Element
Element
represents a graphical object on the page or group. An element can have one of these types:
text
image
svg
line
group
const element = store.activePage.addElement({
type: 'text',
x: 50,
y: 50,
fill: 'black',
text: 'hello',
});
// logs 50
console.log(element.x);
// set new position
element.set({ x: 100 });
Basic actions
Read properties
At any time you can access any property of an element. See documentation for every type of element to see all available properties.
const element = store.selectedElements[0];
// logs type of element
console.log(element.type);
// logs id of element
console.log(element.id);
element.set(attrs)
Set new attributes to the element.
text.set({ x: text.x + 10, text: 'new text' });
Custom properties
You can't write ANY property directly into element. If you want to write some additional data into an element, you can use custom
attribute.
// this line will not work, because elements has no attribute userId
element.set({ userId: '12' });
// you can write such data into "custom" attribute
element.set({ custom: { userId: '12' } });
// read custom attribute
console.log(element.custom?.userId);
element.moveUp()
Move element up on z-index.
text.moveUp();
element.moveDown()
Move element down on z-index.
text.moveToBottom();
element.moveTop()
Move element to the top of the page or a group.
text.moveTop();
element.moveBottom()
Move element to the bottom of the page or a group.
text.moveBottom();
Locking
You can use draggable
, contentEditable
and styleEditable
attributes to lock element editing.
// lock the object
element.set({
// can element be moved and rotated
draggable: false,
// can we change content of element?
contentEditable: false,
// can we change style of element?
styleEditable: false,
// can we resize element?
resizable: false,
});
console.log(element.locked); // true
// unlock it
element.set({
// can element be moved and rotated
draggable: true,
// can we change content of element?
contentEditable: true,
// can we change style of element?
styleEditable: true,
// can we resize element?
resizable: false,
});
Text element
Text elements allows you to create a text on the canvas.
Here is the example of default properties.
page.addElement({
type: 'text',
x: 0,
y: 0,
rotation: 0,
locked: false, // deprecated
blurEnabled: false,
blurRadius: 10,
brightnessEnabled: false,
brightness: 0,
shadowEnabled: false,
shadowBlur: 5,
shadowOffsetX: 0,
shadowOffsetY: 0,
shadowColor: 'black',
shadowOpacity: 1,
name: '', // name of element, can be used to find element in the store
text: 'Hey, polotno',
// placeholder is working similar to input placeholder
// it will be rendered if no text is defined
// and we will use it in input element too
// useful for template canvas, where users will need to replace text elements
// important (!) placeholders are removed from export result
placeholder: '',
fontSize: 14,
fontFamily: 'Roboto',
fontStyle: 'normal', // can be normal or italic
fontWeight: 'normal', // can be normal or bold or some other CSS variations
textDecoration: '',
fill: 'black',
align: 'center',
width: 0,
strokeWidth: 0,
stroke: 'black',
lineHeight: 1,
letterSpacing: 0, // % from font size,
backgroundEnabled: false,
backgroundColor: '#7ED321',
backgroundOpacity: 1,
backgroundCornerRadius: 0.5, // % from half line height
backgroundPadding: 0.5, //% from half line height
// can user select element?
// if false, element will be "invisible" for user clicks
selectable: true,
// use for absolute positing of element
alwaysOnTop: false,
// also we can hide some elements from the export
showInExport: true,
// can element be moved and rotated
draggable: true,
// can we change content of element?
contentEditable: true,
// can we remove element from UI with button or keyboard?
removable: true,
// can we resize element?
resizable: true,
// can we change style of element?
styleEditable: true,
});
text.toggleEditMode()
Enable edit mode for the text. It puts cursor inside the text and a user can do regular text editing.
You can use text.toggleEditMode()
to enter "edit mode" programmatically. For example, right after you created a new text element.
Image element
Image element will draw an image on the canvas. By default images will do smart-cropping to fit into its size.
page.addElement({
type: 'image',
x: 0,
y: 0,
rotation: 0,
locked: false, // deprecated
blurEnabled: false,
blurRadius: 10,
brightnessEnabled: false,
brightness: 0,
shadowEnabled: false,
shadowBlur: 5,
shadowOffsetX: 0,
shadowOffsetY: 0,
shadowColor: 'black',
shadowOpacity: 1,
name: '', // name of element, can be used to find element in the store
// url path to image
src: 'https://example.com/image.png',
keepRatio: false, // can we change aspect ratio of image
// url path to svg or image that will be used to clip image
// cab be used for image framing
clipSrc: '',
width: 100,
height: 100,
cropX: 0, // 0-1 : % from original image width
cropY: 0, // 0-1 : % from original image height
cropWidth: 1, // 0-1 : % from original image width
cropHeight: 1, // 0-1 : % from original image height
cornerRadius: 0,
borderColor: 'black',
borderSize: 0,
flipX: false,
flipY: false,
// can user select element?
