Type hierarchy: Add drag & drop into editor splits

Change-Id: I8fec78779d4241988bd4987a5d86020cea83d077
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

4 files changed, 126 insertions, 41 deletions

diff --git a/src/plugins/cppeditor/cpptypehierarchy.cpp b/src/plugins/cppeditor/cpptypehierarchy.cpp
index d42de60483..6026d36120 100644
--- a/src/plugins/cppeditor/cpptypehierarchy.cpp
+++ b/src/plugins/cppeditor/cpptypehierarchy.cpp
@@ -37,14 +37,14 @@
 
 #include <coreplugin/find/itemviewfind.h>
 #include <utils/algorithm.h>
-#include <utils/navigationtreeview.h>
 #include <utils/annotateditemdelegate.h>
+#include <utils/navigationtreeview.h>
 
+#include <QApplication>
 #include <QLabel>
 #include <QLatin1String>
 #include <QModelIndex>
 #include <QStackedLayout>
-#include <QStandardItemModel>
 #include <QVBoxLayout>
 
 using namespace CppEditor;
@@ -61,6 +61,7 @@ enum ItemRole {
 QStandardItem *itemForClass(const CppClass &cppClass)
 {
     QStandardItem *item = new QStandardItem;
+    item->setFlags(item->flags() | Qt::ItemIsDragEnabled);
     item->setData(cppClass.name, Qt::DisplayRole);
     if (cppClass.name != cppClass.qualifiedName)
         item->setData(cppClass.qualifiedName, AnnotationRole);
@@ -87,40 +88,6 @@ QList<CppClass> sortClasses(const QList<CppClass> &cppClasses)
 namespace CppEditor {
 namespace Internal {
 
-class CppClassLabel : public QLabel
-{
-public:
-    CppClassLabel(QWidget *parent)
-        : QLabel(parent)
-    {}
-
-    void setup(CppClass *cppClass)
-    {
-        setText(cppClass->name);
-        m_link = cppClass->link;
-    }
-
-    void clear()
-    {
-        QLabel::clear();
-        m_link = CppEditorWidget::Link();
-    }
-
-private:
-    void mousePressEvent(QMouseEvent *)
-    {
-        if (!m_link.hasValidTarget())
-            return;
-
-        Core::EditorManager::openEditorAt(m_link.targetFileName,
-                                          m_link.targetLine,
-                                          m_link.targetColumn,
-                                          Constants::CPPEDITOR_ID);
-    }
-
-    CppEditorWidget::Link m_link;
-};
-
 // CppTypeHierarchyWidget
 CppTypeHierarchyWidget::CppTypeHierarchyWidget() :
     QWidget(0),
@@ -129,9 +96,9 @@ CppTypeHierarchyWidget::CppTypeHierarchyWidget() :
     m_delegate(0),
     m_noTypeHierarchyAvailableLabel(0)
 {
-    m_inspectedClass = new CppClassLabel(this);
+    m_inspectedClass = new TextEditor::TextEditorLinkLabel(this);
     m_inspectedClass->setMargin(5);
-    m_model = new QStandardItemModel(this);
+    m_model = new CppTypeHierarchyModel(this);
     m_treeView = new NavigationTreeView(this);
     m_treeView->setActivationMode(Utils::SingleClickActivation);
     m_delegate = new AnnotatedItemDelegate(this);
@@ -141,6 +108,8 @@ CppTypeHierarchyWidget::CppTypeHierarchyWidget() :
     m_treeView->setEditTriggers(QAbstractItemView::NoEditTriggers);
     m_treeView->setItemDelegate(m_delegate);
     m_treeView->setRootIsDecorated(false);
+    m_treeView->setDragEnabled(true);
+    m_treeView->setDragDropMode(QAbstractItemView::DragOnly);
     connect(m_treeView, &QTreeView::activated, this, &CppTypeHierarchyWidget::onItemActivated);
 
