Drag Highlight box

A lightweight Jetpack Compose utility that enables drag-based selection by drawing a selection rectangle and consuming drag gestures to prevent parent scroll or drag conflicts.

Designed as a low-level primitive, this library helps you build selection-based UX such as editors, canvases, dashboards, and boards — without enforcing any opinionated UI or behavior.

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Features

• Draws a visual selection rectangle while dragging
• Consumes drag gestures to avoid parent scroll interference
• Optional hit-testing to start selection only on empty space
• Fully customizable selection style (colors, stroke width)
• Works with Jetpack Compose and Compose Multiplatform
• Small, focused API — no editor logic included

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Installation

Published to Maven Central.

implementation("io.github.iknowdeadpool:dragfeedback-core:0.1.0") 

#  Quick Start
DragHighlightBox(
    enabled = true,
    onSelectionEnd = { rect ->
        // Handle selection rectangle
    }
) {
    // Your composable content
}

Customization

You can customize how the selection rectangle looks using DragFeedbackStyle:

DragHighlightBox(
    style = DragFeedbackStyle(
        fillColor = Color(0x3388BFFF),
        strokeColor = Color(0xFF66AFFF),
        strokeWidthPx = 2f
    ),
    onSelectionEnd = { rect -> }
) {
    CanvasContent()
}

Hit Testing

To prevent selection from starting when the user drags an item (instead of empty space), use canStartSelection:

DragHighlightBox(
    canStartSelection = { downOffset ->
        items.none { it.bounds.contains(downOffset) }
    },
    onSelectionEnd = { rect -> }
) {
    CanvasContent()
}

Demo

A desktop demo application is included in the repository to showcase integration patterns and usage. The demo is not part of the published library.

Contributions

Issues and feature requests are welcome. Please open an issue before submitting large changes.