package com.jackie.lockpattern; 
 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Paint; 
import android.graphics.Point; 
import android.text.TextUtils; 
import android.util.AttributeSet; 
import android.util.TypedValue; 
import android.view.MotionEvent; 
import android.view.View; 
 
import java.util.ArrayList; 
import java.util.List; 
 
/** 
 * Created by Jackie on 2015/12/24. 
 * 圖案解鎖 
 */ 
public class LockPatternView extends View { 
 /** 
  * 圓的畫筆 
  */ 
 private Paint mCirclePaint; 
 /** 
  * 線的畫筆 
  */ 
 private Paint mLinePaint; 
 /** 
  * 圓心數組 
  */ 
 private PointView[][] mPointViewArray = new PointView[3][3]; 
 /** 
  * 保存選中點的集合 
  */ 
 private List<PointView> mSelectedPointViewList; 
 
 
 /** 
  * 解鎖圖案的邊長 
  */ 
 private int mPatternWidth; 
 
 /** 
  * 圖案監(jiān)聽器 
  */ 
 private OnPatternChangeListener mOnPatternChangeListener; 
 
 /** 
  * 半徑 
  */ 
 private float mRadius; 
 
 /** 
  * 每個圓圈的下標 
  */ 
 private int mIndex = 1; 
 
 /** 
  * 第一個點是否選中 
  */ 
 private boolean mIsSelected; 
 /** 
  * 是否繪制結束 
  */ 
 private boolean mIsFinished; 
 
 /** 
  * 正在滑動并且沒有任何點選中 
  */ 
 private boolean mIsMovingWithoutCircle = false; 
 
 private float mCurrentX, mCurrentY; 
 
 /** 
  * 正常狀態(tài)的顏色 
  */ 
 private static final int NORMAL_COLOR = 0xFF70DBDB; 
 /** 
  * 選中狀態(tài)的顏色 
  */ 
 private static final int SELECTED_COLOR = 0xFF979797; 
 
 public LockPatternView(Context context) { 
  this(context, null); 
 } 
 
 public LockPatternView(Context context, AttributeSet attrs) { 
  super(context, attrs); 
 
  mCirclePaint = new Paint(); 
  mCirclePaint.setAntiAlias(true); 
  mCirclePaint.setDither(true); 
  mCirclePaint.setColor(NORMAL_COLOR); 
  mCirclePaint.setStyle(Paint.Style.FILL); 
 
  mLinePaint = new Paint(); 
  mLinePaint.setAntiAlias(true); 
  mLinePaint.setDither(true); 
  mLinePaint.setStrokeWidth(20); 
  mLinePaint.setColor(SELECTED_COLOR); 
  mLinePaint.setStyle(Paint.Style.STROKE); 
 
  mRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 20, getResources().getDisplayMetrics()); 
 
  mSelectedPointViewList = new ArrayList<>(); 
 } 
 
 @Override 
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
  super.onMeasure(widthMeasureSpec, heightMeasureSpec); 
 
  //取屏幕長和寬中的較小值作為圖案的邊長 
  mPatternWidth = Math.min(getMeasuredWidth(), getMeasuredHeight()); 
  setMeasuredDimension(mPatternWidth, mPatternWidth); 
 } 
 
 @Override 
 protected void onDraw(Canvas canvas) { 
  //畫圓 
  drawCircle(canvas); 
 
  //將選中的圓重新繪制一遍，將選中的點和未選中的點區(qū)別開來 
  for (PointView pointView : mSelectedPointViewList) { 
   mCirclePaint.setColor(SELECTED_COLOR); 
   canvas.drawCircle(pointView.x, pointView.y, mRadius, mCirclePaint); 
   mCirclePaint.setColor(NORMAL_COLOR); //每重新繪制一個,將畫筆的顏色重置,保證不會影響其他圓的繪制 
  } 
 
  //點與點畫線 
  if (mSelectedPointViewList.size() > 0) { 
   Point pointViewA = mSelectedPointViewList.get(0); //第一個選中的點為A點 
   for (int i = 0; i < mSelectedPointViewList.size(); i++) { 
    Point pointViewB = mSelectedPointViewList.get(i); //其他依次遍歷出來的點為B點 
    drawLine(canvas, pointViewA, pointViewB); 
    pointViewA = pointViewB; 
   } 
 
   //點與鼠標當前位置繪制軌跡 
   if (mIsMovingWithoutCircle & !mIsFinished) { 
    drawLine(canvas, pointViewA, new PointView((int)mCurrentX, (int)mCurrentY)); 
   } 
  } 
 
  super.onDraw(canvas); 
 } 
 
 /** 
  * 畫圓 
  * @param canvas 畫布 
  */ 
 private void drawCircle(Canvas canvas) { 
  //初始化點的位置 
  for (int i = 0; i < mPointViewArray.length; i++) { 
   for (int j = 0; j < mPointViewArray.length; j++) { 
    //圓心的坐標 
    int cx = mPatternWidth / 4 * (j + 1); 
    int cy = mPatternWidth / 4 * (i + 1); 
 
    //將圓心放在一個點數組中 
    PointView pointView = new PointView(cx, cy); 
    pointView.setIndex(mIndex); 
    mPointViewArray[i][j] = pointView; 
    canvas.drawCircle(cx, cy, mRadius, mCirclePaint); 
    mIndex++; 
   } 
  } 
 
  mIndex = 1; 
 } 
 
 /** 
  * 畫線 
  * @param canvas 畫布 
  * @param pointA 第一個點 
  * @param pointB 第二個點 
  */ 
 private void drawLine(Canvas canvas, Point pointA, Point pointB) { 
  canvas.drawLine(pointA.x, pointA.y, pointB.x, pointB.y, mLinePaint); 
 } 
 
