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在画布中，我绘制了一个矩形并完成了拖动和调整大小功能。绘制圆以表示手柄来调整矩形的大小。但现在我想拖动使用光标类型。如何使用光标类型拖动和调整svg矩形大小
我已经使用光标键入如下：
$("#canvas").css({'cursor':'ne-resize'});
这里是的jsfiddle链接。 http://jsfiddle.net/BaliBalo/9HXMG/
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
rect = {
x: 150,
y: 100,
w: 123,
h: 58
},
handlesSize = 8,
currentHandle = false,
drag = false;
function init() {
canvas.addEventListener('mousedown', mouseDown, false);
canvas.addEventListener('mouseup', mouseUp, false);
canvas.addEventListener('mousemove', mouseMove, false);
}
function point(x, y) {
return {
x: x,
y: y
};
}
function dist(p1, p2) {
return Math.sqrt((p2.x - p1.x) * (p2.x - p1.x) + (p2.y - p1.y) * (p2.y - p1.y));
}
function getHandle(mouse) {
if (dist(mouse, point(rect.x, rect.y)) <= handlesSize) return 'topleft';
if (dist(mouse, point(rect.x + rect.w, rect.y)) <= handlesSize) return 'topright';
if (dist(mouse, point(rect.x, rect.y + rect.h)) <= handlesSize) return 'bottomleft';
if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h)) <= handlesSize) return 'bottomright';
if (dist(mouse, point(rect.x + rect.w/2, rect.y)) <= handlesSize) return 'top';
if (dist(mouse, point(rect.x, rect.y + rect.h/2)) <= handlesSize) return 'left';
if (dist(mouse, point(rect.x + rect.w/2, rect.y + rect.h)) <= handlesSize) return 'bottom';
if (dist(mouse, point(rect.x + rect.w, rect.y + rect.h/2)) <= handlesSize) return 'right';
return false;
}
function mouseDown(e) {
if (currentHandle) drag = true;
draw();
}
function mouseUp() {
drag = false;
currentHandle = false;
draw();
}
function mouseMove(e) {
var previousHandle = currentHandle;
if (!drag) currentHandle = getHandle(point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop));
if (currentHandle && drag) {
var mousePos = point(e.pageX - this.offsetLeft, e.pageY - this.offsetTop);
switch (currentHandle) {
case 'topleft':
rect.w += rect.x - mousePos.x;
rect.h += rect.y - mousePos.y;
rect.x = mousePos.x;
rect.y = mousePos.y;
break;
case 'topright':
rect.w = mousePos.x - rect.x;
rect.h += rect.y - mousePos.y;
rect.y = mousePos.y;
break;
case 'bottomleft':
rect.w += rect.x - mousePos.x;
rect.x = mousePos.x;
rect.h = mousePos.y - rect.y;
break;
case 'bottomright':
rect.w = mousePos.x - rect.x;
rect.h = mousePos.y - rect.y;
break;
case 'top':
rect.h += rect.y - mousePos.y;
rect.y = mousePos.y;
break;
case 'left':
rect.w += rect.x - mousePos.x;
rect.x = mousePos.x;
break;
case 'bottom':
rect.h = mousePos.y - rect.y;
break;
case 'right':
rect.w = mousePos.x - rect.x;
break;
}
}
if (drag || currentHandle != previousHandle) draw();
}
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = 'black';
ctx.fillRect(rect.x, rect.y, rect.w, rect.h);
if (currentHandle) {
var posHandle = point(0, 0);
switch (currentHandle) {
case 'topleft':
posHandle.x = rect.x;
posHandle.y = rect.y;
break;
case 'topright':
posHandle.x = rect.x + rect.w;
posHandle.y = rect.y;
break;
case 'bottomleft':
posHandle.x = rect.x;
posHandle.y = rect.y + rect.h;
break;
case 'bottomright':
posHandle.x = rect.x + rect.w;
posHandle.y = rect.y + rect.h;
break;
case 'top':
posHandle.x = rect.x + rect.w/2;
posHandle.y = rect.y;
break;
case 'left':
posHandle.x = rect.x;
posHandle.y = rect.y + rect.h/2;
break;
case 'bottom':
posHandle.x = rect.x + rect.w/2;
posHandle.y = rect.y + rect.h;
break;
case 'right':
posHandle.x = rect.x + rect.w;
posHandle.y = rect.y + rect.h/2;
break;
}
ctx.globalCompositeOperation = 'xor';
ctx.beginPath();
ctx.arc(posHandle.x, posHandle.y, handlesSize, 0, 2 * Math.PI);
ctx.fill();
ctx.globalCompositeOperation = 'source-over';
}
}
init();
draw();<canvas id="canvas" width="500" height="500"></canvas>
谢谢@ Kaiido.This也已完成我也。在这种情况下，无论你有检查光标在向负方向拖动矩形后键入已经运行你的代码片段。最初的光标绘制为右上角的位置是crct.but当你不得不拖动所有侧面后，你有检查方向是错的。请你检查一下。我在问这个 – Rekha
你是对的，更新。 – Kaiido
是的，现在工作正常。感谢很多。 – Rekha