From deba06e71141520e872cf4b9809cab64c2fa37c9 2017-10-25 07:11:22
From: Thibaud Rabillard <trabillard@itlink.fr>
Date: 2017-10-25 07:11:22
Subject: [PATCH] New helper class for the drag&drop

---

diff --git a/gui/include/DragDropHelper.h b/gui/include/DragDropHelper.h
new file mode 100644
index 0000000..d103039
--- /dev/null
+++ b/gui/include/DragDropHelper.h
@@ -0,0 +1,42 @@
+#ifndef DRAGDROPHELPER_H
+#define DRAGDROPHELPER_H
+
+#include <Common/spimpl.h>
+#include <QWidget>
+
+class QVBoxLayout;
+class QScrollArea;
+class VisualizationDragWidget;
+class QMimeData;
+
+/**
+ * @brief Helper class for drag&drop operations.
+ */
+class DragDropHelper
+{
+public:
+    DragDropHelper();
+    ~DragDropHelper();
+
+    static const QString MIME_TYPE_GRAPH;
+    static const QString MIME_TYPE_ZONE;
+
+    void setCurrentDragWidget(VisualizationDragWidget* dragWidget);
+    VisualizationDragWidget* getCurrentDragWidget() const;
+
+    QWidget &placeHolder() const;
+    void insertPlaceHolder(QVBoxLayout* layout, int index);
+    void removePlaceHolder();
+    bool isPlaceHolderSet() const;
+
+    void addDragDropScrollArea(QScrollArea* scrollArea);
+    void removeDragDropScrollArea(QScrollArea* scrollArea);
+
+    QUrl imageTemporaryUrl(const QImage& image) const;
+
+private:
+    class DragDropHelperPrivate;
+    spimpl::unique_impl_ptr<DragDropHelperPrivate> impl;
+};
+
+#endif // DRAGDROPHELPER_H
diff --git a/gui/include/SqpApplication.h b/gui/include/SqpApplication.h
index a23bd7f..d7049ba 100644
--- a/gui/include/SqpApplication.h
+++ b/gui/include/SqpApplication.h
@@ -20,6 +20,7 @@ class NetworkController;
 class TimeController;
 class VariableController;
 class VisualizationController;
+class DragDropHelper;
 
 /**
  * @brief The SqpApplication class aims to make the link between SciQlop
@@ -44,6 +45,9 @@ public:
     VariableController &variableController() noexcept;
     VisualizationController &visualizationController() noexcept;
 
