# XRUI Framework [![release](https://camo.githubusercontent.com/0863d2f7118d2b6656d55211943146ec54dafd33a57c8a446687e5567b224809/68747470733a2f2f666c61742e62616467656e2e6e65742f6769746875622f72656c656173652f63687761722f78727569)](https://github.com/chwar/xrui) [![Unity 2021.2+](https://camo.githubusercontent.com/17d25d59875b0ce12a740e44fd6c386a0c6aeaeb8e39c70b9a7de6a5fea1a3ed/68747470733a2f2f666c61742e62616467656e2e6e65742f62616467652f756e6974792f323032312e322b)](https://unity3d.com/get-unity/download) [![MIT](https://camo.githubusercontent.com/133b66767efb6433d834c07d44b0b876d6fc730234edd1da0adf4a03e4f99a2c/68747470733a2f2f666c61742e62616467656e2e6e65742f62616467652f6c6963656e73652f4d49542f677265656e)](https://github.com/chwar/XRUI/raw/main/LICENSE) [![Coverage](https://camo.githubusercontent.com/58d73dfca8ab6424724c4cbea6ee1f829f7360b7a31d6f58bc770c6903e4cfe0/68747470733a2f2f666c61742e62616467656e2e6e65742f62616467652f636f7665726167652f39302532352f677265656e)](https://github.com/chwar/XRUI/raw/main/Tests)


2D Landscape (PC)	2D Portrait (Android)	World Space (Meta Quest 2)

XRUI is a responsive UI framework for making cross-platform XR applications with the Unity 3D editor. Its purpose is to assist users in creating efficient and adaptive UIs that can easily be adjusted to be rendered in 2D (for environments with a 2D screen, e.g. PC, mobile) and 3D (i.e., rendered in world space, required to render UI in VR and MR, can also be used in AR). This way, XRUI users only need to design and implement their UI once for all platforms, resulting in some time saving. This can also provide memorability and familiarity to end-users that use XRUI enhanced apps on different platforms. XRUI is based on Unity's new UI system, [UI Toolkit](https://docs.unity3d.com/Manual/UIElements.html). Internally, it uses UXML and USS, so a basic knowledge and understanding of these technologies are required to use this framework. ## Getting started 1. In the package manager, click on `Add package from git URL` and insert the repository's URL: [https://github.com/chwar/XRUI.git](https://github.com/chwar/XRUI.git) * Alternatively, you can unzip and import the package manually. 2. Add the XRUI controller to your scene by navigating to `XRUI > Add XRUI Controller`. You can also create an empty game object and attach the main XRUI script (`XRUI.cs`). This script is a singleton flagged as `DontDestroyOnLoad`. It contains the main API that can be easily accessed through the instance: ```csharp using com.chwar.xrui; void Start(){ // XRUI.Instance... } ``` 3. The package uses a default configuration that references the default UXML templates for UI elements. You can create your own by navigating to `Assets > Create > XRUI > Create XRUI Configuration asset`. You can then override the default templates for UI elements with your own (see [Custom UI Elements](https://github.com/chwar/XRUI/raw/main/#custom-ui-elements)). Don't forget to reference your own XRUI configuration asset to the XRUI controller. 4. You can have a look at the provided Demo scenes to get a better idea of how XRUI works. ## UI Elements


2D Landscape Overview	3D (World Space) Overview

XRUI provides a few UI Elements. The style is minimalistic and inspired from [Bootstrap](https://getbootstrap.com). You can add them in your project by navigating from the Unity menu to `XRUI > Add XRUI Element`. This creates a game object containing a `UIDocument` (which contains the UXML template and USS styles) and an XRUI script that matches the element. Add your own scripts to this object with a reference to the XRUI script to define the behaviour of the UI. XRUI elements are thought as basic containers for user content. Given the hierarchic nature of UXML, it is easy to append content within the UI elements at runtime. To easily access your UXML contents and append them into various XRUI elements, reference them in the intended UI Elements list within the XRUI controller: ![xruiController](https://user-images.githubusercontent.com/25299178/204763743-bbb68101-10be-4258-8bd4-05d675a42fca.png) The list of UI elements is accessible within the XRUI controller's instance. Use the `GetUIElement` method for easy access: ```csharp // Use the name of the VisualTreeAsset you put in the inspector list VisualTreeAsset myElement = XRUI.Instance.GetUIElement("MyElement"); ``` ### XRUI Element

Click to expand!

