Add limitation of image's max zoom rate (max to the original size of image) (#15094)

* limit image max scale rate to fit the actual image size

* replace with MIN_SCALE

* fix behavior on touch screen
pull/1453/head
Mashiro 2020-11-05 03:43:31 +08:00 committed by GitHub
parent ab00998503
commit f720af6b72
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 51 additions and 18 deletions

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@ -113,7 +113,8 @@ class ZoomableImage extends React.PureComponent {
state = {
scale: MIN_SCALE,
zoomMatrix: {
type: null, // 'full-width' 'full-height'
type: null, // 'width' 'height'
fullScreen: null, // bool
rate: null, // full screen scale rate
clientWidth: null,
clientHeight: null,
@ -122,12 +123,15 @@ class ZoomableImage extends React.PureComponent {
clientHeightFixed: null,
scrollTop: null,
scrollLeft: null,
translateX: null,
translateY: null,
},
zoomState: 'expand', // 'expand' 'compress'
navigationHidden: false,
dragPosition: { top: 0, left: 0, x: 0, y: 0 },
dragged: false,
lockScroll: { x: 0, y: 0 },
lockTranslate: { x: 0, y: 0 },
}
removers = [];
@ -168,18 +172,24 @@ class ZoomableImage extends React.PureComponent {
}
componentDidUpdate () {
this.setState({ zoomState: this.state.scale >= this.state.zoomMatrix.rate ? 'compress' : 'expand' });
if (this.state.scale === MIN_SCALE) {
this.container.style.removeProperty('cursor');
}
}
UNSAFE_componentWillReceiveProps () {
// reset when slide to next image
if (this.props.zoomButtonHidden) {
this.setState({ scale: MIN_SCALE }, () => {
this.setState({
scale: MIN_SCALE,
lockTranslate: { x: 0, y: 0 },
}, () => {
this.container.scrollLeft = 0;
this.container.scrollTop = 0;
});
}
this.setState({ zoomState: this.state.scale >= this.state.zoomMatrix.rate ? 'compress' : 'expand' });
if (this.state.scale === 1) {
this.container.style.removeProperty('cursor');
}
}
removeEventListeners () {
@ -192,7 +202,7 @@ class ZoomableImage extends React.PureComponent {
const event = normalizeWheel(e);
if (this.state.zoomMatrix.type === 'full-width') {
if (this.state.zoomMatrix.type === 'width') {
// full width, scroll vertical
this.container.scrollTop = Math.max(this.container.scrollTop + event.pixelY, this.state.lockScroll.y);
} else {
@ -268,7 +278,7 @@ class ZoomableImage extends React.PureComponent {
}
zoom(nextScale, midpoint) {
const { scale } = this.state;
const { scale, zoomMatrix } = this.state;
const { scrollLeft, scrollTop } = this.container;
// math memo:
@ -283,6 +293,15 @@ class ZoomableImage extends React.PureComponent {
this.setState({ scale: nextScale }, () => {
this.container.scrollLeft = nextScrollLeft;
this.container.scrollTop = nextScrollTop;
// reset the translateX/Y constantly
if (nextScale < zoomMatrix.rate) {
this.setState({
lockTranslate: {
x: zoomMatrix.fullScreen ? 0 : zoomMatrix.translateX * ((nextScale - MIN_SCALE) / (zoomMatrix.rate - MIN_SCALE)),
y: zoomMatrix.fullScreen ? 0 : zoomMatrix.translateY * ((nextScale - MIN_SCALE) / (zoomMatrix.rate - MIN_SCALE)),
},
});
}
});
}
@ -307,14 +326,18 @@ class ZoomableImage extends React.PureComponent {
const { offsetWidth, offsetHeight } = this.image;
const clientHeightFixed = clientHeight - NAV_BAR_HEIGHT;
const type = width/height < clientWidth / clientHeightFixed ? 'full-width' : 'full-height';
const rate = type === 'full-width' ? clientWidth / offsetWidth : clientHeightFixed / offsetHeight;
const scrollTop = type === 'full-width' ? (clientHeight - offsetHeight) / 2 - NAV_BAR_HEIGHT : (clientHeightFixed - offsetHeight) / 2;
const type = width / height < clientWidth / clientHeightFixed ? 'width' : 'height';
const fullScreen = type === 'width' ? width > clientWidth : height > clientHeightFixed;
const rate = type === 'width' ? Math.min(clientWidth, width) / offsetWidth : Math.min(clientHeightFixed, height) / offsetHeight;
const scrollTop = type === 'width' ? (clientHeight - offsetHeight) / 2 - NAV_BAR_HEIGHT : (clientHeightFixed - offsetHeight) / 2;
const scrollLeft = (clientWidth - offsetWidth) / 2;
const translateX = type === 'width' ? (width - offsetWidth) / (2 * rate) : 0;
const translateY = type === 'height' ? (height - offsetHeight) / (2 * rate) : 0;
this.setState({
zoomMatrix: {
type: type,
fullScreen: fullScreen,
rate: rate,
clientWidth: clientWidth,
clientHeight: clientHeight,
@ -323,6 +346,8 @@ class ZoomableImage extends React.PureComponent {
clientHeightFixed: clientHeightFixed,
scrollTop: scrollTop,
scrollLeft: scrollLeft,
translateX: translateX,
translateY: translateY,
},
});
}
@ -340,6 +365,10 @@ class ZoomableImage extends React.PureComponent {
x: 0,
y: 0,
},
lockTranslate: {
x: 0,
y: 0,
},
}, () => {
this.container.scrollLeft = 0;
this.container.scrollTop = 0;
@ -351,6 +380,10 @@ class ZoomableImage extends React.PureComponent {
x: zoomMatrix.scrollLeft,
y: zoomMatrix.scrollTop,
},
lockTranslate: {
x: zoomMatrix.fullScreen ? 0 : zoomMatrix.translateX,
y: zoomMatrix.fullScreen ? 0 : zoomMatrix.translateY,
},
}, () => {
this.container.scrollLeft = zoomMatrix.scrollLeft;
this.container.scrollTop = zoomMatrix.scrollTop;
@ -371,15 +404,15 @@ class ZoomableImage extends React.PureComponent {
render () {
const { alt, src, width, height, intl } = this.props;
const { scale } = this.state;
const overflow = scale === 1 ? 'hidden' : 'scroll';
const zoomButtonSshouldHide = !this.state.navigationHidden && !this.props.zoomButtonHidden ? '' : 'media-modal__zoom-button--hidden';
const { scale, lockTranslate } = this.state;
const overflow = scale === MIN_SCALE ? 'hidden' : 'scroll';
const zoomButtonShouldHide = this.state.navigationHidden || this.props.zoomButtonHidden || this.state.zoomMatrix.rate <= MIN_SCALE ? 'media-modal__zoom-button--hidden' : '';
const zoomButtonTitle = this.state.zoomState === 'compress' ? intl.formatMessage(messages.compress) : intl.formatMessage(messages.expand);
return (
<React.Fragment>
<IconButton
className={`media-modal__zoom-button ${zoomButtonSshouldHide}`}
className={`media-modal__zoom-button ${zoomButtonShouldHide}`}
title={zoomButtonTitle}
icon={this.state.zoomState}
onClick={this.handleZoomClick}
@ -402,7 +435,7 @@ class ZoomableImage extends React.PureComponent {
width={width}
height={height}
style={{
transform: `scale(${scale})`,
transform: `scale(${scale}) translate(-${lockTranslate.x}px, -${lockTranslate.y}px)`,
transformOrigin: '0 0',
}}
draggable={false}