Add maxMessageCharactersPerLine setting

Can be set to -1 for no maximum width.

src/backend/user_files.py

@@ -238,6 +238,7 @@ class UISettings(JSONDataFile):
             "hideProfileChangeEvents": True,
             "hideMembershipEvents": False,
             "hideUnknownEvents": False,
+            "maxMessageCharactersPerLine": 65,
             "theme": "Midnight.qpl",
             "writeAliases": {},
             "media": {

src/gui/Pages/Chat/Timeline/EventContent.qml

@@ -62,8 +62,13 @@ HRowLayout {
         ) :
         0
 
-    // ~600px max with a 16px font
-    readonly property int maxMessageWidth: theme.fontSize.normal * 0.5 * 75
+    readonly property int maxMessageWidth:
+        window.settings.maxMessageCharactersPerLine < 0 ?
+        -1 :
+        Math.ceil(
+            mainUI.fontMetrics.averageCharacterWidth *
+            window.settings.maxMessageCharactersPerLine
+        )
 
     readonly property alias selectedText: contentLabel.selectedText
 

src/gui/UI.qml

@@ -32,6 +32,7 @@ Item {
     readonly property alias mainPane: mainPane
     readonly property alias pageLoader: pageLoader
     readonly property alias pressAnimation: pressAnimation
+    readonly property alias fontMetrics: fontMetrics
 
 
     function reloadSettings() {
@@ -82,6 +83,13 @@ Item {
         }
     }
 
+    FontMetrics {
+        id: fontMetrics
+        font.family: theme.fontFamily.sans
+        font.pixelSize: theme.fontSize.normal
+        font.pointSize: -1
+    }
+
     DebugConsole {
         id: debugConsole
         target: mainUI