// if false, element will be "invisible" for user clicks
selectable: true,
// use for absolute positing of element
alwaysOnTop: false,
// also we can hide some elements from the export
showInExport: true,
// can element be moved and rotated
draggable: true,
// can we change content of element?
contentEditable: true,
// can we remove element from UI with button or keyboard?
removable: true,
// can we resize element?
resizable: true,
});
image.toggleCropMode()
Enter into "crop mode" of the image programmatically.
SVG element
SVG
elements works very similar to Image
element, but has ability to replace its internal colors (not supported for all possible svgs).
const svgElement = page.addElement({
type: 'svg',
src: 'https://example.com/image.svg',
maskSrc: '', // should we draw mask image over svg element?
keepRatio: false, // can we change aspect ratio of svg?
x: 0,
y: 0,
rotation: 0,
locked: false, // deprecated
blurEnabled: false,
blurRadius: 10,
brightnessEnabled: false,
brightness: 0,
shadowEnabled: false,
shadowBlur: 5,
shadowOffsetX: 0,
shadowOffsetY: 0,
shadowColor: 'black',
shadowOpacity: 1,
name: '', // name of element, can be used to find element in the store
width: 100,
height: 100,
flipX: false,
flipY: false,
cornerRadius: 0,
// can user select element?
// if false, element will be "invisible" for user clicks
selectable: true,
// use for absolute positing of element
alwaysOnTop: false,
// also we can hide some elements from the export
showInExport: true,
// can element be moved and rotated
draggable: true,
// can we change content of element?
contentEditable: true,
// can we remove element from UI with button or keyboard?
removable: true,
// can we resize element?
resizable: true,
// map of originalColor -> newColor, used to replace colors in svg image
// do not change it manually. Instead use `el.replaceColor(originalColor, newColor)
colorsReplace: {},
});
svgElement.colors
Removed from v1.0.0-5. Don't use it!
Array of colors detected in the svg image. You can use this array to replace colors in the svg image.
console.log(svgElement.colors);
Workaround:
If you want to detect colors in svg string you can use this:
import { urlToString, getColors, useSvgColors } from 'polotno/utils/svg';
// in react component:
const Toolbar = ({ element }) => {
const colors = useSvgColors(element.src); // will return array of colors detected in the svg image
};
// in functions:
async function getSvgColors(element) {
const svgString = await urlToString(element.src);
const colors = getColors(svgString);
}
svgElement.replaceColor(oldColor, newColor)
Some svg files support color replacement. Polotno
can do that when a color of internal svg node is defined as fill
property.
You can replace some colors, to modify original image.
svgElement.replaceColor('red', 'blue');
Line element
You can use line
element to draw lines and arrows on the canvas. For now line elements may not support all available filters from JSON.
const lineElement = page.addElement({
type: 'line',
x: 0,
y: 0,
width: 400,
height: 10,
name: '', // name of element, can be used to find element in the store
color: 'black',
rotation: 0,
dash: [], // array of numbers, like [5, 5]
startHead: '', // can be empty, arrow, triangle, circle, square, bar
endHead: '', // can be empty, arrow, triangle, circle, square, bar
// can user select element?
// if false, element will be "invisible" for user clicks
selectable: true,
// use for absolute positing of element
alwaysOnTop: false,
// also we can hide some elements from the export
showInExport: true,
// can element be moved and rotated
draggable: true,
// can we change content of element?
contentEditable: true,
// can we remove element from UI with button or keyboard?
removable: true,
// can we resize element?
resizable: true,
styleEditable: true,
});
Group element
Group element is a container for other elements. It can be used to move multiple elements together.
Here is the example of default properties.
const page = store.addPage();
page.addElement({
type: 'text',
text: 'Hello world',
id: 'text-1',
});
page.addElement({
type: 'text',
text: 'Hello world',
id: 'text-1',
});
store.groupElements(['text-1', 'text-2']);
const group = page.children[0];
group.set({
name: 'group',
opacity: 0.5,
custom: {},
visible: true,
selectable: true,
removable: true,
alwaysOnTop: false,
showInExport: true,
});