SwitchButton.java

package cn.mutils.app.ui;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.View;

import cn.mutils.app.util.AppUtil;

@SuppressWarnings({"UnnecessaryInterfaceModifier", "unused"})
public class SwitchButton extends View {

    public static interface OnCheckedChangeListener {

        boolean onCheckedChanging(SwitchButton v, boolean checked);

        void onCheckedChanged(SwitchButton v, boolean checked);

    }

    protected int mChromeColor = 0xFF4DD963;

    protected int mBorderColor = 0xFFDADADA;

    protected Paint mPaint = new Paint();

    protected Path mPath = new Path();

    protected RectF mRect = new RectF();

    protected boolean mChecked;

    protected int mPadding;

    protected int mWrapContentWidth;

    protected int mWrapContentHeight;

    protected OnCheckedChangeListener mListener;

    public SwitchButton(Context context) {
        super(context);
        init(context, null);
    }

    public SwitchButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public SwitchButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    protected void init(Context context, AttributeSet attrs) {
        DisplayMetrics metrics = AppUtil.getDisplayMetrics(context);
        mWrapContentWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 46, metrics);
        mWrapContentHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 26, metrics);
        mPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 2, metrics);
        int minWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 48, metrics);
        this.setMinimumWidth(minWidth);
        int minHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 24, metrics);
        this.setMinimumHeight(minHeight);
        super.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                if (mListener != null) {
                    if (mListener.onCheckedChanging((SwitchButton) v, mChecked)) {
                        setChecked(!mChecked);
                    }
                } else {
                    setChecked(!mChecked);
                }
            }
        });
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int w = this.getWidth();
        int h = this.getHeight();
        int padding2 = mPadding << 1;
        int r = (int) ((w - 4 - padding2) * 0.295);
        int r2 = r << 1;
        int offsetX = mPadding;
        int offsetY = mPadding + ((h - padding2) >> 1) - r - 1;
        mPath.reset();
        mPath.moveTo(offsetX + r + 1, offsetY);
        mPath.lineTo(w - r - 1 - offsetX, offsetY);
        mRect.set(w - r2 - 2 - offsetX, offsetY, w - offsetX, offsetY + r2 + 2);
        mPath.arcTo(mRect, 270, 180);
        mPath.lineTo(offsetX + r + 1, offsetY + r2 + 2);
        mRect.set(offsetX, offsetY, offsetX + r2 + 2, offsetY + r2 + 2);
        mPath.arcTo(mRect, 90, 180);
        mPath.close();
        mPaint.reset();
        mPaint.setAntiAlias(true);
        if (mChecked) {
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(mChromeColor);
            canvas.drawPath(mPath, mPaint);

            int circleX = w - r - 1 - offsetX;
            int circleY = offsetY + r + 1;
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(0xFFFFFFFF);
            canvas.drawCircle(circleX, circleY, r, mPaint);
        } else {
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(0xFFFFFFFF);
            canvas.drawPath(mPath, mPaint);
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setColor(mBorderColor);
            mPaint.setStrokeWidth(1);
            canvas.drawPath(mPath, mPaint);

            int circleX = offsetX + r + 1;
            int circleY = offsetY + r + 1;
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(0xFFFFFFFF);
            canvas.drawCircle(circleX, circleY, r, mPaint);
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setColor(mBorderColor);
            mPaint.setStrokeWidth(1);
            canvas.drawCircle(circleX, circleY, r, mPaint);
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.AT_MOST) {
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(mWrapContentWidth, MeasureSpec.EXACTLY);
        }
        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(mWrapContentHeight, MeasureSpec.EXACTLY);
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public boolean isChecked() {
        return mChecked;
    }

    public void setChecked(boolean checked) {
        mChecked = checked;
        invalidate();
        if (mListener != null) {
            mListener.onCheckedChanged(SwitchButton.this, mChecked);
        }
    }

    public int getChromeColor() {
        return mChromeColor;
    }

    public void setChromeColor(int chromeColor) {
        mChromeColor = chromeColor;
        invalidate();
    }

    public int getBorderColor() {
        return mBorderColor;
    }

    public void setBorderColor(int borderColor) {
        mBorderColor = borderColor;
        invalidate();
    }

    @Override
    public void setOnClickListener(OnClickListener l) {
        throw new IllegalArgumentException("You can not call this method");
    }

    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
        mListener = listener;
    }

}