问题描述
Jsfiddle:http://jsfiddle.net/6NBy2/
代码:
var in_editor_drag = d3.behavior.drag()
.origin(function() {
var g = this.parentNode;
return {x: d3.transform(g.getAttribute("transform")).translate[0],
y: d3.transform(g.getAttribute("transform")).translate[1]};
})
.on("drag", function(d,i) {
g = this.parentNode;
translate = d3.transform(g.getAttribute("transform")).translate;
x = d3.event.dx + translate[0],
y = d3.event.dy + translate[1];
d3.select(g).attr("transform", "translate(" + x + "," + y + ")");
d3.event.sourceEvent.stopPropagation();
});
svg = d3.select("svg");
d = {x: 20, y: 20 };
groups = svg
.append("g")
.attr("transform", "translate(20, 20)");
groups
.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 100)
.attr("height", 100)
.style("fill", "green")
.call(in_editor_drag)
.style("opacity", 0.4);
我正在尝试通过使用其中一个孩子作为句柄来拖动一个组.简单地说，我想要做的是，当一个组的孩子被拖动时:
I'm trying to drag a group by using one of it's children as a handle. Simply, what i'm trying to do is, when a groups child is dragged:
- 获取组的翻译转换
- 从 d3.event.dx、d3.event.dy 获取拖动距离
- 对组的变换属性应用差异
当拖动孩子时，组不会按预期移动.它移动的距离小于拖动的距离，并开始在这里和那里跳跃.
When child dragged, group does not move as expected. It moves less than the dragged distance, and it begins to jump here and there.
我在这里做错了什么?
更新的 jsfiddle:http://jsfiddle.net/6NBy2/2/
Updated jsfiddle: http://jsfiddle.net/6NBy2/2/
我正在尝试通过使用一个或多个孩子作为拖动手柄来拖动整个组.
I'm trying to drag the whole group by using one or more of it's children as dragging handles.
推荐答案
这是一个老问题，但没有真正回答.我遇到了完全相同的问题，并且只想将组拖动一个子元素(不是 <g> 的所有子元素).问题是，d3.event.dx/y 是相对于 <g> 的位置计算的.一旦 <g> 被 .attr(transform", translate(x, y)") 移动，d3.event.dx/dy 被调整为新的(较小的)值.这会导致不平稳的运动，大约.光标速度的一半.我为此找到了两种可能的解决方案:
This is an old question, but not really answered. I had exactly the same problem and wanted to drag the group by only one child (not all child elements of the <g>).
The problem is, that the d3.event.dx/y is calculated relatively to the position of the <g>. And as soon as the <g> is moved by .attr("transform", "translate(x, y)"), the d3.event.dx/dy is adjusted to the new (smaller) value. This results in a jerky movement with approx. the half of the speed of the cursor. I found two possible solutions for this:
首先(最后我采用了这种方法):
将拖动句柄 rect 直接附加到 svg 而不是 <g>.所以它相对于 <svg> 而不是 <g> 定位.然后在 on drag 函数中同时移动(<rect> 和 <g>).
Append the drag handle rect directly to the svg and not to the <g>. So it is positioned relatively to the <svg> and not to the <g>. Then move both (the <rect> and the <g>) within the on drag function.
var svg = d3.select("svg");
var group = svg
.append("g").attr("id", "group")
.attr("transform", "translate(0, 0)");
group
.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 100)
.attr("height", 100)
.style("fill", "green")
.style("opacity", 0.4);
group
.append("text")
.attr("x", 10)
.attr("y", 5)
.attr("dominant-baseline", "hanging")
.text("drag me");
handle = svg
.append("rect")
.data([{
// Position of the rectangle
x: 0,
y: 0
}])
.attr("class", "draghandle")
.attr("x", 0)
.attr("y", 0)
.attr("width", 100)
.attr("height", 20)
.style("fill", "blue")
.style("opacity", 0.4)
.attr("cursor", "move")
.call(d3.drag().on("drag", function (d) {
console.log("yep");
d.x += d3.event.dx;
d.y += d3.event.dy;
// Move handle rect
d3.select(this)
.attr("x", function (d) {
return d.x;
})
.attr("y", function (d) {
return d.y;
});
// Move Group
d3.select("#group").attr("transform", "translate(" + [d.x, d.y] + ")");
}));<body>
<svg width="400" height="400"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
</body>第二:
使用 d3.event.sourceEvent.path[0] 检查拖动事件期间光标在哪个元素上，仅当句柄 <rect> 时才运行拖动功能代码>被点击.使用这种方法，所有元素都可以在一个 <g> 中进行分组(无需在组外添加额外的 <rect>).这种方法的缺点是，如果鼠标向下移动光标到拖动手柄上，也会执行拖动.
Check on which element the cursor was during the drag event with d3.event.sourceEvent.path[0] and run the drag function only if the handle <rect> was clicked. With this approach, all elements can be grouped within one <g> (no need for an additional <rect> outside the group). The downside of this method is, that the drag is also executed, if the cursor is moved over the drag handle with mouse down.
var svg = d3.select("svg");
var group = svg
.append("g")
.data([{
// Position of the rectangle
x: 0,
y: 0
}])
.attr("id", "group")
.attr("transform", function (d) {
return "translate(" + d.x + ", " + d.y + ")"
})
.call(d3.drag().on("drag", function (d) {
if (d3.event.sourceEvent.target.classList.value === "draghandle") {
console.log("yep");
d.x += d3.event.dx;
d.y += d3.event.dy;
d3.select(this).attr("transform", function (d) {
return "translate(" + [d.x, d.y] + ")"
})
} else {
console.log("nope");
return;
}
}));
group
.append("rect")
.attr("x", 0)
.attr("y", 0)
.attr("width", 100)
.attr("height", 100)
.style("fill", "green")
.style("opacity", 0.4);
group
.append("text")
.attr("x", 10)
.attr("y", 5)
.attr("dominant-baseline", "hanging")
.text("drag me");
handle = group
.append("rect")
.attr("class", "draghandle")
.attr("x", 0)
.attr("y", 0)
.attr("width", 100)
.attr("height", 20)
.style("fill", "blue")
.style("opacity", 0.4)
.attr("cursor", "move");<body>
<svg width="400" height="400"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
</body>这篇关于D3js:使用其中一个子级拖动组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！