Mastering the Art of Positioning: A Guide to Floating Toolbars in Lexical Editors

As a developer, you know how crucial it is to provide an exceptional user experience in your lexical editor. One of the most critical aspects of achieving this is positioning a floating toolbar when a selection spans across multiple lines. In this comprehensive guide, we’ll dive into the world of lexical editors and explore the ins and outs of getting your floating toolbar to behave as expected.

Understanding the Challenge

When a user selects text that spans across multiple lines, the floating toolbar should reposition itself to remain visible and accessible. However, achieving this can be a daunting task, especially for those new to lexical editors. The main challenge lies in determining the correct position of the toolbar based on the selection’s coordinates.

The Importance of Precise Positioning

A poorly positioned floating toolbar can lead to a frustrating user experience, causing users to lose focus and struggle to interact with the editor. On the other hand, a well-positioned toolbar can significantly enhance the overall usability of your lexical editor. It’s essential to get it right!

Calculating the Toolbar’s Position

To determine the correct position of the floating toolbar, you’ll need to calculate the bounding rectangle of the selection. This can be achieved using the following steps:

1. Get the selection object: Use your lexical editor’s API to obtain the current selection object, which typically contains the start and end coordinates of the selection.
2. Calculate the bounding rectangle: Use the selection object’s coordinates to calculate the bounding rectangle, taking into account the line heights and character widths.
3. Determine the toolbar's position: Based on the bounding rectangle, calculate the x and y coordinates where the toolbar should be positioned.

// Example code snippet in JavaScript
const selection = editor.getSelection();
const boundingRect = calcBoundingRect(selection);
const toolbarX = boundingRect.left + (boundingRect.width / 2);
const toolbarY = boundingRect.top + (boundingRect.height / 2);

Handling Edge Cases

When dealing with selections that span across multiple lines, you’ll encounter edge cases that require special attention. Be prepared to handle the following scenarios:

• Selection at the beginning or end of a line: Ensure the toolbar doesn’t overlap with the line numbers or gutter areas.
• Selection across multiple blocks or paragraphs: Take into account the block or paragraph spacing and adjust the toolbar’s position accordingly.
• Selection that wraps around to the next line: Handle cases where the selection starts at the end of a line and continues on the next line.

Implementing the Solution

Now that you’ve calculated the toolbar’s position, it’s time to implement the solution. You’ll need to:

1. Create a container element for the toolbar: Use an HTML element (e.g., a div) to wrap the toolbar and position it absolutely.
2. : Apply styles to the toolbar container to set its position, display, and z-index.
3. Update the toolbar's position on selection change: Use event listeners to track changes to the selection and recalculate the toolbar's position accordingly.

// Example HTML structure
<div id="toolbar-container" style="position: absolute; display: block; z-index: 1;">
  <!-- Your toolbar content here -->
</div>

// Example JavaScript code
const toolbarContainer = document.getElementById("toolbar-container");
editor.onSelectionChange(() => {
  const selection = editor.getSelection();
  const boundingRect = calcBoundingRect(selection);
  const toolbarX = boundingRect.left + (boundingRect.width / 2);
  const toolbarY = boundingRect.top + (boundingRect.height / 2);
  toolbarContainer.style.left = `${toolbarX}px`;
  toolbarContainer.style.top = `${toolbarY}px`;
});