fix(ui): tighten idealSize() for chatlog Timestamps

Make Text::idealSize() a virtual function and override it in the derived
class Timestamp. The idealSize() function for Timestamps now returns a
tighter size to enable better right-alignment of the timestamps in
chatlog.

Fixes #3957. Note that this change assumes that timestamps do not
contain RTL text.

src/chatlog/content/text.h

@@ -70,7 +70,7 @@ protected:
     void regenerate();
     void freeResources();
 
-    QSizeF idealSize();
+    virtual QSizeF idealSize();
     int cursorFromPos(QPointF scenePos, bool fuzzy = true) const;
     int getSelectionEnd() const;
     int getSelectionStart() const;
@@ -78,14 +78,16 @@ protected:
     QString extractSanitizedText(int from, int to) const;
     QString extractImgTooltip(int pos) const;
 
+    QTextDocument* doc = nullptr;
+    QSizeF size;
+    qreal width = 0.0;
+
 private:
     void selectText(QTextCursor& cursor, const std::pair<int, int>& point);
 
-    QTextDocument* doc = nullptr;
     QString text;
     QString rawText;
     QString selectedText;
-    QSizeF size;
     bool keepInMemory = false;
     bool elide = false;
     bool dirty = false;
@@ -93,7 +95,6 @@ private:
     int selectionEnd = -1;
     int selectionAnchor = -1;
     qreal ascent = 0.0;
-    qreal width = 0.0;
     QFont defFont;
     QString defStyleSheet;
     QColor color;

src/chatlog/content/timestamp.cpp

@@ -29,3 +29,11 @@ QDateTime Timestamp::getTime()
 {
     return time;
 }
+
+QSizeF Timestamp::idealSize()
+{
+    if (doc) {
+        return QSizeF(qMin(doc->idealWidth(), width), doc->size().height());
+    }
+    return size;
+}

src/chatlog/content/timestamp.h

@@ -22,6 +22,9 @@
 
 #include "text.h"
 #include <QDateTime>
+#include <QTextDocument>
+
+class QTextDocument;
 
 class Timestamp : public Text
 {
@@ -30,6 +33,9 @@ public:
     Timestamp(const QDateTime& time, const QString& format, const QFont& font);
     QDateTime getTime();
 
+protected:
+    QSizeF idealSize();
+
 private:
     QDateTime time;
 };