Add app path functions to TactilityC

TactilityC/Include/tt_app.h

@@ -7,6 +7,7 @@ extern "C" {
 #endif
 
 typedef void* AppHandle;
+typedef void* AppPathsHandle;
 
 /** @return the bundle that belongs to this application, or null if it wasn't started with parameters. */
 BundleHandle _Nullable tt_app_get_parameters(AppHandle handle);
@@ -14,7 +15,7 @@ BundleHandle _Nullable tt_app_get_parameters(AppHandle handle);
 /**
  * Set the result before closing an app.
  * The result and bundle are passed along to the app that launched this app, when this app is closed.
- * @param[in] handle the app context handle to set the result for
+ * @param[in] handle the app handle to set the result for
  * @param[in] result the result state to set
  * @param[in] bundle the result bundle to set
  */
@@ -23,6 +24,21 @@ void tt_app_set_result(AppHandle handle, AppResult result, BundleHandle _Nullabl
 /** @return true if a result was set for this app context */
 bool tt_app_has_result(AppHandle handle);
 
+/** Get the path to the data directory of this app.
+ * @param[in] handle the app handle
+ * @param[out] buffer the output buffer (recommended size is 256 bytes)
+ * @param[inout] size used as input for maximum buffer size (including null terminator) and is set with the path string length by this function
+ */
+void tt_app_get_data_directory(AppPathsHandle handle, char* buffer, size_t& size);
+
+/** Get the path to the data directory of this app, with LVGL drive letter prefix applied.
+ * The recommended buffer size is 256 bytes.
+ * @param[in] handle the app handle
+ * @param[out] buffer the output buffer (recommended size is 256 bytes)
+ * @param[inout] size used as input for maximum buffer size (including null terminator) and is set with the path string length by this function
+ */
+void tt_app_get_data_directory_lvgl(AppPathsHandle handle, char* buffer, size_t& size);
+
 /**
  * Start an app by id.
  * @param[in] appId the app manifest id

TactilityC/Source/tt_app.cpp

@@ -4,6 +4,8 @@
 
 extern "C" {
 
+constexpr auto* TAG = "tt_app";
+
 #define HANDLE_AS_APP_CONTEXT(handle) ((tt::app::AppContext*)(handle))
 
 BundleHandle _Nullable tt_app_get_parameters(AppHandle handle) {
@@ -31,4 +33,38 @@ void tt_app_stop() {
     tt::app::stop();
 }
 
+void tt_app_get_data_directory(AppPathsHandle handle, char* buffer, size_t& size) {
+    assert(buffer != nullptr);
+    assert(size > 0);
+    auto paths = HANDLE_AS_APP_CONTEXT(handle)->getPaths();
+    auto data_path = paths->getDataDirectory();
+    auto expected_length = data_path.length() + 1;
+    if (size < expected_length) {
+        TT_LOG_E(TAG, "Path buffer not large enough (%d < %d)", size, expected_length);
+        size = 0;
+        buffer[0] = 0;
+        return;
+    }
+
+    strcpy(buffer, data_path.c_str());
+    size = data_path.length();
+}
+
+void tt_app_get_data_directory_lvgl(AppPathsHandle handle, char* buffer, size_t& size) {
+    assert(buffer != nullptr);
+    assert(size > 0);
+    auto paths = HANDLE_AS_APP_CONTEXT(handle)->getPaths();
+    auto data_path = paths->getDataDirectoryLvgl();
+    auto expected_length = data_path.length() + 1;
+    if (size < expected_length) {
+        TT_LOG_E(TAG, "Path buffer not large enough (%d < %d)", size, expected_length);
+        size = 0;
+        buffer[0] = 0;
+        return;
+    }
+
+    strcpy(buffer, data_path.c_str());
+    size = data_path.length();
+}
+
 }

TactilityC/Source/tt_init.cpp

@@ -119,6 +119,8 @@ const esp_elfsym elf_symbols[] {
     ESP_ELFSYM_EXPORT(tt_app_selectiondialog_get_result_index),
     ESP_ELFSYM_EXPORT(tt_app_alertdialog_start),
     ESP_ELFSYM_EXPORT(tt_app_alertdialog_get_result_index),
+    ESP_ELFSYM_EXPORT(tt_app_get_data_directory),
+    ESP_ELFSYM_EXPORT(tt_app_get_data_directory_lvgl),
     ESP_ELFSYM_EXPORT(tt_bundle_alloc),
     ESP_ELFSYM_EXPORT(tt_bundle_free),
     ESP_ELFSYM_EXPORT(tt_bundle_opt_bool),