new class QgsAnimatedIcon

python/core/qgsdataitem.sip

@@ -145,7 +145,6 @@ class QgsDataItem : QObject
     void emitDataChanged( );
     void emitStateChanged( QgsDataItem* item, QgsDataItem::State oldState );
     virtual void childrenCreated();
-    void setPopulatingIcon();
 
   signals:
     void beginInsertItems( QgsDataItem* parent, int first, int last );

src/core/qgsdataitem.cpp

@@ -43,6 +43,57 @@
 #include "cpl_vsi.h"
 #include "cpl_string.h"
 
+QgsAnimatedIcon::QgsAnimatedIcon( const QString & iconPath )
+    : QObject()
+    , mCount( 0 )
+    , mMovie( 0 )
+{
+  // QApplication as parent to ensure that it is deleted before QApplication
+  mMovie = new QMovie( QApplication::instance() );
+  if ( !iconPath.isEmpty() )
+  {
+    mMovie->setFileName( iconPath );
+  }
+  mMovie->setCacheMode( QMovie::CacheAll );
+  connect( mMovie, SIGNAL( frameChanged( int ) ), SLOT( onFrameChanged() ) );
+}
+
+QString QgsAnimatedIcon::iconPath() const
+{
+  return mMovie->fileName();
+}
+
+void QgsAnimatedIcon::setIconPath( const QString & iconPath )
+{
+  mMovie->setFileName( iconPath );
+}
+
+void QgsAnimatedIcon::onFrameChanged()
+{
+  mIcon = QIcon( mMovie->currentPixmap() );
+  emit frameChanged();
+}
+
+void QgsAnimatedIcon::connectFrameChanged( const QObject * receiver, const char * method )
+{
+  if ( connect( this, SIGNAL( frameChanged() ), receiver, method ) )
+  {
+    mCount++;
+  }
+  mMovie->setPaused( mCount == 0 );
+  QgsDebugMsg( QString( "mCount = %1" ).arg( mCount ) );
+}
+
+void QgsAnimatedIcon::disconnectFrameChanged( const QObject * receiver, const char * method )
+{
+  if ( disconnect( this, SIGNAL( frameChanged() ), receiver, method ) )
+  {
+    mCount--;
+  }
+  mMovie->setPaused( mCount == 0 );
+  QgsDebugMsg( QString( "mCount = %1" ).arg( mCount ) );
+}
+
 // shared icons
 const QIcon &QgsLayerItem::iconPoint()
 {
@@ -153,9 +204,7 @@ const QIcon &QgsZipItem::iconZip()
 
 QMap<QString, QIcon> QgsDataItem::mIconMap = QMap<QString, QIcon>();
 
-int QgsDataItem::mPopulatingCount = 0;
-QMovie * QgsDataItem::mPopulatingMovie = 0;
-QIcon QgsDataItem::mPopulatingIcon = QIcon();
+QgsAnimatedIcon * QgsDataItem::mPopulatingIcon = 0;
 
 QgsDataItem::QgsDataItem( QgsDataItem::Type type, QgsDataItem* parent, QString name, QString path )
 // Do not pass parent to QObject, Qt would delete this when parent is deleted
@@ -247,8 +296,8 @@ void QgsDataItem::moveToThread( QThread * targetThread )
 
 QIcon QgsDataItem::icon()
 {
-  if ( state() == Populating )
-    return mPopulatingIcon;
+  if ( state() == Populating && mPopulatingIcon )
+    return mPopulatingIcon->icon();
 
   if ( !mIcon.isNull() )
     return mIcon;
@@ -574,11 +623,6 @@ bool QgsDataItem::equal( const QgsDataItem *other )
   return false;
 }
 