When adding UI Elements through the XRUI menu in Unity, the system uses the template referenced in the XRUI Configuration asset (see [Installation](https://github.com/chwar/XRUI/raw/main/#installation)). Each XRUI element script inherits from the `XRUIElement` class, which comes with some useful generic methods. To add or remove visual elements from the UI element, call these methods: ```csharp VisualElement myElement = someVisualTreeAsset.Instantiate(); XRUICard card = GetComponent(); // Appends a visual element inside a parent element card.AddUIElement(myElement, "xrui-card__container"); card.RemoveUIElement(myElement); ``` Get an XRUI related visual element from the UI element: ```csharp XRUICard card = FindObjectOfType(); XRUIMenu menu = FindObjectOfType(); // Get a generic Visual Element from the card var cardHeader = card.GetXRUIVisualElement("xrui-card__header"); // Get the title Label from the menu var menuTitle = menu.GetXRUIVisualElement("xrui-menu__title"); ``` You can also show or hide XRUI elements at any time: ```csharp card.Show(true); // Display.Flex, enables MeshRenderer and Collider for world UI card.Show(false); // Display.None, disables MeshRenderer and Collider for world UI card.Show(myElement, false); // Hides myElement ``` > Note: Keep in mind that hidden elements will not be found with a regular QML query, as they are hidden. You can still find them by either keeping a reference to the visual element in your code, or by querying it like this: > > ```csharp > card.Query().Where(ve => > ve.style.display.value.Equals(DisplayStyle.None)).First(); > ```

### XRUI Menu

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2D Landscape	2D Portrait	World Space

The provided XRUI Menu template is designed as a side menu that collapses out of the view frustum. It can be configured in the inspector (see screenshot above). The list element template is the UXML template that is used to create entries. You can provide a template with a simple button, or more complex compositions with images, text, buttons, etc. to suit your needs. Add entries to your menu: ```csharp var menu = GetComponent(); // The menu returns the created entry to be configured var element = menu.AddElement(); element.Q("MyElementLabel").text = "myLabelTitle"; ```

### XRUI List

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2D Landscape	2D Portrait	World Space

The XRUI List works in the same way as the menu: ```csharp var list = GetComponent(); // The list returns the created entry to be configured var element = list.AddElement(); element.Q("MyElementLabel").text = "myLabelTitle"; ```

### XRUI Navbar

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2D Landscape	2D Portrait	World Space

The provided navbar is a very simple dark top bar. Since XRUI does not provide any third-party assets, it is provided empty. However, the default template contains a row of buttons (three justified on the left side, one justified on the right side) to get you started. Since navbar designs can be very different, the adopted solution was to propose a very generic template to fit the most users. You could use the template as a base to add your own elements (buttons, dropdowns, labels) to tailor the navbar to your needs.

### XRUI Card

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2D Landscape	2D Portrait	World Space

The XRUI Card is floating on the right corner in the 2D landscape format, and sticks to the bottom of the screen in portrait format. Use the `AddUIElement` method (see [XRUI Element](https://github.com/chwar/XRUI/raw/main/#xrui-element)) to fill the card with content.

