Panzoom
Panzoom is a small library (~3.7kb gzipped) to add panning and zooming functionality to an element. Rather than using absolute positioning or setting width and height, Panzoom uses CSS transforms to take advantage of hardware/GPU acceleration in the browser, which means the element can be anything: an image, a video, an iframe, a canvas, text, WHATEVER.
For common support questions, see the FAQ.
Browser support
Here is a list of currently supported browsers.
Mobile support
iOS, Android, and Windows Mobile are supported.
Panzoom includes support for touch gestures and even supports pinch gestures for zooming. It is perfectly suited for both mobile and desktop browsers. It uses pointer events by default wherever supported.
SVG support
Panzoom supports panning and zooming SVG elements directly.
In IE11, CSS animations/transitions do not work on SVG elements, at least for the transform style. They do work in other browsers.
One could implement transitions manually in IE11 using the setTransform
option and integrating a tweening library for javascript animations (such as tween.js).
Installing
With npm:
$ npm install --save @panzoom/panzoom
With yarn:
$ yarn add @panzoom/panzoom
Panzoom uses UMD and can be loaded a lot of ways.
With ES6 imports:
import Panzoom from '@panzoom/panzoom'
With commonjs or browserify:
const Panzoom = require('@panzoom/panzoom')
With an AMD loader in an anonymous module:
define(['@panzoom/panzoom'], function (Panzoom) {
const elem = document.getElementById('panzoom-element')
Panzoom(elem)
})
With a script tag:
<script src="/js/panzoom.js"></script>
With a script tag from a CDN:
<script src="https://unpkg.com/@panzoom/panzoom@4.5.1/dist/panzoom.min.js"></script>
Usage
const elem = document.getElementById('panzoom-element')
const panzoom = Panzoom(elem, {
maxScale: 5
})
panzoom.pan(10, 10)
panzoom.zoom(2, { animate: true })
// Panning and pinch zooming are bound automatically (unless disablePan is true).
// There are several available methods for zooming
// that can be bound on button clicks or mousewheel.
button.addEventListener('click', panzoom.zoomIn)
elem.parentElement.addEventListener('wheel', panzoom.zoomWithWheel)
FAQ
1. What is transform-origin
and why is it added to the panzoom element?
- The
transform-origin
is the origin from which transforms are applied. Panzoom ensures the defaults are set to what it expects to calculate focal point zooming. - HTML elements default to '50% 50%'.
- SVG elements default to '0 0'.
2. I am using Panzoom with an <object>
tag and it's not working. What's wrong?
Object elements can eat up events, making it so they never reach Panzoom. To fix this, disable pointer events (pointer-events: none
) on the <object>
tag and call Panzoom using a wrapper.
3. My links aren't working! How do I enable an anchor within a panzoom element?
Add class options.excludeClass
(default is "panzoom-exclude"
) to whatever element you want to be clickable. Panzoom will check for this class before handling the event.
Alternatively, add a reference to the element to the exclude
option, or call event.stopImmediatePropagation()
in an event handler on the clickable element.
A note on the async nature of Panzoom
In some cases, setting one thing and then setting another synchronously will not work as intended.
For instance, the following usually works fine.
const panzoom = Panzoom(elem)
panzoom.zoom(2)
panzoom.pan(100, 100)
However, you might find that the things start breaking when the contain
option is set.
This is due to the fact that in order for Panzoom to retrieve proper dimensions, the scale needs to be painted.
If you find that things aren't looking quite right, try the following instead...
panzoom.zoom(2)
setTimeout(() => panzoom.pan(100, 100))
4. I'm using Panzoom with SVG text elements and am seeing some weird text resizing. How do I fix this?
Add text-rendering="geometricPrecision"
to your <text>
elements.
<text text-rendering="geometricPrecision" x="40" y="120">Hello World</text>
5. I'm using Panzoom on a canvas element that renders a PDF. How do I avoid the PDF getting blurry when scaled?
See this stackoverflow question
Documentation
Panzoom
▸ Panzoom(elem
, options?