-void QgsDataItem::setPopulatingIcon()
-{
-  mPopulatingIcon = QIcon( mPopulatingMovie->currentPixmap() );
-}
-
 QgsDataItem::State QgsDataItem::state() const
 {
   // for backward compatibility (if subclass set mPopulated directly)
@@ -598,26 +642,15 @@ void QgsDataItem::setState( State state )
 
   if ( state == Populating ) // start loading
   {
-    if ( !mPopulatingMovie )
+    if ( !mPopulatingIcon )
     {
-      // QApplication as parent to ensure that it is deleted before QApplication
-      mPopulatingMovie = new QMovie( QApplication::instance() );
-      mPopulatingMovie->setFileName( QgsApplication::iconPath( "/mIconLoading.gif" ) );
-      mPopulatingMovie->setCacheMode( QMovie::CacheAll );
-      connect( mPopulatingMovie, SIGNAL( frameChanged( int ) ), SLOT( setPopulatingIcon() ) );
+      mPopulatingIcon = new QgsAnimatedIcon( QgsApplication::iconPath( "/mIconLoading.gif" ) );
     }
-    connect( mPopulatingMovie, SIGNAL( frameChanged( int ) ), SLOT( emitDataChanged() ) );
-    mPopulatingCount++;
-    mPopulatingMovie->setPaused( false );
+    mPopulatingIcon->connectFrameChanged( this, SLOT( emitDataChanged() ) );
   }
-  else if ( mState == Populating && mPopulatingMovie ) // stop loading
+  else if ( mState == Populating && mPopulatingIcon ) // stop loading
   {
-    disconnect( mPopulatingMovie, SIGNAL( frameChanged( int ) ), this, SLOT( emitDataChanged() ) );
-    mPopulatingCount--;
-    if ( mPopulatingCount == 0 )
-    {
-      mPopulatingMovie->setPaused( true );
-    }
+    mPopulatingIcon->disconnectFrameChanged( this, SLOT( emitDataChanged() ) );
   }
 
   mState = state;
@@ -730,7 +763,7 @@ QgsDirectoryItem::~QgsDirectoryItem()
 QIcon QgsDirectoryItem::icon()
 {
   if ( state() == Populating )
-    return populatingIcon();
+    return QgsDataItem::icon();
   return iconDir();
 }
 

src/core/qgsdataitem.h

@@ -37,6 +37,38 @@ class QgsDataItem;
 
 typedef QgsDataItem * dataItem_t( QString, QgsDataItem* );
 
+/** Animated icon is keeping an animation running if there are listeners connected to frameChanged */
+class QgsAnimatedIcon : public QObject
+{
+    Q_OBJECT
+  public:
+
+    /** Constructor
+     * @param iconPath path to a movie, e.g. animated GIF */
+    QgsAnimatedIcon( const QString & iconPath = QString::null );
+
+    QString iconPath() const;
+    void setIconPath( const QString & iconPath );
+    QIcon icon() const { return mIcon; }
+
+    /** Connect listener to frameChanged() signal */
+    void connectFrameChanged( const QObject * receiver, const char * method );
+    /** Disconnect listener from frameChanged() signal */
+    void disconnectFrameChanged( const QObject * receiver, const char * method );
+
+  public slots:
+    void onFrameChanged();
+
+  signals:
+    /** Emited when icon changed */
+    void frameChanged();
+
+  private:
+    void resetMovie();
+    int mCount; // number of listeners
+    QMovie * mMovie;
+    QIcon mIcon;
+};
 
 /** Base class for all items in the model.
  *  Parent/children hierarchy is not based on QObject. */
@@ -172,7 +204,6 @@ class CORE_EXPORT QgsDataItem : public QObject
   protected:
     virtual void populate( QVector<QgsDataItem*> children );
     virtual void refresh( QVector<QgsDataItem*> children );
-    QIcon populatingIcon() { return mPopulatingIcon; }
     /** The item is scheduled to be deleted. E.g. if deleteLater() is called when
      * item is in Populating state (createChildren() running in another thread),
      * the deferredDelete() returns true and item will be deleted once Populating finished.
@@ -225,7 +256,6 @@ class CORE_EXPORT QgsDataItem : public QObject
     void emitDataChanged( );
     void emitStateChanged( QgsDataItem* item, QgsDataItem::State oldState );
     virtual void childrenCreated();
-    void setPopulatingIcon();
 
   signals:
     void beginInsertItems( QgsDataItem* parent, int first, int last );
@@ -242,9 +272,7 @@ class CORE_EXPORT QgsDataItem : public QObject
     bool mDeferredDelete;
     QFutureWatcher< QVector <QgsDataItem*> > *mFutureWatcher;
     // number of items currently in loading (populating) state
-    static int mPopulatingCount;
-    static QMovie * mPopulatingMovie;
-    static QIcon mPopulatingIcon;
+    static QgsAnimatedIcon * mPopulatingIcon;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsDataItem::Capabilities )