From f6c70f583f69e7364056b67f92f756ab540e0fb5 Mon Sep 17 00:00:00 2001
From: Thomas Wilshaw <thomaswilshaw@gmail.com>
Date: Mon, 1 Jun 2020 19:11:33 +0100
Subject: [PATCH] Panning now only works if the viewier is zoomed

---
 app/widget/viewer/viewer.cpp        |  1 +
 app/widget/viewer/viewerdisplay.cpp | 17 ++++++++++++++---
 app/widget/viewer/viewerdisplay.h   |  4 ++++
 app/widget/viewer/viewersizer.cpp   |  3 ++-
 app/widget/viewer/viewersizer.h     |  1 +
 5 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/app/widget/viewer/viewer.cpp b/app/widget/viewer/viewer.cpp
index 17b5ac8c7..a90c7242d 100644
--- a/app/widget/viewer/viewer.cpp
+++ b/app/widget/viewer/viewer.cpp
@@ -79,6 +79,7 @@ ViewerWidget::ViewerWidget(QWidget *parent) :
   connect(display_widget_, &ViewerDisplayWidget::ColorProcessorChanged, this, &ViewerWidget::ColorProcessorChanged);
   connect(display_widget_, &ViewerDisplayWidget::ColorManagerChanged, this, &ViewerWidget::ColorManagerChanged);
   connect(sizer_, &ViewerSizer::RequestMatrix, display_widget_, &ViewerDisplayWidget::SetMatrixZoom);
+  connect(sizer_, &ViewerSizer::SetZoomFlag, display_widget_, &ViewerDisplayWidget::SetZoomFlag);
   sizer_->SetWidget(display_widget_);
 
   // Create waveform view when audio is connected and video isn't
diff --git a/app/widget/viewer/viewerdisplay.cpp b/app/widget/viewer/viewerdisplay.cpp
index b438a4414..1228530de 100644
--- a/app/widget/viewer/viewerdisplay.cpp
+++ b/app/widget/viewer/viewerdisplay.cpp
@@ -47,7 +47,8 @@ ViewerDisplayWidget::ViewerDisplayWidget(QWidget *parent) :
   signal_cursor_color_(false),
   gizmos_(nullptr),
   gizmo_click_(false),
-  last_loaded_buffer_(nullptr)
+  last_loaded_buffer_(nullptr),
+  zoomed_(false)
 {
 }
 
@@ -68,6 +69,16 @@ void ViewerDisplayWidget::SetMatrixZoom(const QMatrix4x4 &mat)
   update();
 }
 
+void ViewerDisplayWidget::SetZoomFlag(bool flag)
+{
+  zoomed_ = flag;
+  // If not scaled reset translation matrix to identity
+  if (!flag) {
+    QMatrix4x4 mat;
+    SetMatrixTranslate(mat);
+  }
+}
+
 QMatrix4x4 ViewerDisplayWidget::GetCompleteMatrix()
 {
   QMatrix4x4 mat;
@@ -164,7 +175,7 @@ void ViewerDisplayWidget::mousePressEvent(QMouseEvent *event)
   }
 
   // get current position in preperation for move event
-  if (event->button() == Qt::MiddleButton) {
+  if (event->button() == Qt::MiddleButton && zoomed_) {
     position_ = event->pos();
     return;
   }
@@ -178,7 +189,7 @@ void ViewerDisplayWidget::mousePressEvent(QMouseEvent *event)
 
 void ViewerDisplayWidget::mouseMoveEvent(QMouseEvent *event)
 {
-  if (event->buttons() & Qt::MiddleButton) {
+  if (event->buttons() & Qt::MiddleButton && zoomed_) {
     QPointF delta = event->pos() - position_;
     // scale delta to widget size
     delta.setX(delta.x() / width());
diff --git a/app/widget/viewer/viewerdisplay.h b/app/widget/viewer/viewerdisplay.h
index a1f8cec66..4d98af1ce 100644
--- a/app/widget/viewer/viewerdisplay.h
+++ b/app/widget/viewer/viewerdisplay.h
@@ -116,6 +116,8 @@ public slots:
    */
   void SetImage(FramePtr in_buffer);
 
+  void SetZoomFlag(bool flag);
+
 signals:
   /**
    * @brief Signal emitted when the user starts dragging from the viewer
@@ -179,6 +181,8 @@ private:
    */
   QMatrix4x4 scale_matrix_;
 
+  bool zoomed_;
+
 #ifdef Q_OS_LINUX
   static bool nouveau_check_done_;
 #endif
diff --git a/app/widget/viewer/viewersizer.cpp b/app/widget/viewer/viewersizer.cpp
index 8f492d488..0780f3c58 100644
--- a/app/widget/viewer/viewersizer.cpp
+++ b/app/widget/viewer/viewersizer.cpp
@@ -105,6 +105,7 @@ void ViewerSizer::UpdateSize()
       // This container is taller than the image, scale by width
       child_size = QSize(width(), qRound(child_size.width() / aspect_ratio_));
     }
+    emit SetZoomFlag(false);
 
   } else {
 
@@ -128,7 +129,7 @@ void ViewerSizer::UpdateSize()
     child_matrix.scale(x_scale, y_scale, 1.0F);
 
     child_size = QSize(zoomed_width, zoomed_height);
-
+    emit SetZoomFlag(true);
   }
 
   widget_->resize(child_size);
diff --git a/app/widget/viewer/viewersizer.h b/app/widget/viewer/viewersizer.h
index 2363f28cf..6728018a6 100644
--- a/app/widget/viewer/viewersizer.h
+++ b/app/widget/viewer/viewersizer.h
@@ -65,6 +65,7 @@ public:
 
 signals:
   void RequestMatrix(const QMatrix4x4& matrix);
+  void SetZoomFlag(bool flag);
 
 protected:
   /**