Naming and coding style convention, new linter tool. (#945)

* Makefile, Scripts: new linter
* About: remove ID from IC
* Firmware: remove double define for DIVC/DIVR
* Scripts: check folder names too. Docker: replace syntax check with make lint.
* Reformat Sources and Migrate to new file naming convention
* Docker: symlink clang-format-12 to clang-format
* Add coding style guide

applications/dialogs/view_holder.h

@@ -0,0 +1,98 @@
+#pragma once
+
+#include <gui/view.h>
+#include <gui/gui.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct ViewHolder ViewHolder;
+
+/** 
+ * @brief Free callback type
+ */
+typedef void (*FreeCallback)(void* free_context);
+
+/** 
+ * @brief Back callback type
+ * @warning comes from GUI thread
+ */
+typedef void (*BackCallback)(void* back_context);
+
+/**
+ * @brief Allocate ViewHolder
+ * @return pointer to ViewHolder instance
+ */
+ViewHolder* view_holder_alloc();
+
+/**
+ * @brief Free ViewHolder and call Free callback
+ * @param view_holder pointer to ViewHolder
+ */
+void view_holder_free(ViewHolder* view_holder);
+
+/**
+ * @brief Set view for ViewHolder
+ * 
+ * @param view_holder ViewHolder instance
+ * @param view View instance
+ */
+void view_holder_set_view(ViewHolder* view_holder, View* view);
+
+/**
+ * @brief Set Free callback
+ * 
+ * @param view_holder ViewHolder instance
+ * @param free_callback callback pointer
+ * @param free_context callback context
+ */
+void view_holder_set_free_callback(
+    ViewHolder* view_holder,
+    FreeCallback free_callback,
+    void* free_context);
+
+/**
+ * @brief Free callback context getter. Useful if your Free callback is a module destructor, so you can get an instance of the module using this method.
+ * 
+ * @param view_holder ViewHolder instance
+ * @return void* free callback context
+ */
+void* view_holder_get_free_context(ViewHolder* view_holder);
+
+void view_holder_set_back_callback(
+    ViewHolder* view_holder,
+    BackCallback back_callback,
+    void* back_context);
+
+/**
+ * @brief Attach ViewHolder to GUI
+ * 
+ * @param view_holder ViewHolder instance
+ * @param gui GUI instance to attach to
+ */
+void view_holder_attach_to_gui(ViewHolder* view_holder, Gui* gui);
+
+/**
+ * @brief Enable view processing
+ * 
+ * @param view_holder 
+ */
+void view_holder_start(ViewHolder* view_holder);
+
+/**
+ * @brief Disable view processing
+ * 
+ * @param view_holder 
+ */
+void view_holder_stop(ViewHolder* view_holder);
+
+/** View Update Handler
+ * @param view, View Instance
+ * @param context, ViewHolder instance
+ */
+void view_holder_update(View* view, void* context);
+
+#ifdef __cplusplus
+}
+#endif