Files
advanced-camera-card/src/components-lib/zoom/zoom-controller.ts
T

455 lines
14 KiB
TypeScript

import Panzoom, {
type PanzoomEventDetail,
type PanzoomObject,
} from '@dermotduffy/panzoom';
import { round, throttle } from 'lodash-es';
import { arefloatsApproximatelyEqual, isHoverableDevice } from '../../utils/basic';
import { fireAdvancedCameraCardEvent } from '../../utils/fire-advanced-camera-card-event';
import {
isZoomEmpty,
ZOOM_DEFAULT_PAN_X,
ZOOM_DEFAULT_PAN_Y,
ZOOM_DEFAULT_SCALE,
ZOOM_PRECISION,
type PartialZoomSettings,
type ZoomSettingsObserved,
} from './types';
export class ZoomController {
private _element: HTMLElement;
private _panzoom: PanzoomObject | null = null;
// Is the controller zoomed in at all?
private _zoomed = false;
// Should clicks be allowed to propagate, or consumed as a pan/zoom action?
private _allowClick = true;
// Whether zoom/pan gestures are active. When `false`, all gesture events pass
// through untouched (used to yield to PTZ gesture mode).
private _zoom = true;
private _defaultSettings: PartialZoomSettings | null;
private _settings: PartialZoomSettings | null;
// These values should be suitably less than the value of STEP_DELAY_SECONDS
// in the ptz_digital action, in order to ensure smooth movements of the
// digital PTZ actions.
private _debouncedChangeHandler = throttle(this._changeHandler.bind(this), 50);
private _debouncedUpdater = throttle(this._updateBasedOnConfig.bind(this), 50);
private _resizeObserver = new ResizeObserver(this._debouncedUpdater);
private _events = isHoverableDevice()
? {
down: ['pointerdown'],
move: ['pointermove'],
up: ['pointerup', 'pointerleave', 'pointercancel'],
}
: {
down: ['touchstart'],
move: ['touchmove'],
up: ['touchend', 'touchcancel'],
};
private _downHandler = (ev: Event) => {
if (this._shouldZoomOrPan(ev)) {
this._panzoom?.handleDown(ev as PointerEvent);
ev.stopPropagation();
// If we do not prevent default here, the media carousels scroll.
ev.preventDefault();
this._allowClick = false;
} else {
this._allowClick = true;
}
};
private _clickHandler = (ev: Event) => {
// When mouse clicking is used to pan, need to avoid that causing a click
// handler elsewhere in the card being called. Example: Viewing a snapshot,
// and panning within it should not cause a related clip to play (the click
// handler in the viewer).
if (!this._allowClick) {
ev.stopPropagation();
}
this._allowClick = true;
};
private _moveHandler = (ev: Event) => {
if (this._shouldZoomOrPan(ev)) {
this._panzoom?.handleMove(ev as PointerEvent);
ev.stopPropagation();
}
};
private _upHandler = (ev: Event) => {
if (this._shouldZoomOrPan(ev)) {
this._panzoom?.handleUp(ev as PointerEvent);
ev.stopPropagation();
}
};
private _wheelHandler = (ev: Event) => {
if (ev instanceof WheelEvent && this._shouldZoomOrPan(ev)) {
this._panzoom?.zoomWithWheel(ev);
ev.stopPropagation();
}
};
constructor(
element: HTMLElement,
options?: {
config?: PartialZoomSettings | null;
defaultConfig?: PartialZoomSettings | null;
},
) {
this._element = element;
this._settings = options?.config ?? null;
this._defaultSettings = options?.defaultConfig ?? null;
}
public activate(): void {
const config = this._getConfigToUse();
const converted = this._convertPercentToXYPan(
config?.pan?.x ?? ZOOM_DEFAULT_PAN_X,
config?.pan?.y ?? ZOOM_DEFAULT_PAN_Y,
config?.zoom ?? ZOOM_DEFAULT_SCALE,
);
const startScale = config?.zoom ?? ZOOM_DEFAULT_SCALE;
this._panzoom = Panzoom(this._element, {
contain: 'outside',
maxScale: 10,
minScale: 1,
noBind: true,
// Do not force the cursor style (by default it will always show the
// 'move' type cursor whether or not it is zoomed in).
cursor: undefined,
// Disable automatic touchAction setting from Panzoom() as otherwise it
// effectively disables dashboard scrolling. See:
// https://github.com/dermotduffy/advanced-camera-card/issues/1181
touchAction: '',
// Set the initial pan/zoom values to avoid an initial unzoomed view.
