Library: resize the Played checkbox and BPM lock with the library font

res/skins/default.qss

@@ -11,13 +11,11 @@
   image: url(:/images/library/ic_library_preview_play.svg);
 }
 
-/* These library table indicators are scaled with the library font:
-checkbox next to the 'Played' counter */
+/* 'Played' checkbox */
 WTrackTableView::indicator,
 /* BPM lock icon */
 #LibraryBPMButton::indicator {
-  width: 0.5em;
-  height: 0.5em;
+  /* The indicator size is set dynamically according to the library font */
 }
 /* Style the library BPM Button with a default image */
 QPushButton#LibraryBPMButton {

src/widget/wlibrarytableview.cpp

@@ -134,6 +134,17 @@ void WLibraryTableView::setTrackTableFont(const QFont& font) {
     setFont(font);
     QFontMetrics metrics(font);
     verticalHeader()->setMinimumSectionSize(metrics.height());
+    // Resize the 'Played' checkbox and the BPM lock icon.
+    // Note: this works well for library font sizes up to 200% of the original
+    // system font's size. Above that, the indicators start to overlap the
+    // item text because the painter rectangle is not resized (also depending on
+    // the system font size).
+    setStyleSheet(QStringLiteral(
+            "WTrackTableView::indicator,"
+            "#LibraryBPMButton::indicator {"
+            "height: %1px;"
+            "width: %1px;}")
+                          .arg(metrics.height() * 0.5));
 }
 
 void WLibraryTableView::setTrackTableRowHeight(int rowHeight) {