迷茫2017-04-17 16:53:30
这个问题不难，在触发A画板绘制的时候，得倒A的点的坐标，根据换算关系，算出B的点坐标，在绘制B里面的。https://segmentfault.com/n/1330000005040693
MainActivity
package com.cyrus.demoboard;
import android.app.Activity;
import android.os.Bundle;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import com.cyrus.demoboard.BoardView.OnPositionListener;
/**@author CyrusCao
*
*/
class MainActivity extends Activity {
private BoardView aView;
private BoardViewB bView;
private int wA,hA;
private int wB,hB;
private float sX = 0.0f;
private float sY = 0.0f;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
aView = (BoardView)findViewById(R.id.a_boardview);
bView = (BoardViewB)findViewById(R.id.b_boardview);
aView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
// TODO Auto-generated method stub
hA = aView.getHeight();
wA = aView.getWidth();
}
});
bView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
// TODO Auto-generated method stub
hB = bView.getHeight();
wB = bView.getWidth();
}
});
aView.setOnPositionListener(new OnPositionListener() {
@Override
public void onPositionListener(float x,float y,int action) {
// TODO Auto-generated method stub
if (sX == 0 || sY == 0) {
sX = (wB*1.0f)/wA;
sY = (hB*1.0f)/hA;
}
bView.triggerDraw(x*sX,y*sY,action);
}
});
}}
Board A
com.cyrus.demoboard;
android.annotation.SuppressLint;
android.content.Context;
android.graphics.Canvas;
android.graphics.Paint;
android.graphics.Path;
android.util.AttributeSet;
android.view.MotionEvent;
android.view.View;
/**
@author CyrusCao
*
*/
class BoardView extends View {
private float mX, mY;
private Path mPath;
private static final float TOUCH_TOLERANCE = 4;
private Paint mPaint;
private OnPositionListener mPositionListener;
@SuppressLint("NewApi")
public BoardView(Context context, AttributeSet attrs, int defStyleAttr,
int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardView(Context context) {
super(context);
// TODO Auto-generated constructor stub
initPaint();
}
public void initPaint(){
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFF00FF00);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(10);
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
float x = event.getX();
float y = event.getY();
if (mPositionListener != null) {
mPositionListener.onPositionListener(x, y,event.getAction());
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPath = new Path();
touchStart(x, y);
break;
case MotionEvent.ACTION_MOVE:
touchMove(x, y);
break;
case MotionEvent.ACTION_UP:
touchUp();
break;
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
if (mPath != null) {
canvas.drawPath(mPath, mPaint);
}
}
private void touchStart(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
mPath = null;
}
public void setOnPositionListener(OnPositionListener mPositionListener) {
this.mPositionListener = mPositionListener;
}
public interface OnPositionListener {
void onPositionListener(float x,float y,int action);
}
}
Board B
com.cyrus.demoboard;
android.annotation.SuppressLint;
android.content.Context;
android.graphics.Canvas;
android.graphics.Paint;
android.graphics.Path;
android.util.AttributeSet;
android.view.MotionEvent;
android.view.View;
/**
@author CyrusCao
*
*/
class BoardViewB extends View {
private float mX, mY;
private Path mPath;
private static final float TOUCH_TOLERANCE = 4;
private Paint mPaint;
@SuppressLint("NewApi")
public BoardViewB(Context context, AttributeSet attrs, int defStyleAttr,
int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardViewB(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardViewB(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
initPaint();
}
public BoardViewB(Context context) {
super(context);
// TODO Auto-generated constructor stub
initPaint();
}
public void initPaint() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(10);
}
public void triggerDraw(float x, float y, int action) {
switch (action) {
case MotionEvent.ACTION_DOWN:
mPath = new Path();
touchStart(x, y);
break;
case MotionEvent.ACTION_MOVE:
touchMove(x, y);
break;
case MotionEvent.ACTION_UP:
touchUp();
break;
}
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
if (mPath != null) {
canvas.drawPath(mPath, mPaint);
}
}
private void touchStart(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
mPath = null;
}
}
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.cyrus.demoboard.BoardViewB
android:id="@+id/b_boardview"
android:layout_width="300dp"
android:layout_height="250dp"
android:background="#fff000" />
<com.cyrus.demoboard.BoardView
android:id="@+id/a_boardview"
android:layout_width="200dp"
android:layout_height="200dp"
android:layout_alignParentBottom="true"
android:background="#fff000" />
</RelativeLayout>
