allow Node/Ref to accept drag&drop

CMakeLists.txt

@@ -57,6 +57,7 @@ target_sources(nf7
     common/generic_memento.hh
     common/generic_type_info.hh
     common/generic_watcher.hh
+    common/gui_dnd.hh
     common/gui_file.hh
     common/gui_node.hh
     common/gui_resizer.hh

common/dir_item.hh

@@ -10,10 +10,11 @@ namespace nf7 {
 class DirItem : public File::Interface {
  public:
   enum Flag : uint8_t {
-    kNone    = 0,
+    kNone           = 0,
-    kTree    = 1 << 0,
+    kTree           = 1 << 0,
-    kMenu    = 1 << 1,
+    kMenu           = 1 << 1,
-    kTooltip = 1 << 2,
+    kTooltip        = 1 << 2,
+    kDragDropTarget = 1 << 3,
   };
   using Flags = uint8_t;
 
@@ -28,6 +29,7 @@ class DirItem : public File::Interface {
   virtual void UpdateTree() noexcept { }
   virtual void UpdateMenu() noexcept { }
   virtual void UpdateTooltip() noexcept { }
+  virtual void UpdateDragDropTarget() noexcept { }
 
   Flags flags() const noexcept { return flags_; }
 

common/gui_dnd.hh

@@ -0,0 +1,69 @@
+#pragma once
+
+#include <cstring>
+#include <optional>
+#include <string>
+#include <string_view>
+
+#include <imgui.h>
+
+#include "nf7.hh"
+
+
+namespace nf7::gui::dnd {
+
+// data entity is char[] of file path
+constexpr const char* kFilePath = "nf7::File::Path";
+
+
+template <typename T>
+bool Send(const char* type, const T&) noexcept;
+
+template <>
+inline bool Send<std::string>(const char* type, const std::string& v) noexcept {
+  return ImGui::SetDragDropPayload(type, v.data(), v.size());
+}
+template <>
+inline bool Send<std::string_view>(const char* type, const std::string_view& v) noexcept {
+  return ImGui::SetDragDropPayload(type, v.data(), v.size());
+}
+template <>
+inline bool Send<File::Path>(const char* type, const File::Path& p) noexcept {
+  return Send(type, p.Stringify());
+}
+
+
+template <typename T>
+T To(const ImGuiPayload&) noexcept;
+
+template <>
+inline std::string To<std::string>(const ImGuiPayload& pay) noexcept {
+  std::string ret;
+  ret.resize(static_cast<size_t>(pay.DataSize));
+  std::memcpy(ret.data(), pay.Data, ret.size());
+  return ret;
+}
+template <>
+inline File::Path To<File::Path>(const ImGuiPayload& pay) noexcept {
+  return File::Path::Parse(To<std::string>(pay));
+}
+
+
+template <typename T>
+std::optional<T> Accept(const char* type, ImGuiDragDropFlags flags = 0) noexcept {
+  if (auto pay = ImGui::AcceptDragDropPayload(type, flags)) {
+    return To<T>(*pay);
+  }
+  return std::nullopt;
+}
+template <typename T>
+const ImGuiPayload* Peek(const char* type, auto& v, ImGuiDragDropFlags flags = 0) noexcept {
+  flags |= ImGuiDragDropFlags_AcceptBeforeDelivery;
+  if (auto pay = ImGui::AcceptDragDropPayload(type, flags)) {
+    if (pay->IsDelivery()) v = To<T>(*pay);
+    return pay;
+  }
+  return nullptr;
+}
+
+}  // namespace nf7::gui::dnd

common/gui_file.hh

@@ -7,6 +7,8 @@
 
 #include "nf7.hh"
 
+#include "common/gui_dnd.hh"
+
 
 namespace nf7::gui {
 
@@ -128,4 +130,18 @@ struct FileCreatePopup final {
   std::string type_filter_;
 };
 
