Created attachment 101659 [details]
demo showing the bug

Which window/widget style are you using? I cannot properly recognize in the video.

It looks a lot like the widget style is triggering a window move. This is something that breeze and oxygen do. The explanation for openbox not triggering it would be that this window manager doesn't support the respective hint.

If that's the case we need to bounce the bug back to krita as they need to properly mark the widget as interactive.

I am using default breeze theme , I have windows can cover option enabled in the pannel and moved its position to the top. I have enabled no border on the window , moved the close maximise and minise buttons to left and kept the buttons to small in the settings apart from this I haven't modified anything that is in default breeze theme. 

 Due to some technical reasons krita uses fusion theme hence it looks different.

The default style for Krita is Fusion, and it's in fact really hard to use Breeze or Oxygen because both of those styles are too broken to be used, at least in the versions currently shipped by distributions. So, Krita on startup forces Fusion, which doesn't have that move-by-clicking-on-empty-space-drag feature. I can try to explicitly set the canvas widget to interactive: what is the flag for that?

to add to the information. I have enabled move windows by using title bar only option , and kept the trigger key to Meta(windows) + drag .

Are you pressing the Alt key anywhen during interacting with the window?

Could you please provide the output of:
qdbus org.kde.KWin /KWin supportInformation

Also could you please switch to the default breeze cursor theme and rerecord the video? The "drag" cursor icon is confusing to me as KWin doesn't use it. I need to see the which cursor icon is used during the drag to evaluate whether that's actually KWin moving the window.

(In reply to Boudewijn Rempt from comment #5)
> The default style for Krita is Fusion, and it's in fact really hard to use
> Breeze or Oxygen because both of those styles are too broken to be used, at
> least in the versions currently shipped by distributions
@boud: can we please get this fixed? Having a consistent look and feel is very important for us and Krita is a very important application for our ecosystem. Let's try to work together and prioritize any issues in breeze and oxygen and also get all distributions to ship the fixes. We can do that!

"Are you pressing the Alt key anywhen during interacting with the window?"
 No I am just left clicking on the canvas with pentip (wacom) .( Although I can reproduce this with mouse too .)

I have re assigned Alt to meta key for moving windows

i will share the other information in an hour or so. 

thank you very much for the response.

Created attachment 101663 [details]
demo showing the bug with breeze theme

re recorded demo shaowing the bug with breeze theme in krita

output of qdbus org.kde.KWin /KWin supportInformation as reqested

KWin Support Information:
The following information should be used when requesting support on e.g. http://forum.kde.org.
It provides information about the currently running instance, which options are used,
what OpenGL driver and which effects are running.
Please post the information provided underneath this introductory text to a paste bin service
like http://paste.kde.org instead of pasting into support threads.

==========================

Version
=======
KWin version: 5.8.2
Qt Version: 5.7.0
Qt compile version: 5.7.0
XCB compile version: 1.12

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_INPUT: yes
HAVE_DRM: yes
HAVE_GBM: yes
HAVE_X11_XCB: yes
HAVE_EPOXY_GLX: yes
HAVE_WAYLAND_EGL: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 11804000
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb
XFIXES: yes; Version: 0x50
SYNC: yes; Version: 0x31
GLX: yes; Version: 0x0

Decoration
==========
Plugin: org.kde.breeze
Theme: 
Blur: 0
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 5, 3, 4
decorationButtonsRight: 9
borderSize: 0
gridUnit: 10
font: Noto Sans,10,-1,5,50,0,0,0,0,0
smallSpacing: 2
largeSpacing: 10

Options
=======
focusPolicy: 0
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: true
focusStealingPreventionLevel: 1
legacyFullscreenSupport: false
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 1
glSmoothScale: 2
colorCorrected: false
xrenderSmoothScale: false
maxFpsInterval: 16666666
refreshRate: 0
vBlankTime: 6000000
glStrictBinding: false
glStrictBindingFollowsDriver: true
glCoreProfile: false
glPreferBufferSwap: 0
glPlatformInterface: 1
windowsBlockCompositing: true

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Multi-Head: no
Active screen follows mouse:  no
Number of Screens: 1

Screen 0:
---------
Name: DVI-D-0
Geometry: 0,0,1920x1080
Refresh Rate: 60


Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GTX 750 Ti/PCIe/SSE2
OpenGL version string: 4.5.0 NVIDIA 370.28
OpenGL platform interface: GLX
OpenGL shading language version string: 4.50 NVIDIA
Driver: NVIDIA
Driver version: 370.28
GPU class: Unknown
OpenGL version: 4.5
GLSL version: 4.50
X server version: 1.18.4
Linux kernel version: 4.8.2
Direct rendering: Requires strict binding: no
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used
Painting blocks for vertical retrace:  no

