Graphical Programming Examples
Desiderato Merriwether
In computing, a visual programming language (visual programming system, VPL, or, VPS), also known as diagrammatic programming,[1][2] graphical programming or block coding, is a programming language that lets users create programs by manipulating program elements graphically rather than by specifying them textually.[3] A VPL allows programming with visual expressions, spatial arrangements of text and graphic symbols, used either as elements of syntax or secondary notation. For example, many VPLs are based on the idea of "boxes and arrows", where boxes or other screen objects are treated as entities, connected by arrows, lines or arcs which represent relations. VPLs are generally the basis of Low-code development platforms.
VPLs may be further classified, according to the type and extent of visual expression used, into icon-based languages, form-based languages, and diagram languages. Visual programming environments provide graphical or iconic elements which can be manipulated by users in an interactive way according to some specific spatial grammar for program construction.
As of 2005, current developments try to integrate the visual programming approach with dataflow programming languages to either have immediate access to the program state, resulting in online debugging, or automatic program generation and documentation. Dataflow languages also allow automatic parallelization, which is likely to become one of the greatest programming challenges of the future.[5]
The Visual Basic, Visual C#, Visual J# etc. languages of the Microsoft Visual Studio integrated development environment (IDE) are not visual programming languages: the representation of algorithms etc. is textual even though the IDE embellishes the editing and debugging activities with a rich user interface. A similar consideration applies to most other rapid application development environments which typically support a form designer and sometimes also have graphical tools to illustrate (but not define) control flow and data dependencies.
The following list is not mutually exclusive, as some visual programming environments may incorporate elements from multiple paradigms. The choice of visual programming paradigm often depends on the specific requirements of the application or the preferences of the users or the developers.
Most of the VPLs are designed for education or domain-specific usage where is the target users are novice programmers. But there are some research projects try to provide a general-purpose visual programming language that can be used by mainstream programmers in any software project instead of using textual programming languages like (C, C++, Java, etc.).
For example, research projects such as Envision [8][9] and PWCT[10] are designed to achieve this goal. It's common for a VPL to be developed using a textual programming language. Developing general-purpose VPLs allows the other way around. For example, a new textual programming language Compiler and Virtual Machine is developed using visual programming in 2016.[11]
Many modern video games make use of behavior trees, which are in principle a family of simple programming languages designed to model behaviors for non-player characters. The behaviors are modeled as trees, and are often edited in graphical editors.
Does anyone have a working example (simpler the better) of a Rust program that uses GTK4 and draws graphical stuff, not just text? All I can find on the web either use GTK3 or are coded in C rather than rust. There is a nice tutorial at Building a Simple To-Do App - GUI development with Rust and GTK 4, but it uses only textual widgets.
You are asking about Cairo drawing? I ported my toy chess game to Rust recently, see GitHub - StefanSalewski/rust-chess: Port of salewski-chess from Nim to Rust. The GUI stuff is still ugly, sorry. But maybe it helps you to start with cairo. I can currently not remember other Rust cairo examples, but I would assume there is something in gtk4-rs/examples at master gtk-rs/gtk4-rs GitHub. Personally, I have some hope for Xilem and Vello for the end of this year.
Many thanks for that, Stefan. I tried to build your chess project, but it needs GTK4 version 4.10 and my system has only 4.6.9. Fixed it by removing the 'features = ["v4_12"]' from Cargo.toml. I'm sure the source code will give me lots of good examples anyway.
The Blockly library adds a customizable editor to your app that presents coding concepts as interlocking blocks. It produces clean code in your desired language and allows for custom blocks tailored to your application.
The Blockly editor uses interlocking, graphical blocks to represent code concepts like variables, logical expressions, loops, and more. It allows users to apply programming principles without worrying about syntax.
A platform-agnostic library, Blockly is preferred by coding platforms seeking consistency, flexibility and convenience. Blockly is compatible with all major browsers and works on both web and mobile.
Add functionality to Blockly with Plugins. Add fields, define themes, create renderers, and much more. Explore plugins Codelabs Blockly codelabs provide step-by-step instructions on how to use and customize Blockly.