     m_noTypeHierarchyAvailableLabel = new QLabel(tr("No type hierarchy available"), this);
@@ -190,7 +159,8 @@ void CppTypeHierarchyWidget::perform()
         const QSharedPointer<CppElement> &cppElement = evaluator.cppElement();
         CppElement *element = cppElement.data();
         if (CppClass *cppClass = dynamic_cast<CppClass *>(element)) {
-            m_inspectedClass->setup(cppClass);
+            m_inspectedClass->setText(cppClass->name);
+            m_inspectedClass->setLink(cppClass->link);
             QStandardItem *bases = new QStandardItem(tr("Bases"));
             m_model->invisibleRootItem()->appendRow(bases);
             buildHierarchy(*cppClass, bases, true, &CppClass::bases);
@@ -257,6 +227,37 @@ Core::NavigationView CppTypeHierarchyFactory::createWidget()
     return Core::NavigationView(w);
 }
 
+CppTypeHierarchyModel::CppTypeHierarchyModel(QObject *parent)
+    : QStandardItemModel(parent)
+{
+}
+
+Qt::DropActions CppTypeHierarchyModel::supportedDragActions() const
+{
+    // copy & move actions to avoid idiotic behavior of drag and drop:
+    // standard item model removes nodes automatically that are
+    // dropped anywhere with move action, but we do not want the '+' sign in the
+    // drag handle that would appear when only allowing copy action
+    return Qt::CopyAction | Qt::MoveAction;
+}
+
+QStringList CppTypeHierarchyModel::mimeTypes() const
+{
+    return FileDropSupport::mimeTypesForFilePaths();
+}
+
+QMimeData *CppTypeHierarchyModel::mimeData(const QModelIndexList &indexes) const
+{
+    auto data = new FileDropMimeData;
+    data->setOverrideFileDropAction(Qt::CopyAction); // do not remove the item from the model
+    foreach (const QModelIndex &index, indexes) {
+        auto link = index.data(LinkRole).value<TextEditor::TextEditorWidget::Link>();
+        if (link.hasValidTarget())
+            data->addFile(link.targetFileName, link.targetLine, link.targetColumn);
+    }
+    return data;
+}
+
 } // namespace Internal
 } // namespace CppEditor
 
diff --git a/src/plugins/cppeditor/cpptypehierarchy.h b/src/plugins/cppeditor/cpptypehierarchy.h
index 0d78a61591..e924800465 100644
--- a/src/plugins/cppeditor/cpptypehierarchy.h
+++ b/src/plugins/cppeditor/cpptypehierarchy.h
@@ -36,19 +36,21 @@
 #include <QString>
 #include <QWidget>
 #include <QStackedWidget>
+#include <QStandardItemModel>
 
 QT_BEGIN_NAMESPACE
 class QLabel;
 class QModelIndex;
 class QStackedLayout;
 class QStandardItem;
-class QStandardItemModel;
 template <class> class QVector;
 template <class> class QList;
 QT_END_NAMESPACE
 
 namespace Core { class IEditor; }
 
+namespace TextEditor { class TextEditorLinkLabel; }
+
 namespace Utils {
 class NavigationTreeView;
 class AnnotatedItemDelegate;
@@ -61,6 +63,18 @@ class CppEditorWidget;
 class CppClass;
 class CppClassLabel;
 
+class CppTypeHierarchyModel : public QStandardItemModel
+{
+    Q_OBJECT
+
+public:
+    CppTypeHierarchyModel(QObject *parent);
+
+    Qt::DropActions supportedDragActions() const;
+    QStringList mimeTypes() const;
+    QMimeData *mimeData(const QModelIndexList &indexes) const;
+};
+
 class CppTypeHierarchyWidget : public QWidget
 {
     Q_OBJECT
@@ -86,7 +100,7 @@ private:
     QStackedLayout *m_stackLayout;
     QStandardItemModel *m_model;
     Utils::AnnotatedItemDelegate *m_delegate;
-    CppClassLabel *m_inspectedClass;
+    TextEditor::TextEditorLinkLabel *m_inspectedClass;
     QLabel *m_noTypeHierarchyAvailableLabel;
 };
 
