图片放缩
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/534390/1580075/imageresize.js
//revised from https://gist.github.com/p1coderblog/24cdae9fa923193f45f3583c2265161d
;
function enableImageResizeInDiv(editor) {
if (!editor) {
return
}
// firefox valid
/*if (!(/chrome/i.test(navigator.userAgent) && /google/i.test(window.navigator.vendor))) {
return;
}*/
//const editor = document.getElementById(id);
let resizing = false;
let currentImage;
const createDOM = function (elementType, className, styles) {
let ele = document.createElement(elementType);
ele.className = className;
setStyle(ele, styles);
return ele;
};
const setStyle = function (ele, styles) {
for (let key in styles) {
ele.style[key] = styles[key];
}
return ele;
};
const removeResizeFrame = function () {
document.querySelectorAll(".resize-frame,.resizer").forEach((item) => item.parentNode.removeChild(item));
};
const offset = function offset(el) {
const rect = el.getBoundingClientRect(),
scrollLeft = window.pageXOffset || document.documentElement.scrollLeft,
scrollTop = window.pageYOffset || document.documentElement.scrollTop;
return {top: rect.top + scrollTop, left: rect.left + scrollLeft}
};
const append = (img, dom) => {
const next = img.nextElementSibling;
next ? img.parentElement.insertBefore(dom, next) : img.parentElement.append(dom)
}
const clickImage = function (img) {
removeResizeFrame();
currentImage = img;
const imgHeight = img.offsetHeight;
const imgWidth = img.offsetWidth;
const imgPosition = {top: img.offsetTop, left: img.offsetLeft};
const editorScrollTop = img.parentElement.scrollTop;
const editorScrollLeft = img.parentElement.scrollLeft;
const top = imgPosition.top - editorScrollTop - 1;
const left = imgPosition.left - editorScrollLeft - 1;
append(currentImage, createDOM('span', 'resize-frame', {
margin: '10px',
position: 'absolute',
top: (top + imgHeight - 10) + 'px',
left: (left + imgWidth - 10) + 'px',
border: 'solid 3px blue',
width: '6px',
height: '6px',
cursor: 'se-resize',
zIndex: 1
}));
append(currentImage, createDOM('span', 'resizer top-border', {
position: 'absolute',
top: (top) + 'px',
left: (left) + 'px',
border: 'dashed 1px grey',
width: imgWidth + 'px',
height: '0px'
}));
append(currentImage, createDOM('span', 'resizer left-border', {
position: 'absolute',
top: (top) + 'px',
left: (left) + 'px',
border: 'dashed 1px grey',
width: '0px',
height: imgHeight + 'px'
}));
append(currentImage, createDOM('span', 'resizer right-border', {
position: 'absolute',
top: (top) + 'px',
left: (left + imgWidth) + 'px',
border: 'dashed 1px grey',
width: '0px',
height: imgHeight + 'px'
}));
append(currentImage, createDOM('span', 'resizer bottom-border', {
position: 'absolute',
top: (top + imgHeight) + 'px',
left: (left) + 'px',
border: 'dashed 1px grey',
width: imgWidth + 'px',
height: '0px'
}));
document.querySelector('.resize-frame').onmousedown = () => {
resizing = true;
return false;
};
editor.onmouseup = () => {
if (resizing) {
//const newHeight = document.querySelector('.left-border').offsetHeight;
//resize equal ratio
const width = document.querySelector('.top-border').offsetWidth;
if (currentImage.parentElement.style.width !== 'auto' && currentImage.parentElement.style.width < width + 'px') {
currentImage.parentElement.style.width = 'auto'
}
currentImage.style.width = width + 'px';
//currentImage.style.height = 'auto';
refresh();
currentImage.click();
resizing = false;
}
};
editor.onmousemove = (e) => {
if (currentImage && resizing) {
let height = e.pageY - offset(currentImage).top;
let width = e.pageX - offset(currentImage).left;
height = height < 1 ? 1 : height;
width = width < 1 ? 1 : width;
const top = imgPosition.top - editorScrollTop - 1;
const left = imgPosition.left - editorScrollLeft - 1;
setStyle(document.querySelector('.resize-frame'), {
top: (top + height - 10) + 'px',
left: (left + width - 10) + "px"
});
setStyle(document.querySelector('.top-border'), {width: width + "px"});
setStyle(document.querySelector('.left-border'), {height: height + "px"});
setStyle(document.querySelector('.right-border'), {
left: (left + width) + 'px',
height: height + "px"
});
setStyle(document.querySelector('.bottom-border'), {
top: (top + height) + 'px',
width: width + "px"
});
}
return false;
};
};
const bindClickListener = function () {
editor.querySelectorAll('img').forEach((img) => {
img.onclick = (e) => {
if (e.target === img) {
clickImage(img);
}
};
});
};
const refresh = function () {
bindClickListener();
removeResizeFrame();
if (!currentImage) {
return;
}
const img = currentImage;
const imgHeight = img.offsetHeight;
const imgWidth = img.offsetWidth;
const imgPosition = {top: img.offsetTop, left: img.offsetLeft};
const editorScrollTop = img.parentElement.scrollTop;
const editorScrollLeft = img.parentElement.scrollLeft;
const top = imgPosition.top - editorScrollTop - 1;
const left = imgPosition.left - editorScrollLeft - 1;
append(img, createDOM('span', 'resize-frame', {
position: 'absolute',
top: (top + imgHeight) + 'px',
left: (left + imgWidth) + 'px',
border: 'solid 2px red',
width: '6px',
height: '6px',
cursor: 'se-resize',
zIndex: 1
}));
append(img, createDOM('span', 'resizer', {
position: 'absolute',
top: (top) + 'px',
left: (left) + 'px',
border: 'dashed 1px grey',
width: imgWidth + 'px',
height: '0px'
}));
append(img, createDOM('span', 'resizer', {
position: 'absolute',
top: (top) + 'px',
left: (left + imgWidth) + 'px',
border: 'dashed 1px grey',
width: '0px',
height: imgHeight + 'px'
}));
append(img, createDOM('span', 'resizer', {
position: 'absolute',
top: (top + imgHeight) + 'px',
left: (left) + 'px',
border: 'dashed 1px grey',
width: imgWidth + 'px',
height: '0px'
}));
};
const reset = function () {
if (currentImage != null) {
currentImage = null;
resizing = false;
removeResizeFrame();
}
bindClickListener();
};
editor.addEventListener('scroll', function () {
reset();
}, false);
editor.addEventListener('mouseup', function (e) {
if (!resizing) {
const x = (e.x) ? e.x : e.clientX;
const y = (e.y) ? e.y : e.clientY;
let mouseUpElement = document.elementFromPoint(x, y);
if (mouseUpElement) {
let matchingElement = null;
if (mouseUpElement.tagName === 'IMG') {
matchingElement = mouseUpElement;
}
if (!matchingElement) {
reset();
} else {
clickImage(matchingElement);
}
}
}
});
}