): [PanzoomObject](#PanzoomObject)
Parameters
Name | Type |
---|---|
elem |
HTMLElement | SVGElement
|
options? |
Omit <[PanzoomOptions](#PanzoomOptions) , "force" > |
Returns
[PanzoomObject](#PanzoomObject)
Defined in
PanzoomOptions
Includes MiscOptions
, PanOptions
, and ZoomOptions
MiscOptions
These options can be passed to Panzoom()
, as well as any pan or zoom function. One exception is force
, which can only be passed to methods like pan()
or zoom()
, but not Panzoom()
or setOptions()
as it should not be set globally.
animate
• Optional
animate: boolean
(Default: false)
Whether to animate transitions
Defined in
canvas
• Optional
canvas: boolean
(Default: false)
This option treats the Panzoom element's parent as a canvas. Effectively, Panzoom binds the down handler to the parent instead of the Panzoom element, so that pointer events anywhere on the "canvas" moves its children. See issue #472.
Note: setting this option to true
also changes
where the cursor
style is applied (i.e. the parent).
Defined in
duration
• Optional
duration: number
(Default: 200)
Duration of the transition (ms)
Defined in
easing
• Optional
easing: string
(Default: "ease-in-out")
CSS Easing used for transitions
Defined in
exclude
• Optional
exclude: Element
[] (Default: [])
Add elements to this array that should be excluded from Panzoom handling. Ancestors of event targets are also checked. e.g. links and buttons that should not propagate the click event.
Defined in
excludeClass
• Optional
excludeClass: string
(Default: "panzoom-exclude")
Add this class to any element within the Panzoom element that you want to exclude from Panzoom handling. That element's children will also be excluded. e.g. links and buttons that should not propagate the click event.
Defined in
force
• Optional
force: boolean
force
should be used sparingly to temporarily
override and ignore options such as disablePan,
disableZoom, and panOnlyWhenZoomed.
This option cannot be passed to the
Panzoom constructor or setOptions (to avoid
setting this option globally).
// Overrides disablePan and panOnlyWhenZoomed
panzoom.pan(50, 100, { force: true })
// Overrides disableZoom
panzoom.zoom(1, { force: true })
Defined in
handleStartEvent
• Optional
handleStartEvent: (event
: Event
) => void
(Default: (e: Event) => {
e.preventDefault()
e.stopPropagation()
})
On the first pointer event, when panning starts,
the default Panzoom behavior is to call
event.preventDefault()
and event.stopPropagation()
on that event. The former is almost certainly a necessity;
the latter enables Panzoom elements within Panzoom elements.
But there are some cases where the default is not the desired behavior. Set this option to override that behavior.
// Only call preventDefault()
Panzoom(elem, {
handleStartEvent: (event) => {
event.preventDefault()
}
})
// Do nothing.
// This can change dragging behavior on mobile.
Panzoom(elem, {
handleStartEvent: () => {}
})
Parameters
Name | Type |
---|---|
event |
Event |
Returns
void
Defined in
noBind
• Optional
noBind: boolean
Skip binding the default Panzoom event listeners
Defined in
origin
• Optional
origin: string
Change this at your own risk.
The transform-origin
is the origin from which transforms are applied.
Default: '50% 50%'
for HTML and '0 0'
for SVG.
The defaults are set because changing the transform-origin
on
SVG elements doesn't work in IE.
Changing this should work with many things, but it will break focal point zooming, which assumes the defaults are set to do the more complicated calculations.
And again, changing this for SVG in IE doesn't work at all.
Defined in
overflow
• Optional
overflow: string
(Default: "hidden")
The overflow CSS value for the parent. Defaults to 'hidden'
Defined in
pinchAndPan
• Optional
pinchAndPan: boolean
(Default: false)
Set to true to enable panning during pinch zoom. Note: this is zooming to a point and panning in the same frame. In other words, the zoom has not yet painted and therefore the pan is working with old dimensions. Essentially, it may be best to avoid using this option when using contain.
Related issues: https://github.com/timmywil/panzoom/issues/512 https://github.com/timmywil/panzoom/issues/606
Defined in
setTransform
• Optional
setTransform: (elem
: HTMLElement
| SVGElement
, __namedParameters
: CurrentValues
, _options?