### XRUI Modals

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2D Landscape	2D Portrait	World Space

XRUI creates modals at runtime rather than requiring you to create all of them in the editor in order to save resources. Given the hierarchic nature of UXML, modals are easy to reproduce. XRUI provides a modal template, which consists of a title, empty container, two buttons (main and secondary) sticking at the bottom, and a closing button in the top right corner. You can use this template and fill its container dynamically at runtime. In Unity, you can reference your modals in the intended list: modals

The name given to each modal entry can be used to find the matching template and create a modal from it, with the `CreateModal` method: ```csharp // Adapt the namespace to your own Type t = Type.GetType("myModalScript"); XRUI.Instance.ShowModal("DemoModal", t); ``` > Note: The user script type has to be passed outside of the XRUI package, because Unity packages can't access the Assembly-CSharp assembly, i.e. can't find user namespaces, and hence, can't find user scripts located in the Assets automatically. It's also not possible to reference it through the inspector, as it only accepts instances of a script and not the script itself. This creates a modal game object on which the `XRUIModal` script is attached, as well as a `UIDocument` script that contains the main template. You can access the modal system's API through the `XRUIModal` script. The user script type is used to create an instance of said script when the modal is created. This lets you define the behaviour of your elements. One approach is to create one method per page, and to setup event handlers on your buttons to navigate them. To create modal pages, use the `UpdateModalFlow` method. Its last parameter is a callback function that is fired once upon the page's creation. ```csharp private XRUIModal _xruiModal; private UIDocument _uiDocument; void Start() { _xruiModal = GetComponent(); _uiDocument = GetComponent(); StartPage(); } void StartPage() { _xruiModal.UpdateModalFlow("MyModalPage", "MainContainer", () => { // This callback is only fired once, when the page is created for the first time // Put here initialization code, event subscriptions, etc. Button myButton = RootElement.Q

### XRUI Alerts

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2D Landscape - Primary	2D Portrait - Success	World Space - Warning

![Peek 2021-08-03 00-03](https://user-images.githubusercontent.com/25299178/127934108-1784dc2d-36d3-4452-8119-3f910f9a258a.gif) ![Peek 2021-08-03 00-05](https://user-images.githubusercontent.com/25299178/127934111-57e1859b-5900-4487-995f-9d3f55e8da68.gif) The provided alert template creates floating cards in 2D landscape and 3D formats, and as notifications at the top of the screen in 2D portrait mode. They also come with animations to attract the attention of users. You can show alerts for different purposes; the types of alerts are inspired from [Bootstrap](https://getbootstrap.com/docs/5.0/components/alerts/). Show alerts using the `ShowAlert` method: ```csharp XRUI.Instance.ShowAlert(XRUI.AlertType.Primary, "Primary message."); XRUI.Instance.ShowAlert(XRUI.AlertType.Success, "Success message."); XRUI.Instance.ShowAlert(XRUI.AlertType.Warning, "Warning message."); XRUI.Instance.ShowAlert(XRUI.AlertType.Danger, "Error message."); XRUI.Instance.ShowAlert(XRUI.AlertType.Info, "Info message."); ``` You can also provide a title: ```csharp XRUI.Instance.ShowAlert(XRUI.AlertType.Primary, "Title", "Primary message."); ``` You can also give a callback, which will be triggered upon clicking the alert: ```csharp XRUI.Instance.ShowAlert(XRUI.AlertType.Primary, "Click me!", "Click to trigger callback", () => MyCallback()); ``` Or, you can set a countdown after which the alert will disappear: ```csharp XRUI.Instance.ShowAlert(XRUI.AlertType.Primary, "Title", "This alert will disappear in 5 seconds", 5); ```

### XRUI Contextual Menu

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2D Landscape	2D Portrait

XRUI can create contextual menus dynamically. The contextual menu is shown as a floating list. Similarly to the menu and list templates, a menu element template is also given to create entries in the contextual menu. Because the entries are context-dependent, they need to be generated dynamically at runtime. The `ShowContextualMenu` method needs at least the x and y coordinates of the parent element (i.e. the element that was interacted which caused the contextual menu to appear), and a boolean to indicate whether or not the styling should include an arrow pointing at the parent element. A first overload gives the possibility to provide a custom template. A second overload lets developers provide left and right offsets for finer tuning of the menu’s position. The method returns a `XRUIContextualMenu` instance, which is required to add entries to the menu. ```csharp var myElement = GetComponent(); var myBtn = myElement.rootVisualElement.Q