 @Override 
 public boolean onTouchEvent(MotionEvent event) { 
  mCurrentX = event.getX(); 
  mCurrentY = event.getY(); 
  PointView selectedPointView = null; 
 
  switch(event.getAction()) { 
   case MotionEvent.ACTION_DOWN: 
    //重新繪制 
    if (mOnPatternChangeListener != null) { 
     mOnPatternChangeListener.onPatternStarted(true); 
    } 
 
    mSelectedPointViewList.clear(); 
    mIsFinished = false; 
 
    selectedPointView = checkSelectPoint(); 
 
    if (selectedPointView != null) { 
     //第一次按下的位置在圓內，被選中 
     mIsSelected = true; 
    } 
    break; 
   case MotionEvent.ACTION_MOVE: 
    if (mIsSelected) { 
     selectedPointView = checkSelectPoint(); 
    } 
 
    if (selectedPointView == null) { 
     mIsMovingWithoutCircle = true; 
    } 
    break; 
   case MotionEvent.ACTION_UP: 
    mIsFinished = true; 
    mIsSelected = false; 
    break; 
  } 
 
  //將選中的點收集起來 
  if (!mIsFinished && mIsSelected && selectedPointView != null) { 
   if (!mSelectedPointViewList.contains(selectedPointView)) { 
    mSelectedPointViewList.add(selectedPointView); 
   } 
  } 
 
  if (mIsFinished) { 
   if (mSelectedPointViewList.size() == 1) { 
    mSelectedPointViewList.clear(); 
   } else if (mSelectedPointViewList.size() < 5 && mSelectedPointViewList.size() > 0) { 
    //繪制錯誤 
    if (mOnPatternChangeListener != null) { 
     mOnPatternChangeListener.onPatternChange(null); 
    } 
   } else { 
    //繪制成功 
    String patternPassword = ""; 
    if (mOnPatternChangeListener != null) { 
     for (PointView pointView : mSelectedPointViewList) { 
      patternPassword += pointView.getIndex(); 
     } 
 
     if (!TextUtils.isEmpty(patternPassword)) { 
      mOnPatternChangeListener.onPatternChange(patternPassword); 
     } 
    } 
   } 
  } 
 
  invalidate(); 
  return true; 
 } 
 
 /** 
  * 判斷當前按下的位置是否在圓心數組中 
  * @return 返回選中的點 
  */ 
 private PointView checkSelectPoint() { 
  for (int i = 0; i < mPointViewArray.length; i++) { 
   for (int j = 0; j < mPointViewArray.length; j++) { 
    PointView pointView = mPointViewArray[i][j]; 
    if (isWithinCircle(mCurrentX, mCurrentY, pointView.x, pointView.y, mRadius)) { 
     return pointView; 
    } 
   } 
  } 
 
  return null; 
 } 
 
 /** 
  * 判斷點是否在圓內 
  * @param x  點X軸坐標 
  * @param y  點Y軸坐標 
  * @param cx  圓心X坐標 
  * @param cy  圓心Y坐標 
  * @param radius 半徑 
  * @return  true表示在圓內，false表示在圓外 
  */ 
 private boolean isWithinCircle(float x, float y, float cx, float cy, float radius) { 
  //如果點和圓心的距離小于半徑，則證明點在圓內 
  if (Math.sqrt(Math.pow(x - cx, 2) + Math.pow(y- cy, 2)) <= radius) { 
   return true; 
  } 
 
  return false; 
 } 
 
 /** 
  * 設置圖案監(jiān)聽器 
  */ 
 public void setOnPatternChangeListener(OnPatternChangeListener onPatternChangeListener) { 
  if (onPatternChangeListener != null) { 
   this.mOnPatternChangeListener = onPatternChangeListener; 
  } 
 } 
 
 /** 
  * 圖案監(jiān)聽器 
  */ 
 public interface OnPatternChangeListener { 
  /** 
   * 圖案改變 
   * @param patternPassword 圖案密碼 
   */ 
  void onPatternChange(String patternPassword); 
 
  /** 
   * 圖案是否重新繪制 
   * @param isStarted 重新繪制 
   */ 
  void onPatternStarted(boolean isStarted); 
 } 
}

PointView.java

package com.jackie.lockpattern; 
 
import android.graphics.Point; 
 
/** 
 * Created by Jackie on 2015/12/25. 
 * 自定義點對象 
 */ 
public class PointView extends Point { 
 //用于轉化密碼的下標 
 public int index; 
 
 public PointView(int x, int y) { 
  super(x, y); 
 } 
 
 public int getIndex() { 
  return index; 
 } 
 
 public void setIndex(int index) { 
  this.index = index; 
 } 
}

MainActivity.java

package com.jackie.lockpattern; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.widget.TextView; 
 
public class MainActivity extends Activity implements LockPatternView.OnPatternChangeListener { 
 private TextView mLockPatternHint; 
 private LockPatternView mLockPatternView; 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
 
  mLockPatternHint = (TextView) findViewById(R.id.lock_pattern_hint); 
  mLockPatternView = (LockPatternView) findViewById(R.id.lock_pattern_view); 
  mLockPatternView.setOnPatternChangeListener(this); 
 
 } 
 
 @Override 
 public void onPatternChange(String patternPassword) { 
  if (patternPassword == null) { 
   mLockPatternHint.setText("至少5個點"); 
  } else { 
   mLockPatternHint.setText(patternPassword); 
  } 
 } 
 
 @Override 
 public void onPatternStarted(boolean isStarted) { 
  if (isStarted) { 
   mLockPatternHint.setText("請繪制圖案"); 
  } 
 } 
}

效果圖如下：