Suggestions/Ideas about a file browser

[SkripT]

Hi all, one of the options in my application is to browse all the images in a specified directory and move them to other directories (that could not exist). I have some ideas but I will be thankfully if you give me some other ideas before I program it. The only restriction is that the re-ubication of the image files has to be in a simple way like a drag-and-drop. I have thought in having a QListWidget with a thumbnailing of all the images in the "source" directory. This directory is inserted in a QLineEdit or chosen using a button connected to QFileDialog::getExistingDirectory. For the destination folder I have thought in having the same widgets: a list view, a line edit and the button. So the user only should has to select the destination folder and drag and drop all the files from the source directory to the destination. Another posssiblity could be in replacing the QListWidget in the destination for a tree showing the file system giving the possiblity to create new directories and drag the list widget items of the source directory to an entry of this tree. I don't know if this could be possible. I also have thought in having another tree in the source folder too... Anyway, what do you suggest me?

Thanks.

[SkripT]

Hi again, I've thought in another solution: having a QDirModel with a tree structure showing the dirs of the file system in one place and on the other place a QListWidget that will contains the thumbnailed images for the current/selected directory in the dir model. I have some questions about it:
1) To copy image files between directories, is possible to drag QListWidgetItems from the list widget to drop them in a directory entry of the dir model?
2) Is possible to show a menu when the user clicks with the right button of the mouse an entry of the dir model? This menu will show the actions to do with a directory: rename it, delete it, create sub-directory, view the images in the list widget, ...

[jpn]

I'd say, forget about the QListWidget and use a QDirModel+QListView instead..

[SkripT]

I'd say, forget about the QListWidget and use a QDirModel+QListView instead..

jpn I appreciate your suggestion but can you give me some reasons and how you think that I should use the list view?

[jpn]

Because it's this simple:

#include <QtGui>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
	// a "file manager" at simplest :)
	QSplitter* splitter = new QSplitter;
	QDirModel* model = new QDirModel;
	QTreeView* tree = new QTreeView(splitter);
	tree->setModel(model);
	QListView* list = new QListView(splitter);
	list->setModel(model);
	list->setDragEnabled(true);
	splitter->show();
 
	// tree navigation by click
	QObject::connect(tree, SIGNAL(clicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// list navigation by dbl click
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// update tree upon list change
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		tree, SLOT(setCurrentIndex(const QModelIndex&)));
 
	a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

#include <QtGui>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

	// a "file manager" at simplest :)
	QSplitter* splitter = new QSplitter;
	QDirModel* model = new QDirModel;
	QTreeView* tree = new QTreeView(splitter);
	tree->setModel(model);
	QListView* list = new QListView(splitter);
	list->setModel(model);
	list->setDragEnabled(true);
	splitter->show();

	// tree navigation by click
	QObject::connect(tree, SIGNAL(clicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// list navigation by dbl click
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// update tree upon list change
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		tree, SLOT(setCurrentIndex(const QModelIndex&)));
	
	a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

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Notice the amount of code ..with this, you can already drag'n drop a file from the list view to e.g. desktop..

[SkripT]

Cool jpn thanks , where have you get this example? Is it from your creation?

[jpn]

No problem. Yep, I did it myself..
It's not a complete solution, just a small example demonstrating the power of QDirModel

[Lemming]

You can further improve the above implementation by setting the file icon provider for your list to show the thumbnails for your images in the list. Refer to the QFileIconProvider class in QT documentation. Implementing the icon provider for the thumbnails will look like this:

QIcon MyIconProvider::icon ( const QFileInfo & info ) const
{
//Initializing the pixmap from file
QPixmap pixmap( info.filePath() );
//Processing the valid pixmap
if ( !pixmap.isNull() )
{
//Resizing the pixmap to the required thumbnail size
pixmap = pixmap.scaled( mySize );
return QIcon( pixmap );
}
else return QIcon();
}

QIcon MyIconProvider::icon ( const QFileInfo & info ) const
{
//Initializing the pixmap from file
QPixmap pixmap( info.filePath() );
//Processing the valid pixmap
if ( !pixmap.isNull() )
{
//Resizing the pixmap to the required thumbnail size
pixmap = pixmap.scaled( mySize );
return QIcon( pixmap );
}
else return QIcon();
}

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You'll have to set-up the icon size of your list view to mySize by calling the setIconSize() method and set the icon provider for your QDirModel. This implementation can be further improved, but this is something to start with.

[SkripT]

Do you know if there's any documentation that shows detailed some examples on how to work with a QDirModel and its communication with a QListView or how to create a complete file manager with it?

[jpn]

Not that I know. The only example of QDirModel usage provided with Qt is the Dir View example.
Neither does the QDirModel documentation provide much of example usage, but the common model/view programming concept applies here too..

[Lemming]

From my experience of implementing the full-scale file browser, QT documentation is sufficient to get things working if you're familiar with Model/View architecture. If not, you probably shold start with reading the Model/View tutorial that is supplied with QT.

BTW, there was a nice file browser example in QT3 solutions. Unfortunately it is not yet ported to QT4, causing a lot of troubles for those who need a file browser in their application.