: PanzoomOptions
) => void
Set the transform using the proper prefix
Override the transform setter. This is exposed mostly so the user could set other parts of a transform aside from scale and translate. Default is defined in src/css.ts.
// This example always sets a rotation
// when setting the scale and translation
const panzoom = Panzoom(elem, {
setTransform: (elem, { scale, x, y }) => {
panzoom.setStyle('transform', `rotate(0.5turn) scale(${scale}) translate(${x}px, ${y}px)`)
}
})
Parameters
Name | Type |
---|---|
elem |
HTMLElement | SVGElement
|
__namedParameters |
CurrentValues |
_options? |
PanzoomOptions |
Returns
void
Defined in
silent
• Optional
silent: boolean
Silence all events
Defined in
startScale
• Optional
startScale: number
(Default: 1)
Scale used to set the beginning transform
Defined in
startX
• Optional
startX: number
(Default: 0)
X Value used to set the beginning transform
Defined in
startY
• Optional
startY: number
(Default: 0)
Y Value used to set the beginning transform
Defined in
touchAction
• Optional
touchAction: string
(Default: "none")
This value is used to set touch-action on both the Panzoom element and its parent. It is needed because that the native scroll on mobile interferes with panning and pinch zooming. Set this to empty string to re-enable scrolling on mobile, but note that both scrolling and panning cannot work at the same time.
Defined in
PanOptions (includes MiscOptions)
contain
• Optional
contain: "inside"
| "outside"
Contain the panzoom element either inside or outside the parent. Inside: The panzoom element is smaller than its parent and cannot be panned to the outside. Outside: The panzoom element is larger than its parent and cannot be panned to the inside. In other words, no empty space around the element will be shown.
Note: the containment pan adjustment is not affected by the disablePan
option.
Defined in
cursor
• Optional
cursor: string
(Default: "move")
The cursor style to set on the panzoom element
Defined in
disablePan
• Optional
disablePan: boolean
(Default: false)
Disable panning functionality. Note: disablePan does not affect focal point zooming or the contain option. The element will still pan accordingly.
Defined in
disableXAxis
• Optional
disableXAxis: boolean
(Default: false)
Pan only on the Y axis
Defined in
disableYAxis
• Optional
disableYAxis: boolean
(Default: false)
Pan only on the X axis
Defined in
panOnlyWhenZoomed
• Optional
panOnlyWhenZoomed: boolean
(Default: false)
Disable panning while the scale is equal to the starting value
Defined in
relative
• Optional
relative: boolean
(Default: false)
When passing x and y values to .pan(), treat the values as relative to their current values
Defined in
roundPixels
• Optional
roundPixels: boolean
Round x and y values to whole numbers. This can help prevent images and text from looking blurry, but the higher the scale, the more it becomes necessary to use fractional pixels. Use your own judgment on how much to limit zooming in when using this option.
Defined in
ZoomOptions (includes MiscOptions)
disableZoom
• Optional
disableZoom: boolean
(Default: false)
Disable zooming functionality
Defined in
focal
• Optional
focal: Object
Zoom to the given point on the panzoom element. This point is expected to be relative to the panzoom element's dimensions and is unrelated to the parent dimensions.
Type declaration
Name | Type |
---|---|
x |
number |
y |
number |
Defined in
maxScale
• Optional
maxScale: number
(Default: 4)
The maximum scale when zooming
Defined in
minScale
• Optional
minScale: number
(Default: 0.125)
The minimum scale when zooming
Defined in
step
• Optional
step: number
(Default: 0.3)
The step affects zoom calculation when zooming with a mouse wheel, when pinch zooming, or when using zoomIn/zoomOut
Defined in
PanzoomObject
These methods are available after initializing Panzoom.
bind
• bind: () => void
Bind the default down, move, and up event listeners to the Panzoom element.
This does not normally need to be called.