-}  // namespace nf7
+
+inline bool InputFilePath(const char* id, std::string* path) noexcept {
+  bool ret = ImGui::InputText(id, path, ImGuiInputTextFlags_EnterReturnsTrue);
+
+  if (ImGui::BeginDragDropTarget()) {
+    if (auto str = gui::dnd::Accept<std::string>(gui::dnd::kFilePath)) {
+      *path = *str;
+      ret   = true;
+    }
+    ImGui::EndDragDropTarget();
+  }
+  return ret;
+}
+
+}  // namespace nf7::gui

file/luajit_node.cc

@@ -19,6 +19,7 @@
 #include "common/generic_context.hh"
 #include "common/generic_type_info.hh"
 #include "common/generic_watcher.hh"
+#include "common/gui_dnd.hh"
 #include "common/lambda.hh"
 #include "common/logger_ref.hh"
 #include "common/luajit_obj.hh"
@@ -47,7 +48,8 @@ class Node final : public nf7::File, public nf7::DirItem, public nf7::Node {
   Node(Env& env, File::Path&& path = {}, std::string_view desc = "",
        std::vector<std::string>&& in  = {},
        std::vector<std::string>&& out = {}) noexcept :
-      File(kType, env), DirItem(DirItem::kMenu | DirItem::kTooltip),
+      File(kType, env),
+      DirItem(DirItem::kMenu | DirItem::kTooltip | DirItem::kDragDropTarget),
       log_(std::make_shared<nf7::LoggerRef>()),
       obj_(*this, std::move(path)), desc_(desc) {
     input_  = std::move(in);
@@ -84,6 +86,7 @@ class Node final : public nf7::File, public nf7::DirItem, public nf7::Node {
   static void UpdateList(std::vector<std::string>&) noexcept;
   void UpdateMenu() noexcept override;
   void UpdateTooltip() noexcept override;
+  void UpdateDragDropTarget() noexcept override;
   void UpdateNode(Node::Editor&) noexcept override;
 
   File::Interface* interface(const std::type_info& t) noexcept override {
@@ -404,6 +407,13 @@ void Node::UpdateTooltip() noexcept {
     ImGui::TextUnformatted(desc_.c_str());
   }
   ImGui::Unindent();
+
+  ImGui::TextDisabled("drop a file here to set it as source");
+}
+void Node::UpdateDragDropTarget() noexcept {
+  if (auto p = gui::dnd::Accept<Path>(gui::dnd::kFilePath)) {
+    obj_ = std::move(*p);
+  }
 }
 void Node::UpdateNode(Node::Editor&) noexcept {
 }

file/luajit_obj.cc

@@ -18,6 +18,7 @@
 #include "common/generic_context.hh"
 #include "common/generic_type_info.hh"
 #include "common/generic_watcher.hh"
+#include "common/gui_dnd.hh"
 #include "common/lock.hh"
 #include "common/luajit.hh"
 #include "common/luajit_obj.hh"
@@ -46,7 +47,8 @@ class Obj final : public nf7::File,
   class ExecTask;
 
   Obj(Env& env, Path&& path = {}) noexcept :
-      File(kType, env), DirItem(DirItem::kTooltip | DirItem::kMenu),
+      File(kType, env),
+      DirItem(DirItem::kTooltip | DirItem::kMenu | DirItem::kDragDropTarget),
       log_(std::make_shared<nf7::LoggerRef>()),
       src_(*this, std::move(path)) {
   }
@@ -65,6 +67,7 @@ class Obj final : public nf7::File,
   void Update() noexcept override;
   void UpdateMenu() noexcept override;
   void UpdateTooltip() noexcept override;
+  void UpdateDragDropTarget() noexcept override;
 
   nf7::Future<std::shared_ptr<nf7::luajit::Ref>> Build() noexcept override;
 
