rid of the pointer glitch. Technically you have probably slowed your graphics processing down by a bit but there doesn’t seem to be a huge impact, at least on my machine.

Another thing to try is to add the following lines to your /etc/environment file. This in theory stops tearing but I think is more applicable to SNA acceleration which you have just disabled above. This for a different bug though so doesn't apply. I have been told there is also a performance penalty

Code (Text):

CLUTTER_PAINT=disable-clipped-redraws:disable-culling
CLUTTER_VBLANK=True

Ultimate fix

Roll back xorg

sudo apt-get remove linux-generic-lts-utopic xserver-xorg-lts-utopic libgl1-mesa-glx-lts-utopic libegl1-mesa-drivers-lts-utopic

sudo apt-get install xserver-xorg

sudo apt-get install linux-generic

(Warning: This seems not to be reversible. Reinstalling the Hardware Enablement Stack will Break Elementary)

This will roll back to the standard trusty xorg stack and remove the Utopic Harware Enablement Stack. Seemed to go smoothly but it is a dangerous operation if something goes wrong.

For me this seems to have resolved things and also some other software install problems caused by incompatibility with the Utopic HWE. I have lost edge scrolling on my Trackpad and the drag drop animation.



Non-Fixes:

Things that won't fix the issue:-

Edgers xorg drivers - same issue, don't bother if you don't need to for another reason.
Updating Utopic HWE - no change in behaviour

 

Thanks for doing this. Can you link or post a screen of what the problem looks like? I do have an issue on my laptop where dragging an icon sometimes cuts it in half and then its stuck to the mouse. just wondering if its the same one.

 

I've added someone else's image from the Elementary OS google+ page. My next step is to have a look at the source code from the Utopic Hardware Enablement Stack to see if there is anything in there that might be able to be tweaked to compensate for the issue. The issue affects other Ubuntu variants which use the Utopic HWE. I'm going to try Utopic vanilla and see if I have the same issue.

 

Yep i have the same issue on 2 of my laptops that both have intel graphics. Seems like a common problem.

 

yeap, i have the same problem

 

Thanks to Sadanandan Krishnan from https://www.facebook.com/groups/elementary.talk/ my problem is now fixed

install fix for double pointer:
sudo apt-get install xserver-xorg xserver-xorg-core

in case your mousepad doesn't work install this:
sudo apt-get install xserver-xorg-input-synaptics

then reboot

P.S. This will also fix your video tearing problem in elementary OS

 

Elementary 0.3.1 does resolve that issue:

Source: http://blog.elementary.io/post/128271333121/freya-031-is-here

sudo apt-get update && sudo apt-get upgrade