有趣的问题。您可以通过在所有其他对象后面放置一个与画布大小相同的矩形“垫子”,并在其上附加一个拖动事件以选择其他元素。(请注意,此解决方案使用较新版本的 Raphael 2.1.0:
var paper = Raphael(0, 0, '100%', '100%');
//make an object in the background on which to attach drag events
var mat = paper.rect(0, 0, paper.width, paper.height).attr("fill", "#FFF");
var circle = paper.circle(75, 75, 50);
var rect = paper.rect(150, 150, 50, 50);
var set = paper.set();
set.push(circle, rect);
set.attr({
fill: 'red',
stroke: 0
});
//the box we're going to draw to track the selection
var box;
//set that will receive the selected items
var selections = paper.set();
现在,我们添加一个拖动事件——类似于鼠标悬停事件,但具有三个功能(参见文档),并绘制一个框来跟踪选择空间:
//DRAG FUNCTIONS
//when mouse goes down over background, start drawing selection box
function dragstart (x, y, event) {
box = paper.rect(x, y, 0, 0).attr("stroke", "#9999FF");
}
// When mouse moves during drag, adjust box.
// If the drag is to the left or above original point,
// you have to translate the whole box and invert the dx
// or dy values since .rect() doesn't take negative width or height
function dragmove (dx, dy, x, y, event) {
var xoffset = 0,
yoffset = 0;
if (dx < 0) {
xoffset = dx;
dx = -1 * dx;
}
if (dy < 0) {
yoffset = dy;
dy = -1 * dy;
}
box.transform("T" + xoffset + "," + yoffset);
box.attr("width", dx);
box.attr("height", dy);
}
function dragend (event) {
//get the bounds of the selections
var bounds = box.getBBox();
box.remove();
reset();
console.log(bounds);
for (var c in set.items) {
// Here, we want to get the x,y vales of each object
// regardless of what sort of shape it is.
// But rect uses rx and ry, circle uses cx and cy, etc
// So we'll see if the bounding boxes intercept instead
var mybounds = set[c].getBBox();
//do bounding boxes overlap?
//is one of this object's x extremes between the selection's xe xtremes?
if (mybounds.x >= bounds.x && mybounds.x <= bounds.x2 || mybounds.x2 >= bounds.x && mybounds.x2 <= bounds.x2) {
//same for y
if (mybounds.y >= bounds.y && mybounds.y <= bounds.y2 || mybounds.y2 >= bounds.y && mybounds.y2 <= bounds.y2) {
selections.push(set[c]);
}
}
selections.attr("opacity", 0.5);
}
}
function reset () {
//empty selections and reset opacity;
selections = paper.set();
set.attr("opacity", 1);
}
mat.drag(dragmove, dragstart, dragend);
mat.click(function(e) {
reset();
});
就像那样,您有一个新的集合(选择),其中包含通过鼠标拖动选择的每个对象。然后,您可以将鼠标悬停事件从原始应用到该集合。
请注意,如果您用选择框在其边界框的角上划线,这将选择圆形对象,即使它不与圆形区域重叠。如果这是一个问题,您可以为圆圈制作一个特殊情况。
jsFiddle