Canvas Operations

Overview of Canvas Operations

G6 provides a series of canvas operation APIs to control and obtain basic information about the canvas. With these APIs, you can:

• Get the canvas instance
• Get and set the canvas size
• Operate the canvas renderer and layers

API Reference

Graph.getCanvas()

Get the canvas instance, which can be used for low-level canvas operations.

getCanvas(): Canvas;

Return Value Description

The Canvas instance includes the following main functions:

• getLayer(name?: string): Get the specified layer
• getLayers(): Get all layers
• getCamera(): Get the camera instance
• getRoot(): Get the root node
• setCursor(cursor: string): Set the mouse cursor style

Example

// Get the canvas instance
const canvas = graph.getCanvas();

// Get the main layer
const mainLayer = canvas.getLayer('main');

// Set the mouse cursor style
canvas.setCursor('pointer');

// Get the root node of the canvas
const root = canvas.getRoot();

Graph.getSize()

Get the size of the current canvas container. Returns an array containing the width and height.

getSize(): [number, number];

Example

// Get the canvas size
const [width, height] = graph.getSize();
console.log('Canvas width:', width);
console.log('Canvas height:', height);

// Use the size information for calculations
const centerX = width / 2;
const centerY = height / 2;

Graph.setSize(width, height)

Set the size of the canvas container. This method will update both the canvas and container size.

setSize(width: number, height: number): void;

Parameters

Example

// Set a fixed size
graph.setSize(800, 600);