@@ -314,6 +317,12 @@ void Obj::UpdateMenu() noexcept {
 void Obj::UpdateTooltip() noexcept {
   ImGui::Text("source: %s", src_.path().Stringify().c_str());
   ImGui::Text("cache : %d", cache_? cache_->index(): -1);
+  ImGui::TextDisabled("drop a file here to set it as source");
+}
+void Obj::UpdateDragDropTarget() noexcept {
+  if (auto p = gui::dnd::Accept<Path>(gui::dnd::kFilePath)) {
+    src_ = std::move(*p);
+  }
 }
 
 }

file/node_ref.cc

@@ -18,6 +18,7 @@
 #include "common/generic_context.hh"
 #include "common/generic_memento.hh"
 #include "common/generic_type_info.hh"
+#include "common/gui_dnd.hh"
 #include "common/gui_node.hh"
 #include "common/lambda.hh"
 #include "common/logger_ref.hh"
@@ -41,16 +42,11 @@ class Ref final : public nf7::File, public nf7::Node {
       std::vector<std::string>&& out = {}) noexcept :
       File(kType, env),
       mem_(*this, {*this, std::move(path), std::move(in), std::move(out)}) {
-    auto& d = mem_.data();
-    d.input  = std::move(in);
-    d.output = std::move(out);
-    CopySock();
   }
 
   Ref(Env& env, Deserializer& ar) : Ref(env) {
     auto& d = mem_.data();
     ar(d.target, d.input, d.output);
-    CopySock();
   }
   void Serialize(Serializer& ar) const noexcept override {
     const auto& d = mem_.data();
@@ -60,15 +56,21 @@ class Ref final : public nf7::File, public nf7::Node {
     const auto& d = mem_.data();
     return std::make_unique<Ref>(
         env, Path{d.target.path()},
-        std::vector<std::string>{d.input}, std::vector<std::string>{d.output});
+        std::vector<std::string>{input_}, std::vector<std::string>{output_});
   }
 
   std::shared_ptr<nf7::Lambda> CreateLambda() noexcept override;
 
   void Handle(const Event& ev) noexcept {
+    const auto& d = mem_.data();
+
     switch (ev.type) {
     case Event::kAdd:
       log_.SetUp(*this);
+      /* fallthrough */
+    case Event::kUpdate:
+      input_  = d.input;
+      output_ = d.output;
       return;
     case Event::kRemove:
       log_.TearDown();
@@ -106,35 +108,42 @@ class Ref final : public nf7::File, public nf7::Node {
   nf7::GenericMemento<Data> mem_;
 
 
-  void Sync(bool quiet = true) noexcept
+  void SyncQuiet() noexcept {
-  try {
-    auto& n = target();
     auto& d = mem_.data();
+    try {
+      auto& n = target();
 
-    const auto i = n.input();
+      const auto i = n.input();
-    d.input = std::vector<std::string>{i.begin(), i.end()};
+      d.input = std::vector<std::string>{i.begin(), i.end()};
 
-    const auto o = n.output();
+      const auto o = n.output();
-    d.output = std::vector<std::string>{o.begin(), o.end()};
+      d.output = std::vector<std::string>{o.begin(), o.end()};
-
+    } catch (nf7::Exception& e) {
-    CopySock(quiet);
+      d.input  = {};
-  } catch (nf7::Exception& e) {
+      d.output = {};
-    log_.Error("failed to sync: "+e.msg());
+      log_.Error("failed to sync: "+e.msg());
+    }
   }
-  void CopySock(bool quiet = true) noexcept {
+  void Sync() noexcept {
-    std::vector<std::string> in, out;
+    SyncQuiet();
-    if (!quiet) {
-      in  = std::move(input_);
-      out = std::move(output_);
-    }
     const auto& d = mem_.data();
-    input_  = d.input;
+    if (input_ != d.input || output_ != d.output) {
-    output_ = d.output;
+      mem_.Commit();
-    if (!quiet) {
-      if (in != input_ || out != output_) Touch();
     }
   }
 
