Q3FileDialog Class Reference
^{[Qt3Support module]}

Creating and using preview widgets

There are two kinds of preview widgets that can be used with Q3FileDialogs: content preview widgets and information preview widgets. They are created and used in the same way except that the function names differ, e.g. setContentsPreview() and setInfoPreview().

A preview widget is a widget that is placed inside a Q3FileDialog so that the user can see either the contents of the file, or information about the file.

      class Preview : public QLabel, public Q3FilePreview
      {
      public:
          Preview(QWidget *parent=0) : QLabel(parent) {}

          void previewUrl(const Q3Url &u)
          {
              QString path = u.path();
              QPixmap pix(path);
              if (pix.isNull())
                  setText("This is not a pixmap");
              else
                  setPixmap(pix);
          }
      };

In the above snippet, we create a preview widget which inherits from QLabel and Q3FilePreview. File preview widgets must inherit from Q3FilePreview.

Inside the class we reimplement Q3FilePreview::previewUrl(), this is where we determine what happens when a file is selected. In the above example we only show a preview of the file if it is a valid pixmap. Here's how to make a file dialog use a preview widget:

      Preview* p = new Preview;

      Q3FileDialog* fd = new Q3FileDialog(this);
      fd->setContentsPreviewEnabled(true);
      fd->setContentsPreview(p, p);
      fd->setPreviewMode(Q3FileDialog::Contents);
      fd->show();

The first line creates an instance of our preview widget. We then create our file dialog and call setContentsPreviewEnabled(true), this tell the file dialog to preview the contents of the currently selected file. We then call setContentsPreview() -- note that we pass the same preview widget twice. Finally, before showing the file dialog, we call setPreviewMode() setting the mode to Contents which will show the contents preview of the file that the user has selected.

If you create another preview widget that is used for displaying information about a file, create it in the same way as the contents preview widget and call setInfoPreviewEnabled(), and setInfoPreview(). Then the user will be able to switch between the two preview modes.

For more information about creating a Q3FilePreview widget see Q3FilePreview.

Member Type Documentation

enum Q3FileDialog::Mode

This enum is used to indicate what the user may select in the file dialog, i.e. what the dialog will return if the user clicks OK.

See setMode().

enum Q3FileDialog::PreviewMode

This enum describes the preview mode of the file dialog.

See setPreviewMode(), setContentsPreview() and setInfoPreview().

enum Q3FileDialog::ViewMode

This enum describes the view mode of the file dialog, i.e. what information about each file will be displayed.

See setViewMode().

Property Documentation

contentsPreview : bool

This property holds whether the file dialog can provide a contents preview of the currently selected file.

The default is false.

Access functions:

• bool isContentsPreviewEnabled () const
• void setContentsPreviewEnabled ( bool )

See also setContentsPreview() and setInfoPreviewEnabled().

dirPath : const QString

This property holds the file dialog's working directory.

Access functions:

• QString dirPath () const

See also dir() and setDir().

infoPreview : bool

This property holds whether the file dialog can provide preview information about the currently selected file.

The default is false.

Access functions:

• bool isInfoPreviewEnabled () const
• void setInfoPreviewEnabled ( bool )

mode : Mode

This property holds the file dialog's mode.

The default mode is ExistingFile.

Access functions:

• Mode mode () const
• void setMode ( Mode )

previewMode : PreviewMode

This property holds the preview mode for the file dialog.

If you set the mode to be a mode other than NoPreview, you must use setInfoPreview() or setContentsPreview() to set the dialog's preview widget to your preview widget and enable the preview widget(s) with setInfoPreviewEnabled() or setContentsPreviewEnabled().

Access functions:

• PreviewMode previewMode () const
• void setPreviewMode ( PreviewMode m )

See also infoPreview, contentsPreview, and viewMode.

selectedFile : const QString

This property holds the name of the selected file.

If a file was selected selectedFile contains the file's name including its absolute path; otherwise selectedFile is empty.

Access functions:

• QString selectedFile () const

See also QString::isEmpty(), selectedFiles, and selectedFilter.

selectedFiles : const QStringList

This property holds the list of selected files.

If one or more files are selected, selectedFiles contains their names including their absolute paths. If no files are selected or the mode isn't ExistingFiles selectedFiles is an empty list.

It is more convenient to use selectedFile() if the mode is ExistingFile, Directory or DirectoryOnly.

