Qt: Initialize QFontDatabase in a worker thread.

QFontDatabase uses an internal list of system fonts which might take a
while to initialize depending on your platform and hardware. On my
notebook here it takes about 45 to 50 ms. Create a worker thread for
QFontDatabase initialization similar to QMimeDatabase.

Change-Id: Ieff683b023537a6c104a80f2611ea1e966b65610
Reviewed-on: https://code.wireshark.org/review/24841
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Gerald Combs <gerald@wireshark.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/ui/qt/wireshark_application.cpp b/ui/qt/wireshark_application.cpp
index af1f8e0f5e..143cd65dc9 100644
--- a/ui/qt/wireshark_application.cpp
+++ b/ui/qt/wireshark_application.cpp
@@ -98,6 +98,7 @@
 #include <qmath.h>
 
 #if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+#include <QFontDatabase>
 #include <QMimeDatabase>
 #include <QThreadPool>
 #endif
@@ -133,6 +134,16 @@ private:
         mime_db.mimeTypeForData(QByteArray());
     }
 };
+
+// Populating the font database can be slow as well.
+class FontDatabaseInitThread : public QRunnable
+{
+private:
+    void run()
+    {
+        QFontDatabase font_db;
+    }
+};
 #endif
 
 void
@@ -751,6 +762,8 @@ WiresharkApplication::WiresharkApplication(int &argc,  char **argv) :
 #if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
     MimeDatabaseInitThread *mime_db_init_thread = new(MimeDatabaseInitThread);
     QThreadPool::globalInstance()->start(mime_db_init_thread);
+    FontDatabaseInitThread *font_db_init_thread = new (FontDatabaseInitThread);
+    QThreadPool::globalInstance()->start(font_db_init_thread);
 #endif
 
     Q_INIT_RESOURCE(about);