+  void ExecChangePath(Path&& p) noexcept {
+    auto& target = mem_.data().target;
+    if (p == target.path()) return;
+    env().ExecMain(
+        std::make_shared<nf7::GenericContext>(*this, "change path"),
+        [this, &target, p = std::move(p)]() mutable {
+          target = std::move(p);
+          SyncQuiet();
+          mem_.Commit();
+        });
+  }
+
   nf7::Node& target() const {
     auto& f = *mem_.data().target;
     if (&f == this) throw nf7::Exception("self reference");
@@ -242,15 +251,7 @@ void Ref::Update() noexcept {
 
     if (!err && (ImGui::Button("ok") || submit)) {
       ImGui::CloseCurrentPopup();
-      if (path != d.target.path()) {
+      ExecChangePath(std::move(path));
-        env().ExecMain(
-            std::make_shared<nf7::GenericContext>(*this, "change path"),
-            [this, path = std::move(path)]() {
-              mem_.data().target = std::move(path);
-              Sync(true  /* = quiet */);
-              mem_.Commit();
-            });
-      }
     }
     ImGui::EndPopup();
   }
@@ -264,7 +265,7 @@ void Ref::UpdateNode(Node::Editor&) noexcept {
   if (ImGui::SmallButton("sync")) {
     env().ExecMain(
         std::make_shared<nf7::GenericContext>(*this, "synchornizing with target node"),
-        [this]() { Sync(false  /* = quiet */); });
+        [this]() { Sync(); });
   }
 
   const auto pathstr = mem_.data().target.path().Stringify();
@@ -288,6 +289,12 @@ void Ref::UpdateNode(Node::Editor&) noexcept {
   if (ImGui::Button(pathstr.c_str(), {w, 0})) {
     popup_ = "ConfigPopup";
   }
+  if (ImGui::BeginDragDropTarget()) {
+    if (auto p = gui::dnd::Accept<Path>(gui::dnd::kFilePath)) {
+      ExecChangePath(std::move(*p));
+    }
+    ImGui::EndDragDropTarget();
+  }
 
   const auto right = ImGui::GetCursorPosX() + w;
   ImGui::BeginGroup();

file/system_dir.cc

@@ -15,6 +15,7 @@
 #include "common/dir_item.hh"
 #include "common/generic_context.hh"
 #include "common/generic_type_info.hh"
+#include "common/gui_dnd.hh"
 #include "common/gui_file.hh"
 #include "common/gui_window.hh"
 #include "common/ptr_selector.hh"
@@ -236,8 +237,7 @@ void Dir::UpdateTree() noexcept {
       flags |= ImGuiTreeNodeFlags_Leaf;
     }
 
-    const bool open = ImGui::TreeNodeEx(
+    const bool open = ImGui::TreeNodeEx(item.second.get(), flags, "%s", name.c_str());
-        item.second.get(), flags, "%s", name.c_str());
 
     // tooltip
     if (ImGui::IsItemHovered()) {
@@ -274,6 +274,23 @@ void Dir::UpdateTree() noexcept {
       ImGui::EndPopup();
     }
 
+    // dnd source
+    if (ImGui::BeginDragDropSource()) {
+      gui::dnd::Send(gui::dnd::kFilePath, item.second->abspath());
+      ImGui::TextUnformatted(file.type().name().c_str());
+      ImGui::SameLine();
+      ImGui::TextDisabled(file.abspath().Stringify().c_str());
+      ImGui::EndDragDropSource();
+    }
+
+    // dnd target
+    if (ditem && (ditem->flags() & DirItem::kDragDropTarget)) {
+      if (ImGui::BeginDragDropTarget()) {
+        ditem->UpdateDragDropTarget();
+        ImGui::EndDragDropTarget();
+      }
+    }
+
     // displayed contents
     if (open) {
       ImGui::TreePush(&file);