Added old abandoned KDE3 version of gwenview

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/applications/gwenview@1088034 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 108 insertions, 0 deletions

diff --git a/src/gvcore/busylevelmanager.cpp b/src/gvcore/busylevelmanager.cpp
new file mode 100644
index 0000000..adfdf55
--- /dev/null
+++ b/src/gvcore/busylevelmanager.cpp
@@ -0,0 +1,108 @@
+// vim: set tabstop=4 shiftwidth=4 noexpandtab
+/*
+Gwenview - A simple image viewer for KDE
+Copyright 2000-2004 Aur�lien G�teau
+ 
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ as published by the Free Software Foundation; either version 2
+ of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+// Qt
+#include <qtimer.h>
+
+// KDE
+#include <kdebug.h>
+
+// Local
+#include "busylevelmanager.moc"
+namespace Gwenview {
+
+#undef ENABLE_LOG
+#undef LOG
+//#define ENABLE_LOG
+#ifdef ENABLE_LOG
+#define LOG(x) kdDebug() << k_funcinfo << x << endl
+#else
+#define LOG(x) ;
+#endif
+
+BusyLevelManager::BusyLevelManager()
+: mCurrentBusyLevel( BUSY_NONE )
+{
+	connect( &mDelayedBusyLevelTimer, SIGNAL( timeout()),
+		this, SLOT( delayedBusyLevelChanged()));
+}
+
+BusyLevelManager* BusyLevelManager::instance() {
+	static BusyLevelManager manager;
+	return &manager;
+}
+
+// How the busy level stuff works:
+// This system allows suspending less important tasks while more important
+// task are active, i.e. no thumbnails are generated when the viewed
+// image is being loaded and painted.
+// All objects responsible for operations set their busy level
+// to the matching value when the operation starts and reset their busy
+// level when the operation is done. They all connect to busyLevelChanged()
+// signal and suspend their operation if the current busy level is higher
+// than the busy level of their operation. If a new operation is started,
+// it needs to be immediatelly suspended if the current busy level is higher!
+// Note that there can be only one level per object,
+// so if one object is responsible for more operations,
+// it needs to use helper objects for setBusyLevel().
+
+void BusyLevelManager::setBusyLevel( QObject* obj, BusyLevel level ) {
+	LOG("BUSY:" << level << ":" << obj << ":" << obj->className() );
+	if( level > BUSY_NONE ) {
+		if( mBusyLevels.contains( obj ) && mBusyLevels[ obj ] == level ) return;
+		if( !mBusyLevels.contains( obj )) {
+			connect( obj, SIGNAL( destroyed( QObject* )), this, SLOT( objectDestroyed( QObject* )));
+		}
+		mBusyLevels[ obj ] = level;
+	} else {
+		mBusyLevels.remove( obj );
+		disconnect( obj, SIGNAL( destroyed( QObject* )), this, SLOT( objectDestroyed( QObject* )));
+	}
+	mDelayedBusyLevelTimer.start( 0, true );
+}
+
+void BusyLevelManager::objectDestroyed( QObject* obj ) {
+	LOG("DESTROYED:" << obj );
+	mBusyLevels.remove( obj );
+	mDelayedBusyLevelTimer.start( 0, true );
+}
+
+void BusyLevelManager::delayedBusyLevelChanged() {
+	BusyLevel newLevel = BUSY_NONE;
+	for( QMap< QObject*, BusyLevel >::ConstIterator it = mBusyLevels.begin();
+		it != mBusyLevels.end();
+		++it ) {
+		newLevel = QMAX( newLevel, *it );
+	}
+
+	if( newLevel != mCurrentBusyLevel ) {
+		LOG("CHANGED BUSY:" << newLevel);
+		mCurrentBusyLevel = newLevel;
+		emit busyLevelChanged( newLevel );
+	}
+}
+
+BusyLevel BusyLevelManager::busyLevel() const {
+	return mCurrentBusyLevel;
+}
+
+
+} // namespace