ogs-site/en/news/2016-09-03_2016-august-recap.md

Title: August 2016 recap Date: 2016-09-03 00:00 Category: News Slug: 2016-august-recap Lang: en

This article explains the most important technical details about development in August: UIQt module, its refactoring, a new feature based development approach, and its benefits.

UIQt module is a collection of UI components backed by Qt. We only use it for Editor UI at the moment.

Here is a list of UIQt module components with their description and current code size:

**№**	**Component**	**Description**	**Size (B)**	**Size (%)**
1	UIQtAction	Actions (events) for menus	11224	9
2	UIQtAux	Initializes Qt and main window. Provides widget resolution by name to other components	15518	12
3	UIQtDock	Widget docks	5273	4
4	UIQtFileDialog	File selection dialogs	8960	7
5	UIQtMenu	Menus for main window and pop-ups (like node's add/copy/paste/delete menu)	4566	3
6	UIQtMenuBar	Menu bar for main window	4222	3
7	UIQtRunner	Allows to start QApplication	2450	2
8	UIQtThumbnailDialog	Dialog with thumbnail images	18615	14
9	UIQtToolBar	Tool bar for main window	4276	3
10	UIQtTree	Provides complex widgets like Scene tree and Property browser	51216	39
11	UIQtWidget	Common widget properties like focus and visibility	5465	4

UIQt module refactoring purpose was to replace old State API with new Environment API, which allows to achieve the same functionality with less code, i.e., makes development easier and faster.

Refactoring started in July and should have been done the same month. However, we only finished the work in August. Initial plan assumed 28 hours would be enough, but we spent 65 instead. We estimated planned time by relying on the number of public API calls of each component. That worked fine for small components, because the number of their public API calls was roughly equal to the number of their features, and features themselves were very small. However, it totally failed for UIQtTree, which contains 39% of UIQt module code, because there was no direct connection between public API and features.

Feature based development approach was born as a result of UIQtTree refactoring struggle. Since Qt uses MVC, UIQtTree component consists of several classes. By the time UIQtTree could display and manage a hierarchy of items, the component was already 27K in size. We noticed UIQtTree started to require abnormal amount of development time even for tiny features. This was an obvious quantitative complexity manifestation.

We decided to separate UIQtTree into base part and additional ones. Base would only contain minimal code required by all features. Addition would contain specific feature code and could be safely modified. In the case of UIQtTree, item hierarchy display and modification is the minimal functionality, while item renaming is an addition.

Here is a list of current UIQtTree features:

**№**	**Feature**	**Description**	**Size (B)**	**Size (%)**
1	Base	Allows to construct item hierarchy, modify it, and display it	26966	52
2	Item open state	Keeps track of collapsed/expanded item properties	3094	6
3	Item renaming	Allows to rename an item	3471	7
4	Item selection	Allows to get/set selected item	2338	5
5	Item value	Provides 2nd and the rest columns for items, used by Property browser	1307	3
6	Item value editing	Allows to edit item values with a default editor widget	1996	4
7	Item value editing with combobox	Provides combobox editor	5819	11
8	Item value editing with spinner	Provides spinbox editor	5290	10
9	Menu	Provides pop-up menu	1248	2

Here's an example of UIQtTree Menu feature file: TREE_MENU.

Benefits of the approach include:

1. Faster code reading/understanding due to small size
2. Easier and safer modification due to isolated code

There's a drawback, too: new approach requires learning.

That's it for the most important technical details about development in August: UIQt module, its refactoring, a new feature based development approach, and its benefits.