API Reference

This section provides detailed documentation for the gwm.js API.

Overview

gwm.js exposes a global gwm object with the following methods:

Method	Description
creation(options)	Creates a watermark with the specified options.
observing()	Manually starts observing the watermark for tampering.
cancel()	Cancels observation and allows the watermark to be removed.

Basic Usage

// Create a watermark with default options
gwm.creation();

// Create a watermark with custom options
gwm.creation({
  txt: 'Confidential',
  fontSize: 14,
  color: '#ff0000'
});

// Manually observe the watermark
const observer = gwm.observing();

// Cancel observation
gwm.cancel();

Options

The creation method accepts an options object with the following properties:

Property	Type	Default	Description
txt	string	Current date + "Top secret"	The text content of the watermark.
width	number	158	The width of the watermark canvas.
height	number	100	The height of the watermark canvas.
x	number	0	The x-coordinate of the watermark text.
y	number	50	The y-coordinate of the watermark text.
font	string	'Arial'	The font family for the watermark text.
fontSize	number	12	The font size for the watermark text.
color	string	'#000'	The color of the watermark text.
alpha	number	0.1	The transparency of the watermark (0-1).
angle	number	-15	The rotation angle of the watermark text.
mode	string	'canvas'	The rendering mode ('canvas', 'svg', or 'element').
watch	boolean	true	Whether to monitor for tampering.
css	object	null	Custom CSS styles for the watermark container.
destroy	boolean	true	Deprecated. Previously prevented multiple calls to creation, now has no effect.
container	string | HTMLElement	document.body	The container element for the watermark.
count	number	null	Optional parameter to set the number of watermarks.

For more detailed information about each option, see the table above. (Options page link removed)

Return Values

creation()

Returns: undefined

The creation method does not return a value. It creates a watermark and adds it to the DOM.

observing()

Returns: GwmObserver | GwmObserverEvent

The observing method returns an observer object that can be used to manually control the observation.

cancel()

Returns: void

The cancel method does not return a value. It cancels the current observation.

Type Definitions

(Types page link removed)