<template>
	<view class="progress_box">
		<canvas class="progress_bg" canvas-id="cpbg"></canvas>
		<canvas class="progress_bar" canvas-id="cpbar"></canvas>
		<canvas class="progress_line" canvas-id="cpline"></canvas>
		<view class="progress_txt">
			<view class="progress_info">{{ progress_txt }}%</view>
		</view>
	</view>
</template>

<script>
	export default {
		props: {
			progress_txt: {
				type: Number,
				default: 80
			}
		},
		name:"progress",
		mounted() {
			this.drawProgressbg();
			this.drawCircle(this.progress_txt); //参数为1-100
			this.drawLine();
		},
		data() {
			return {
				
			};
		},
		methods:{
			drawProgressbg(){
				// 自定义组件实例 this ，表示在这个自定义组件下查找拥有 canvas-id 的 <canvas/>
				var ctx = uni.createCanvasContext('cpbg', this);
				ctx.setLineWidth(12); // 设置圆环的宽度
				ctx.setStrokeStyle('#E9E9E9'); // 设置圆环的颜色
				ctx.setLineCap('round'); // 设置圆环端点的形状
				ctx.setLineCap('square'); // 设置圆环端点的形状
				ctx.beginPath(); //开始一个新的路径
				ctx.arc(110, 110, 70, 0 * Math.PI, 2 * Math.PI, false);
				//设置一个原点(110,110)，半径为100的圆的路径到当前路径
				ctx.stroke(); //对当前路径进行描边
				ctx.draw();
			},
			drawCircle(step){
				var ctx = uni.createCanvasContext('cpbar', this);
				// 进度条的渐变(中心x坐标-半径-边宽，中心Y坐标，中心x坐标+半径+边宽，中心Y坐标)
				var gradient = ctx.createLinearGradient(0, 0, 130, 0);

				let increase = 0.05;
				let end = (step / 100) * 2 * Math.PI - Math.PI / 2; // 最后的角度
				let current = -Math.PI / 2; // 起始角度
				let timer = setInterval(() => {
					gradient.addColorStop('0', '#00F2FE');
					gradient.addColorStop('1.0', '#4FACFE');
					ctx.setLineWidth(12);
					ctx.setStrokeStyle(gradient);
					ctx.setLineCap('square');
					ctx.beginPath();
					// 参数step 为绘制的百分比
					if (current < end) {
						current = current + increase;
					}
					if (current >= end) {
						current = end;
						clearInterval(timer);
					}
					ctx.arc(110, 110, 70, -Math.PI / 2, current, false);
					ctx.stroke();
					ctx.draw();
				}, 20);
			},
			drawLine(){
				var context = uni.createCanvasContext("cpline",this);
				var r = 70;
				var x0 = 110;
				var y0 = 110;
				var x;
				var y;
				var lineWidth = 12;
	
				for (let i = 0; i < 60; i++) {
				  context.beginPath();
				  context.setLineWidth(lineWidth);
				  context.setStrokeStyle("#FFFFFF");
					
				  x = x0 - r * Math.sin(((6 * (i + 1) - 3) * Math.PI) / 180);
				  y = y0 - r * Math.cos(((6 * (i + 1) - 3) * Math.PI) / 180);
	
				  // console.log('x0:' + x0 + '   y0:' + y0 + '    x:' + x + '    y:' + y);
				  context.moveTo(x, y);
				  context.arc(
					x0,
					y0,
					r,
					((270 - 6 * (i + 1) + 3) * Math.PI) / 180,
					((270 - 6 * i) * Math.PI) / 180,
					false
				  );
				  context.stroke();
				  context.closePath();
				}
				context.stroke();
				context.draw();
			}
		}
	}
</script>

<style lang="scss" scoped>
	.progress_box {
		position: relative;
		width: 400rpx;
		height: 400rpx;
		display: flex;
		align-items: center;
		justify-content: center;
		text-align: center;
	}
	.progress_bg {
		position: absolute;
		width: 220px;
		height: 220px;
	}
	.progress_bar {
		position: absolute;
		width: 220px;
		height: 220px;
	}
	.progress_line {
		position: absolute;
		width: 220px;
		height: 220px;
	}
	.progress_txt {
		position: absolute;
		font-size: 28upx;
		color: #999999;
	}
	.progress_info {
		font-size: 36upx;
		padding-left: 16upx;
		letter-spacing: 2upx;
		font-size: 52upx;
		color: #333333;
	}
	.progress_dot {
		width: 16upx;
		height: 16upx;
		border-radius: 50%;
		background-color: #fb9126;
	}
</style>