Understanding how Stickers work in React Video Editor

Stickers are a new and engaging way to enhance videos. In React Video Editor, we've built a modular system to handle adding, displaying, and managing stickers. This post will walk you through the core components involved and show you how easy it is to add your own custom stickers!

We'll focus on three main files and one directory:

1. sticker-templates/: The directory where all individual sticker components and their configurations live.
2. sticker-helpers.tsx: A helper file that acts as a central registry for all available sticker templates.
3. StickersPanel.tsx: The UI component that users interact with to browse and add stickers to the timeline.
4. StickerLayerContent.tsx: The component responsible for rendering a specific sticker onto the video canvas based on its properties.

Let's dive into how they work together.

1. The Sticker Templates (sticker-templates/)

This directory is the heart of our sticker collection. Each subdirectory or file within sticker-templates/ typically represents a single sticker or a group of related stickers (like emoji-sticker or shapes).

Inside each template's file (e.g., discount-sticker.tsx), you'll usually find two main parts:

• The React Component: This is the visual part of the sticker. It's a standard React component that defines what the sticker looks like and how it behaves (e.g., animations). It receives props like dimensions, position, and any specific configuration defined for that sticker type.
• The Configuration Object: This object, often defined using a structure like StickerTemplate (likely defined in base-template.tsx), holds metadata about the sticker. This includes:
  • id: A unique identifier (e.g., "discount-sticker").
  • category: How the sticker should be grouped in the UI (e.g., "Animated", "Shapes").
  • Component: A reference to the React component itself.
  • defaultProps: Default settings like initial size, duration, or custom styles.
  • layout: Optional info on how it should appear in the preview panel (e.g., double width).

Think of sticker-templates/ as a library of available sticker designs and their blueprints.

2. The Sticker Registry

sticker-helpers.tsx

How does the rest of the application know which stickers exist and where to find them? The sticker-helpers.tsx file acts as a central hub or "registry":

1. Imports Templates: It explicitly imports the configuration object (like discountSticker, emojiStickers) from each template file within sticker-templates/.
2. Creates Master List: It aggregates all imported templates into a single array (e.g., templates).
3. Organizes Templates: It processes this list to create useful data structures:
   • templatesByCategory: An object where keys are category names (e.g., "Shapes") and values are arrays of templates belonging to that category. This is perfect for organizing the UI.
   • templateMap: An object where keys are the unique sticker ids and values are the corresponding template objects. This allows for quick lookups when we need to render a specific sticker.
4. Provides Helper Functions: It exports functions like getStickerCategories and getTemplatesForCategory for easy access to this organized data.

Essentially, sticker-helpers.tsx knows everything about the available stickers without needing to contain the visual rendering logic itself.

3. The Browsing UI

StickersPanel.tsx

This is what the user sees when they want to add a sticker. StickersPanel.tsx uses the information provided by sticker-helpers.tsx to build the UI:

1. Gets Categories: It calls getStickerCategories() to get a list of all categories.
2. Creates Tabs: It renders tabs for each category.
3. Gets Templates for Category: For the selected tab, it calls getTemplatesForCategory(categoryName) or uses templatesByCategory directly.
4. Renders Previews: It maps over the templates for the current category and renders a StickerPreview component for each one.
   • The StickerPreview component is clever: it uses Remotion's <Player> component to show a small, animated preview of what the sticker actually looks like in action! It uses the Component and defaultProps from the template's configuration.
5. Handles Adding Stickers: When a user clicks a StickerPreview, the handleStickerClick function is triggered. This function:
   • Finds the full template configuration using the template ID.
   • Determines a suitable position (from, row) on the timeline using useTimelinePositioning.
   • Creates a new Overlay object. This object represents the specific instance of the sticker being added to the timeline. Crucially, it includes:
     • type: OverlayType.STICKER
     • content: template.config.id (This links the overlay instance back to its template!)
     • Position (left, top), dimensions (width, height), timing (from, durationInFrames), and styling information.
   • Calls addOverlay (from EditorContext) to add this new overlay object to the editor's state.

So, the StickersPanel is the bridge between browsing available designs and placing a specific instance onto the editing timeline.

4. Rendering the Sticker on Canvas

StickerLayerContent.tsx

Okay, an overlay object representing our chosen sticker exists in the editor's state. How does it actually appear on the main video preview canvas? Yep you guessed it. StickerLayerContent.tsx.

