学习资料：
- GcsSloop 同学的特殊控件的事件处理方案
效果图
1. TaiJiView代码
绘制考虑使用的是Path，通过Region可以通过点的坐标(x,y)来判断是否在Path所围成的区域内
public class TaiJiView extends View {
//黑色区域
private Paint mPaint;
private Path blackPath;
private Region blackRegion;
//白色区域
private Path whitePath;
private Region whiteRegion;
private float center;//中心点
private final int BLACK_FLAG = 0;
private final int WRITE_FLAG = 1;
private int touchFlag = -1;
private TaiJiListener mListener;
public TaiJiView(Context context, AttributeSet attrs) {
super(context, attrs);
initPaint();
}
/**
* 初始化画笔
*/
private void initPaint() {
//画笔
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(2);
mPaint.setStyle(Paint.Style.FILL);
//黑色路径
blackPath = new Path();
//黑色区域
blackRegion = new Region();
//白色路径
whitePath = new Path();
//白色区域
whiteRegion = new Region();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
int side = w > h ? h : w;//取小的值
Region totalRegion = new Region(0, 0, w, h);
RectF bigRectF = new RectF(0, 0, side, side);
center = side / 2;
RectF smallTopRectF = new RectF(center / 2, 0, (center + center / 2), center);
RectF smallBottomRectF = new RectF(center / 2, center, (center + center / 2), h);
//添加黑色路径信息
blackPath.addArc(bigRectF, 90, 180);
blackPath.moveTo(center, 0);
blackPath.arcTo(smallTopRectF, 270, 180);
blackPath.moveTo(center, center);
blackPath.arcTo(smallBottomRectF, 270, -180);
//将黑色路径信息存入Region
blackRegion.setPath(blackPath, totalRegion);
//添加白色路径信息
whitePath.addArc(bigRectF, 270, 180);
whitePath.moveTo(center, 0);
whitePath.arcTo(smallTopRectF, -270, -180);
whitePath.moveTo(center, center);
whitePath.arcTo(smallBottomRectF, 90, 180);
//将白色路径信息存入Region
whiteRegion.setPath(whitePath, totalRegion);
}
/**
* 触摸消费事件
* 需要考虑当落下的点和抬起的点是否在同一个有效区域内
*/
@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getX();
int y = (int) event.getY();
int currentFlag = -1;
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
touchFlag = getTouchFlag(x, y);
currentFlag = touchFlag;
break;
case MotionEvent.ACTION_MOVE:
currentFlag = getTouchFlag(x, y);
break;
case MotionEvent.ACTION_UP:
currentFlag = getTouchFlag(x, y);
if (null != mListener && currentFlag == touchFlag && currentFlag != -1) {
if (currentFlag == BLACK_FLAG) {
mListener.onBlackClick();
} else if (currentFlag == WRITE_FLAG) {
mListener.onWriteClick();
}
}
touchFlag = currentFlag = -1;
break;
case MotionEvent.ACTION_CANCEL:
touchFlag = currentFlag = -1;
break;
}
Log.e("currentFlag", "-->" + currentFlag);
return true;
}
/**
* 判断落在哪个区域
*/
private int getTouchFlag(int x, int y) {
if (blackRegion.contains(x, y)) {
return BLACK_FLAG;
} else if (whiteRegion.contains(x, y)) {
return WRITE_FLAG;
}
return -1;
}
public void setListener(TaiJiListener mListener) {
this.mListener = mListener;
}
/**
* 设置触摸监听
*/
public interface TaiJiListener {
void onBlackClick();
void onWriteClick();
}
/**
* 绘制方法
*/
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//绘制黑色路径
mPaint.setColor(Color.BLACK);
canvas.drawPath(blackPath, mPaint);
//绘制白色路径
mPaint.setColor(Color.WHITE);
canvas.drawPath(whitePath, mPaint);
//绘制白色小圆
canvas.drawCircle(center, center / 2, 60, mPaint);
//绘制黑色小圆
mPaint.setColor(Color.BLACK);
canvas.drawCircle(center, (center + center / 2), 60, mPaint);
}
/**
* 测量方法
* 当宽高都为 wrap_content 时，图形最小为 300 * 300
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int wSpecMode = MeasureSpec.getMode(widthMeasureSpec);
int wSpecSize = MeasureSpec.getSize(widthMeasureSpec);
int hSpecMode = MeasureSpec.getMode(heightMeasureSpec);
int hSpecSize = MeasureSpec.getSize(heightMeasureSpec);
if (wSpecMode == MeasureSpec.AT_MOST && hSpecMode == MeasureSpec.AT_MOST) {
setMeasuredDimension(300, 300);
} else if (wSpecMode == MeasureSpec.AT_MOST) {
setMeasuredDimension(300, hSpecSize);
} else if (hSpecMode == MeasureSpec.AT_MOST) {
setMeasuredDimension(wSpecSize, 300);
}
}
}
绘制的过程分了三步：
- 绘制黑色路径区域
- 绘制白色路径区域
- 绘制黑白两个小圆
重写onTouchEvent()方法，通过Region.contains(x, y)方法判断触摸点坐标所在区域
需要考虑落点在一个有效区域，而手指抬起离开屏幕时，抬起点坐标和落点不在同一个有效区域时这种情况，这时，可以根据需求，来决定触摸事件是否有效
例如，手指落在黑色区域，手指不离开屏幕，move到白色区域，此时判定触摸事件无效
2. Activity
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView() {
TaiJiView taiJiView = (TaiJiView) findViewById(R.id.tjv);
taiJiView.setListener(new TaiJiView.TaiJiListener() {
@Override
public void onBlackClick() {
ToastUtil.show(MainActivity.this, "黑色被点击");
}
@Override
public void onWriteClick() {
ToastUtil.show(MainActivity.this, "白色被点击");
}
});
}
}
3. 最后
有错误，请指出
共勉 ：）