Mark Friedman, Co-founder, App Inventor Proven and reliable 100+ partners 10+ years 94+ translations Trusted by developers Blockly is the engine behind some of the largest and most loved block-based coding products.
If you are a software developer who wants to get started with Blockly, you should begin by reading our Get Started Docs and then try our Get Started Codelab.
If you are a teacher or student interested in block-based coding, you should check out a lesson through an educational product built on Blockly, such as CS First, Code.org, or Scratch.
The Blockly library is for software developers that want to add an editor to their app that represents coding concepts as interlocking blocks. From a developer's perspective, Blockly is a ready-made UI for creating a block-based language.
If you are not a developer, you most likely will want to engage with Blockly through a product that is built on Blockly, like Scratch or App Inventor. Check out the Blockly partnerships section for examples of other applications that are built on Blockly.
Block-based coding allows users to apply programming principles without having to worry about syntax or the intimidation of a blinking cursor on the command line, making the learning curve for aspiring programmers easier. By reducing the need to learn syntax, block-based coding allows users to focus entirely on the logic behind conditionals, loops, variables and other core concepts without worrying about unbalanced parenthesis or missing semicolons.
So far, we have covered the basic programming constructs (such as variables, data types, decision, loop, array and method) and introduced the important concept of Object-Oriented Programming (OOP). As discussed, OOP permits higher level of abstraction than traditional Procedural-Oriented Languages (such as C). You can create high-level abstract data types called classes to mimic real-life things. These classes are self-contained and are reusable.
In this article, I shall show you how you can reuse the graphics classes provided in JDK for constructing your own Graphical User Interface (GUI) applications. Writing your own graphics classes (and re-inventing the wheels) is mission impossible! These graphics classes, developed by expert programmers, are highly complex and involve many advanced design patterns. However, re-using them are not so difficult, if you follow the API documentation, samples and templates provided.
I shall assume that you have a good grasp of OOP, including composition, inheritance, polymorphism, abstract class and interface; otherwise, read the earlier articles. I will describe another important OO concept called nested class (or inner class) in this article.
Other than AWT/Swing/JavaFX graphics APIs provided in JDK, other organizations/vendors have also provided graphics APIs that work with Java, such as Eclipse's Standard Widget Toolkit (SWT) (used in Eclipse), Google Web Toolkit (GWT) (used in Android), 3D Graphics API such as Java bindings for OpenGL (JOGL), Java3D, and etc. Furthermore, developers have moved to use technologies such as HTML5 as the basis of webapps.
You need to refer to the "JDK API documentation" for the AWT/Swing APIs (under module java.desktop) while reading this chapter. The best online reference for Graphics programming is the "Swing Tutorial" @ For advanced 2D graphics programming, read "Java 2D Tutorial" @ For 3D graphics, read my 3D articles.
In the above figure, there are three containers: a Frame and two Panels. A Frame is the top-level container of an AWT program. A Frame has a title bar (containing an icon, a title, and the minimize/maximize/close buttons), an optional menu bar and the content display area. A Panel is a rectangular area used to group related GUI components in a certain layout. In the above figure, the top-level Frame contains two Panels. There are five components: a Label (providing description), a TextField (for users to enter text), and three Buttons (for user to trigger certain programmed actions).
In a GUI program, a component must be kept (or added) in a container. You need to identify a container to hold the components. Every container has a method called add(Component c). A container (say aContainer) can invoke aContainer.add(aComponent) to add aComponent into itself. For example,
GUI components are also called controls (e.g., Microsoft ActiveX Control), widgets (e.g., Eclipse's Standard Widget Toolkit, Google Web Toolkit), which allow users to interact with (or control) the application.
AWT provides many ready-made and reusable GUI components in package java.awt. The frequently-used are: Button, TextField, Label, Checkbox, CheckboxGroup (radio buttons), List, and Choice, as illustrated below.
A java.awt.Label provides a descriptive text string. Take note that System.out.println() prints to the system console, NOT to the graphics screen. You could use a Label to label another component (such as text field) to provide a text description.
93ddb68554