Schematic glitches fedora 37 [Qt6]

[aviadb]

In the schematic viewer,
moving parts or wires makes the wires to disappear until the component is released.

Fedora 37, Qt6, KDE desktop with dark theme

[ra3xdh]

It was already reported here #190 (comment) I remember about this issue, but unfortunately I cannot reproduce and debug it. I have tried Fedora installation into the VM and everything works as expected here. Physical installation of the Ubuntu22.04 with Qt6 also works as expected. I only may suspect this may be related to Wayland.

[cznwhale]

The same behavior is on the raspberry pi version. (I use the September 22nd 2022 release of Raspberry Pi OS, 32 bit version, Kernel: Linux 5.15.84-v7l+, on a 4B model)

[ra3xdh]

The issue also may be fixed by fe135fa Did you try compile the latest current branch?

[cznwhale]

in my case (Raspberry Pi version) I used the precompiled binary (qucs-s_1.0.1-1_armhf.deb)

[cznwhale]

I now realize that the same behavior is for Windows portable version (qucs_s_win64_1_0_1.zip). I have a Win 10 system.

[ra3xdh]

I have just tested the Windows v1.0.1 package using the physical Windows installation (not VM) and also cannot reproduce the issue. Component dragging works as expected on my hardware. Therefore I cannot provide a fix, because I still cannot reproduce this bug.

[aviadb]

Tried with the latest, problem still exists.
Any log dump that I can provide to help you in analyzing this behavior?

[ra3xdh]

The information related to this problem is not logged by application. I suspect this may be hardware-dependent bug in Qt itself. Qt relies on OpenGL for the rendering and this may interact with the Wayland or graphic card driver in a weird way. The main problem is that I have tried different hardware including Nvidia, Radeon, and Intel and everything works as expected on my hardware. No issue observed with X11 and Windows. I still cannot reproduce this issue. And therefore I cannot provide a workaround. Contribution is highly welcome here. Currntly I can only speculate about its reason. Also there may be something in the Qt configuration related to the rendering settings or scaling.

[ra3xdh]

@aviadb You may try the fix proposed in #229 I didn't merge it into the current branch, you need to apply patch manually. I suspect these two issues may be related. I also cannot reproduce #229 on my hardware.

[aviadb]

Hi @ra3xdh , thank you for your suggestion.

Tried to comment out this line:

No success, the issue is still there.

[dsm]

I tried fedora 37 with qt6 same issue is still there.

[ra3xdh]

@dsm please consider providing a fix if you can reproduce this issue. I have tried different hardware and OS combinations including Windows10 and 11 and still cannot reproduce it. The start point for debugger may be Component::paintScheme() method in component.cpp.

[dsm]

I tried something but I cannot resolve symbols redraw every move but lines are not. maybe new lines coordinate not calculate while moving.

[dsm]

windows 10 with qucs 1.0.1 and current branch with qt6 have the same issue

[dsm]

if you move components using keyboard it's working. I didn't find any solution

[ra3xdh]

if you move components using keyboard it's working.

The moving of the component with keyboard doesn't invoke the Component::paintScheme() I guess this issue lies somewhere in in this method. I cannot provide you a more info because I cannot reproduce it on my hardware.

windows 10 with qucs 1.0.1 and current branch with qt6 have the same issue

It is not bug because of Qt5 migration and not related to this issue. I have just checked old Qt4 version and it also doesn't render wires while moving with mouse. But the component outline is rendered normally like on your screenshot.

[dsm]

qt5 or qt6 build have same behaviour on my machine. I don't know it's qt related bug but if you not release mouse button while moving not update the wires maybe it's mouse action problem I cannot debug correctly. it's not important it's just an cosmetic bug. we will fix anytime

[ra3xdh]

I still cannot reproduce this issue and provide debugging. @aviadb Could you try this patch for schematic.cpp and tell the result? This may fix the contour drawing.

diff --git a/qucs/schematic.cpp b/qucs/schematic.cpp
index 01fe40aa..41c883a1 100644
--- a/qucs/schematic.cpp
+++ b/qucs/schematic.cpp
@@ -462,7 +462,10 @@ void Schematic::drawContents(QPainter *p, int, int, int, int)
   {
     // QPainter painter2(viewport()); for if(p.PaintOnViewport)
     QPen pen(Qt::black);
-    Painter.Painter->setPen(Qt::black);
+    QPen pen1(Qt::black);
+    pen1.setWidth(1);
+    Painter.Painter->setPen(pen1);
+    //Painter.Painter->setPen(Qt::black);
     switch(p.pe)
     {
       case _NotRop:

[aviadb]

@ra3xdh ,
The issue still persist with the suggested fix.
Using the arrow keys, I do not see the problem. Only when dragging elements with mouse.

[ra3xdh]

#467 provides a fix for this issue. @aviadb , Could you test it, because I still cannot reproduce a bug with moving.

[aviadb]

Thanks @ra3xdh, the provided solution fixes the problem.