Loaded Effects:
---------------
zoom
slidingpopups
kwin4_effect_login
slide
screenshot
minimizeanimation
desktopgrid
kwin4_effect_fade
kwin4_effect_maximize
kwin4_effect_morphingpopups
presentwindows
highlightwindow
blur
contrast
startupfeedback
kscreen

Currently Active Effects:
-------------------------
blur
contrast

Effect Settings:
----------------
zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: false
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

slidingpopups:
fadeInTime: 150
fadeOutTime: 250

kwin4_effect_login:

slide:

screenshot:

minimizeanimation:

desktopgrid:
zoomDuration: 300
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: true

kwin4_effect_fade:

kwin4_effect_maximize:

kwin4_effect_morphingpopups:

presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: false
accuracy: 20
fillGaps: true
fadeDuration: 150
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0

highlightwindow:

blur:
blurRadius: 12
cacheTexture: true

contrast:

startupfeedback:
type: 0

kscreen:

Thanks for the updated video, looks like it is KWin which is moving the window. I have absolutely no idea how that can happen. KWin itself only triggers the window moving when you interact with the decoration, but that's not what you are doing. So something must be triggering the window move and normally that would come from the application.

Could you please run:
xev -root > xev.out

Trigger the problem, terminate xev and attach the output. This records all X events, so please don't type to not get any sensitive data in.

Created attachment 101667 [details]
xev output

I logged into plasma , then opened krita , xterm , I then ran xev and reproduced the problem and then stopped xev by Ctrl + c .

the xev output is attached in above comment.

Thanks, I expected to see:
ClientMessage event, serial 21, synthetic YES, window 0x3000005,
    message_type 0x132 (_NET_WM_MOVERESIZE), format 32

which is not there. That means KWin does trigger the move. But why? There are three different ways how KWin could trigger the move itself:
1. Right click window decoration -> More Actions -> Move
2. Click window decoration
3. Modifier+click anywhere on the window

Given the videos we can clearly rule out option 1. So somehow we go into possibility 2 or 3. First thing: could it be that your tool triggers the meta key? I have heard that some tablets do that. To rule out please change the setting back to Alt.

For the possibility 2: please use xev again but slightly different. Use xwininfo, click on krita. That will give you a window id. Now pass that to xev with:
xev -id <id from xwininfo>

This will record all motion events. Thus we should hopefully be able to reconstruct where the actual mouse events are, whether they go into the window decoration, but we just don't see it.

I would like to add that i can reproduce this issue with mouse too. so tablet sending meta key press may be doubtful.

nevertheless I will reset it back to alt and try this again just to be sure.

Created attachment 101669 [details]
xev krita output

I have set the move window key to Alt and reproduced the problem. I ran xwininfo and xev as you suggested. please take a look at the attachement in the above comment

I don't see any key press/release or pointer events there. Shot in the blue. Please restart KWin with the following command:

KWIN_NO_XI2=1 kwin_x11 --replace &

I have now installed krtia on my system and are (of course) not able to reproduce the problem. When using the wacom tablet the cursor never turns into a mouse cursor. In fact I cannot leave the drawing area at all while drawing. Which I think is what is expected.

Some investigation results: if one removes the window decoration the problem is not triggered. Krita starts as a normal window and directly maximizes. This might cause a problem with the decoration not having a correct geometry and then accepting events.

I triggered the bug!

Yay!

(On the breeze topic, we've got a plan to see if there are any more issues. See https://bugs.kde.org/show_bug.cgi?id=361811 -- and then we can re-enable it, maybe with a version check.)

Possible fix at https://phabricator.kde.org/D3151

*** Bug 371725 has been marked as a duplicate of this bug. ***

Git commit 2e3c6c92e94e9902a9c808f6af92aa3afc797fdc by Martin Gräßlin.
Committed on 28/10/2016 at 14:06.
Pushed by graesslin into branch 'Plasma/5.8'.

Trigger resize of input window when deco size changes

Summary:
Client::updateInputWindow operates with the decoration size. The method
gets called from various points when changing the window geometry. If at
that moment the decoration has not updated yet, the borders might be at
a wrong position.

This behavior could be triggered when a window requested to change the
state to maximized. During maximization the decoration still had the
wrong size when updateInputWindow was called, thus an interactive area
inside the window was created.

To circumvent this problem updateInputWindow is now also called whenever
the window decoration changes.

As a note: that a maximized window has resize only borders is wrong. Kwin
should be protected against that.
FIXED-IN: 5.8.3

Test Plan: Checked xwininfo for the deco extends window

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D3151

M  +2    -0    client.cpp

http://commits.kde.org/kwin/2e3c6c92e94e9902a9c808f6af92aa3afc797fdc