...(config && converted && { startX: converted.x }),
...(config && converted && { startY: converted.y }),
...(config && converted && { startScale }),
});
const registerListeners = (
events: string[],
func: (ev: Event) => void,
options?: AddEventListenerOptions,
) => {
events.forEach((eventName) => {
this._element.addEventListener(eventName, func, options);
});
};
registerListeners(this._events['down'], this._downHandler, { capture: true });
registerListeners(this._events['move'], this._moveHandler, { capture: true });
registerListeners(this._events['up'], this._upHandler, { capture: true });
registerListeners(['wheel'], this._wheelHandler);
registerListeners(['click'], this._clickHandler, { capture: true });
this._resizeObserver.observe(this._element);
this._element.addEventListener('panzoomchange', this._debouncedChangeHandler);
}
public deactivate(): void {
const unregisterListener = (
events: string[],
func: (ev: Event) => void,
options?: EventListenerOptions,
) => {
events.forEach((eventName) => {
this._element.removeEventListener(eventName, func, options);
});
};
unregisterListener(this._events['down'], this._downHandler, { capture: true });
unregisterListener(this._events['move'], this._moveHandler, { capture: true });
unregisterListener(this._events['up'], this._upHandler, { capture: true });
unregisterListener(['wheel'], this._wheelHandler);
unregisterListener(['click'], this._clickHandler, { capture: true });
this._resizeObserver.disconnect();
this._element.removeEventListener('panzoomchange', this._debouncedChangeHandler);
this._panzoom = null;
}
public setDefaultSettings(config: PartialZoomSettings | null): void {
this._defaultSettings = config;
this._debouncedUpdater();
}
public setSettings(config: PartialZoomSettings | null): void {
this._settings = config;
this._debouncedUpdater();
}
public isActivated(): boolean {
return !!this._panzoom;
}
public setZoom(value: boolean): void {
this._zoom = value;
}
private _changeHandler(ev: Event): void {
const pz = (<CustomEvent<PanzoomEventDetail>>ev).detail;
const unzoomed = this._isUnzoomed(pz.scale);
// Take care here to only dispatch the zoomed/unzoomed events when the
// absolute state changes (rather than on every single zoom adjustment).
if (unzoomed && this._zoomed) {
this._zoomed = false;
this._setTouchAction(true);
fireAdvancedCameraCardEvent(this._element, 'zoom:unzoomed');
} else if (!unzoomed && !this._zoomed) {
this._zoomed = true;
this._setTouchAction(false);
fireAdvancedCameraCardEvent(this._element, 'zoom:zoomed');
}
const converted = this._convertXYPanToPercent(pz.x, pz.y, pz.scale);
const observed: ZoomSettingsObserved = {
pan: {
x: converted?.x ?? ZOOM_DEFAULT_PAN_X,
y: converted?.y ?? ZOOM_DEFAULT_PAN_Y,
},
zoom: pz.scale,
isDefault: this._isAtDefaultZoomAndPan(pz.x, pz.y, pz.scale),
unzoomed: unzoomed,
};
fireAdvancedCameraCardEvent(this._element, 'zoom:change', observed);
}
private _isZoomEqual(a: PartialZoomSettings, b: PartialZoomSettings): boolean {
// The ?? clauses below cannot be reached since this function is only ever
// used fully specified by this object. It's kept as-is for completeness.
return (
arefloatsApproximatelyEqual(
a.zoom ?? ZOOM_DEFAULT_SCALE,
b.zoom ?? ZOOM_DEFAULT_SCALE,
ZOOM_PRECISION,
) &&
arefloatsApproximatelyEqual(
a.pan?.x ?? ZOOM_DEFAULT_PAN_X,
b.pan?.x ?? ZOOM_DEFAULT_PAN_X,
ZOOM_PRECISION,
) &&
arefloatsApproximatelyEqual(
/* v8 ignore next @preserve */
a.pan?.y ?? ZOOM_DEFAULT_PAN_Y,
/* v8 ignore next @preserve */
b.pan?.y ?? ZOOM_DEFAULT_PAN_Y,
ZOOM_PRECISION,
)
);
}
private _getConfigToUse(): PartialZoomSettings | null {
return isZoomEmpty(this._settings) ? this._defaultSettings : this._settings;
}
private _updateBasedOnConfig(): void {
if (!this._panzoom) {
return;
}
const config = this._getConfigToUse();
const desiredScale = config?.zoom ?? ZOOM_DEFAULT_SCALE;
// Transform won't exist (will be null) if the element has no dimensions, or
// if the desired scale has no zoom (i.e. is 1).
const converted = this._convertPercentToXYPan(
config?.pan?.x ?? ZOOM_DEFAULT_PAN_X,
config?.pan?.y ?? ZOOM_DEFAULT_PAN_Y,
desiredScale,
);
const x = converted?.x ?? 0;
const y = converted?.y ?? 0;
// Verify there is a material change in the pan/zoom settings before acting.
if (
this._isZoomEqual(
{ zoom: desiredScale, pan: { x: x, y: y } },
{
zoom: this._panzoom.getScale(),
pan: this._panzoom.getPan(),
},
)
) {
return;
}
this._panzoom.zoom(desiredScale, {
// Zoom is stepped, not animated. If it is animated, there is interaction
// between the zoom and the pan below, and the pan would need to be
// delayed until after the zoom is complete.
animate: false,
});
// Panzoom must allow the browser to paint the zoomed image in order to
// "contain" the pan within the parent, this creates somewhat of an async
// situation where we need to ensure the zoom completes first. Using
// `requestAnimationFrame` appears to reliably allow the zoom to finish
// rendering first, before the pan is applied.