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    QStringList list = myFileDialog.selectedFiles();
    QStringList::Iterator it = list.begin();
    while(it != list.end()) {
        myProcessing(*it);
        ++it;
    }

Access functions:

• QStringList selectedFiles () const

See also selectedFile, selectedFilter, and QList::isEmpty().

selectedFilter : const QString

This property holds the filter which the user has selected in the file dialog.

Access functions:

• QString selectedFilter () const

See also filterSelected(), selectedFiles, and selectedFile.

showHiddenFiles : bool

This property holds whether hidden files are shown in the file dialog.

The default is false, i.e. don't show hidden files.

Access functions:

• bool showHiddenFiles () const
• void setShowHiddenFiles ( bool s )

viewMode : ViewMode

This property holds the file dialog's view mode.

If you set the view mode to be Detail (the default), then you will see the file's details, such as the size of the file and the date the file was last modified in addition to the file's name.

If you set the view mode to be List, then you will just see a list of the files and folders.

See Q3FileDialog::ViewMode

Access functions:

• ViewMode viewMode () const
• void setViewMode ( ViewMode m )

Member Function Documentation

Q3FileDialog::Q3FileDialog ( const QString & dirName, const QString & filter = QString(), QWidget * parent = 0, const char * name = 0, bool modal = false )

Constructs a file dialog called name with the parent, parent. If modal is true then the file dialog is modal; otherwise it is modeless.

If dirName is specified then it will be used as the dialog's working directory, i.e. it will be the directory that is shown when the dialog appears. If filter is specified it will be used as the dialog's file filter.

Q3FileDialog::Q3FileDialog ( QWidget * parent = 0, const char * name = 0, bool modal = false )

Constructs a file dialog called name, with the parent, parent. If modal is true then the file dialog is modal; otherwise it is modeless.

Q3FileDialog::~Q3FileDialog ()

Destroys the file dialog.

void Q3FileDialog::addFilter ( const QString & filter )

Adds the filter filter to the list of filters and makes it the current filter.

    Q3FileDialog* fd = new Q3FileDialog(this);
    fd->addFilter("Images (*.png *.jpg *.xpm)");
    fd->show();

In the above example, a file dialog is created, and the file filter "Images (*.png *.jpg *.xpm)" is added and is set as the current filter. The original filter, "All Files (*)", is still available.

See also setFilter() and setFilters().

void Q3FileDialog::addLeftWidget ( QWidget * w )   [protected]

Adds the widget w to the left-hand side of the file dialog.

See also addRightWidget(), addWidgets(), and addToolButton().

void Q3FileDialog::addRightWidget ( QWidget * w )   [protected]

Adds the widget w to the right-hand side of the file dialog.

See also addLeftWidget(), addWidgets(), and addToolButton().

void Q3FileDialog::addToolButton ( QAbstractButton * b, bool separator = false )   [protected]

Adds the tool button b to the row of tool buttons at the top of the file dialog. The button is appended to the right of this row. If separator is true, a small space is inserted between the last button of the row and the new button b.

See also addWidgets(), addLeftWidget(), and addRightWidget().

void Q3FileDialog::addWidgets ( QLabel * l, QWidget * w, QPushButton * b )   [protected]

Adds the specified widgets to the bottom of the file dialog. The label l is placed underneath the "file name" and the "file types" labels. The widget w is placed underneath the file types combobox. The button b is placed underneath the Cancel pushbutton.

    MyFileDialog::MyFileDialog(QWidget* parent, const char* name) :
        Q3FileDialog(parent, name)
    {
        QLabel* label = new QLabel("Added widgets", this);
        QLineEdit* lineedit = new QLineEdit(this);
        QPushButton* pushbutton = new QPushButton(this);

        addWidgets(label, lineedit, pushbutton);
    }

If you don't want to have one of the widgets added, pass 0 in that widget's position.

Every time you call this function, a new row of widgets will be added to the bottom of the file dialog.

See also addToolButton(), addLeftWidget(), and addRightWidget().

const QDir * Q3FileDialog::dir () const

Returns the current directory shown in the file dialog.

The ownership of the QDir pointer is transferred to the caller, so it must be deleted by the caller when no longer required.

See also setDir().

void Q3FileDialog::dirEntered ( const QString & directory )   [signal]

This signal is emitted when the user enters the given directory.

