Editors: Support dragging from outline views

Fill the line and column information in the location returned by
QmlOutlineModel::sourceLocation for that.
The drag & drop code also needed a way to override the executed drop
action for file drops, because the QML outline supports move-drags, which
would lead to the items being removed from the outline when dragged onto
a split...

Change-Id: I2478abc7d5aa2f3aa676cdd609ecb69a50adce8c
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

src/libs/cplusplus/OverviewModel.cpp

@@ -34,6 +34,7 @@
 #include <cplusplus/Scope.h>
 #include <cplusplus/Literals.h>
 #include <cplusplus/Symbols.h>
+#include <utils/fileutils.h>
 
 using namespace CPlusPlus;
 
@@ -242,3 +243,35 @@ void OverviewModel::rebuild(Document::Ptr doc)
     _cppDocument = doc;
     endResetModel();
 }
+
+Qt::ItemFlags OverviewModel::flags(const QModelIndex &index) const
+{
+    Q_UNUSED(index)
+    return Qt::ItemIsEnabled | Qt::ItemIsSelectable | Qt::ItemIsDragEnabled;
+}
+
+Qt::DropActions OverviewModel::supportedDragActions() const
+{
+    return Qt::MoveAction;
+}
+
+QStringList OverviewModel::mimeTypes() const
+{
+    return Utils::FileDropSupport::mimeTypesForFilePaths();
+}
+
+QMimeData *OverviewModel::mimeData(const QModelIndexList &indexes) const
+{
+    auto mimeData = new Utils::FileDropMimeData;
+    foreach (const QModelIndex &index, indexes) {
+        const QVariant fileName = data(index, FileNameRole);
+        if (!fileName.canConvert<QString>())
+            continue;
+        const QVariant lineNumber = data(index, LineNumberRole);
+        if (!fileName.canConvert<unsigned>())
+            continue;
+        mimeData->addFile(fileName.toString(), lineNumber.value<unsigned>());
+    }
+    return mimeData;
+}
+

src/libs/cplusplus/OverviewModel.h

@@ -61,6 +61,11 @@ public:
     Document::Ptr document() const;
     Symbol *symbolFromIndex(const QModelIndex &index) const;
 
+    Qt::ItemFlags flags(const QModelIndex &index) const;
+    Qt::DropActions supportedDragActions() const;
+    QStringList mimeTypes() const;
+    QMimeData *mimeData(const QModelIndexList &indexes) const;
+
 public Q_SLOTS:
     void rebuild(CPlusPlus::Document::Ptr doc);
 

src/libs/utils/fileutils.cpp

@@ -778,12 +778,22 @@ bool FileDropSupport::eventFilter(QObject *obj, QEvent *event)
         QList<FileSpec> tempFiles;
         if (isFileDrop(de->mimeData(), &tempFiles)
                 && (!m_filterFunction || m_filterFunction(de))) {
+            const FileDropMimeData *fileDropMimeData = qobject_cast<const FileDropMimeData *>(de->mimeData());
             event->accept();
-            de->acceptProposedAction();
+            if (fileDropMimeData && fileDropMimeData->isOverridingFileDropAction())
+                de->setDropAction(fileDropMimeData->overrideFileDropAction());
+            else
+                de->acceptProposedAction();
             bool needToScheduleEmit = m_files.isEmpty();
             m_files.append(tempFiles);
-            if (needToScheduleEmit) // otherwise we already have a timer pending
-                QTimer::singleShot(0, this, SLOT(emitFilesDropped()));
+            if (needToScheduleEmit) { // otherwise we already have a timer pending
+                // Delay the actual drop, to avoid conflict between
+                // actions that happen when opening files, and actions that the item views do
+                // after the drag operation.
+                // If we do not do this, e.g. dragging from Outline view crashes if the editor and
+                // the selected item changes
+                QTimer::singleShot(100, this, SLOT(emitFilesDropped()));
+            }
         } else {
             event->ignore();
         }
@@ -799,6 +809,34 @@ void FileDropSupport::emitFilesDropped()
     m_files.clear();
 }
 
