TypeError: Cannot read property 'height' of null in HistoryGraph.qml:41

[ironsigma]

Issue

I keep seeing these log messages two every second when running journalctl -f

Mar 10 14:25:09 apollo plasmashell[1271]: file:///home/xxxxx/.local/share/plasma/plasmoids/org.kde.networkMonitor/contents/ui/HistoryGraph.qml:41: TypeError: Cannot read property 'height' of null

Environment

Operating System: Fedora 33 KDE Plasma Version: 5.20.5 KDE Frameworks Version: 5.79.0 Qt Version: 5.15.2 Kernel Version: 5.10.19-200.fc33.x86_64 OS Type: 64-bit Processors: 8 × Intel® Core™ i7-8565U CPU @ 1.80GHz Memory: 15.3 GiB of RAM Graphics Processor: Mesa Intel® UHD Graphics 620

HistoryGraph.qml

  17 import QtQuick 2.2
  18 
  19 Item {
  20     id: historyGraph
  21     
  22     anchors.fill: parent
  23     
  24     property var listViewModel
  25     property color barColor
  26     
  27     ListView {
  28         anchors.fill: parent
  29         
  30         interactive: false
  31         orientation: Qt.Horizontal
  32         layoutDirection: Qt.LeftToRight
  33         spacing: 0
  34         
  35         model: listViewModel
  36         
  37         delegate: Rectangle {
  38             width: historyGraph.width / graphGranularity
  39             height: historyGraph.height * graphItemPercent
  40             x: 0
  41             y: parent.height - height
  42             color: barColor
  43             radius: 3
  44         }
  45     }
  46     
  47 }

[torokati44]

+1

[Termuellinator]

can confirm

[CrazyManLabs]

I'm also seeing this message constantly spamming in systemd logs and as there is no known way to fix it listed here yet - I decided to fix it by myself. I've done these changes to file in question (file:///home/<user>/.local/share/plasma/plasmoids/org.kde.networkMonitor/contents/ui/HistoryGraph.qml):

 import QtQuick 2.2

 Item {
-    id: historyGraph
-    
     anchors.fill: parent
     
     property var listViewModel
     property color barColor
     
     ListView {
+        id: listView
+        
         anchors.fill: parent
         
         interactive: false
         orientation: Qt.Horizontal
         layoutDirection: Qt.LeftToRight
         spacing: 0
         
         model: listViewModel
         
         delegate: Rectangle {
-            width: historyGraph.width / graphGranularity
+            width: listView.width / graphGranularity
-            height: historyGraph.height * graphItemPercent
+            height: listView.height * graphItemPercent
             x: 0
-            y: parent.height - height
+            y: listView.height - height
             color: barColor
             radius: 3
         }
     }
 }

It seems to be enough for stopping this logging spam and keeping plasmoid in working state.

UPD: Here are some system details, if they are needed.

Operating System: KDE neon 5.22 (based on Ubuntu 20.04) KDE Plasma Version: 5.22.0 KDE Frameworks Version: 5.82.0 Qt Version: 5.15.3 Kernel Version: 5.8.0-55-generic (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-4710HQ CPU @ 2.50GHz Memory: 15.1 GiB of RAM Graphics Processor: Mesa DRI Intel® HD Graphics 4600

[Termuellinator]

It seems to be enough for stopping this logging spam and keeping plasmoid in working state.

not for me apparently. But thanks to your work i managed to stop it by editing line 41 to:

y: listView.height - listView.height * graphItemPercent

[kotelnik]

Hi! Sorry for being unresponsive for so long. I had some personal problems. I'll add this change and will try to make the widget work in plasma 5.22.

Thanks for your code!

[zyf0330]

@kotelnik Hello, I use plasma 5.22.5 now, but this log still occurs. Has it beed fixed?