Reset user colors on theme change (in qml timeline)

src/timeline/TimelineViewManager.cpp

@@ -18,6 +18,8 @@ Q_DECLARE_METATYPE(mtx::events::collections::TimelineEvents)
 void
 TimelineViewManager::updateColorPalette()
 {
+        userColors.clear();
+
         if (settings->theme() == "light") {
                 QPalette lightActive(/*windowText*/ QColor("#333"),
                                      /*button*/ QColor("#333"),
@@ -53,6 +55,15 @@ TimelineViewManager::updateColorPalette()
         }
 }
 
+QColor
+TimelineViewManager::userColor(QString id, QColor background)
+{
+        if (!userColors.contains(id))
+                userColors.insert(
+                  id, QColor(utils::generateContrastingHexColor(id, background.name())));
+        return userColors.value(id);
+}
+
 TimelineViewManager::TimelineViewManager(QSharedPointer<UserSettings> userSettings, QWidget *parent)
   : imgProvider(new MxcImageProvider())
   , colorImgProvider(new ColorImageProvider())