+/*!
+    Sets the drop action to effectively use, instead of the "proposed" drop action from the
+    drop event. This can be useful when supporting move drags within an item view, but not
+    "moving" an item from the item view into a split.
+ */
+FileDropMimeData::FileDropMimeData()
+    : m_overrideDropAction(Qt::IgnoreAction),
+      m_isOverridingDropAction(false)
+{
+
+}
+
+void FileDropMimeData::setOverrideFileDropAction(Qt::DropAction action)
+{
+    m_isOverridingDropAction = true;
+    m_overrideDropAction = action;
+}
+
+Qt::DropAction FileDropMimeData::overrideFileDropAction() const
+{
+    return m_overrideDropAction;
+}
+
+bool FileDropMimeData::isOverridingFileDropAction() const
+{
+    return m_isOverridingDropAction;
+}
+
 void FileDropMimeData::addFile(const QString &filePath, int line, int column)
 {
     // standard mime data

src/libs/utils/fileutils.h

@@ -236,11 +236,19 @@ class QTCREATOR_UTILS_EXPORT FileDropMimeData : public QMimeData
 {
     Q_OBJECT
 public:
+    FileDropMimeData();
+
+    void setOverrideFileDropAction(Qt::DropAction action);
+    Qt::DropAction overrideFileDropAction() const;
+    bool isOverridingFileDropAction() const;
+
     void addFile(const QString &filePath, int line = -1, int column = -1);
     QList<FileDropSupport::FileSpec> files() const;
 
 private:
     QList<FileDropSupport::FileSpec> m_files;
+    Qt::DropAction m_overrideDropAction;
+    bool m_isOverridingDropAction;
 };
 
 } // namespace Utils

src/plugins/cppeditor/cppoutline.cpp

@@ -51,6 +51,8 @@ CppOutlineTreeView::CppOutlineTreeView(QWidget *parent) :
     Utils::NavigationTreeView(parent)
 {
     setExpandsOnDoubleClick(false);
+    setDragEnabled(true);
+    setDragDropMode(QAbstractItemView::DragOnly);
 }
 
 void CppOutlineTreeView::contextMenuEvent(QContextMenuEvent *event)
@@ -90,6 +92,11 @@ bool CppOutlineFilterModel::filterAcceptsRow(int sourceRow,
     return QSortFilterProxyModel::filterAcceptsRow(sourceRow, sourceParent);
 }
 
+Qt::DropActions CppOutlineFilterModel::supportedDragActions() const
+{
+    return sourceModel()->supportedDragActions();
+}
+
 
 CppOutlineWidget::CppOutlineWidget(CppEditorWidget *editor) :
     TextEditor::IOutlineWidget(),

src/plugins/cppeditor/cppoutline.h

@@ -60,6 +60,7 @@ public:
     // QSortFilterProxyModel
     bool filterAcceptsRow(int sourceRow,
                           const QModelIndex &sourceParent) const;
+    Qt::DropActions supportedDragActions() const;
 private:
     CPlusPlus::OverviewModel *m_sourceModel;
 };

src/plugins/qmljseditor/qmljsoutline.cpp

@@ -82,6 +82,11 @@ QVariant QmlJSOutlineFilterModel::data(const QModelIndex &index, int role) const
     return QSortFilterProxyModel::data(index, role);
 }
 
+Qt::DropActions QmlJSOutlineFilterModel::supportedDragActions() const
+{
+    return sourceModel()->supportedDragActions();
+}
+
 bool QmlJSOutlineFilterModel::filterBindings() const
 {
     return m_filterBindings;

src/plugins/qmljseditor/qmljsoutline.h

@@ -54,6 +54,7 @@ public:
     bool filterAcceptsRow(int sourceRow,
                           const QModelIndex &sourceParent) const;
     QVariant data(const QModelIndex &index, int role) const;
+    Qt::DropActions supportedDragActions() const;
 
     bool filterBindings() const;
     void setFilterBindings(bool filterBindings);

src/plugins/qmljseditor/qmloutlinemodel.cpp

@@ -37,6 +37,7 @@
 #include <qmljs/qmljsrewriter.h>
 #include <qmljstools/qmljsrefactoringchanges.h>
 
+#include <utils/fileutils.h>
 #include <utils/qtcassert.h>
 
 #include <coreplugin/icore.h>
@@ -53,6 +54,8 @@ enum {
     debug = false
 };
 
+static const char INTERNAL_MIMETYPE[] = "application/x-qtcreator-qmloutlinemodel";
+
 namespace QmlJSEditor {
 namespace Internal {
 