## XR adaptation XRUI's main functionality is to provide responsiveness for different XR variants. This is done by setting the chosen XRUI format during the app's initialization, which all XRUI Elements (both static and dynamic) adopt thanks to USS styles. To change the XRUI format, change the related value in the XRUI controller: The XRUI API provides a method to assess the current XRUI format. You can use it to do target-specific manipulations like so: ```csharp if(XRUI.IsCurrentXRUIFormat(XRUI.XRUIFormat.ThreeDimensional)) { // MR/VR specific code here } ``` ### Two Dimensional Format For 2D UI, additional USS styles are provided to adapt for both landscape and portrait orientations. These classes are automatically added when the device (i.e., a smartphone) changes orientation. For ease of use, you can force the portrait mode while working in the Unity editor by checking the `Set Two Dimensional Format to Portrait in Editor` checkbox in the XRUI controller. ### Three Dimensional Format (World Space UI) When XRUI is set to Three Dimensional format, UI is rendered on panels in world space. Each XRUI Element contains a set of `World UI Parameters` which can alter the way it is rendered in world space. worlduiparameters

- The `Bend Panel` property will slightly bend the panel, which is a common practice in VR apps. - The `Anchor Panel To Camera` property makes the panel follow the gaze of the camera, with a slight delay. - The `Camera Follow Threshold` property defines the minimum distance that needs to be between the panel and the camera gaze before the panel recenters itself. - The `Custom Panel Dimensions` overrides the size of the panel, which is otherwise calculated from the ratio of the width and height of the UI element defined in the USS sheet. - The `Custom Panel Position` property sets the panel to the specified position in world coordinates. This is overriden if the `Anchor Panel To Camera` checkbox is checked. - The `Panel Scale` property lets you alter the scale of the panel. By default, the size of panels tend towards one world space unit. ## XRUI Grid System In order to organize easily and efficiently UI elements on screen, XRUI makes use of a grid system. You can use it by navigating to `XRUI > Add XRUI Grid`. In the Unity editor, you can group UI components inside rows through the scene hierarchy. The `XRUIGridController` component is attached to the root of the grid, and contains the list of all rows. A weighting system allows you to define which rows should take which amount of space (this uses the `flex-grow` attribute of CSS/USS Flexbox). For example, a top navbar can be setup in one row, with a weight of 0, i.e., it should not "grow"--as in, take space--more than its initial size. A second row containing the rest of the on-screen UI can have a weight of 1, i.e. it should take more of the available space than what its initial size requires. Since there are two rows and the first row has a weight of 0, this results in the second row using all remaining screen space. Horizontally, elements are contained in absolute containers, which mean they all take the entire horizontal space and can therefore overlap.

