מודולים

Ink API הוא מודולרי, כך שאפשר להשתמש רק במה שצריך.

תנועות

The strokes module serves as the foundation of the Ink API. Key data types within this module are:

  • StrokeInputBatch: Represents a series of pointer inputs, including their position, timestamp, and optionally pressure, tilt, and orientation.
  • InProgressStroke: Represents a stroke that is actively being drawn. InProgressStroke is used to render partial strokes with low latency and to build the final Stroke once input is complete, after which the object can be reused. InProgressStroke is used by the InProgressStrokes composable.
  • Stroke: An immutable representation of a finalized stroke with fixed geometry. Each Stroke has an ImmutableStrokeInputBatch (input points), a Brush (style), and a PartitionedMesh (geometric shape). You can store, manipulate, and render strokes within your application.

גיאומטריה

The Geometry module supports geometric operations on primitive shapes (using dedicated classes like Box and Vec), as well as arbitrary shapes (using PartitionedMesh), including intersection detection and transformation. PartitionedMesh can also hold additional data to support rendering.

מכחול

The brush module defines the style of strokes. It consists of two main parts:

  • Brush: Specifies the style of a stroke including base color, base size, and BrushFamily. BrushFamily is analogous to a font family, it defines a stroke's style. For example, a BrushFamily can represent a specific style of marker or highlighter, allowing strokes with different sizes and colors to share that style.
  • StockBrushes: Provides factory functions for creating ready-to-use BrushFamily instances.

יצירת תוכן

The Compose Authoring module lets you capture user touch input and render it as low-latency strokes on the screen in real time. This is achieved through the InProgressStrokes composable, which processes motion events and displays the strokes as they are drawn.

Once a stroke is completed, the composable notifies the client application using an InProgressStrokesFinishedListener callback. This allows the application to retrieve the finished strokes for rendering or storage.

In Compose, InProgressStrokes takes this callback in the onStrokesFinished parameter. Pass the finished strokes to another composable to commit them to the screen using the rendering module.

רינדור

מודול העיבוד מפשט את ציור המשיכות של הדיו ב-Android Canvas. הוא מספק CanvasStrokeRenderer לכתיבה וViewStrokeRenderer לפריסות מבוססות-תצוגה. המעבדים האלה מבצעים אופטימיזציה של ביצועי העיבוד ועוזרים לספק תוכן ויזואלי באיכות גבוהה, כולל החלקת קצוות.

כדי לעבד את הקווים, קוראים ל-method‏ create() כדי לקבל מופע CanvasStrokeRenderer, ואז קוראים ל-method‏ draw() כדי לעבד קווים שהושלמו (Stroke) או קווים בתהליך (InProgressStroke) על Canvas.

אפשר לשנות את הצורה של הקנבס כשמציירים קו. לדוגמה, הזזה, שינוי גודל וסיבוב. כדי שהקו יופיע בצורה נכונה, צריך להעביר גם את טרנספורמציית canvas אל CanvasStrokeRenderer.draw.

כדי להימנע ממעקב נפרד של טרנספורמציית canvas, משתמשים במקום זאת ב-ViewStrokeRenderer.

אחסון

The storage module provides utilities for efficiently serializing and deserializing stroke data, primarily focusing on StrokeInputBatch.

The module uses protocol buffers and optimized delta compression techniques, resulting in significant storage savings compared to naive methods.

The storage module simplifies saving, loading, and sharing strokes.