Guide

Editor tools

Everything the engine adds to the Unity editor is in one menu, Tools → DevCore. Creating things is also in the right-click menus of the Project and Hierarchy windows.

The menu

Tools → DevCore	What it does
Live Preview, New Live Preview	Shows a page or a component while you edit it
Inspector	The element tree, styles, layout and performance of a view
Locales	The locale editor
Create App	Writes the files of a new app
Add App (2D) to Scene, Add 3D View to Scene	Adds a `DevCoreApp` or a `DevCore3DView`
Download Used Icons	Saves the Iconify icons your components name
Live Session	Turns hot reload on and off
Recompile All Components	Compiles every `.dcue` file again

Live Preview

The preview window shows a page or a component outside Play mode. Open it from the menu, by right-clicking a .dcue file (Open in DevCore Live Preview), or with the preview button in VS Code.

Device presets: Full HD, HD, laptop, 4K, handheld, TV, phone, tablet and custom sizes, with Rotate.
Switches: dark mode, touch, language and direction.
Pick: point at an element to see its box model, and grid and flex overlays.
A panel on the left lists every .dcue file; a click previews it, a double click opens it in your editor.
The preview takes the mouse and the keyboard, so you can use the page in it.

Hot reload

While a Live Preview shows a file, saving it (or a component it uses) updates the preview without waiting for Unity to recompile:

You change	What happens
A style sheet	It is reloaded in place
A page	The page is rebuilt
A component	It is compiled in memory and swapped in, keeping its `[State]`. A starting value you changed wins
A locale file	Its texts are merged in; removed keys are removed

Errors appear as an overlay with a clickable file:line:column. Unity's own compile waits until you press Apply, close the last preview or leave Play mode. Hot reload works in Play mode too.

Inspector

Tools → DevCore → Inspector shows the element tree of a view, with a tab for each question:

Tab	Shows
Styles	The rules that match, each with its file and line; overridden declarations crossed out
Computed	The computed value of every property
Box model	Content, padding, border and margin sizes
Component	The component's `[State]`, editable live
Listeners	The event listeners on the element
Layers	Paint nodes, draw calls, why a batch breaks, atlas pages
Performance	The last frame's timings and a graph

VS Code extension

The package includes the DevCore UI extension for .dcue files. Install it with

code --install-extension Packages/com.devcore.uiengine/Editor/VSCode/dcue-<version>.vsix

or Extensions → … → Install from VSIX. Its language server understands the C# of a component, in the script and in the template:

Completion of the script's members, the project's types, the engine's attributes, component tags and their props, and icon names.
Auto-import: choosing a component writes its import line; a type of another namespace brings its using line.
Hover shows a member's documentation; F12 goes to its definition; signature help shows parameters.
Problems while typing, from the C# compiler and the component compiler, with quick fixes.
Highlighting of the markup, the script, the styles and the template syntax; snippets; Emmet; Format Document.
Open in Live Preview opens the file in Unity's preview window.
Generated .dcue.cs files open as a do-not-edit notice; *.dcue.locale files are treated as YAML.

Code completion needs .NET 8 or newer on the machine, and the C# project files Unity writes. Install Unity's Visual Studio Editor package, then in Edit → Preferences → External Tools choose Visual Studio Code, tick Embedded packages and press Regenerate project files.

In Rider and Visual Studio, map *.dcue to the HTML editor.

In the Project window

.dcue files show the engine's icon on a blue tile, generated .dcue.cs files on a purple one.
Selecting a .dcue file shows whether it is a component or a page, with Watch live and Edit.
Selecting a generated file shows a warning not to edit it.
Compiler errors appear in the Console at the .dcue line and column.

Licences in builds

After every player build, a Licenses folder beside the game holds the engine's licence, the notices of the third-party material it contains, and every .txt file you put in Assets/DevCoreUIEngine/Licenses (a font's OFL.txt, the icons' licence file). You do not have to remember to copy them.