仿华为天气预报圆形刻度图的代码实现

仿华为天气预报圆形刻度图的代码实现

public class scaleprogressview extends view {
 private int len;
 private final int startangle = 40;
 private final int sweepangle = 280;
 private final int rotateanglenum = 70;
 private paint bgpaint;
 private paint linepaint;
 private paint arrowpaint;
 private int percentrotateanglenum;
 private float currentprogress;
 private int arrowwidth = densityutil.dp2px(6);
 private int arrowheight = densityutil.dp2px(10);
 private int radius;
 private int scalewidth = densityutil.dp2px(3);
 private int scaleheight = densityutil.dp2px(8);
 private float rotateangle;
 private valueanimator animator;

 public scaleprogressview(context context) {
  this(context, null, 0);
 }

 public scaleprogressview(context context, @nullable attributeset attrs) {
  this(context, attrs, 0);
 }

 public scaleprogressview(context context, @nullable attributeset attrs, int defstyleattr) {
  super(context, attrs, defstyleattr);
  init();
 }

 private void init() {
  bgpaint = new paint();
  bgpaint.setcolor(color.parsecolor("#66ffffff"));
  bgpaint.setantialias(true);
  bgpaint.setstyle(paint.style.stroke);
  bgpaint.setstrokewidth(scalewidth);
  bgpaint.setstrokecap(paint.cap.round);
  linepaint = new paint();
  linepaint.setcolor(color.green);
  linepaint.setantialias(true);
  linepaint.setstyle(paint.style.stroke);
  linepaint.setstrokewidth(scalewidth);
  linepaint.setstrokecap(paint.cap.round);
  arrowpaint = new paint();
  arrowpaint.setcolor(color.parsecolor("#ffe400"));
  arrowpaint.setantialias(true);
  arrowpaint.setstyle(paint.style.fill);
  rotateangle = sweepangle / rotateanglenum;
 }

 private void startanimator() {
  if (animator == null) {
animator = valueanimator.offloat(0, 1);
  } else {
animator.cancel();
  }
  animator.addupdatelistener(new valueanimator.animatorupdatelistener() {
@override
public void onanimationupdate(valueanimator animation) {
 currentprogress = (float) animation.getanimatedvalue();
 postinvalidate();
}
  });
  animator.setduration(2000);
  animator.start();
 }

 @override
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
  super.onmeasure(widthmeasurespec, heightmeasurespec);
  int width = measurespec.getsize(widthmeasurespec);
  int height = measurespec.getsize(heightmeasurespec);
  len = math.min(width, height);
  radius = len / 2 - arrowheight;
  setmeasureddimension(len, len);
 }

 @override
 protected void ondraw(canvas canvas) {
  super.ondraw(canvas);
  drawbackgroundline(canvas);
  drawcurrentline(canvas);
 }

 private void drawbackgroundline(canvas canvas) {
  canvas.save();
  canvas.translate(len / 2, len / 2);
  canvas.rotate(startangle);
  canvas.drawline(0, radius, 0, radius - scaleheight, bgpaint);
  for (int i = 0; i < rotateanglenum; i++) {
canvas.rotate(rotateangle);
canvas.drawline(0, radius, 0, radius - scaleheight, bgpaint);
  }
  canvas.restore();
 }

 private void drawcurrentline(canvas canvas) {
  canvas.save();
  canvas.translate(len / 2, len / 2);
  canvas.rotate(startangle);
  canvas.drawline(0, radius, 0, radius - scaleheight, linepaint);
  for (int i = 0, size = (int) (percentrotateanglenum * currentprogress); i < size; i++) {
canvas.rotate(rotateangle);
canvas.drawline(0, radius, 0, radius - scaleheight, linepaint);
  }
  path path = new path();
  path.moveto(arrowwidth / 2, radius + arrowheight);
  path.lineto(-arrowwidth / 2, radius + arrowheight);
  path.lineto(-arrowwidth / 2, radius + densityutil.dp2px(3));
  path.lineto(0, radius);
  path.lineto(arrowwidth / 2, radius + densityutil.dp2px(3));
  path.close();
  canvas.drawpath(path, arrowpaint);
  canvas.restore();
 }

 public void setprogress(string progress) {
  if (textutils.isempty(progress)) {
percentrotateanglenum = rotateanglenum;
  } else {
percentrotateanglenum = (int) (float.parsefloat(progress) * rotateanglenum / 100);
  }
  startanimator();
 }
}