> Note: In case all UI elements within a row are absolute, the row's height becomes zero, because its USS property is set to `height: auto`. You should then indicate a minimum height in the indicated field to obtain the expected behaviour. ## Custom UI Elements You can create your own UXML templates and refer them in the XRUI Configuration asset. You should however be careful in naming your elements, should you want to inherit the functionalities provided by the default UI elements. You can check them with Unity's UI Builder, or you can simply duplicate the UXML files and start working from here. Also, the root visual element of your custom templates must have the `.xrui` USS class. ### USS styles XRUI comes with its own set of styles that are imported just after Unity's in UI Toolkit's pipeline. They are imported through a theme file which is used in the provided Panel Settings assets (also linked in the XRUI Configuration asset). You can add your own root styles to this theme file, override the root XRUI styles, or remove some of the imported assets if you don't need them. Should you want to inherit some of the XRUI styles for your own UI elements, you can add the related USS classes to the desired visual elements. Additionally, when creating your custom elements based on existing ones, it is recommended that you add the following USS classes to keep the XRUI functionalities (e.g., updating the title from the inspector). They are the following: | XRUI Element | Root USS Class | Sub USS Classes | |:-----------------------:|:--------------------------------:|:----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Menu | `.xrui-menu` | `.xrui-menu__title`
`.xrui-menu__subtitle`
`.xrui-menu__container`
`.xrui-menu__btn-container`
`.xrui-menu__close-btn`
`.xrui-menu__main-btn` | | Menu item | `.xrui-menu-item` | | | List | `.xrui-list` | `.xrui-list__title`
`.xrui-list__add-btn`
`.xrui-list__container` | | List item | `.xrui-list-item` | `.xrui-list-item__icon`
`.xrui-list-item__text` | | Navbar | `.xrui-navbar` | | | Card | `.xrui-card` | `.xrui-card__title`
`.xrui-card__subtitle`
`.xrui-card__container`
`.xrui-card__close-btn`
| | Alert | `.xrui-alert` | `.xrui-alert__title`
`.xrui-alert__content` | | Modal | `.xrui-modal` | `.xrui-modal__title`
`.xrui-modal__close-btn`
`.xrui-modal__container`
`.xrui-modal__btn-container`
`.xrui-modal__cancel-btn`
`.xrui-modal__validate-btn` | | Contextual Menu | `.xrui-contextual-menu ` | `.xrui-contextual-menu__arrow`
`.xrui-contextual-menu__container` | | Contextual Menu Element | `.xrui-contextual-menu-element ` | `.xrui-contextual-menu-element__text` | | Icons | `.xrui-icon` | `.xrui-icon--white`
`.xrui-icon--black` | | Templates | | `.xrui-templates__btn`
`.xrui-templates__separator`
`.xrui-templates__textfield` | | Backgrounds | | `.xrui-background--primary`
`.xrui-background--secondary`
`.xrui-background--warning`
`.xrui-background--success`
`.xrui-background--danger`
`.xrui-background--info`
`.xrui-background--light-grey`
`.xrui-background--dark` | ## XR Interactions See the `XRUIDemoInteraction` scene in the Demo folder. To enable interactions with world UI (i.e., make your UI react to MR/VR pointers), you need to add a few objects from the XR Interaction package in your scene: - An `Event Handler` component - The `Input Action Manager` component from the XRI package - The `XR Interaction Manager` from the XRI package - The `XR UI Input Module` from the XRI package Your controllers need: - The `XR Controller` component from the XRI package (preferably with the XRI input actions configured) - The `XR Ray Interactor` component from the XRI package - You must check the "Enable Interaction with UI GameObjects" checkbox XRUI automatically adds the `Tracked Device Physics Raycaster` component to World UI game objects. ## Acknowledgements - Thanks to [katas94](https://gist.github.com/katas94/7b220a591215efc36110860a0b1125eb) for the inspiration on interfacing XRUI with Unity Event Handlers and the XR Interaction package. - Thanks to [mattvr](https://gist.github.com/mattvr/8cdcc922d1a75d0a7a7abf5d46e23ef0) for their gist to create curved panels. - Thanks to [swifter14](https://forum.unity.com/threads/lock-auto-rotation-on-android-doesnt-work.842893/) for the fix on Android auto-rotation lock. - Thanks to [NormandErwan](https://github.com/NormandErwan/DocFxForUnity) for DocFxForUnity. ## Roadmap - Grid system for World UI - Implement keyboard support in MR/VR - Animation mechanism for all XRUI Elements - Add XRUIFormat override for XRUIElements, so that the app can have both 2D and 3D UI at once in the same scene (e.g., for mobile AR) - Custom inspectors for ease of use ## Known bugs - On mobile (Android), rotations show UI elements that had been previously hidden - Raycasts on World UI Interactions do not entirely match the visuals shown to the users when using the Oculus SDK. Collisions are detected on the left of panels although they should not, and they stop too early before the right border of the panel. - When scripts are recompiled in the Editor, 2D UI Elements will sometimes not update properly. This is not really problematic as going into play mode re-renders all UI Elements correctly.