Qt: don't try to show an uninitialized time tooltip

(cherry picked from commit 0891bbe75522d1c523ae75063ea7c1d0aedabc23)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/util/timetooltip.cpp

 /*****************************************************************************
- * Copyright © 2011 VideoLAN
+ * Copyright © 2011-2012 VideoLAN
  * $Id$
  *
  * Authors: Ludovic Fauvet <etix@l0cal.com>
@@ -30,7 +30,7 @@
 #define TIP_HEIGHT 5
 
 TimeTooltip::TimeTooltip( QWidget *parent ) :
-    QWidget( parent )
+    QWidget( parent ), mInitialized( false )
 {
     setWindowFlags( Qt::Window                  |
                     Qt::WindowStaysOnTopHint    |
@@ -108,6 +108,7 @@ void TimeTooltip::buildPath()
 
 void TimeTooltip::setText( const QString& time, const QString& text )
 {
+    mInitialized = true;
     mDisplayedText = time;
     if ( !text.isEmpty() )
         mDisplayedText.append( " - " ).append( text );
@@ -120,6 +121,11 @@ void TimeTooltip::setText( const QString& time, const QString& text )
     update();
 }
 
+void TimeTooltip::show()
+{
+    QWidget::setVisible( mInitialized );
+}
+
 void TimeTooltip::paintEvent( QPaintEvent * )
 {
     QPainter p( this );

modules/gui/qt4/util/timetooltip.hpp

@@ -37,6 +37,7 @@ class TimeTooltip : public QWidget
 public:
     explicit TimeTooltip( QWidget *parent = 0 );
     void setText( const QString& time, const QString& text );
+    virtual void show();
 
 protected:
     virtual void paintEvent( QPaintEvent * );
@@ -51,6 +52,7 @@ private:
     QPainterPath mPainterPath;
     QBitmap mMask;
     int mPreviousMetricsWidth;
+    bool mInitialized;
 };
 
 #endif // TIMETOOLTIP_H