diff --git a/src/plugins/texteditor/texteditor.cpp b/src/plugins/texteditor/texteditor.cpp
index 82bddcaac5..06c0a4edeb 100644
--- a/src/plugins/texteditor/texteditor.cpp
+++ b/src/plugins/texteditor/texteditor.cpp
@@ -70,6 +70,7 @@
 #include <coreplugin/manhattanstyle.h>
 #include <coreplugin/find/basetextfind.h>
 #include <utils/linecolumnlabel.h>
+#include <utils/fileutils.h>
 #include <utils/hostosinfo.h>
 #include <utils/qtcassert.h>
 #include <utils/stylehelper.h>
@@ -89,6 +90,7 @@
 #include <QPainter>
 #include <QPrintDialog>
 #include <QPrinter>
+#include <QDrag>
 #include <QScrollBar>
 #include <QShortcut>
 #include <QStyle>
@@ -7206,6 +7208,55 @@ void TextEditorWidget::setupAsPlainEditor()
 }
 
 //
+// TextEditorLinkLabel
+//
+TextEditorLinkLabel::TextEditorLinkLabel(QWidget *parent)
+    : QLabel(parent)
+{
+}
+
+void TextEditorLinkLabel::setLink(TextEditorWidget::Link link)
+{
+    m_link = link;
+}
+
+TextEditorWidget::Link TextEditorLinkLabel::link() const
+{
+    return m_link;
+}
+
+void TextEditorLinkLabel::mousePressEvent(QMouseEvent *event)
+{
+    if (event->button() == Qt::LeftButton)
+        m_dragStartPosition = event->pos();
+}
+
+void TextEditorLinkLabel::mouseMoveEvent(QMouseEvent *event)
+{
+    if (!(event->buttons() & Qt::LeftButton))
+        return;
+    if ((event->pos() - m_dragStartPosition).manhattanLength() < QApplication::startDragDistance())
+        return;
+
+    auto data = new Utils::FileDropMimeData;
+    data->addFile(m_link.targetFileName, m_link.targetLine, m_link.targetColumn);
+    auto drag = new QDrag(this);
+    drag->setMimeData(data);
+    drag->exec(Qt::MoveAction);
+}
+
+void TextEditorLinkLabel::mouseReleaseEvent(QMouseEvent *event)
+{
+    Q_UNUSED(event)
+    if (!m_link.hasValidTarget())
+        return;
+
+    Core::EditorManager::openEditorAt(m_link.targetFileName,
+                                      m_link.targetLine,
+                                      m_link.targetColumn);
+}
+
+//
 // BaseTextEditorFactory
 //
 
diff --git a/src/plugins/texteditor/texteditor.h b/src/plugins/texteditor/texteditor.h
index 71b83c8aee..9c1f833814 100644
--- a/src/plugins/texteditor/texteditor.h
+++ b/src/plugins/texteditor/texteditor.h
@@ -45,6 +45,7 @@
 
 #include <utils/uncommentselection.h>
 
+#include <QLabel>
 #include <QPlainTextEdit>
 #include <functional>
 
@@ -623,6 +624,24 @@ private:
     friend class RefactorOverlay;
 };
 
+class TEXTEDITOR_EXPORT TextEditorLinkLabel : public QLabel
+{
+public:
+    TextEditorLinkLabel(QWidget *parent = 0);
+
+    void setLink(TextEditorWidget::Link link);
+    TextEditorWidget::Link link() const;
+
+protected:
+    void mousePressEvent(QMouseEvent *event);
+    void mouseMoveEvent(QMouseEvent *event);
+    void mouseReleaseEvent(QMouseEvent *event);
+
+private:
+    QPoint m_dragStartPosition;
+    TextEditorWidget::Link m_link;
+};
+
 class TEXTEDITOR_EXPORT TextEditorFactory : public Core::IEditorFactory
 {
     Q_OBJECT