Load file metadata asynchronously

Synchronous load of metadata resulted in big delays when opening a
directory with substantial amount of files.

Closes: https://mirror.git.trinitydesktop.org/gitea/TDE/gwenview/issues/17
Signed-off-by: Alexander Golubev <fatzer2@gmail.com>

src/gvcore/fileviewcontroller.cpp

@@ -48,6 +48,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <kurldrag.h>
 #include <tdeio/job.h>
 #include <tdeio/file.h>
+#include <tdeio/metainfojob.h>
 
 // Local
 #include "archive.h"
@@ -188,6 +189,9 @@ public:
 	TQComboBox* mFilterComboBox;
 	TQCheckBox* mShowFilterBarCheckBox;
 
+	TDEIO::MetaInfoJob* mMetaInfoJob;
+	KFileItemList mMetaInfoTodo;
+
 	void initFilterBar() {
 		mFilterBar=new FilterBar(that);
 		mFilterBar->setSizePolicy(TQSizePolicy::Preferred, TQSizePolicy::Fixed);
@@ -266,6 +270,7 @@ FileViewController::FileViewController(TQWidget* parent,TDEActionCollection* act
 	d->initFilterBar();
 	d->initFilterCombo();
 	d->mStack=new TQWidgetStack(this);
+	d->mMetaInfoJob=NULL;
 	
 	TQVBoxLayout *layout=new TQVBoxLayout(this);
 	layout->addWidget(d->mToolBar);
@@ -470,6 +475,7 @@ FileViewController::~FileViewController() {
 	FileViewConfig::setToDateFilter(d->mFilterBar->mToDateEdit->date());
 	
 	FileViewConfig::writeConfig();
+	stopMetaInfoUpdate();
 	delete mDirLister;
 	delete d;
 }
@@ -1022,6 +1028,12 @@ void FileViewController::dirListerDeleteItem(KFileItem* item) {
 		if (!newShownItem) newShownItem=findPreviousImage();
 	}
 
+	// Remove item from metadata todo list and job's pending update lists
+	d->mMetaInfoTodo.remove(item);
+	if (d->mMetaInfoJob) {
+		d->mMetaInfoJob->removeItem(item);
+	}
+
 	currentFileView()->removeItem(item);
 
 	if (shownItem==item) {
@@ -1040,21 +1052,24 @@ void FileViewController::dirListerNewItems(const KFileItemList& items) {
 	LOG("");
 	mThumbnailsNeedUpdate=true;
 	currentFileView()->addItemList(items);
+	loadMetaInfo(items);
 }
 
 
 void FileViewController::dirListerRefreshItems(const KFileItemList& list) {
 	LOG("");
-	const KFileItem* item=currentFileView()->shownFileItem();
 	KFileItemListIterator it(list);
 	for (; *it!=0L; ++it) {
-		currentFileView()->updateView(*it);
+		updateViewItem(*it);
-		if (*it==item) {
-			emit shownFileItemRefreshed(item);
-		}
 	}
 }
 
+void FileViewController::updateViewItem(const KFileItem *item) {
+	currentFileView()->updateView(item);
+	if (item==currentFileView()->shownFileItem()) {
+		emit shownFileItemRefreshed(item);
+	}
+}
 
 void FileViewController::refreshItems(const KURL::List& urls) {
 	LOG("");
@@ -1145,6 +1160,7 @@ void FileViewController::dirListerCanceled() {
 	if (mMode!=FILE_LIST) {
 		mFileThumbnailView->stopThumbnailUpdate();
 	}
+	stopMetaInfoUpdate();
 
 	browseToFileNameToSelect();
 }
@@ -1316,5 +1332,45 @@ KFileItem* FileViewController::findItemByFileName(const TQString& fileName) cons
 	return 0L;
 }
 
+//-----------------------------------------------------------------------------
+//
+// MetaInfo loading
+//
+//-----------------------------------------------------------------------------
+
+void FileViewController::loadMetaInfo(const KFileItemList& items) {
+	if(d->mMetaInfoTodo.isEmpty()) {
+		d->mMetaInfoTodo = items;
+	} else {
+		for(const auto& item: items) {
+			d->mMetaInfoTodo.append(item);
+		}
+	}
+
+	if(!d->mMetaInfoJob) {
+		nextMetaInfoJob();
+	}
+}
+
+void FileViewController::nextMetaInfoJob() {
+	if( !d->mMetaInfoTodo.isEmpty() ) {
+		d->mMetaInfoJob = new TDEIO::MetaInfoJob(d->mMetaInfoTodo);
+		connect( d->mMetaInfoJob, TQ_SIGNAL(result(TDEIO::Job *)),
+				this, TQ_SLOT(nextMetaInfoJob()) );
+		connect( d->mMetaInfoJob, TQ_SIGNAL( gotMetaInfo(const KFileItem *)),
+				this, TQ_SLOT(updateViewItem(const KFileItem *)) );
+		d->mMetaInfoTodo.clear();
+	} else {
+		d->mMetaInfoJob = NULL;
+	}
+}
+
+void FileViewController::stopMetaInfoUpdate() {
+	d->mMetaInfoTodo.clear();
+	if(d->mMetaInfoJob) {
+		d->mMetaInfoJob->kill();
+		d->mMetaInfoJob = 0;
+	}
+}
 
 } // namespace

src/gvcore/fileviewcontroller.h

@@ -174,6 +174,7 @@ private slots:
 	void toggleShowDotFiles();
 	void setSorting();
 	void updateSortMenu(TQDir::SortSpec);
+	void updateViewItem(const KFileItem *item);
 
 	// Dir lister slots
 	void dirListerDeleteItem(KFileItem* item);
@@ -184,6 +185,11 @@ private slots:
 	void dirListerCanceled();
 	void dirListerCompleted();
 
+	// Metadata info loader jobs
+	void loadMetaInfo(const KFileItemList& items);
+	void nextMetaInfoJob();
+	void stopMetaInfoUpdate();
+
 	void openDropURLMenu(TQDropEvent*, KFileItem*);
 
 	void prefetchDone();

src/gvcore/timeutils.cpp

@@ -30,7 +30,7 @@ namespace Gwenview {
 namespace TimeUtils {
 
 time_t getTime(const KFileItem* item) {
-	const KFileMetaInfo& info = item->metaInfo();
+	const KFileMetaInfo& info = item->metaInfo(/*autogen=*/false);
 	if (info.isValid()) {
 		TQVariant value = info.value("Date/time");
 		TQDateTime dt = value.toDateTime();

src/gvcore/timeutils.h

@@ -29,7 +29,7 @@ namespace Gwenview {
 namespace TimeUtils {
 
 /**
- * Returns the time of an item, using EXIF info if available
+ * Returns the time of an item, using EXIF info if available and already loaded
  */
 time_t getTime(const KFileItem*);