See also dir().

void Q3FileDialog::fileHighlighted ( const QString & file )   [signal]

This signal is emitted when the user highlights the given file, i.e. makes it the current file.

See also fileSelected() and filesSelected().

void Q3FileDialog::fileSelected ( const QString & file )   [signal]

This signal is emitted when the user selects the given file.

See also filesSelected(), fileHighlighted(), and selectedFile().

void Q3FileDialog::filesSelected ( const QStringList & files )   [signal]

This signal is emitted when the user selects the given files in ExistingFiles mode.

See also fileSelected(), fileHighlighted(), and selectedFiles().

void Q3FileDialog::filterSelected ( const QString & filter )   [signal]

This signal is emitted when the user selects the given filter.

See also selectedFilter().

QString Q3FileDialog::getExistingDirectory ( const QString & dir = QString(), QWidget * parent = 0, const char * name = 0, const QString & caption = QString(), bool dirOnly = true, bool resolveSymlinks = true )   [static]

This is a convenience static function that will return an existing directory selected by the user.

    QString s = Q3FileDialog::getExistingDirectory(
                    "/home",
                    this,
                    "get existing directory",
                    "Choose a directory",
                    true);

This function creates a modal file dialog called name, with parent, parent. If parent is not 0, the dialog will be shown centered over the parent.

The dialog's working directory is set to dir, and the caption is set to caption. Either of these may be an empty string in which case the current directory and a default caption will be used respectively.

If dirOnly is true, then only directories will be shown in the file dialog; otherwise both directories and files will be shown.

Under Unix/X11, the normal behavior of the file dialog is to resolve and follow symlinks. For example, if /usr/tmp is a symlink to /var/tmp, the file dialog will change to /var/tmp after entering /usr/tmp. If resolveSymlinks is false, the file dialog will treat symlinks as regular directories.

Note that on Windows the dialog will spin a blocking modal event loop that will not dispatch any QTimers and if parent is not 0 then it will position the dialog just under the parent's title bar.

See also getOpenFileName(), getOpenFileNames(), and getSaveFileName().

QString Q3FileDialog::getOpenFileName ( const QString & startWith = QString(), const QString & filter = QString(), QWidget * parent = 0, const char * name = 0, const QString & caption = QString(), QString * selectedFilter = 0, bool resolveSymlinks = true )   [static]

This is a convenience static function that returns an existing file selected by the user. If the user pressed Cancel, it returns a null string.

    QString s = Q3FileDialog::getOpenFileName(
                    "/home",
                    "Images (*.png *.xpm *.jpg)",
                    this,
                    "open file dialog",
                    "Choose a file to open");

The function creates a modal file dialog called name, with parent, parent. If a parent is not 0, the dialog will be shown centered over the parent.

The file dialog's working directory will be set to startWith. If startWith includes a file name, the file will be selected. The filter is set to filter so that only those files which match the filter are shown. The filter selected is set to selectedFilter. The parameters startWith, selectedFilter and filter may be an empty string.

The dialog's caption is set to caption. If caption is not specified then a default caption will be used.

Under Windows and Mac OS X, this static function will use the native file dialog and not a Q3FileDialog, unless the style of the application is set to something other than the native style (Note that on Windows the dialog will spin a blocking modal event loop that will not dispatch any QTimers and if parent is not 0 then it will position the dialog just under the parent's title bar).

Under Unix/X11, the normal behavior of the file dialog is to resolve and follow symlinks. For example, if /usr/tmp is a symlink to /var/tmp, the file dialog will change to /var/tmp after entering /usr/tmp. If resolveSymlinks is false, the file dialog will treat symlinks as regular directories.

See also getOpenFileNames(), getSaveFileName(), and getExistingDirectory().

QStringList Q3FileDialog::getOpenFileNames ( const QString & filter = QString(), const QString & dir = QString(), QWidget * parent = 0, const char * name = 0, const QString & caption = QString(), QString * selectedFilter = 0, bool resolveSymlinks = true )   [static]

This is a convenience static function that will return one or more existing files selected by the user.

    QStringList files = Q3FileDialog::getOpenFileNames(
                            "Images (*.png *.xpm *.jpg)",
                            "/home",
                            this,
                            "open files dialog",
                            "Select one or more files to open");

This function creates a modal file dialog called name, with parent parent. If parent is not 0, the dialog will be shown centered over the parent.