//
// See: https://github.com/timmywil/panzoom?tab=readme-ov-file#a-note-on-the-async-nature-of-panzoom
window.requestAnimationFrame(() => {
// On slow Android WebView devices, the zoom transform may not have fully
// painted by the time this callback runs. Panzoom's contain logic would
// then clip the pan to incorrect bounds. Temporarily disable containment
// for this programmatic pan, then restore it.
// See: https://github.com/dermotduffy/advanced-camera-card/issues/2223
this._panzoom?.setOptions({ contain: undefined });
this._panzoom?.pan(x, y, {
animate: true,
duration: 100,
});
this._panzoom?.setOptions({ contain: 'outside' });
});
}
/**
* Convert from Advanced Camera Card pan % values to Panzoom X/Y transformation
* coordinates.
* @param x The x translation value.
* @param y The y translation value.
* @param scale The desired (not current) scale.
* @returns An object with x/y pan % values or null on error.
*/
private _convertPercentToXYPan(
x: number,
y: number,
scale: number,
): { x: number; y: number } | null {
const minMax = this._getTransformMinMax(scale, this._panzoom?.getScale());
if (minMax === null) {
return null;
}
return {
x: minMax.minX + (minMax.maxX - minMax.minX) * (x / 100),
y: minMax.minY + (minMax.maxY - minMax.minY) * (y / 100),
};
}
private _convertXYPanToPercent(
x: number,
y: number,
scale: number,
): { x: number; y: number } | null {
const minMax = this._getTransformMinMax(scale, this._panzoom?.getScale());
if (minMax === null) {
return null;
}
return {
x:
((-x + Math.abs(minMax.minX)) /
(Math.abs(minMax.maxX) + Math.abs(minMax.minX))) *
100,
y:
((-y + Math.abs(minMax.minY)) /
(Math.abs(minMax.maxY) + Math.abs(minMax.minY))) *
100,
};
}
private _getTransformMinMax(
desiredScale: number,
currentScale?: number,
): {
minX: number;
maxX: number;
minY: number;
maxY: number;
} | null {
const rendered = this._getRenderedSize(currentScale);
if (!rendered.width || !rendered.height) {
return null;
}
const minX = (rendered.width * (desiredScale - 1)) / desiredScale / 2;
const minY = (rendered.height * (desiredScale - 1)) / desiredScale / 2;
if (arefloatsApproximatelyEqual(minX, 0) || arefloatsApproximatelyEqual(minY, 0)) {
return null;
}
return {
minX: minX,
maxX: -minX,
minY: minY,
maxY: -minY,
};
}
private _getRenderedSize(scale?: number): { width: number; height: number } {
const rect = this._element.getBoundingClientRect();
return {
width: rect.width / (scale ?? ZOOM_DEFAULT_SCALE),
height: rect.height / (scale ?? ZOOM_DEFAULT_SCALE),
};
}
private _isUnzoomed(scale?: number): boolean {
return scale !== undefined && round(scale, ZOOM_PRECISION) <= 1;
}
private _isAtDefaultZoomAndPan(x: number, y: number, scale: number): boolean {
if (!this._defaultSettings) {
return this._isUnzoomed(scale);
}
const convertedDefault = this._convertPercentToXYPan(
this._defaultSettings.pan?.x ?? ZOOM_DEFAULT_PAN_X,
this._defaultSettings.pan?.y ?? ZOOM_DEFAULT_PAN_Y,
this._defaultSettings.zoom ?? ZOOM_DEFAULT_SCALE,
);
if (!convertedDefault) {
return true;
}
// The ZOOM_DEFAULT_SCALE fallback cannot be reached: when
// this._defaultSettings.zoom is undefined, convertedDefault ends up null
// above and this function has already returned.
/* v8 ignore next @preserve */
const defaultScale = this._defaultSettings.zoom ?? ZOOM_DEFAULT_SCALE;
return (
arefloatsApproximatelyEqual(x, convertedDefault.x) &&
arefloatsApproximatelyEqual(y, convertedDefault.y) &&
arefloatsApproximatelyEqual(scale, defaultScale)
);
}
private _shouldZoomOrPan(ev: Event): boolean {
if (!this._zoom) {
return false;
}
return (
!this._isUnzoomed(this._panzoom?.getScale()) ||
// TouchEvent does not exist on Firefox on non-touch events. See:
// https://github.com/dermotduffy/advanced-camera-card/issues/1174
(window.TouchEvent && ev instanceof TouchEvent && ev.touches.length > 1) ||
(ev instanceof WheelEvent && ev.ctrlKey)
);
}
private _setTouchAction(touchEnabled: boolean): void {
this._element.style.touchAction = touchEnabled ? '' : 'none';
}
}