Refactor app loading and window management (#609)

Modules/app-module/include/app/metadata.h

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/error.h>
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define APP_METADATA_TARGET_SDK_LENGTH 16
+#define APP_METADATA_APP_ID_LENGTH 32
+#define APP_METADATA_APP_NAME_LENGTH 32
+#define APP_METADATA_APP_VERSION_NAME_LENGTH 16
+
+struct AppMetadata {
+
+    /**
+     * The SDK version that was used to compile this app. (e.g. "0.6.0")
+     * Must be NULL-terminated.
+     */
+    char target_sdk[APP_METADATA_TARGET_SDK_LENGTH + 1];
+
+    /**
+     * The identifier by which the app is launched by the system and other apps.
+     * Must be NULL-terminated.
+     */
+    char app_id[APP_METADATA_APP_ID_LENGTH + 1];
+
+    /**
+     * The user-readable name of the app. Used in UI.
+     * Must be NULL-terminated.
+     */
+    char app_name[APP_METADATA_APP_NAME_LENGTH + 1];
+
+    /**
+     * The version as it is displayed to the user (e.g. "1.2.0")
+     * Must be NULL-terminated.
+     */
+    char app_version_name[APP_METADATA_APP_VERSION_NAME_LENGTH + 1];
+
+    /** The technical version (must be incremented with new releases of the app) */
+    uint64_t app_version_code;
+};
+
+/**
+ * Parses a manifest.properties file at @a path into @a out_metadata, auto-detecting the V1
+ * (sectioned, e.g. "[app]id=...") or V2 (flat dot-notation, e.g. "app.id=...") format from its
+ * first line.
+ * @retval ERROR_NONE on success
+ * @retval ERROR_NOT_FOUND the file doesn't exist / couldn't be opened
+ * @retval ERROR_INVALID_ARGUMENT the file isn't a valid manifest, or a field's value doesn't fit
+ * @a out_metadata's fixed-size buffers
+ */
+error_t app_metadata_parse(const char* path, struct AppMetadata* out_metadata);
+
+#ifdef __cplusplus
+}
+#endif