primo rom: DashPathEffect, apply dash effect on path

الأربعاء، 4 يونيو 2014

DashPathEffect, apply dash effect on path

To apply DashPathEffect on path:

  //init DashPathEffect
  dashPathEffect = new DashPathEffect(
    new float[]{10.0f, 5.0f}, //interval 
    0);       //phase

  paintDash.setPathEffect(dashPathEffect);

Example:

Modify from last example "Draw rotated path by rotating canvas".

MyView.java

package com.example.androiddrawpath;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;

public class MyView extends View {
 
 MyShape myShape;
 float ratioRadius, ratioInnerRadius;
 int numberOfPoint = 3; //default
 
 float rotate;
 
 //corresponding to UI element
 TextView textLayerInfo;
 
 DashPathEffect dashPathEffect;

 public MyView(Context context) {
  super(context);
  initMyView();
 }

 public MyView(Context context, AttributeSet attrs) {
  super(context, attrs);
  initMyView();
 }

 public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  initMyView();
 }
 
 public void initMyView(){
  myShape = new MyShape();
  
  //init DashPathEffect
  dashPathEffect = new DashPathEffect(
    new float[]{10.0f, 5.0f}, //interval 
    0);       //phase
 }
 
 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  
  long starting = System.nanoTime();
  
  int w = getWidth();
  int h = getHeight();
  
  if((w==0) || (h==0)){
   return;
  }
  
  float x = (float)w/2.0f;
  float y = (float)h/2.0f;
  float radius, innerRadius;
  if(w > h){
   radius = h * ratioRadius;
   innerRadius = h * ratioInnerRadius;
  }else{
   radius = w * ratioRadius;
   innerRadius = w * ratioInnerRadius;
  }
  
  myShape.setStar(x, y, radius, innerRadius, numberOfPoint);
  
  //Save and rotate canvas 
  canvas.save();
  canvas.rotate(rotate, x, y);

  Paint paintDash = myShape.getPaint();
  paintDash.setPathEffect(dashPathEffect);
  
  canvas.drawPath(myShape.getPath(), myShape.getPaint());
  
  //restore canvas
  canvas.restore();
  
  long end = System.nanoTime();
  
  String info = "myView.isHardwareAccelerated() = " + isHardwareAccelerated() + "\n"
    + "canvas.isHardwareAccelerated() = " + canvas.isHardwareAccelerated() + "\n"
    + "processing time (reference only) : " + String.valueOf(end - starting) + " (ns)";
  textLayerInfo.setText(info);
  
 }
 
 public void setShapeRadiusRatio(float ratio){
  ratioRadius = ratio;
 }
 
 public void setShapeInnerRadiusRatio(float ratio){
  ratioInnerRadius = ratio;
 }
 
 public void setNumberOfPoint(int pt){
  numberOfPoint = pt;
 }
 
 public void passElements(TextView textLayerInfo){
  this.textLayerInfo = textLayerInfo;
 }

 public void setShapeRotate(int rot){
  rotate = (float)rot;
 }

}

Modify MyShape.java to call paint.setStyle(Paint.Style.STROKE).

package com.example.androiddrawpath;

import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;

public class MyShape {

 private Paint paint;
 private Path path;

 public MyShape() {
  paint = new Paint();
  paint.setColor(Color.BLUE);
  paint.setStrokeWidth(3);
  paint.setStyle(Paint.Style.STROKE);
  //paint.setStyle(Paint.Style.FILL);
  //paint.setStyle(Paint.Style.FILL_AND_STROKE);
  
  path = new Path();
 }

 public void setCircle(float x, float y, float radius, Path.Direction dir){
  path.reset();
  path.addCircle(x, y, radius, dir);
 }
 
 public void setStar(float x, float y, float radius, float innerRadius, int numOfPt){
  
  double section = 2.0 * Math.PI/numOfPt;
  
  path.reset();
  path.moveTo(
   (float)(x + radius * Math.cos(0)), 
   (float)(y + radius * Math.sin(0)));
  path.lineTo(
   (float)(x + innerRadius * Math.cos(0 + section/2.0)), 
   (float)(y + innerRadius * Math.sin(0 + section/2.0)));
  
  for(int i=1; i<numOfPt; i++){
   path.lineTo(
    (float)(x + radius * Math.cos(section * i)), 
    (float)(y + radius * Math.sin(section * i)));
   path.lineTo(
     (float)(x + innerRadius * Math.cos(section * i + section/2.0)), 
     (float)(y + innerRadius * Math.sin(section * i + section/2.0)));
  }
  
  path.close();
  
 }
 
 public Path getPath(){
  return path;
 }
 
 public Paint getPaint(){
  return paint;
 }

}