+      /// Accessors for the differents sciqlop helpers
+    DragDropHelper &dragDropHelper() noexcept;
+
 private:
     class SqpApplicationPrivate;
     spimpl::unique_impl_ptr<SqpApplicationPrivate> impl;
diff --git a/gui/src/DragDropHelper.cpp b/gui/src/DragDropHelper.cpp
new file mode 100644
index 0000000..9f7cc58
--- /dev/null
+++ b/gui/src/DragDropHelper.cpp
@@ -0,0 +1,105 @@
+#include "DragDropHelper.h"
+#include "Visualization/VisualizationDragWidget.h"
+#include "SqpApplication.h"
+
+#include <QDragMoveEvent>
+#include <QDragEnterEvent>
+#include <QScrollBar>
+#include <QScrollArea>
+#include <QVBoxLayout>
+#include <QTimer>
+#include <QDir>
+
+const QString DragDropHelper::MIME_TYPE_GRAPH = "scqlop/graph";
+const QString DragDropHelper::MIME_TYPE_ZONE = "scqlop/zone";
+
+
+struct DragDropHelper::DragDropHelperPrivate {
+
+    VisualizationDragWidget* m_currentDragWidget = nullptr;
+    std::unique_ptr<QWidget> m_placeHolder = nullptr;
+    std::unique_ptr<DragDropScroller> m_dragDropScroller = nullptr;
+    QString m_imageTempUrl; //Temporary file for image url generated by the drag & drop. Not using QTemporaryFile to have a name which is not generated.
+
+    explicit DragDropHelperPrivate()
+        : m_placeHolder{std::make_unique<QWidget>()},
+          m_dragDropScroller{std::make_unique<DragDropScroller>()}
+    {
+         m_placeHolder->setStyleSheet("background-color: #BBD5EE; border:2px solid #2A7FD4");
+         sqpApp->installEventFilter(m_dragDropScroller.get());
+
+
+         m_imageTempUrl = QDir::temp().absoluteFilePath("Scqlop_graph.png");
+    }
+
+    void preparePlaceHolder() const
+    {
+        if (m_currentDragWidget)
+        {
+            m_placeHolder->setMinimumSize(m_currentDragWidget->size());
+            m_placeHolder->setSizePolicy(m_currentDragWidget->sizePolicy());
+        }
+        else
+        {
+            m_placeHolder->setMinimumSize(200, 200);
+        }
+    }
+};
+
+
+DragDropHelper::DragDropHelper() :
+    impl{spimpl::make_unique_impl<DragDropHelperPrivate>()}
+{
+}
+
+DragDropHelper::~DragDropHelper()
+{
+    QFile::remove(impl->m_imageTempUrl);
+}
+
+void DragDropHelper::setCurrentDragWidget(VisualizationDragWidget *dragWidget)
+{
+    impl->m_currentDragWidget = dragWidget;
+}
+
+VisualizationDragWidget *DragDropHelper::getCurrentDragWidget() const
+{
+    return impl->m_currentDragWidget;
+}
+
+
+QWidget& DragDropHelper::placeHolder() const
+{
+    return *impl->m_placeHolder;
+}
+
+void DragDropHelper::insertPlaceHolder(QVBoxLayout *layout, int index)
+{
+    removePlaceHolder();
+    impl->preparePlaceHolder();
+    layout->insertWidget(index, impl->m_placeHolder.get());
+    impl->m_placeHolder->show();
+}
+
+void DragDropHelper::removePlaceHolder()
+{
+    auto parentWidget = impl->m_placeHolder->parentWidget();
+    if (parentWidget)
+    {
+        parentWidget->layout()->removeWidget(impl->m_placeHolder.get());
+        impl->m_placeHolder->setParent(nullptr);
+        impl->m_placeHolder->hide();
+    }
+}
+
+bool DragDropHelper::isPlaceHolderSet() const
+{
+    return impl->m_placeHolder->parentWidget();
+}
+
+QUrl DragDropHelper::imageTemporaryUrl(const QImage& image) const
+{
+    image.save(impl->m_imageTempUrl);
+    return QUrl::fromLocalFile(impl->m_imageTempUrl);
+}
+
diff --git a/gui/src/SqpApplication.cpp b/gui/src/SqpApplication.cpp
index 4968eb0..1187cc9 100644
--- a/gui/src/SqpApplication.cpp
+++ b/gui/src/SqpApplication.cpp
@@ -8,6 +8,7 @@
 #include <Variable/Variable.h>
 #include <Variable/VariableController.h>
 #include <Visualization/VisualizationController.h>
+#include <DragDropHelper.h>
 
 Q_LOGGING_CATEGORY(LOG_SqpApplication, "SqpApplication")
 
@@ -18,7 +19,8 @@ public:
               m_NetworkController{std::make_unique<NetworkController>()},
               m_TimeController{std::make_unique<TimeController>()},
               m_VariableController{std::make_unique<VariableController>()},
-              m_VisualizationController{std::make_unique<VisualizationController>()}
+              m_VisualizationController{std::make_unique<VisualizationController>()},
+              m_DragDropHelper{std::make_unique<DragDropHelper>()}
     {
         // /////////////////////////////// //
         // Connections between controllers //
@@ -82,6 +84,8 @@ public:
     QThread m_NetworkControllerThread;
     QThread m_VariableControllerThread;
     QThread m_VisualizationControllerThread;
+
+    std::unique_ptr<DragDropHelper> m_DragDropHelper;
 };
 
 
@@ -148,3 +152,8 @@ VisualizationController &SqpApplication::visualizationController() noexcept
 {
     return *impl->m_VisualizationController;
 }
+
+DragDropHelper &SqpApplication::dragDropHelper() noexcept
+{
+    return *impl->m_DragDropHelper;
+}