Start on TTS support by logging the data that will become TTS lines

Includes some misc cleanup of haptic double-triggering (or
non-triggering), since those cases all end up being TTS event
double-reporting, which to me crosses the threshold from "annoying" to
"usability issue"

3 files changed, 102 insertions, 0 deletions

diff --git a/src/tangara/tts/events.hpp b/src/tangara/tts/events.hpp
new file mode 100644
index 00000000..21199db1
--- /dev/null
+++ b/src/tangara/tts/events.hpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2024 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once
+
+#include <optional>
+#include <string>
+#include <variant>
+
+namespace tts {
+
+/*
+ * 'Simple' TTS events are events that do not have any extra event-specific
+ * details.
+ */
+enum class SimpleEvent {
+  /*
+   * Indicates that the screen's content has substantially changed. e.g. a new
+   * screen has been pushed.
+   */
+  kContextChanged,
+};
+
+/*
+ * Event indicating that the currently selected LVGL object has changed.
+ */
+struct SelectionChanged {
+  struct Selection {
+    std::optional<std::string> description;
+    bool is_interactive;
+  };
+
+  std::optional<Selection> new_selection;
+};
+
+using Event = std::variant<SimpleEvent, SelectionChanged>;
+
+}  // namespace tts
diff --git a/src/tangara/tts/provider.cpp b/src/tangara/tts/provider.cpp
new file mode 100644
index 00000000..7d33bae6
--- /dev/null
+++ b/src/tangara/tts/provider.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2024 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "tts/provider.hpp"
+
+#include <optional>
+#include <string>
+#include <variant>
+
+#include "esp_log.h"
+
+#include "tts/events.hpp"
+
+namespace tts {
+
+[[maybe_unused]] static constexpr char kTag[] = "tts";
+
+Provider::Provider() {}
+
+auto Provider::feed(const Event& e) -> void {
+  if (std::holds_alternative<SimpleEvent>(e)) {
+    // ESP_LOGI(kTag, "context changed");
+  } else if (std::holds_alternative<SelectionChanged>(e)) {
+    auto ev = std::get<SelectionChanged>(e);
+    if (!ev.new_selection) {
+      // ESP_LOGI(kTag, "no selection");
+    } else {
+      // ESP_LOGI(kTag, "new selection: '%s', interactive? %i",
+      // ev.new_selection->description.value_or("").c_str(),
+      // ev.new_selection->is_interactive);
+    }
+  }
+}
+
+}  // namespace tts
diff --git a/src/tangara/tts/provider.hpp b/src/tangara/tts/provider.hpp
new file mode 100644
index 00000000..59f61a6c
--- /dev/null
+++ b/src/tangara/tts/provider.hpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2024 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once
+
+#include <optional>
+#include <string>
+#include <variant>
+
+#include "tts/events.hpp"
+
+namespace tts {
+
+class Provider {
+ public:
+  Provider();
+  auto feed(const Event&) -> void;
+};
+
+}  // namespace tts