1
在畫布中，我繪製了一個矩形並完成了拖動和調整大小功能。繪製圓以表示手柄來調整矩形的大小。但現在我想拖動使用光標類型。如何使用光標類型拖動和調整svg矩形大小
我已經使用光標鍵入如下：
$("#canvas").css({'cursor':'ne-resize'});
這裏是的jsfiddle鏈接。 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>
謝謝@ Kaiido.This也已完成我也。在這種情況下，無論你有檢查光標在向負方向拖動矩形後鍵入已經運行你的代碼片段。最初的光標繪製爲右上角的位置是crct.but當你不得不拖動所有側面後，你有檢查方向是錯的。請你檢查一下。我在問這個 – Rekha
你是對的，更新。 – Kaiido
是的，現在工作正常。感謝很多。 – Rekha