From 31745736b8b31647f6224c5a3fe9e82e0320f0f1 Mon Sep 17 00:00:00 2001
From: Manuel Nickschas <sputnick@quassel-irc.org>
Date: Fri, 7 Nov 2008 08:44:12 +0100
Subject: [PATCH] Enable auto-scrolling while selecting text in ChatViews

---
 src/qtui/chatscene.cpp |  1 +
 src/qtui/chatscene.h   |  1 +
 src/qtui/chatview.cpp  | 30 ++++++++++++++++++++++++++++--
 src/qtui/chatview.h    |  9 ++++++++-
 4 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/src/qtui/chatscene.cpp b/src/qtui/chatscene.cpp
index e21d625c..8d3eed48 100644
--- a/src/qtui/chatscene.cpp
+++ b/src/qtui/chatscene.cpp
@@ -516,6 +516,7 @@ void ChatScene::updateSelection(const QPointF &pos) {
 void ChatScene::mouseMoveEvent(QGraphicsSceneMouseEvent *event) {
   if(_isSelecting && event->buttons() == Qt::LeftButton) {
     updateSelection(event->scenePos());
+    emit mouseMoveWhileSelecting(event->scenePos());
     event->accept();
   } else {
     QGraphicsScene::mouseMoveEvent(event);
diff --git a/src/qtui/chatscene.h b/src/qtui/chatscene.h
index a60b8428..a932380b 100644
--- a/src/qtui/chatscene.h
+++ b/src/qtui/chatscene.h
@@ -92,6 +92,7 @@ public:
 signals:
   void lastLineChanged(QGraphicsItem *item, qreal offset);
   void layoutChanged(); // indicates changes to the scenerect due to resizing of the contentsitems
+  void mouseMoveWhileSelecting(const QPointF &scenePos);
 
 protected:
   virtual void mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent);
diff --git a/src/qtui/chatview.cpp b/src/qtui/chatview.cpp
index ed71dd07..d360d9de 100644
--- a/src/qtui/chatview.cpp
+++ b/src/qtui/chatview.cpp
@@ -55,11 +55,16 @@ void ChatView::init(MessageFilter *filter) {
   // setOptimizationFlags(QGraphicsView::DontAdjustForAntialiasing);
   setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
   // setTransformationAnchor(QGraphicsView::NoAnchor);
-  setTransformationAnchor(QGraphicsView::AnchorViewCenter); 
+  setTransformationAnchor(QGraphicsView::AnchorViewCenter);
+
+  _scrollTimer.setInterval(100);
+  _scrollTimer.setSingleShot(true);
+  connect(&_scrollTimer, SIGNAL(timeout()), SLOT(scrollTimerTimeout()));
 
   _scene = new ChatScene(filter, filter->idString(), viewport()->width() - 2, this); // see below: resizeEvent()
   connect(_scene, SIGNAL(sceneRectChanged(const QRectF &)), this, SLOT(sceneRectChanged(const QRectF &)));
   connect(_scene, SIGNAL(lastLineChanged(QGraphicsItem *, qreal)), this, SLOT(lastLineChanged(QGraphicsItem *, qreal)));
+  connect(_scene, SIGNAL(mouseMoveWhileSelecting(const QPointF &)), this, SLOT(mouseMoveWhileSelecting(const QPointF &)));
   setScene(_scene);
   // installEventFilter(_scene);
 
@@ -80,6 +85,27 @@ void ChatView::resizeEvent(QResizeEvent *event) {
   verticalScrollBar()->setValue(verticalScrollBar()->maximum());
 }
 
+void ChatView::mouseMoveWhileSelecting(const QPointF &scenePos) {
+  int y = (int)mapFromScene(scenePos).y();
+  _scrollOffset = 0;
+  if(y < 0)
+    _scrollOffset = y;
+  else if(y > height())
+    _scrollOffset = y - height();
+
+  if(_scrollOffset && !_scrollTimer.isActive())
+    _scrollTimer.start();
+}
+
+void ChatView::scrollTimerTimeout() {
+  // scroll view
+  QAbstractSlider *vbar = verticalScrollBar();
+  if(_scrollOffset < 0 && vbar->value() > 0)
+    vbar->setValue(qMax(vbar->value() + _scrollOffset, 0));
+  else if(_scrollOffset > 0 && vbar->value() < vbar->maximum())
+    vbar->setValue(qMin(vbar->value() + _scrollOffset, vbar->maximum()));
+}
+
 void ChatView::lastLineChanged(QGraphicsItem *chatLine, qreal offset) {
   Q_UNUSED(chatLine)
   QAbstractSlider *vbar = verticalScrollBar();
@@ -117,7 +143,7 @@ MsgId ChatView::lastMsgId() const {
   return model->data(model->index(model->rowCount() - 1, 0), MessageModel::MsgIdRole).value<MsgId>();
 }
 
-void ChatView::zoomIn() { 
+void ChatView::zoomIn() {
     _currentScaleFactor *= 1.2;
     scale(1.2, 1.2);
     scene()->setWidth(viewport()->width() / _currentScaleFactor - 2);
diff --git a/src/qtui/chatview.h b/src/qtui/chatview.h
index 11bd4174..e0ea20be 100644
--- a/src/qtui/chatview.h
+++ b/src/qtui/chatview.h
@@ -22,6 +22,7 @@
 #define CHATVIEW_H_
 
 #include <QGraphicsView>
+#include <QTimer>
 
 #include "abstractbuffercontainer.h"
 
@@ -51,16 +52,22 @@ protected:
   virtual void resizeEvent(QResizeEvent *event);
 
 protected slots:
-  void lastLineChanged(QGraphicsItem *chatLine, qreal offset);
   virtual inline void sceneRectChanged(const QRectF &rect) { setSceneRect(rect); }
   virtual void verticalScrollbarChanged(int);
 
+private slots:
+  void lastLineChanged(QGraphicsItem *chatLine, qreal offset);
+  void mouseMoveWhileSelecting(const QPointF &scenePos);
+  void scrollTimerTimeout();
+
 private:
   void init(MessageFilter *filter);
 
   ChatScene *_scene;
   int _lastScrollbarPos;
   qreal _currentScaleFactor;
+  QTimer _scrollTimer;
+  int _scrollOffset;
 };
 
 
-- 
2.20.1