The edge of windows get a blur when docked to a panel. This blur looks unprecise, I always catch myself checking if the form isn't placed underneath the panel. The issue is illustrated in the screen shot. Reproducible: Always >qdbus org.kde.KWin /KWin org.kde.KWin.supportInformation Version ======= KWin version: 5.5.1 Qt Version: 5.5.1 Qt compile version: 5.5.1 XCB compile version: 1.11.1 Operation Mode: X11 only Decoration ========== Plugin: org.kde.breeze Theme: Blur: 0 onAllDesktopsAvailable: false alphaChannelSupported: true closeOnDoubleClickOnMenu: false decorationButtonsLeft: 0, 2 decorationButtonsRight: 6, 3, 4, 5 borderSize: 3 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: false focusStealingPreventionLevel: 2 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: 16777250 showGeometryTip: true condensedTitle: false electricBorderMaximize: false electricBorderTiling: false electricBorderCornerRatio: 0.25 borderlessMaximizedWindows: false killPingTimeout: 5000 hideUtilityWindowsForInactive: true inactiveTabsSkipTaskbar: false autogroupSimilarWindows: false autogroupInForeground: true compositingMode: 1 useCompositing: true compositingInitialized: true hiddenPreviews: 1 unredirectFullscreen: false glSmoothScale: 2 colorCorrected: false xrenderSmoothScale: false maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: false glStrictBindingFollowsDriver: true glCoreProfile: true glPreferBufferSwap: 112 glPlatformInterface: 2 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: yes Number of Screens: 2 Screen 0: --------- Name: HDMI1 Geometry: 0,0,1920x1080 Refresh Rate: 60 Screen 1: --------- Name: eDP1 Geometry: 1920,180,1600x900 Refresh Rate: 60 Compositing =========== Compositing is active Compositing Type: OpenGL OpenGL vendor string: Intel Open Source Technology Center OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile OpenGL version string: 3.3 (Core Profile) Mesa 11.0.7 OpenGL platform interface: EGL OpenGL shading language version string: 3.30 Driver: Intel GPU class: Haswell OpenGL version: 3.3 GLSL version: 3.30 Mesa version: 11.0.7 X server version: 1.18 Linux kernel version: 4.2.5 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 kwin4_effect_windowaperture flipswitch desktopgrid coverswitch kwin4_effect_fade kwin4_effect_maximize presentwindows highlightwindow kwin4_effect_dialogparent blur contrast logout windowgeometry startupfeedback screenedge 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: kwin4_effect_windowaperture: flipswitch: tabBox: true tabBoxAlternative: false duration: 200 angle: 30 xPosition: 0.33000001311302185 yPosition: 1 windowTitle: true desktopgrid: zoomDuration: 300 border: 10 desktopNameAlignment: 0 layoutMode: 0 customLayoutRows: 2 usePresentWindows: true coverswitch: animationDuration: 200 animateSwitch: true animateStart: true animateStop: true reflection: true windowTitle: true zPosition: 900 primaryTabBox: false secondaryTabBox: false
Created attachment 96165 [details] KMail docked to the (upper) panel KMail docked to the (upper) panel
Created attachment 96166 [details] KMail free floating KMail free floating
that's not a blur, it's a drop shadow of the panel
"Drop shadow" is the perfect keyword to dig the web and to find this thread https://www.reddit.com/r/kde/comments/2nshc1/panel_shadow_in_plasma_5/ with the solution: |For anyone coming across this thread, this is what worked for me: |(1) xprop -remove _KDE_NET_WM_SHADOW |(2) click the panel from which you want to remove the shadow I'm too lazy to read all the posts about drop shadows but obviously I'm not the only one who dislike this "feature". No idea for what it is good for. So I vote for removing it.
This is not a kwin issue. KWin is doing exactly what it advertises to do if a window decided that it wants a shadow.