pbakaus/scroller
Scroller
Scroller is a JavaScript library for implementing pan-and-zoom interactions on HTML elements and Canvas rendering surfaces. It functions as a viewport state manager and kinetic scrolling engine that translates touch and mouse pointer events into scaled offsets for fluid navigation.
The library features a kinetic motion system that simulates deceleration and edge bouncing. It includes specific mechanisms for pull-to-refresh triggers and supports point-relative zoom scaling to keep the focal point centered on the user's cursor.
The system provides a range of movement controls, including axis-locked drag behaviors and grid-snapping alignment. It manages viewport scale through configurable minimum and maximum zoom limits and calculates coordinate transitions independently of the rendering layer.
Integration with the DOM is handled through data attributes for automatic initialization of the scrolling and zooming logic.
Features
- Canvas Pan and Zoom Controls - Provides the core logic for panning and zooming across HTML elements and canvas rendering surfaces.
- Canvas Navigation - Provides a comprehensive pan-and-zoom viewport system specifically designed for HTML Canvas rendering surfaces.
- Point-Relative Scaling - Supports point-relative zoom scaling to keep the focal point centered on the user's cursor.
- DOM and Canvas Pan-Zoom Utilities - Implements smooth panning and zooming interactions across both HTML elements and Canvas surfaces.
- State-Based Offset Calculation - Decouples the calculation of pan and zoom offsets from the rendering layer to ensure fluid navigation.
- Physical Motion Simulators - Simulates physical inertia, deceleration, and rubber-band bouncing for fluid scrolling motion.
- Pointer-to-Offset Translators - Translates raw mouse and touch pointer events into scaled offsets for the panning and zooming system.
- Scroll - Provides a kinetic engine that calculates momentum and friction for smooth, physics-based scrolling.
- Scroll Behavior Control - Implements motion-based scrolling behaviors including deceleration and edge bouncing.
- Coordinate-to-Translation Mapping - Translates raw mouse and touch coordinates into translation offsets for viewport positioning.
- User Input Processing - Captures and interprets mouse and touch events to drive the state of the interactive viewport.
- Zoom Limit Constraints - Controls the viewport scale and focal point while enforcing configurable minimum and maximum zoom limits.
- Zoom Magnification Controls - Implements zoom magnification controls with configurable minimum and maximum scale limits.
- Viewport State Management - Manages the logical state of viewport positions and zoom levels independently of the rendering layer.
- Focal Point Scaling - Provides point-relative zoom scaling to keep the focal point centered on the user's cursor.
- Rendering-Agnostic State Tracking - Calculates scroll and zoom coordinates independently of the rendering system to maintain consistency across platforms.
- Movement Constraints - Implements axis-locked drag behaviors and grid-snapping alignment for precise viewport navigation.
- Movement Range Restrictions - Implements logic to restrict panning to specific axes and enforce movement boundaries with bounce effects.
- Boundary-Crossing Gesture Detectors - Detects when a user pulls content beyond the top boundary to initiate a refresh sequence.
- Grid Snapping - Aligns viewport movement to specific pixel grids or page-based increments during scrolling.
- Multi-Touch Gesture Systems - Processes complex multi-touch gestures including multi-finger zooming for mobile web interfaces.
- Pull-to-Refresh Libraries - Implements a specialized JavaScript library mechanism for pull-to-refresh gestures in web pages.
Star history
How this analysis was created: This summary and feature list were written by an AI model that read the project's README and public documentation pages. Each feature links to the documentation it came from; stars, license and language come straight from the GitHub API. The model does not read the source code, and the analysis is refreshed when the project is re-analysed. Learn more on our About page.
