OSD: Fix subtitle window painting order.

The order of iterating over a QHash is arbitrary and the fact that
subtitle and interactive screens have (mostly) been drawn in the correct
order since the OSD re-write is pure luck.

So switch to a QMap which, while marginally slower, will order on the
basis of the key (QString) and force the subtitle/interactive screens to
be painted first by adding some numerics to their identifiers.

Should fix the ordering issue seen in #9822 and occasionally in the yet
to be enabled blu-ray HDMV navigation mode.

Refs #9822

mythtv/libs/libmythtv/osd.cpp

@@ -202,7 +202,7 @@ void OSD::SetPainter(MythPainter *painter)
         return;
 
     m_CurrentPainter = painter;
-    QHashIterator<QString, MythScreenType*> it(m_Children);
+    QMapIterator<QString, MythScreenType*> it(m_Children);
     while (it.hasNext())
     {
         it.next();
@@ -278,7 +278,7 @@ bool OSD::IsVisible(void)
 
 void OSD::HideAll(bool keepsubs, MythScreenType* except)
 {
-    QMutableHashIterator<QString, MythScreenType*> it(m_Children);
+    QMutableMapIterator<QString, MythScreenType*> it(m_Children);
     while (it.hasNext())
     {
         it.next();
@@ -542,7 +542,7 @@ bool OSD::DrawDirect(MythPainter* painter, QSize size, bool repaint)
     QTime now = QTime::currentTime();
 
     CheckExpiry();
-    QHash<QString,MythScreenType*>::iterator it;
+    QMap<QString,MythScreenType*>::const_iterator it;
     for (it = m_Children.begin(); it != m_Children.end(); ++it)
     {
         if (it.value()->IsVisible())
@@ -598,7 +598,7 @@ QRegion OSD::Draw(MythPainter* painter, QPaintDevice *device, QSize size,
     CheckExpiry();
 
     // first update for alpha pulse and fade
-    QHash<QString,MythScreenType*>::iterator it;
+    QMap<QString,MythScreenType*>::const_iterator it;
     for (it = m_Children.begin(); it != m_Children.end(); ++it)
     {
         if (it.value()->IsVisible())
@@ -1007,6 +1007,8 @@ TeletextScreen* OSD::InitTeletext(void)
             if (tt->Create())
             {
                 m_Children.insert(OSD_WIN_TELETEXT, tt);
+                VERBOSE(VB_PLAYBACK, LOC + QString("Created window %1")
+                    .arg(OSD_WIN_TELETEXT));
             }
             else
             {
@@ -1083,6 +1085,8 @@ SubtitleScreen* OSD::InitSubtitles(void)
             if (sub->Create())
             {
                 m_Children.insert(OSD_WIN_SUBTITLE, sub);
+                VERBOSE(VB_PLAYBACK, LOC + QString("Created window %1")
+                    .arg(OSD_WIN_SUBTITLE));
             }
             else
             {

mythtv/libs/libmythtv/osd.h

@@ -16,10 +16,14 @@
 #define OSD_DLG_CUTPOINT  "OSD_CUTPOINT"
 #define OSD_DLG_DELETE    "OSD_DELETE"
 #define OSD_DLG_CONFIRM   "mythconfirmpopup"
-#define OSD_WIN_TELETEXT  "OSD_TELETEXT"
-#define OSD_WIN_SUBTITLE  "OSD_SUBTITLES"
-#define OSD_WIN_INTERACT  "OSD_INTERACTIVE"
-#define OSD_WIN_BDOVERLAY "OSD_BDOVERLAY"
+// Force subtitle/interactive screens to be drawn first (i.e. at the back) by
+// prepending their identifiers with a low numeric (may not always work as
+// QMap/QString ordering is based on unicode values)
+#define OSD_WIN_TELETEXT  "00_OSD_TELETEXT"
+#define OSD_WIN_SUBTITLE  "00_OSD_SUBTITLES"
+// MHEG and blu-ray overlay should cover subtitles
+#define OSD_WIN_INTERACT  "01_OSD_INTERACTIVE"
+#define OSD_WIN_BDOVERLAY "01_OSD_BDOVERLAY"
 
 #define kOSDFadeTime 1000
 
@@ -208,7 +212,7 @@ class OSD
     enum OSDFunctionalType m_FunctionalType;
     QString                m_FunctionalWindow;
 
-    QHash<QString, MythScreenType*>   m_Children;
+    QMap<QString, MythScreenType*>    m_Children;
     QHash<MythScreenType*, QDateTime> m_ExpireTimes;
 };