=== Free Canvas ===
Contributors: Katsushi Kawamori
Donate link: https://shop.riverforest-wp.info/donate/
Tags: canvas, handwriting
Requires at least: 4.7
Requires PHP: 5.6
Tested up to: 6.0
Stable tag: 1.10
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html

Provide a canvas. Various cooperation is possible by shortcode and filter.

== Description ==

= Integrates Canvas into WordPress. =
* Provide canvas shortcode.
* Provides a filter hook when saving the canvas.
* It supports both mouse and touch.
* It supports both the management screen and the public screen. The appearance of buttons and select boxes on the public screen depends on the CSS of the theme.

= How to use the canvas =
[youtube https://youtu.be/_9XWJJbY6mQ]

= Sample of how to use the filter hook =
* Shortcode for canvas display
~~~
echo do_shortcode( '[freecanvas height=500]' );
~~~
* shortcode
Attribute : Default : Description
width : 700 : Canvas width
height : 700 : Canvas height
name : The date and time string when the canvas was loaded : Unique name for this canvas
form_name: null : The name of the form value you want to get
form_name2: null : The name of the form value you want to get
form_name3: null : The name of the form value you want to get
* Filter hook & Function
~~~
/**
 * Filter hook & function for outputs a PNG image file */
 *
 * @param string $image_data  image_data.
 * @param string $name  name.
 * @param string $form_value  form_value.
 * @param string $form_value2  form_value2.
 * @param string $form_value3  form_value3.
 */
function canvas_save( $image_data, $name, $form_value, $form_value2, $form_value3 ) {
	$wp_uploads = wp_upload_dir();
	$relation_path_true = strpos( $wp_uploads['baseurl'], '../' );
	if ( $relation_path_true > 0 ) {
		$upload_dir = wp_normalize_path( realpath( $wp_uploads['basedir'] ) );
	} else {
		$upload_dir = wp_normalize_path( $wp_uploads['basedir'] );
	}
	$filename = $upload_dir . '/' . $name . '.png';
	$image = imagecreatefromstring( $image_data );
	imagepng( $image, $filename );
}
add_filter( 'free_canvas_save', 'canvas_save', 10, 5 );
~~~
* Filter hook
Variable : Description : From
$image_data : PNG image data by Base64 : Value of Canvas
$name : Unique name for this canvas : Value of Free Canvas
$form_value : Form value obtained from form_name : Value of Form
$form_value2 : Form value obtained from form_name2 : Value of Form
$form_value3 : Form value obtained from form_name3 : Value of Form

== Installation ==

1. Upload `free-canvas` directory to the `/wp-content/plugins/` directory
2. Activate the plugin through the 'Plugins' menu in WordPress

== Frequently Asked Questions ==

none

== Screenshots ==

1. Canvas

== Changelog ==

= 1.10 =
Modified admin screen.

= 1.09 =
Supported WordPress 5.6.

= 1.08 =
Fixed ajax.

= 1.07 =
Fixed sample code.

= 1.06 =
Add shortcode attributes of form name.

= 1.05 =
Modified documentation.

= 1.04 =
Add shortcode attributes of form name.

= 1.03 =
Suppress screen transition when clicking save button in form.

= 1.02 =
Corrected the description.

= 1.01 =
Change readme.txt.

= 1.00 =
Initial release.

== Upgrade Notice ==

= 1.00 =
Initial release.