Make the generator multithreaded

svn path=/trunk/playground/graphics/okular/; revision=625262

generators/comicbook/generator_comicbook.cpp

@@ -7,7 +7,9 @@
  *   (at your option) any later version.                                   *
  ***************************************************************************/
 
-#include <qpainter.h>
+#include <QtCore/QThread>
+#include <QtGui/QPainter>
+
 #include <kprinter.h>
 
 #include <okular/core/page.h>
@@ -16,13 +18,78 @@
 
 OKULAR_EXPORT_PLUGIN(ComicBookGenerator)
 
+class GeneratorThread : public QThread
+{
+    public:
+        GeneratorThread();
+
+        void startGeneration( Okular::PixmapRequest* request, ComicBook::Document *document );
+        void endGeneration();
+
+        Okular::PixmapRequest *request() const;
+        QImage image();
+
+    private:
+        void run();
+
+        Okular::PixmapRequest* mRequest;
+        QImage mImage;
+        ComicBook::Document* mDocument;
+};
+
+GeneratorThread::GeneratorThread()
+  : QThread(), mRequest( 0 ), mDocument( 0 )
+{
+}
+
+void GeneratorThread::startGeneration( Okular::PixmapRequest* request, ComicBook::Document *document )
+{
+    mRequest = request;
+    mDocument = document;
+    start( QThread::InheritPriority );
+}
+
+void GeneratorThread::endGeneration()
+{
+    mRequest = 0;
+    mDocument = 0;
+}
+
+Okular::PixmapRequest* GeneratorThread::request() const
+{
+    return mRequest;
+}
+
+QImage GeneratorThread::image()
+{
+    const QImage image = mImage;
+    mImage = QImage();
+
+    return image;
+}
+
+void GeneratorThread::run()
+{
+    int width = mRequest->width();
+    int height = mRequest->height();
+
+    mImage = mDocument->pageImage( mRequest->pageNumber() );
+    mImage = mImage.scaled( width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation );
+}
+
 ComicBookGenerator::ComicBookGenerator()
-    : Generator()
+    : Generator(), mReady( false )
 {
+    mThread = new GeneratorThread();
+    connect( mThread, SIGNAL( finished() ), this, SLOT( threadFinished() ), Qt::QueuedConnection );
 }
 
 ComicBookGenerator::~ComicBookGenerator()
 {
+    if ( mThread )
+        mThread->wait();
+
+    delete mThread;
 }
 
 bool ComicBookGenerator::loadDocument( const QString & fileName, QVector<Okular::Page*> & pagesVector )
@@ -38,21 +105,32 @@ bool ComicBookGenerator::loadDocument( const QString & fileName, QVector<Okular:
         pagesVector[i] = page;
     }
 
+    mReady = true;
+
     return true;
 }
 
 bool ComicBookGenerator::closeDocument()
 {
+    mReady = false;
+
     return true;
 }
 
 bool ComicBookGenerator::canGeneratePixmap( bool ) const
 {
-    return true;
+    return mReady;
 }
 
 void ComicBookGenerator::generatePixmap( Okular::PixmapRequest * request )
 {
+    mReady = false;
+
+    if ( request->asynchronous() ) {
+        mThread->startGeneration( request, &mDocument );
+        return;
+    }
+
     int width = request->width();
     int height = request->height();
 
@@ -60,8 +138,22 @@ void ComicBookGenerator::generatePixmap( Okular::PixmapRequest * request )
     image = image.scaled( width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation );
     request->page()->setPixmap( request->id(), new QPixmap( QPixmap::fromImage( image ) ) );
 
+    mReady = true;
+
     // signal that the request has been accomplished
-    signalRequestDone(request);
+    signalRequestDone( request );
+}
+
+void ComicBookGenerator::threadFinished()
+{
+    Okular::PixmapRequest *request = mThread->request();
+    mThread->endGeneration();
+
+    request->page()->setPixmap( request->id(), new QPixmap( QPixmap::fromImage( mThread->image() ) ) );
+
+    mReady = true;
+
+    signalRequestDone( request );
 }
 
 bool ComicBookGenerator::print( KPrinter& printer )

generators/comicbook/generator_comicbook.h

@@ -14,6 +14,8 @@
 
 #include "document.h"
 
+class GeneratorThread;
+
 class ComicBookGenerator : public Okular::Generator
 {
     Q_OBJECT
@@ -35,8 +37,13 @@ class ComicBookGenerator : public Okular::Generator
 
         bool hasFeature( GeneratorFeature feature ) const;
 
+    private Q_SLOTS:
+        void threadFinished();
+
     private:
       ComicBook::Document mDocument;
+      GeneratorThread *mThread;
+      bool mReady;
 };
 
 #endif