Provide functionality for auto-expanding folders (the whole patch has been provided by Simon St James). The setting is currently not offered in the GUI, as some minor remaining issues must be fixed.

CCMAIL: [email protected]

svn path=/trunk/KDE/kdebase/apps/; revision=845975

1 files changed, 155 insertions, 0 deletions

diff --git a/src/folderexpander.cpp b/src/folderexpander.cpp
new file mode 100644
index 000000000..f7b73c1f5
--- /dev/null
+++ b/src/folderexpander.cpp
@@ -0,0 +1,155 @@
+/***************************************************************************
+ *   Copyright (C) 2008 by Simon St James <[email protected]>  *
+ *                                                                         *
+ *   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.,                                       *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
+ ***************************************************************************/
+
+#include "folderexpander.h"
+#include "dolphinview.h"
+
+#include "dolphinsettings.h"
+#include "dolphin_generalsettings.h"
+
+#include <QtCore/QTimer>
+#include <QtGui/QAbstractItemView>
+#include <QtGui/QTreeView>
+#include <QtGui/QScrollBar>
+
+#include <QtCore/QEvent>
+#include <QtGui/QDragMoveEvent>
+
+#include <QtGui/QSortFilterProxyModel>
+
+#include <kdirmodel.h>
+#include <kdebug.h>
+
+FolderExpander::FolderExpander(QAbstractItemView *view, QSortFilterProxyModel *proxyModel) :
+    QObject(view),
+    m_enabled(true),
+    m_view(view),
+    m_proxyModel(proxyModel),
+    m_autoExpandTriggerTimer(0),
+    m_autoExpandPos()
+{
+    // Validation.  If these fail, the event filter is never
+    // installed on the view and the FolderExpander is inactive.
+    if (m_view == 0)  {
+        kWarning() << "Need a view!";
+        return; // Not valid.
+    }
+    if (m_proxyModel == 0)  {
+        kWarning() << "Need a proxyModel!";
+        return; // Not valid.
+    }
+    KDirModel *m_dirModel = qobject_cast< KDirModel* >( m_proxyModel->sourceModel() );  
+    if (m_dirModel == 0) {
+        kWarning() << "Expected m_proxyModel's sourceModel() to be a KDirModel!";
+        return; // Not valid.
+    }
+
+    // Initialise auto-expand timer.
+    m_autoExpandTriggerTimer = new QTimer(this);
+    m_autoExpandTriggerTimer->setSingleShot(true);
+    connect(m_autoExpandTriggerTimer, SIGNAL(timeout()), 
+            this, SLOT(autoExpandTimeout()));
+
+    // The view scrolling complicates matters, so we want to
+    // be informed if they occur.
+    connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
+            this, SLOT(viewScrolled()));
+    connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
+            this, SLOT(viewScrolled()));
+
+    // "Dragging" events are sent to the QAbstractItemView's viewport.
+    m_view->viewport()->installEventFilter(this);
+}
+
+void FolderExpander::setEnabled(bool enabled)
+{
+    m_enabled = enabled;
+}
+
+bool FolderExpander::enabled() const
+{
+    return m_enabled;
+}
+
+FolderExpander::~FolderExpander()
+{
+}
+
+void FolderExpander::viewScrolled()
+{
+    if (m_autoExpandTriggerTimer->isActive())  {
+        kDebug() << "Resetting time due to scrolling!"; 
+        // (Re-)set the timer while we're scrolling the view
+        // (or it's being scrolled by some external mechanism).
+        // TODO - experiment with this.  Cancelling the timer,
+        // or adding a "penalty" on top of AUTO_EXPAND_DELAY
+        // might work more nicely when drilling down through the sidebar
+        // tree.
+        m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
+    }
+}
+
+void FolderExpander::autoExpandTimeout()
+{
+    if (!m_enabled) {
+        return;
+    }
+
+    // We want to find whether the file currently being hovered over is a
+    // directory. TODO - is there a simpler way, preferably without
+    // needing to pass in m_proxyModel that has a KDirModel as its sourceModel() ... ?
+    QModelIndex proxyIndexToExpand = m_view->indexAt(m_autoExpandPos);
+    QModelIndex indexToExpand = m_proxyModel->mapToSource(proxyIndexToExpand);
+    KDirModel* m_dirModel = qobject_cast< KDirModel* >(m_proxyModel->sourceModel()); 
+    Q_ASSERT(m_dirModel != 0);
+    KFileItem itemToExpand = m_dirModel->itemForIndex(indexToExpand );
+
+    kDebug() << "Need to expand: " << itemToExpand.targetUrl() << " isDir? = " << itemToExpand.isDir();
+
+    if (itemToExpand.isDir()) {
+        QTreeView *viewAsTreeView = qobject_cast<QTreeView*>(m_view);
+        if (viewAsTreeView != 0) {
+            // Toggle expanded state of this directory.
+            viewAsTreeView->setExpanded(proxyIndexToExpand, !viewAsTreeView->isExpanded(proxyIndexToExpand));
+        }
+        else {
+            // Enter this directory.
+            emit enterDir(proxyIndexToExpand);
+        }
+    }
+}
+
+bool FolderExpander::eventFilter(QObject* watched, QEvent* event)
+{
+    Q_UNUSED(watched);
+    // We're interested in reading Drag* events, but not filtering them,
+    // so always return false.
+    // We just store the position of the hover, here; actually working out
+    // what the hovered item is and whether it is expandable is done in
+    // autoExpandTimeout.
+    if (event->type() == QEvent::DragMove) {
+        QDragMoveEvent *dragMoveEvent = static_cast<QDragMoveEvent*>(event);
+        // (Re-)set the timer while we're still moving and dragging.
+        m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
+        m_autoExpandPos = dragMoveEvent->pos();
+    } else if (event->type() == QEvent::DragLeave || event->type() == QEvent::Drop) {
+        m_autoExpandTriggerTimer->stop();
+    }
+    return false;
+}