The file dialog's working directory will be set to dir. If dir includes a file name, the file will be selected. The filter is set to filter so that only those files which match the filter are shown. The filter selected is set to selectedFilter. The parameters dir, selectedFilter and filter may be empty strings.

The dialog's caption is set to caption. If caption is not specified then a default caption will be used.

Under Windows and Mac OS X, this static function will use the native file dialog and not a Q3FileDialog, unless the style of the application is set to something other than the native style. (Note that on Windows the dialog will spin a blocking modal event loop that will not dispatch any QTimers and if parent is not 0 then it will position the dialog just under the parent's title bar).

Under Unix/X11, the normal behavior of the file dialog is to resolve and follow symlinks. For example, if /usr/tmp is a symlink to /var/tmp, the file dialog will change to /var/tmp after entering /usr/tmp. If resolveSymlinks is false, the file dialog will treat symlinks as regular directories.

Note that if you want to iterate over the list of files, you should iterate over a copy, e.g.

    QStringList list = files;
    QStringList::Iterator it = list.begin();
    while(it != list.end()) {
        myProcessing(*it);
        ++it;
    }

See also getOpenFileName(), getSaveFileName(), and getExistingDirectory().

QString Q3FileDialog::getSaveFileName ( const QString & startWith = QString(), const QString & filter = QString(), QWidget * parent = 0, const char * name = 0, const QString & caption = QString(), QString * selectedFilter = 0, bool resolveSymlinks = true )   [static]

This is a convenience static function that will return a file name selected by the user. The file does not have to exist.

It creates a modal file dialog called name, with parent, parent. If a parent is not 0, the dialog will be shown centered over the parent.

    QString s = Q3FileDialog::getSaveFileName(
                    "/home",
                    "Images (*.png *.xpm *.jpg)",
                    this,
                    "save file dialog",
                    "Choose a filename to save under");

The file dialog's working directory will be set to startWith. If startWith includes a file name, the file will be selected. The filter is set to filter so that only those files which match the filter are shown. The filter selected is set to selectedFilter. The parameters startWith, selectedFilter and filter may be an empty string.

The dialog's caption is set to caption. If caption is not specified then a default caption will be used.

Under Windows and Mac OS X, this static function will use the native file dialog and not a Q3FileDialog, unless the style of the application is set to something other than the native style. (Note that on Windows the dialog will spin a blocking modal event loop that will not dispatch any QTimers and if parent is not 0 then it will position the dialog just under the parent's title bar. And on the Mac the filter argument is ignored).

Under Unix/X11, the normal behavior of the file dialog is to resolve and follow symlinks. For example, if /usr/tmp is a symlink to /var/tmp, the file dialog will change to /var/tmp after entering /usr/tmp. If resolveSymlinks is false, the file dialog will treat symlinks as regular directories.

See also getOpenFileName(), getOpenFileNames(), and getExistingDirectory().

Q3FileIconProvider * Q3FileDialog::iconProvider ()   [static]

Returns a pointer to the icon provider currently set on the file dialog. By default there is no icon provider, and this function returns 0.

See also setIconProvider() and Q3FileIconProvider.

void Q3FileDialog::rereadDir ()

Rereads the current directory shown in the file dialog.

The only time you will need to call this function is if the contents of the directory change and you wish to refresh the file dialog to reflect the change.

See also resortDir().

void Q3FileDialog::resortDir ()

Re-sorts the displayed directory.

See also rereadDir().

void Q3FileDialog::selectAll ( bool b )

If b is true then all the files in the current directory are selected; otherwise, they are deselected.

void Q3FileDialog::setContentsPreview ( QWidget * w, Q3FilePreview * preview )

Sets the widget to be used for displaying the contents of the file to the widget w and a preview of those contents to the Q3FilePreview preview.

Normally you would create a preview widget that derives from both QWidget and Q3FilePreview, so you should pass the same widget twice.

      class Preview : public QLabel, public Q3FilePreview
      {
      public:
          Preview(QWidget *parent=0) : QLabel(parent) {}

          void previewUrl(const Q3Url &u)
          {
              QString path = u.path();
              QPixmap pix(path);
              if (pix.isNull())
                  setText("This is not a pixmap");
              else
                  setPixmap(pix);
          }
      };

    //...

    int main(int argc, char** argv)
    {
      Preview* p = new Preview;

      Q3FileDialog* fd = new Q3FileDialog(this);
      fd->setContentsPreviewEnabled(true);
      fd->setContentsPreview(p, p);
      fd->setPreviewMode(Q3FileDialog::Contents);
      fd->show();
    }

See also setContentsPreviewEnabled(), setInfoPreview(), and setPreviewMode().

void Q3FileDialog::setDir ( const QDir & dir )

Sets the file dialog's working directory to dir.

