Speeding up SOR Solvers for Constraint-based GUIs with a Warm-Start Strategy

Many computer programs have graphical user interfaces (GUIs), which need good layout to make efficient use of the available screen real estate. Most GUIs do not have a fixed layout, but are resizable and able to adapt themselves. Constraints are a powerful tool for specifying adaptable GUI layouts: they are used to specify a layout in a general form, and a constraint solver is used to find a satisfying concrete layout, e.g.\ for a specific GUI size. The constraint solver has to calculate a new layout every time a GUI is resized or changed, so it needs to be efficient to ensure a good user experience. One approach for constraint solvers is based on the Gauss-Seidel algorithm and successive over-relaxation (SOR). Our observation is that a solution after resizing or changing is similar in structure to a previous solution. Thus, our hypothesis is that we can increase the computational performance of an SOR-based constraint solver if we reuse the solution of a previous layout to warm-start the solving of a new layout. In this paper we report on experiments to test this hypothesis experimentally for three common use cases: big-step resizing, small-step resizing and constraint change. In our experiments, we measured the solving time for randomly generated GUI layout specifications of various sizes. For all three cases we found that the performance is improved if an existing solution is used as a starting solution for a new layout

Source code independent reverse engineering of dynamic web sites

This paper describes source code independent reverse engineering of dynamic web sites. The tool Revangie builds a form-oriented analysis model solely from the usage of a web application. The recovered models can be, for example, exploited for the purpose of requirements engineering and load test development. Revangie can explore a given web application fully automatically or can passively record its usages. The collected data, i.e., data about screens, server-side programs, and system responsiveness, are analyzed in order to build a user interface model. The paper presents several adequate screen classifications, which are utilized to yield significant models

CodeGazer: Making Code Navigation Easy and Natural with Gaze Input

Navigating source code, an activity common in software development,is time consuming and in need of improvement. We present CodeGazer, a prototype for source code navigation using eye gaze for common navigation functions. These functions include actions such as “Go to Definition” and “Find All Usages” of an identifier, navigate to files and methods, move back and forth between visited points in code and scrolling. We present user study results showing that many users liked and even preferred the gaze-based navigation, in particular the “Go to Definition” function. Gaze-based navigation is also holding up well in completion time when compared to traditional methods. We discuss how eye gaze can be integrated into traditional mouse & keyboard applications in order to make “look up” tasks more natural

Reverseorc:Reverse engineering of resizable user interface layouts with or-constraints

Reverse engineering (RE) of user interfaces (UIs) plays an important role in software evolution. However, the large diversity of UI technologies and the need for UIs to be resizable make this challenging. We propose ReverseORC, a novel RE approach able to discover diverse layout types and their dynamic resizing behaviours independently of their implementation, and to specify them by using OR constraints. Unlike previous RE approaches, ReverseORC infers flexible layout constraint specifications by sampling UIs at different sizes and analyzing the differences between them. It can create specifications that replicate even some non-standard layout managers with complex dynamic layout behaviours. We demonstrate that ReverseORC works across different platforms with very different layout approaches, e.g., for GUIs as well as for the Web. Furthermore, it can be used to detect and fix problems in legacy UIs, extend UIs with enhanced layout behaviours, and support the creation of flexible UI layouts.Comment: CHI2021 Full Pape

Modeling a Realistic Workload for Performance Testing

Abstract—Load testing of web applications can be specified by simulating realistic user behavior with stochastic form-oriented analysis models. Stochastic models have advantages over load test models that simply play back recorded session data: they are easier to specify and achieve a higher coverage of the different operational paths. There are challenges when specifying load tests such as the generation of form parameters and the recognition of pages returned by the system. We propose how these challenges can be overcome by adding additional specifications to a form-oriented model. Furthermore, we discuss several workload models and explain why some commonly used workload models are in fact unrealistic and produce misleading results. The stochastic form-oriented load testing approach can be generalized to deal with other submit-response systems such as those consisting of web services. I

ORC Layout: Adaptive GUI Layout with OR-Constraints

We propose a novel approach for constraint-based graphical user interface (GUI) layout based on OR-constraints (ORC) in standard soft/hard linear constraint systems. ORC layout unifies grid layout and flow layout, supporting both their features as well as cases where grid and flow layouts individually fail. We describe ORC design patterns that enable designers to safely create flexible layouts that work across different screen sizes and orientations. We also present theORC Editor, a GUI editor that enables designers to apply ORC in a safe and effective manner, mixing grid, flow and new ORC layout features as appropriate. We demonstrate that our prototype can adapt layouts to screens with different aspect ratios with only a single layout specification, easing the burden of GUI maintenance. Finally, we show that ORC specifications can be modified interactively and solved efficiently at runtime

Virtual Performance Augmentation in an Immersive Jump & Run Exergame

Human performance augmentation through technology has been a recurring theme in science and culture, aiming to increase human capabilities and accessibility. We investigate a related concept: virtual performance augmentation (VPA), using VR to give users the illusion of greater capabilities than they actually have.We propose a method for VPA of running and jumping, based on in place movements, and studied its effects in a VR exergame. We found that in place running and jumping in VR can be used to create a somewhat natural experience and can elicit medium to high physical exertion in an immersive and intrinsically motivating manner. We also found that virtually augmenting running and jumping can increase intrinsic motivation, perceived competence and flow, and may also increase motivation for physical activity in general. We discuss implications of VPA for safety and accessibility, with initial evidence suggesting that VPA may help users with physical impairments enjoy the benefits ofexergaming

BECOMING AVATAR:CO-CREATING GIRL’S PHYSICAL EDUCATION KIT ON 3D GAMING BODIES

For almost four decades, research within the field of physical education (PE) pedagogy has studied girls’ disengagement. Findings from these studies have highlighted several barriers to engagement such as the kit. The exploration of how PE kits affect young girls has not been widely researched within the social sciences and therefore, a gap in the literature has been identified. This pilot study, which is part of a wider PhD project, seeks to understand how the uniformed body affects girls felt experiences of PE. The kits worn for PE can be viewed as a means to discipline and control the body. Therefore, by giving power and agency back to girls to re-design the materiality of their PE kit, an improvement in engagement within PE may occur. A new materialist co-creative methodology was developed that applied fashion design principles and 3D video gaming to enable girls to re-imagine their school PE kit. Using print design on custom-made content for the SIMS 4 video game, four girls ages 10 -14 re-designed their school kit and wore them virtually in the game. The findings showed that using a co-creative approach, incorporating fashion design and video game avatars, to help facilitate the design of a kit relevant to the girls does have the potential to engage girls within school PE lessons. It is suggested that for more robust and conclusive findings, a larger study should be undertaken in UK secondary schools