From 149b9a6766dbeeeb2b8f2168cb36df8dbf2612ed Mon Sep 17 00:00:00 2001
From: Brian Hrebec <brianh32@gmail.com>
Date: Sat, 2 Oct 2010 21:41:59 -0500
Subject: [PATCH] partial old-style drag support

---
 src/playlist/playlistview.cpp | 66 ++++++++++-------------------------
 src/playlist/playlistview.h   |  1 +
 2 files changed, 20 insertions(+), 47 deletions(-)

diff --git a/src/playlist/playlistview.cpp b/src/playlist/playlistview.cpp
index 415c3dc..128b61c 100644
--- a/src/playlist/playlistview.cpp
+++ b/src/playlist/playlistview.cpp
@@ -24,6 +24,7 @@
 #include "skin.h"
 #include "skinmanager.h"
 
+#include <QDebug>
 #include <QColor>
 #include <QMenu>
 #include <QPaintEvent>
@@ -31,6 +32,7 @@
 #include <QPalette>
 #include <QSettings>
 #include <QFontMetrics>
+#include <QScrollBar>
 
 #include <QSizePolicy>
 
@@ -123,7 +125,7 @@ PlaylistView::PlaylistView (QWidget *parent) : QListView (parent)
 
 	setSelectionMode (QAbstractItemView::ExtendedSelection);
 	setUniformItemSizes(true);
-	//setDragEnabled(true);
+	setDragEnabled(true);
 	setAcceptDrops(true);
 
 	// TODO make sure delegate gets deleted
@@ -325,17 +327,19 @@ PlaylistView::mouseMoveEvent (QMouseEvent *event)
 
 	if (mouseIndex.row () < 0 || sel.empty())
 		return;
-	
-	if (mouseIndex != currentIndex () && m_old_selection.empty()) {
+
+	if (mouseIndex != currentIndex () && m_old_selection.isEmpty()) {
 		m_old_current_index = currentIndex ().row();
 
 		qSort(sel);
 
 		int diff = mouseIndex.row () - currentIndex ().row ();
-		if (!(sel.first().row () + diff >= 0) || 
+		if (!(sel.first ().row () + diff >= 0) || 
 			!(sel.last ().row () + diff < model ()->rowCount ()))
 			return;
 
+		m_prev_scroll_pos = verticalScrollBar ()->value();
+
 		if (diff < 0 ) {
 			// move selection up
 			for (int i = 0; i < sel.size (); i++) {
@@ -355,46 +359,7 @@ PlaylistView::mouseMoveEvent (QMouseEvent *event)
 				m_old_selection.insert(row);
 			}
 		}
-		setSelectionMode (QAbstractItemView::NoSelection);
-		setCurrentIndex(mouseIndex);
-		setSelectionMode (QAbstractItemView::ExtendedSelection);
 	}
-
-
-	/*
-
-	QRect r = visualRect(currentIndex ());
-	int y = event->pos ().y();
-	if (!(y >= r.y () && 
-		  y <= r.y () + r.height ())) {
-
-		m_old_selection.clear();
-		m_old_current_index = currentIndex ().row();
-
-		QModelIndexList sel = selectedIndexes ();
-		qSort(sel);
-
-		if (y < r.y ()) {
-			// move selection up
-			for (int i = 0; i < sel.size (); i++) {
-				int row = sel[i].row();
-				//qDebug() << "moving " << row << "to" << row - 1;
-				App->client ()->playlist ()->moveEntry (row, row - 1);
-
-				m_old_selection.insert(row);
-			}
-		} else {
-			// move selection down
-			for (int i = sel.size () - 1; i >= 0; i--) {
-				int row = sel[i].row();
-				//qDebug() << "moving " << row << "to" << row + 1;
-				App->client ()->playlist ()->moveEntry (row, row + 1);
-
-				m_old_selection.insert(row);
-			}
-		}
-	}
-	*/
 }
 
 void 
@@ -402,11 +367,18 @@ PlaylistView::entryMoved(QModelIndex a, QModelIndex b)
 {
 	if (m_old_selection.contains (a.row())) {
 		selectionModel ()->select (b, QItemSelectionModel::Select);
-		m_old_selection.remove (a.row());
+		m_old_selection.remove (a.row ());
 	    if (m_old_current_index == a.row ()) {
-			setSelectionMode (QAbstractItemView::NoSelection);
-			setCurrentIndex (b);
-			setSelectionMode (QAbstractItemView::ExtendedSelection);
+			// update currentIndex without losing the selection
+            selectionModel ()->setCurrentIndex(b, 
+                    QItemSelectionModel::NoUpdate);
+
+			// restore the previous scroll position
+			scrollTo(model ()->index (m_prev_scroll_pos, 0),
+					 QAbstractItemView::PositionAtTop);
+
+			// ensure the new one is visible
+			scrollTo (b);
 		}
 	}
 }
diff --git a/src/playlist/playlistview.h b/src/playlist/playlistview.h
index 02e065d..9412569 100644
--- a/src/playlist/playlistview.h
+++ b/src/playlist/playlistview.h
@@ -91,6 +91,7 @@ class PlaylistView : public QListView {
 
 		QSet<int> m_old_selection;
 		int m_old_current_index;
+		int m_prev_scroll_pos;
 };