Allow drag and drop between different kate instances

kate/katetabbar.cpp

@@ -11,6 +11,7 @@
 #include "tabmimedata.h"
 
 #include <QApplication>
+#include <QDataStream>
 #include <QDrag>
 #include <QIcon>
 #include <QMimeData>
@@ -224,7 +225,21 @@ void KateTabBar::mouseMoveEvent(QMouseEvent *event)
     auto parentViewSpace = qobject_cast<KateViewSpace *>(parentWidget());
     Q_ASSERT(parentViewSpace);
 
-    auto mime = new TabMimeData(parentViewSpace, tabDocument(tab), tab);
+    auto view = parentViewSpace->currentView();
+    if (!view) {
+        return;
+    }
+
+    QByteArray data;
+    KTextEditor::Cursor cp = view->cursorPosition();
+    QDataStream ds(&data, QIODevice::WriteOnly);
+    ds << cp.line();
+    ds << cp.column();
+    ds << view->document()->url();
+
+    auto mime = new TabMimeData(parentViewSpace, tabDocument(tab));
+    mime->setData(QStringLiteral("application/kate.tab.mimedata"), data);
+
     drag->setMimeData(mime);
     drag->setPixmap(p);
     QPoint hp;

kate/kateviewspace.cpp

@@ -24,6 +24,7 @@
 
 #include <QApplication>
 #include <QClipboard>
+#include <QDataStream>
 #include <QHelpEvent>
 #include <QMenu>
 #include <QMessageBox>
@@ -430,23 +431,26 @@ void KateViewSpace::closeDocument(KTextEditor::Document *doc)
     }
 }
 
-bool KateViewSpace::acceptsDroppedTab(const class TabMimeData *tabMimeData)
+bool KateViewSpace::acceptsDroppedTab(const QMimeData *md)
 {
-    return tabMimeData && this != tabMimeData->sourceVS && // must not be same viewspace
-        viewManger() == tabMimeData->sourceVS->viewManger() && // for now we don't support dropping into different windows
-        !hasDocument(tabMimeData->doc);
+    if (auto tabMimeData = qobject_cast<const TabMimeData *>(md)) {
+        return this != tabMimeData->sourceVS && // must not be same viewspace
+            viewManger() == tabMimeData->sourceVS->viewManger() && // for now we don't support dropping into different windows
+            !hasDocument(tabMimeData->doc);
+    }
+    return TabMimeData::hasValidData(md);
 }
 
 void KateViewSpace::dragEnterEvent(QDragEnterEvent *e)
 {
-    auto mimeData = qobject_cast<const TabMimeData *>(e->mimeData());
-    if (acceptsDroppedTab(mimeData)) {
+    if (acceptsDroppedTab(e->mimeData())) {
         m_dropIndicator.reset(new QRubberBand(QRubberBand::Rectangle, this));
         m_dropIndicator->setGeometry(rect());
         m_dropIndicator->show();
         e->acceptProposedAction();
         return;
     }
+
     QWidget::dragEnterEvent(e);
 }
 
@@ -464,6 +468,17 @@ void KateViewSpace::dropEvent(QDropEvent *e)
         e->accept();
         return;
     }
+    auto droppedData = TabMimeData::data(e->mimeData());
+    if (droppedData.has_value()) {
+        auto doc = KateApp::self()->documentManager()->openUrl(droppedData.value().url);
+        auto view = m_viewManager->activateView(doc);
+        if (view) {
+            view->setCursorPosition({droppedData.value().line, droppedData.value().col});
+            e->accept();
+            return;
+        }
+    }
+
     QWidget::dropEvent(e);
 }
 

kate/kateviewspace.h

@@ -222,7 +222,7 @@ private Q_SLOTS:
     void createNewDocument();
 
 private:
-    bool acceptsDroppedTab(const class TabMimeData *tabMimeData);
+    bool acceptsDroppedTab(const class QMimeData *tabMimeData);
     /**
      * Returns the amount of documents in KateDocManager that currently
      * have no tab in this tab bar.

kate/tabmimedata.cpp

 #include "tabmimedata.h"
 
-TabMimeData::TabMimeData(KateViewSpace *vs, KTextEditor::Document *d, int sourceTabIdx)
+#include <QDataStream>
+
+TabMimeData::TabMimeData(KateViewSpace *vs, KTextEditor::Document *d)
     : QMimeData()
     , sourceVS(vs)
     , doc(d)
-    , tabIdx(sourceTabIdx)
 {
 }
+
+bool TabMimeData::hasValidData(const QMimeData *md)
+{
+    bool valid = md && md->hasFormat(QStringLiteral("application/kate.tab.mimedata"));
+    if (valid) {
+        QByteArray data = md->data(QStringLiteral("application/kate.tab.mimedata"));
+        QDataStream ds(data);
+        int line = 0;
+        int column = 0;
+        QUrl url;
+        ds >> line;
+        ds >> column;
+        ds >> url;
+        return url.isValid();
+    }
+    return false;
+}
+
+std::optional<TabMimeData::DroppedData> TabMimeData::data(const QMimeData *md)
+{
+    if (!md || !md->hasFormat(QStringLiteral("application/kate.tab.mimedata"))) {
+        return {};
+    }
+
+    QByteArray data = md->data(QStringLiteral("application/kate.tab.mimedata"));
+    QDataStream ds(data);
+    TabMimeData::DroppedData d;
+    ds >> d.line;
+    ds >> d.col;
+    ds >> d.url;
+    if (!d.url.isValid()) {
+        return {};
+    }
+    return d;
+}

kate/tabmimedata.h

@@ -5,6 +5,8 @@
 
 #include "kateviewspace.h"
 
+#include <optional>
+
 namespace KTextEditor
 {
 class Document;
@@ -14,11 +16,20 @@ class TabMimeData : public QMimeData
 {
     Q_OBJECT
 public:
-    TabMimeData(KateViewSpace *vs, KTextEditor::Document *d, int sourceTabIdx);
+    struct DroppedData {
+        int line = -1;
+        int col = -1;
+        QUrl url;
+    };
+
+    TabMimeData(KateViewSpace *vs, KTextEditor::Document *d);
+
+    static bool hasValidData(const QMimeData *md);
+
+    static std::optional<DroppedData> data(const QMimeData *md);
 
     KateViewSpace *const sourceVS;
     KTextEditor::Document *const doc;
-    const int tabIdx;
 };
 
 #endif