[nupul]

The simple file browser provided by jpn is a great example..but it does not have the drop facility within the listview itself...(both, on the left as well as right col. of the splitter)...ummm how would you achieve this!!

Nupul

[Lemming]

You'll have to subclass from QListView and overload the dropEvent

//Enabling the drops for the list viewport
list->viewport()->setAcceptDrops( true );
 
void FileExplorerList::dropEvent( QDropEvent *event )
{
[INDENT]if ( event->mimeData()->hasUrls() )
{
[INDENT]
//Getting the dir model of the list
QDirModel *dirModel = qobject_cast<QDirModel*>( list->model() );
//Dropping the mime data
dirModel->dropMimeData( event->mimeData(), event->proposedAction(), parentIndex );
//Note: it's up to you to get the parent index for the drop operation[/INDENT]
}[/INDENT]}

//Enabling the drops for the list viewport
list->viewport()->setAcceptDrops( true );

void FileExplorerList::dropEvent( QDropEvent *event )
{
[INDENT]if ( event->mimeData()->hasUrls() )
{
[INDENT]
//Getting the dir model of the list
QDirModel *dirModel = qobject_cast<QDirModel*>( list->model() );
//Dropping the mime data
dirModel->dropMimeData( event->mimeData(), event->proposedAction(), parentIndex );
//Note: it's up to you to get the parent index for the drop operation[/INDENT]
}[/INDENT]}

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This should work fine. Actually, there is QDirModel::setReadOnly( bool ) method as well. I'm not sure about it, but setting it to on might possible enable the default drop functionality for the dir model.

[invictus]

Because it's this simple:

#include <QtGui>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
	// a "file manager" at simplest :)
	QSplitter* splitter = new QSplitter;
	QDirModel* model = new QDirModel;
	QTreeView* tree = new QTreeView(splitter);
	tree->setModel(model);
	QListView* list = new QListView(splitter);
	list->setModel(model);
	list->setDragEnabled(true);
	splitter->show();
 
	// tree navigation by click
	QObject::connect(tree, SIGNAL(clicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// list navigation by dbl click
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// update tree upon list change
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		tree, SLOT(setCurrentIndex(const QModelIndex&)));
 
	a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

#include <QtGui>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

	// a "file manager" at simplest :)
	QSplitter* splitter = new QSplitter;
	QDirModel* model = new QDirModel;
	QTreeView* tree = new QTreeView(splitter);
	tree->setModel(model);
	QListView* list = new QListView(splitter);
	list->setModel(model);
	list->setDragEnabled(true);
	splitter->show();

	// tree navigation by click
	QObject::connect(tree, SIGNAL(clicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// list navigation by dbl click
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		list, SLOT(setRootIndex(const QModelIndex&)));
	// update tree upon list change
	QObject::connect(list, SIGNAL(doubleClicked(const QModelIndex&)),
		tree, SLOT(setCurrentIndex(const QModelIndex&)));
	
	a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

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Notice the amount of code ..with this, you can already drag'n drop a file from the list view to e.g. desktop..

Nice... is there any way you can go back to the parent of the "current" modelindex? Or does setRootIndex() overwrite everything "above" the defined index?

I am using a QTreeView with
view->setRootIsDecorated(false);
view->setItemsExpandable(false);

So I can only see the top level list.

[jpn]

You can get the parent via QModelIndex::parent(). If you want to provide a button with "go one level up" -functionality, the slot connected to button's SIGNAL(clicked()) would do roughly:

QModelIndex parent = view->rootIndex().parent();
view->setRootIndex(parent);
button->setEnabled(parent.parent().isValid());

QModelIndex parent = view->rootIndex().parent();
view->setRootIndex(parent);
button->setEnabled(parent.parent().isValid());

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[invictus]

You can get the parent via QModelIndex::parent(). If you want to provide a button with "go one level up" -functionality, the slot connected to button's SIGNAL(clicked()) would do roughly:

QModelIndex parent = view->currentIndex().parent();
view->setCurrentIndex(parent);
button->setEnabled(parent.parent().isValid());

QModelIndex parent = view->currentIndex().parent();
view->setCurrentIndex(parent);
button->setEnabled(parent.parent().isValid());

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This seem to work fine...until I select an item. Then the up-action will no longer work for some reason. Although I am using setRootIndex instead of setCurrentIndex in order to show a flat structure instead of a tree.

[jpn]

This seem to work fine...until I select an item. Then the up-action will no longer work for some reason. Although I am using setRootIndex instead of setCurrentIndex in order to show a flat structure instead of a tree.

Oops, sorry. Those should've been rootIndex() and setRootIndex(). Thanks for pointing it out. I have corrected it to my previous post..

[invictus]

Oops, sorry. Those should've been rootIndex() and setRootIndex(). Thanks for pointing it out. I have corrected it to my previous post..

Yeah, but thats when it is not working, unfortunately

[mchara]

hello all,
and what about providing custom class inherited from QFileIconProvider (QDirModel::setIconProvider()) that generates thumbnails? My app generates them in separate thread & stores thumbnails in xmlfile in each directory it works great, maybe with similar ithumbsProvider you could have only one QTreeView with thumbnails inside & drag&drop functionalities?

[jpn]

QtCentreWiki: Extended Dir View example