Spreadsheet: Enable Drag&Drop and Copy/Paste

These currently only work on the current sheet, in the current
Spreadsheet instance, but they're still freakin' cool!

Applications/Spreadsheet/SpreadsheetModel.cpp

@@ -26,6 +26,7 @@
 
 #include "SpreadsheetModel.h"
 #include "ConditionalFormatting.h"
+#include <AK/URL.h>
 #include <LibJS/Runtime/Error.h>
 #include <LibJS/Runtime/Object.h>
 
@@ -68,6 +69,12 @@ GUI::Variant SheetModel::data(const GUI::ModelIndex& index, GUI::ModelRole role)
         return cell->typed_display();
     }
 
+    if (role == GUI::ModelRole::DragData) {
+        // FIXME: It would be really nice if we could send out a URL *and* some extra data,
+        //        The Event already has support for this, but the user-facing API does not.
+        return Position { m_sheet->column(index.column()), (size_t)index.row() }.to_url().to_string();
+    }
+
     if (role == GUI::ModelRole::TextAlignment) {
         const auto* cell = m_sheet->at({ m_sheet->column(index.column()), (size_t)index.row() });
         if (!cell)

Applications/Spreadsheet/SpreadsheetModel.h

@@ -44,6 +44,7 @@ public:
     virtual void set_data(const GUI::ModelIndex&, const GUI::Variant&) override;
     virtual void update() override;
     virtual bool is_column_sortable(int) const override { return false; }
+    virtual StringView drag_data_type() const override { return "text/x-spreadsheet-data"; }
 
 private:
     explicit SheetModel(Sheet& sheet)

Applications/Spreadsheet/SpreadsheetView.cpp

@@ -27,6 +27,9 @@
 #include "SpreadsheetView.h"
 #include "CellTypeDialog.h"
 #include "SpreadsheetModel.h"
+#include <AK/ScopeGuard.h>
+#include <AK/URL.h>
+#include <LibCore/MimeData.h>
 #include <LibGUI/BoxLayout.h>
 #include <LibGUI/HeaderView.h>
 #include <LibGUI/Menu.h>
@@ -144,6 +147,49 @@ SpreadsheetView::SpreadsheetView(Sheet& sheet)
             m_table_view->update();
         }
     }));
+
+    m_table_view->on_drop = [&](const GUI::ModelIndex& index, const GUI::DropEvent& event) {
+        if (!index.is_valid())
+            return;
+
+        ScopeGuard update_after_drop { [this] { update(); } };
+
+        if (event.mime_data().has_format("text/x-spreadsheet-data")) {
+            auto data = event.mime_data().data("text/x-spreadsheet-data");
+            StringView urls { data.data(), data.size() };
+            bool first = true;
+            for (auto url : urls.lines(false)) {
+                if (!first) { // FIXME: Allow d&d from many cells to many cells, somehow.
+                    dbg() << "Ignored '" << url << "'";
+                    continue;
+                }
+
+                first = false;
+
+                auto& target_cell = m_sheet->ensure({ m_sheet->column(index.column()), (size_t)index.row() });
+                auto* source_cell = m_sheet->from_url(url);
+
+                if (!source_cell) {
+                    target_cell.set_data("");
+                    return;
+                }
+
+                auto ref_cells = target_cell.referencing_cells;
+                target_cell = *source_cell;
+                target_cell.dirty = true;
+                target_cell.referencing_cells = move(ref_cells);
+            }
+            return;
+        }
+
+        if (event.mime_data().has_text()) {
+            auto* target_cell = m_sheet->at({ m_sheet->column(index.column()), (size_t)index.row() });
+            ASSERT(target_cell);
+
+            target_cell->set_data(event.text());
+            return;
+        }
+    };
 }
 
 void SpreadsheetView::hide_event(GUI::HideEvent&)

Applications/Spreadsheet/SpreadsheetWidget.h

@@ -46,6 +46,7 @@ public:
 
     const String& current_filename() const { return m_workbook->current_filename(); }
     const Sheet& current_worksheet() const { return m_selected_view->sheet(); }
+    Sheet& current_worksheet() { return m_selected_view->sheet(); }
     void set_filename(const String& filename);
 
     Workbook& workbook() { return *m_workbook; }

Applications/Spreadsheet/main.cpp

@@ -31,6 +31,7 @@
 #include <LibCore/File.h>
 #include <LibGUI/AboutDialog.h>
 #include <LibGUI/Application.h>
+#include <LibGUI/Clipboard.h>
 #include <LibGUI/FilePicker.h>
 #include <LibGUI/Forward.h>
 #include <LibGUI/Icon.h>
@@ -150,6 +151,73 @@ int main(int argc, char* argv[])
             spreadsheet_widget.set_filename(current_filename);
     }));
 
+    auto& edit_menu = menubar->add_menu("Edit");
+    edit_menu.add_action(GUI::CommonActions::make_copy_action([&](auto&) {
+        auto& cells = spreadsheet_widget.current_worksheet().selected_cells();
+        ASSERT(!cells.is_empty());
+        StringBuilder text_builder, url_builder;
+        bool first = true;
+        for (auto& cell : cells) {
+            url_builder.append(cell.to_url().to_string());
+            url_builder.append('\n');
+
+            auto cell_data = spreadsheet_widget.current_worksheet().at(cell);
+            if (!first)
+                text_builder.append('\t');
+            if (cell_data)
+                text_builder.append(cell_data->data);
+            first = false;
+        }
+        HashMap<String, String> metadata;
+        metadata.set("text/x-spreadsheet-data", url_builder.to_string());
+
+        GUI::Clipboard::the().set_data(text_builder.string_view().bytes(), "text/plain", move(metadata));
+    },
+        window));
+    edit_menu.add_action(GUI::CommonActions::make_paste_action([&](auto&) {
+        auto& cells = spreadsheet_widget.current_worksheet().selected_cells();
+        ASSERT(!cells.is_empty());
+        const auto& data = GUI::Clipboard::the().data_and_type();
+        if (auto spreadsheet_data = data.metadata.get("text/x-spreadsheet-data"); spreadsheet_data.has_value()) {
+            Vector<URL> urls;
+            for (auto line : spreadsheet_data.value().split_view('\n')) {
+                if (line.is_empty())
+                    continue;
+                URL url { line };
+                if (!url.is_valid())
+                    continue;
+                urls.append(move(url));
+            }
+
+            if (urls.size() == 1 && cells.size() == 1) {
+                auto& cell = *cells.begin();
+                auto& url = urls.first();
+
+                auto* source_cell = spreadsheet_widget.current_worksheet().from_url(url);
+                if (source_cell) {
+                    auto& target_cell = spreadsheet_widget.current_worksheet().ensure(cell);
+                    auto references = target_cell.referencing_cells;
+                    target_cell = *source_cell;
+                    target_cell.referencing_cells = move(references);
+                    target_cell.dirty = true;
+                    spreadsheet_widget.update();
+                }
+
+                return;
+            }
+
+            if (urls.size() != cells.size()) {
+                // FIXME: Somehow copy a bunch of cells into another bunch of cells.
+                TODO();
+            }
+        } else {
+            for (auto& cell : spreadsheet_widget.current_worksheet().selected_cells())
+                spreadsheet_widget.current_worksheet().ensure(cell).set_data(StringView { data.data.data(), data.data.size() });
+            spreadsheet_widget.update();
+        }
+    },
+        window));
+
     auto& help_menu = menubar->add_menu("Help");
 
     help_menu.add_action(GUI::Action::create(