source: DataSource, Frame, SourceConfig and the registry (unused yet)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/source/source_kind.hpp

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: 2026 Martino Ferrari
+
+#pragma once
+
+#include "source/data_source.hpp"
+#include "source/source_config.hpp"
+
+#include <gtk/gtk.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace udpscope {
+
+/// A kind's configuration UI, as pieces the chooser places in its own group. The widgets are
+/// floating `AdwPreferencesRow`s; the closures capture them, so a form must not outlive its rows
+/// (the chooser drops the form when it removes the rows).
+struct ConfigForm {
+  std::vector<GtkWidget*> rows;
+  /// Shown under the group's title; empty for none.
+  std::string description;
+  /// The widget that takes focus when the form is shown; may be null.
+  GtkWidget* focus = nullptr;
+  /// Puts `cfg` into the widgets (absent keys leave the kind's defaults).
+  std::function<void(const SourceConfig&)> write;
+  /// The widgets as a `SourceConfig`.
+  std::function<SourceConfig()> read;
+  /// Whether the form is complete enough to connect.
+  std::function<bool()> valid;
+  /// Calls `fn` whenever any widget changes.
+  std::function<void(std::function<void()>)> on_change;
+};
+
+/// A capability panel (signal generator, digital I/O, ...) for the side area.
+struct SourcePanel {
+  std::string id;     ///< stack page name
+  std::string title;
+  std::string icon;   ///< icon name for the tab, may be empty
+  GtkWidget* widget = nullptr;
+};
+
+/// One plugin type: its identity, factory and UI.
+class SourceKind {
+ public:
+  virtual ~SourceKind() = default;
+  virtual std::string id() const = 0;            ///< short, `[a-z0-9]+`; the CLI and session name
+  virtual std::string display_name() const = 0;
+  /// A stable, human-readable name for one configured source (`host:port`, a serial number).
+  virtual std::string identity(const SourceConfig& cfg) const = 0;
+  virtual std::unique_ptr<DataSource> make(const SourceConfig& cfg) const = 0;
+  virtual ConfigForm make_config_form() const = 0;
+  /// Panels for a live source. The widgets must reach the source only through `post()`.
+  virtual std::vector<SourcePanel> make_panels(DataSource& source) const {
+    (void)source;
+    return {};
+  }
+  /// Whether the source reports raw datagrams (enables the packet-capture UI).
+  virtual bool has_datagrams() const { return false; }
+};
+
+}  // namespace udpscope