//Save and rotate canvas
canvas.save();
canvas.rotate(rotate, x, y);
canvas.drawPath(...);
//restore canvas
canvas.restore();
Modify MyView.java in last example "Rotate Path with Matrix", all other files, MainActivity.java, MyShape.java and /res/layout/activity_main.xml, keep no change.
package com.example.androiddrawpath;
import android.content.Context;
import android.graphics.Canvas;
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;
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();
}
@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);
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;
}
}
More example of Drawing Path on canvas of custom View.
No comments:
Post a Comment