From 254ccf8f523c82ffad7f1e4fe0bf70cc39f2f4dd Mon Sep 17 00:00:00 2001
From: Roman Telezhynskyi <kroluku@gmail.com>
Date: Wed, 30 Mar 2016 11:51:09 +0300
Subject: [PATCH] Toggle ScrollHandDrag mode by clicking a middle mouse button.

--HG--
branch : develop
---
 ChangeLog.txt                            |  1 +
 src/libs/vwidgets/vmaingraphicsscene.cpp |  8 ---
 src/libs/vwidgets/vmaingraphicsview.cpp  | 64 +++++++++++++-----------
 3 files changed, 36 insertions(+), 37 deletions(-)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index a7586e318..9d35c42bb 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -1,4 +1,5 @@
 # Version 0.5.0
+- Toggle ScrollHandDrag mode by clicking a middle mouse button.
 - Added horizontal scrolling by pressiong Shift + mouse wheel.
 - [#366] Update 'Point from Distance and Angle' tool to read distance and angle between points.
 - [#395] Create Curve tool which uses point as control handle.
diff --git a/src/libs/vwidgets/vmaingraphicsscene.cpp b/src/libs/vwidgets/vmaingraphicsscene.cpp
index 59e0b0080..30e93f5ad 100644
--- a/src/libs/vwidgets/vmaingraphicsscene.cpp
+++ b/src/libs/vwidgets/vmaingraphicsscene.cpp
@@ -80,14 +80,6 @@ void VMainGraphicsScene::mousePressEvent(QGraphicsSceneMouseEvent *event)
     }
 
     QGraphicsScene::mousePressEvent(event);
-//    if (QGuiApplication::keyboardModifiers() == Qt::ControlModifier)
-//    {
-//        QList<QGraphicsItem *> items = selectedItems();
-//        for (int i=0; i< items.size(); i++)
-//        {
-//            items[i]->setSelected(false);
-//        }
-//    }
 }
 
 //---------------------------------------------------------------------------------------------------------------------
diff --git a/src/libs/vwidgets/vmaingraphicsview.cpp b/src/libs/vwidgets/vmaingraphicsview.cpp
index aea47ee32..10a61f9fa 100644
--- a/src/libs/vwidgets/vmaingraphicsview.cpp
+++ b/src/libs/vwidgets/vmaingraphicsview.cpp
@@ -382,43 +382,49 @@ void VMainGraphicsView::ZoomFitBest()
  */
 void VMainGraphicsView::mousePressEvent(QMouseEvent *mousePress)
 {
-    if (mousePress->button() & Qt::LeftButton)
+    switch (mousePress->button())
     {
-        switch (QGuiApplication::keyboardModifiers())
+        case Qt::LeftButton:
         {
-            case Qt::ControlModifier:
-                QGraphicsView::setDragMode(QGraphicsView::ScrollHandDrag);
-                break;
-            case Qt::NoModifier:
-                if (showToolOptions)
+            QGraphicsView::setDragMode(QGraphicsView::RubberBandDrag);
+            if (showToolOptions)
+            {
+                QList<QGraphicsItem *> list = items(mousePress->pos());
+                if (list.size() == 0)
                 {
-                    QList<QGraphicsItem *> list = items(mousePress->pos());
-                    if (list.size() == 0)
+                    emit itemClicked(nullptr);
+                    break;
+                }
+                for (int i = 0; i < list.size(); ++i)
+                {
+                    if (this->scene()->items().contains(list.at(i)))
                     {
-                        emit itemClicked(nullptr);
-                        break;
-                    }
-                    for (int i = 0; i < list.size(); ++i)
-                    {
-                        if (this->scene()->items().contains(list.at(i)))
+                        if (list.at(i)->type() <= VSimplePoint::Type &&
+                            list.at(i)->type() > QGraphicsItem::UserType)
                         {
-                            if (list.at(i)->type() <= VSimplePoint::Type &&
-                                list.at(i)->type() > QGraphicsItem::UserType)
-                            {
-                                emit itemClicked(list.at(i));
-                                break;
-                            }
-                            else
-                            {
-                                emit itemClicked(nullptr);
-                            }
+                            emit itemClicked(list.at(i));
+                            break;
+                        }
+                        else
+                        {
+                            emit itemClicked(nullptr);
                         }
                     }
                 }
-                break;
-            default:
-                break;
+            }
+            break;
         }
+        case Qt::MiddleButton:
+        {
+            QGraphicsView::setDragMode(QGraphicsView::ScrollHandDrag);
+            // create a new mouse event that simulates a click of the left button instead of the middle button
+            QMouseEvent mouseEvent (mousePress->type(), mousePress->pos(), Qt::LeftButton, Qt::LeftButton,
+                                    mousePress->modifiers());
+            QGraphicsView::mousePressEvent(&mouseEvent);
+            return;
+        }
+        default:
+            break;
     }
     QGraphicsView::mousePressEvent(mousePress);
 }
@@ -431,7 +437,7 @@ void VMainGraphicsView::mousePressEvent(QMouseEvent *mousePress)
 void VMainGraphicsView::mouseReleaseEvent(QMouseEvent *event)
 {
     QGraphicsView::mouseReleaseEvent ( event );
-    QGraphicsView::setDragMode( QGraphicsView::RubberBandDrag );
+    QGraphicsView::setDragMode( QGraphicsView::NoDrag );
     if (event->button() == Qt::LeftButton)
     {
         emit MouseRelease();