This component is rendered for each overlay object that has type: OverlayType.STICKER. Its job is simple but crucial:

1. Receives Overlay Data: It gets the specific overlay object as a prop.
2. Finds the Template: It uses the overlay.content (which holds the template ID) as a key to look up the corresponding template configuration in the templateMap imported from sticker-helpers.tsx.
3. Gets the Component: If a template is found, it extracts the actual React component (template.Component) from the configuration.
4. Renders the Component: It renders the extracted Component, passing down the necessary props derived from the overlay object (like dimensions, styles) and the template's defaultProps.

StickerLayerContent acts as the final step, dynamically rendering the correct sticker visual based on the template ID stored in the overlay data.

Putting it All Together (The Flow)

1. Developer: Creates a new sticker component and config in sticker-templates/.
2. Developer: Imports and adds the new sticker config to the templates array in sticker-helpers.tsx.
3. App: sticker-helpers.tsx automatically organizes the new sticker into templatesByCategory and templateMap.
4. User: Opens the editor, StickersPanel.tsx uses sticker-helpers to display the new sticker in the correct category tab via StickerPreview.
5. User: Clicks the new sticker's preview.
6. App: StickersPanel.tsx creates an Overlay object containing the new sticker's ID (content), position, size, etc., and adds it to the editor state.
7. App: The main editor canvas renders layers based on the editor state. For the new sticker overlay, it renders StickerLayerContent.tsx.
8. App: StickerLayerContent.tsx uses the content (template ID) from the overlay prop, looks up the component in templateMap (from sticker-helpers.tsx), and renders the actual sticker component from sticker-templates/.

How to Add Your Own Sticker

Now for the exciting part! Adding a new sticker is straightforward thanks to this modular design:

1. Create Your Sticker Files:

   • Inside the components/editor/version-7.0.0/templates/sticker-templates/ directory, create a new file (e.g., my-cool-sticker.tsx) or a new directory if it's complex.

2. Define the Component: In your new file, create your React component. This component will receive props based on the Overlay type and any custom defaultProps you define.

   // components/editor/version-7.0.0/templates/sticker-templates/my-cool-sticker.tsx
   import React from "react";
   import { StickerProps } from "./base-template"; // Assuming StickerProps is defined here
   
   export const MyCoolStickerComponent: React.FC<StickerProps> = ({
     overlay,
     isSelected,
   }) => {
     // Use overlay.width, overlay.height, overlay.styles, etc.
     // Add your awesome sticker visuals and animations here!
     return (
       <div
         style={{
           width: "100%",
           height: "100%",
           background: "purple",
           color: "white",
           display: "flex",
           alignItems: "center",
           justifyContent: "center",
           borderRadius: "50%",
         }}
       >
         Cool!
       </div>
     );
   };

3. Define the Configuration: In the same file, define and export the configuration object for your sticker. Make sure the id is unique and the category exists or is a new one you want to create.

   // components/editor/version-7.0.0/templates/sticker-templates/my-cool-sticker.tsx
   import { StickerTemplate } from "./base-template";
   // ... import your Component ...
   
   export const myCoolSticker: StickerTemplate = {
     config: {
       id: "my-cool-sticker", // Unique ID
       name: "My Cool Sticker", // Display name (optional)
       category: "Fun", // Category for the panel
       Component: MyCoolStickerComponent, // Reference your component
       defaultProps: {
         // Default properties when added
         styles: {
           opacity: 1,
           // Any other default styles
         },
         durationInFrames: 90, // Default duration ~3s at 30fps
       },
       // layout: "double", // Optional: if it needs more space in the preview panel
       // isPro: false, // Optional: mark as pro feature
     },
   };

4. Register the Sticker: Open components/editor/version-7.0.0/templates/sticker-templates/sticker-helpers.tsx.

   • Import your newly exported configuration object:

     import { myCoolSticker } from "./my-cool-sticker"; // Add this line

   • Add your imported configuration object to the templates array:

     const templates: StickerTemplate[] = [
       discountSticker,
       circularProgress,
       // ... other stickers
       ...shapeStickers,
       myCoolSticker, // Add your sticker here!
       // Add other sticker templates here
     ];

That's it! The sticker-helpers.tsx file will automatically handle the rest. When you reload the editor, your "My Cool Sticker" should appear in the "Fun" category tab within the StickersPanel, ready to be added and rendered via StickerLayerContent.

Conclusion

The sticker system in React Video Editor is designed to be flexible, intuitive, and developer-friendly. By breaking things down into clear componentsM from templates to rendering, we've made it easy to extend the editor with your own creative ideas.

Whether you're adding fun emojis, animated callouts, or branded overlays, the structure is already in place for you to drop in new stickers with minimal friction.