See also dir().

void Q3FileDialog::setDir ( const QString & pathstr )   [slot]

This is an overloaded member function, provided for convenience.

Sets the file dialog's working directory to pathstr.

See also dir().

void Q3FileDialog::setFilter ( const QString & newFilter )   [slot]

Sets the filter used in the file dialog to newFilter.

If newFilter contains a pair of parentheses containing one or more of "anything*something" separated by spaces or by semicolons then only the text contained in the parentheses is used as the filter. This means that these calls are all equivalent:

    fd->setFilter("All C++ files (*.cpp *.cc *.C *.cxx *.c++)");
    fd->setFilter("*.cpp *.cc *.C *.cxx *.c++");
    fd->setFilter("All C++ files (*.cpp;*.cc;*.C;*.cxx;*.c++)");
    fd->setFilter("*.cpp;*.cc;*.C;*.cxx;*.c++");

See also setFilters().

void Q3FileDialog::setFilters ( const QString & filters )   [slot]

Sets the filters used in the file dialog to filters. Each group of filters must be separated by ;; (two semicolons).

    QString types("Image files (*.png *.xpm *.jpg);;"
                  "Text files (*.txt);;"
                  "Any files (*)");
    Q3FileDialog fd = new Q3FileDialog(this);
    fd->setFilters(types);
    fd->show();

void Q3FileDialog::setFilters ( const char ** types )   [slot]

This is an overloaded member function, provided for convenience.

types must be a null-terminated list of strings.

void Q3FileDialog::setFilters ( const QStringList & types )   [slot]

This is an overloaded member function, provided for convenience.

types is a list of filter strings.

void Q3FileDialog::setIconProvider ( Q3FileIconProvider * provider )   [static]

Sets the Q3FileIconProvider used by the file dialog to provider.

The default is that there is no Q3FileIconProvider and Q3FileDialog just draws a folder icon next to each directory and nothing next to files.

See also Q3FileIconProvider and iconProvider().

void Q3FileDialog::setInfoPreview ( QWidget * w, Q3FilePreview * preview )

Sets the widget to be used for displaying information about the file to the widget w and a preview of that information to the Q3FilePreview preview.

Normally you would create a preview widget that derives from both QWidget and Q3FilePreview, so you should pass the same widget twice.

      class Preview : public QLabel, public Q3FilePreview
      {
      public:
          Preview(QWidget *parent=0) : QLabel(parent) {}

          void previewUrl(const Q3Url &u)
          {
              QString path = u.path();
              QPixmap pix(path);
              if (pix.isNull())
                  setText("This is not a pixmap");
              else
                  setText("This is a pixmap");
          }
      };

    //...

    int main(int argc, char** argv)
    {
      Preview* p = new Preview;

      Q3FileDialog* fd = new Q3FileDialog(this);
      fd->setInfoPreviewEnabled(true);
      fd->setInfoPreview(p, p);
      fd->setPreviewMode(Q3FileDialog::Info);
      fd->show();
    }

See also setContentsPreview(), setInfoPreviewEnabled(), and setPreviewMode().

void Q3FileDialog::setSelectedFilter ( const QString & mask )   [virtual]

Sets the current filter selected in the file dialog to the first one that contains the text mask.

See also selectedFilter().

void Q3FileDialog::setSelectedFilter ( int n )   [virtual]

This is an overloaded member function, provided for convenience.

Sets the current filter selected in the file dialog to the n-th filter in the filter list.

See also filterSelected(), selectedFilter(), selectedFiles(), and selectedFile().

void Q3FileDialog::setSelection ( const QString & filename )

Sets the default selection to filename. If filename is absolute, setDir() is also called to set the file dialog's working directory to the filename's directory.

void Q3FileDialog::setUrl ( const Q3UrlOperator & url )   [slot]

Sets the file dialog's working directory to the directory specified at url.

See also url().

Q3Url Q3FileDialog::url () const

Returns the URL of the current working directory in the file dialog.

See also setUrl().