File System View: Make keyboard navigation magical

Ensuring that there's always a current index is hard work since the
data comes in asynchronously and is unsorted at first.

Task-number: QTCREATORBUG-10250
Change-Id: I2cd1420bb447ad7257f6200bcffc454a214932aa
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/projectexplorer/foldernavigationwidget.cpp

@@ -158,6 +158,8 @@ FolderNavigationWidget::FolderNavigationWidget(QWidget *parent)
             this, SLOT(slotOpenItem(QModelIndex)));
     connect(m_filterHiddenFilesAction, SIGNAL(toggled(bool)), this, SLOT(setHiddenFilesFilter(bool)));
     connect(m_toggleSync, SIGNAL(clicked(bool)), this, SLOT(toggleAutoSynchronization()));
+    connect(m_filterModel, SIGNAL(layoutChanged()),
+            this, SLOT(ensureCurrentIndex()));
 }
 
 void FolderNavigationWidget::toggleAutoSynchronization()
@@ -225,10 +227,17 @@ bool FolderNavigationWidget::setCurrentDirectory(const QString &directory)
         setCurrentTitle(QString(), QString());
         return false;
     }
-    m_listView->setRootIndex(m_filterModel->mapFromSource(index));
+    QModelIndex oldRootIndex = m_listView->rootIndex();
+    QModelIndex newRootIndex = m_filterModel->mapFromSource(index);
+    m_listView->setRootIndex(newRootIndex);
     const QDir current(QDir::cleanPath(newDirectory));
     setCurrentTitle(current.dirName(),
                     QDir::toNativeSeparators(current.absolutePath()));
+    if (oldRootIndex.parent() == newRootIndex) { // cdUp, so select the old directory
+        m_listView->setCurrentIndex(oldRootIndex);
+        m_listView->scrollTo(oldRootIndex, QAbstractItemView::EnsureVisible);
+    }
+
     return !directory.isEmpty();
 }
 
@@ -365,6 +374,17 @@ bool FolderNavigationWidget::hiddenFilesFilter() const
     return m_filterHiddenFilesAction->isChecked();
 }
 
+void FolderNavigationWidget::ensureCurrentIndex()
+{
+    QModelIndex index = m_listView->currentIndex();
+    if (!index.isValid()
+            || index.parent() != m_listView->rootIndex()) {
+        index = m_listView->rootIndex().child(0, 0);
+        m_listView->setCurrentIndex(index);
+    }
+    m_listView->scrollTo(index);
+}
+
 // --------------------FolderNavigationWidgetFactory
 FolderNavigationWidgetFactory::FolderNavigationWidgetFactory()
 {

src/plugins/projectexplorer/foldernavigationwidget.h

@@ -70,6 +70,7 @@ private slots:
     void setCurrentFile(const QString &filePath);
     void slotOpenItem(const QModelIndex &viewIndex);
     void setHiddenFilesFilter(bool filter);
+    void ensureCurrentIndex();
 
 protected:
     virtual void contextMenuEvent(QContextMenuEvent *ev);