It gets called by default when creating a new Panzoom object,
but can be skipped with the noBind
option.
const panzoom = Panzoom(elem, { noBind: true })
// ...
panzoom.bind()
Returns
void
Defined in
destroy
• destroy: () => void
Remove all event listeners bound to the the Panzoom element
Returns
void
Defined in
eventNames
• eventNames: Object
This object exposes the event names used by Panzoom, depending on the current browser's support for Pointer or Touch events.
Type declaration
Name | Type |
---|---|
down |
string |
move |
string |
up |
string |
Defined in
getOptions
• getOptions: () => PanzoomOptions
Returns a copy of the current options object
Returns
PanzoomOptions
Defined in
getPan
• getPan: () => { x
: number
; y
: number
}
Get the current x/y translation
Returns
Object
Name | Type |
---|---|
x |
number |
y |
number |
Defined in
getScale
• getScale: () => number
Get the current scale
Returns
number
Defined in
handleDown
• handleDown: (event
: PointerEvent
) => void
handleDown, handleMove, and handleUp are the exact event handlers that Panzoom binds to pointer events. They are exposed in case you prefer to bind your own events or extend them. Note that move and up are bound to the document, not the Panzoom element. Only the down event is bound to the Panzoom element. To avoid double-binding, also set noBind to true.
const panzoom = Panzoom(elem, { noBind: true })
elem.addEventListener('pointerdown', (event) => {
console.log(event)
panzoom.handleDown(event)
})
document.addEventListener('pointermove', panzoom.handleMove)
document.addEventListener('pointerup', panzoom.handleUp)
Parameters
Name | Type |
---|---|
event |
PointerEvent |
Returns
void
Defined in
handleMove
• handleMove: (event
: PointerEvent
) => void
Parameters
Name | Type |
---|---|
event |
PointerEvent |
Returns
void
Defined in
handleUp
• handleUp: (event
: PointerEvent
) => void
Parameters
Name | Type |
---|---|
event |
PointerEvent |
Returns
void
Defined in
pan
• pan: (x
: string
| number
, y
: string
| number
, panOptions?
: PanOptions
) => [CurrentValues](#CurrentValues)
Pan the Panzoom element to the given x and y coordinates
// Translates the element to 50px, 100px
panzoom.pan(50, 100)
// Pans the element right 10px and down 10px from its current position
panzoom.pan(10, 10, { relative: true })
Parameters
Name | Type |
---|---|
x |
string | number
|
y |
string | number
|
panOptions? |
PanOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
reset
• reset: (resetOptions?
: PanzoomOptions
) => [CurrentValues](#CurrentValues)
Reset the pan and zoom to startX, startY, and startScale.
Animates by default, ignoring the global option.
Pass { animate: false }
to override.
Reset ignores the disablePan
, disableZoom
, and panOnlyWhenZoomed
options.
Pass { force: false }
to override.
panzoom.reset()
panzoom.reset({ animate: false })
Parameters
Name | Type |
---|---|
resetOptions? |
PanzoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
resetStyle
• resetStyle: () => void
Reset the styles set on the Panzoom element and its parent (such as overflow, cursor, etc.)
panzoom.resetStyle()
Returns
void
Defined in
setOptions
• setOptions: (options?
: PanzoomOptions
) => void
Change any number of options on a Panzoom instance. Setting some options will have side-effects. For instance, changing the cursor option will also set the cursor style.
const panzoom = Panzoom(elem, { cursor: 'move' })
// ...
panzoom.setOptions({ cursor: 'default' })
Parameters
Name | Type |
---|---|
options? |
PanzoomOptions |
Returns
void
Defined in
setStyle
• setStyle: (name
: string
, value
: string
) => void
A convenience method for setting prefixed styles on the Panzoom element
Parameters
Name | Type |
---|---|
name |
string |
value |
string |
Returns
void
Defined in
zoom
• zoom: (scale
: number
, zoomOptions?
: ZoomOptions
) => [CurrentValues](#CurrentValues)
Zoom the Panzoom element to the given scale
panzoom.zoom(2.2)
panzoom.zoom(2.2, { animate: true })
Parameters
Name | Type |
---|---|
scale |
number |
zoomOptions? |
ZoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
zoomIn
• zoomIn: (zoomOptions?