@@ -312,7 +315,8 @@ QmlOutlineModel::QmlOutlineModel(QmlJSEditorDocument *document) :
 QStringList QmlOutlineModel::mimeTypes() const
 {
     QStringList types;
-    types << QLatin1String("application/x-qtcreator-qmloutlinemodel");
+    types << QLatin1String(INTERNAL_MIMETYPE);
+    types << Utils::FileDropSupport::mimeTypesForFilePaths();
     return types;
 }
 
@@ -321,9 +325,8 @@ QMimeData *QmlOutlineModel::mimeData(const QModelIndexList &indexes) const
 {
     if (indexes.count() <= 0)
         return 0;
-    QStringList types = mimeTypes();
-    QMimeData *data = new QMimeData();
-    QString format = types.at(0);
+    auto data = new Utils::FileDropMimeData;
+    data->setOverrideFileDropAction(Qt::CopyAction);
     QByteArray encoded;
     QDataStream stream(&encoded, QIODevice::WriteOnly);
     stream << indexes.size();
@@ -331,6 +334,10 @@ QMimeData *QmlOutlineModel::mimeData(const QModelIndexList &indexes) const
     for (int i = 0; i < indexes.size(); ++i) {
         QModelIndex index = indexes.at(i);
 
+        AST::SourceLocation location = sourceLocation(index);
+        data->addFile(m_editorDocument->filePath(), location.startLine,
+                      location.startColumn - 1 /*editors have 0-based column*/);
+
         QList<int> rowPath;
         for (QModelIndex i = index; i.isValid(); i = i.parent()) {
             rowPath.prepend(i.row());
@@ -338,7 +345,7 @@ QMimeData *QmlOutlineModel::mimeData(const QModelIndexList &indexes) const
 
         stream << rowPath;
     }
-    data->setData(format, encoded);
+    data->setData(QLatin1String(INTERNAL_MIMETYPE), encoded);
     return data;
 }
 
@@ -410,8 +417,8 @@ Qt::ItemFlags QmlOutlineModel::flags(const QModelIndex &index) const
 
 Qt::DropActions QmlOutlineModel::supportedDragActions() const
 {
-    // TODO: Maybe add a Copy Action?
-    return Qt::MoveAction;
+    // copy action used for dragging onto editor splits
+    return Qt::MoveAction | Qt::CopyAction;
 }
 
 
@@ -915,7 +922,7 @@ QString QmlOutlineModel::asString(AST::UiQualifiedId *id)
 
 AST::SourceLocation QmlOutlineModel::getLocation(AST::UiObjectMember *objMember) {
     AST::SourceLocation location;
-    location.offset = objMember->firstSourceLocation().offset;
+    location = objMember->firstSourceLocation();
     location.length = objMember->lastSourceLocation().offset
             - objMember->firstSourceLocation().offset
             + objMember->lastSourceLocation().length;
@@ -924,7 +931,7 @@ AST::SourceLocation QmlOutlineModel::getLocation(AST::UiObjectMember *objMember)
 
 AST::SourceLocation QmlOutlineModel::getLocation(AST::ExpressionNode *exprNode) {
     AST::SourceLocation location;
-    location.offset = exprNode->firstSourceLocation().offset;
+    location = exprNode->firstSourceLocation();
     location.length = exprNode->lastSourceLocation().offset
             - exprNode->firstSourceLocation().offset
             + exprNode->lastSourceLocation().length;
@@ -941,7 +948,7 @@ AST::SourceLocation QmlOutlineModel::getLocation(AST::PropertyAssignmentList *pr
 
 AST::SourceLocation QmlOutlineModel::getLocation(AST::PropertyNameAndValue *propertyNode) {
     AST::SourceLocation location;
-    location.offset = propertyNode->name->propertyNameToken.offset;
+    location = propertyNode->name->propertyNameToken;
     location.length = propertyNode->value->lastSourceLocation().end() - location.offset;
 
     return location;
@@ -949,7 +956,7 @@ AST::SourceLocation QmlOutlineModel::getLocation(AST::PropertyNameAndValue *prop
 
 AST::SourceLocation QmlOutlineModel::getLocation(AST::PropertyGetterSetter *propertyNode) {
     AST::SourceLocation location;
-    location.offset = propertyNode->name->propertyNameToken.offset;
+    location = propertyNode->name->propertyNameToken;
     location.length = propertyNode->rbraceToken.end() - location.offset;
 
     return location;