: ZoomOptions
) => [CurrentValues](#CurrentValues)
Zoom in using the predetermined increment set in options.
Animates by default, ignoring the global option.
Pass { animate: false }
to override.
panzoom.zoomIn()
panzoom.zoomIn({ animate: false })
Parameters
Name | Type |
---|---|
zoomOptions? |
ZoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
zoomOut
• zoomOut: (zoomOptions?
: ZoomOptions
) => [CurrentValues](#CurrentValues)
Zoom out using the predetermined increment set in options.
Animates by default, ignoring the global option.
Pass { animate: false }
to override.
panzoom.zoomOut()
panzoom.zoomOut({ animate: false })
Parameters
Name | Type |
---|---|
zoomOptions? |
ZoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
zoomToPoint
• zoomToPoint: (scale
: number
, point
: { clientX
: number
; clientY
: number
}, zoomOptions?
: ZoomOptions
) => [CurrentValues](#CurrentValues)
Zoom the Panzoom element to a focal point using
the given pointer/touch/mouse event or constructed point.
The clientX/clientY values should be calculated
the same way as a pointermove
event on the Panzoom element's parent.
panzoom.zoomToPoint(1.2, pointerEvent)
Parameters
Name | Type |
---|---|
scale |
number |
point |
Object |
point.clientX |
number |
point.clientY |
number |
zoomOptions? |
ZoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
zoomWithWheel
• zoomWithWheel: (event
: WheelEvent
, zoomOptions?
: ZoomOptions
) => [CurrentValues](#CurrentValues)
Zoom the Panzoom element to a focal point using the given WheelEvent
This is a convenience function that may not handle all use cases.
Other cases should handroll solutions using the zoomToPoint
method or the zoom
method's focal option.
Notes:
- the focal point zooming pan adjustment is
not affected by the
disablePan
option. - animate should not be used when zooming with the wheel, and is therefore always disabled.
// Bind to mousewheel
elem.parentElement.addEventListener('wheel', panzoom.zoomWithWheel)
// Bind to shift+mousewheel
elem.parentElement.addEventListener('wheel', function (event) {
if (!event.shiftKey) return
// Panzoom will automatically use `deltaX` here instead
// of `deltaY`. On a mac, the shift modifier usually
// translates to horizontal scrolling, but Panzoom assumes
// the desired behavior is zooming.
panzoom.zoomWithWheel(event)
})
Parameters
Name | Type |
---|---|
event |
WheelEvent |
zoomOptions? |
ZoomOptions |
Returns
[CurrentValues](#CurrentValues)
Defined in
CurrentValues
isSVG
• Optional
isSVG: boolean
Defined in
scale
• scale: number
Defined in
x
• x: number
Defined in
y
• y: number
Defined in
Events
The following events are available as custom events on the panzoom element using the native CustomEvent API. Add listeners the same way you would any other event.
elem.addEventListener('panzoomchange', (event) => {
console.log(event.detail) // => { x: 0, y: 0, scale: 1 }
})
Notes about all events
- The event object passed as an argument to the listener will always have a
detail
object with the following properties:- The current
x
value - The current
y
value - The current
scale
- An
originalEvent
property with the original event that triggered the panzoom event, if applicable. For example, theoriginalEvent
property for apanzoomstart
event would be either apointerdown
,touchstart
, ormousedown
event.
- The current
- Events can be silenced when the
silent
option is set totrue
, either globally or when passed topan
, anyzoom
method, orreset
. - Avoid putting too much logic in these event handlers as it could effect the performance of panning or zooming.
"panzoomstart"
Fired when the user starts a move or pinch zoom gesture on mobile.
"panzoomchange"
Fired whenever there is a pan, zoom, or reset. Note that direct calls to options.setTransform
do not fire this event.
"panzoomzoom"
Fired whenever the zoom is changed by any Panzoom zoom
method, directly or internally.
"panzoompan"
Fired whenever the pan is changed by the pan
method, directly or internally.
"panzoomend"
Fired when the user finishes a move or finishes a pinch zoom gesture on mobile.
"panzoomreset"
Fired whenever reset is called.