import android.study.shift.ItemView;import android.study.shift.MainView;import android.study.shift.Moveview;import android.content.Context;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.view.View.MeasureSpec;public class Moveview extends ViewGroup{ private final static int TOUCH_STATE_REST = 0; private final static int TOUCH_STATE_MOVING = 1; private final static int MOVE_TO_LEFT = 1; //private final static int MOVE_TO_RIGHT = 2; private final static int MOVE_TO_REST = 0; public final static int MAIN = 0; public final static int LEFT = 1; public final static int RIGHT = 2; private int touch_state = TOUCH_STATE_REST; private int move_state = MOVE_TO_REST; private int now_state = MAIN; private final float WIDTH_RATE = 0.18f; private MainView main_show_view; private ItemView left_show_view; private int min_distance = 30;//此處只是初始化為30 ，其實不起作用 private int screen_w; private int screen_h; private int move_x_v; private boolean isAimationMoving = false; private Handler mHandler = new Handler() { public void handleMessage(Message msg) {//處理消息  synchronized (Moveview.this) {//同步  isAimationMoving = true;  int move_change = (int) (screen_w * WIDTH_RATE / 5);  int left = main_show_view.getView().getLeft();  if (msg.what == 1) {//主屏在向右拖曳。。。   move(move_change + left);//參數為拖出來后主屏的坐標。  }  if (msg.what == 11) {   isAimationMoving = false;   moveToLeft(false); //滿足可以顯示的要求開始顯示，false只是一個判定條件，以區別按鈕起的效果  }  if (msg.what == 2) {//代表主屏向左在拖曳。。。   move(-1 * move_change + left);  }  if (msg.what == 12) {   isAimationMoving = false;   //moveToRight(false);  }  if (msg.what == 0) {   if (now_state == LEFT) {//如果現在已經顯示左邊   move(-1 * move_x_v);//那么還原成主屏   } else {   move(move_x_v);   }  }  if (msg.what == 10) {   isAimationMoving = false;   moveToMain(false);  }  } } }; public Moveview(Context context) { super(context); } public Moveview(Context context, AttributeSet attrs) { super(context, attrs); } public Moveview(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public void initView() { if (main_show_view == null) {  main_show_view = new MainView(this.getContext(), this);  left_show_view = new ItemView(this.getContext());  //right_show_view = new ItemView(this.getContext(), "aaa"); } this.addView(left_show_view.getView()); //this.addView(right_show_view.getView()); this.addView(main_show_view.getView()); } public void initContent() { } public void move(int start) {//本函數顯示拖動的時候屏幕的顯示情況。 int left = main_show_view.getView().getLeft();//left代表主屏左邊緣的位置坐標。 if (now_state == MAIN) {  if (left > 0) {//如果屏幕的左邊被移向右，則left變成正數  if (move_state != MOVE_TO_LEFT) {   move_state = MOVE_TO_LEFT;  }  left_show_view.getView().setVisibility(View.VISIBLE);//設置左邊可見  //right_show_view.getView().setVisibility(View.GONE);  } //else if (left < 0) {//如果屏幕的左邊被移向左，則left變成負數  //if (move_state != MOVE_TO_RIGHT) {  // move_state = MOVE_TO_RIGHT;  //}  //right_show_view.getView().setVisibility(View.VISIBLE);  //left_show_view.getView().setVisibility(View.GONE);  //}   else {  move_state = MOVE_TO_REST;  }  main_show_view.getView().layout(start, 0, start + screen_w,   screen_h);//參數依次為左、上、右、下。 } else {  left = (int) (screen_w * WIDTH_RATE);//left為左邊應該留出的控件空間，或者主屏左邊應該在的位置  if (now_state == RIGHT) {  left = -1 * left;//若狀態是在右邊空出來，則主屏的左邊為負數  }  left = left + start;  main_show_view.getView().layout(left, 0, left + screen_w, screen_h); } } @Override protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) { if (move_state == MOVE_TO_REST) {  if (now_state == MAIN) {  int w = (int) (screen_w * WIDTH_RATE);//留下預定的寬度，顯示各個view的參數設置。  main_show_view.getView().layout(0, 0, screen_w, screen_h);  left_show_view.getView().layout(0, 0, w, screen_h);  } else if (now_state == LEFT) {  moveToLeft(false);  } else {  } } } protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { main_show_view.getView().measure(widthMeasureSpec, heightMeasureSpec); left_show_view.getView().measure(MeasureSpec.UNSPECIFIED,//unspecified為未指定的  heightMeasureSpec); left_show_view.setWidth((int) (screen_w * WIDTH_RATE));//設置view寬度 super.onMeasure(widthMeasureSpec, heightMeasureSpec);//調用父類的構造函數 } private int start_x; private int start_y; private boolean isMoved; public boolean dispatchTouchEvent(MotionEvent ev) {//分發觸摸消息事件 if (isAimationMoving) {  return super.dispatchTouchEvent(ev); } else {  int action = ev.getAction();  float x = ev.getX();  float y = ev.getY();  switch (action) {  case MotionEvent.ACTION_DOWN:  super.dispatchTouchEvent(ev);  start_y = (int) y;  move_x_v = 0;  if (this.touch_state == TOUCH_STATE_REST) {   this.touch_state = TOUCH_STATE_MOVING;   start_x = (int) x;   isMoved = false;   move_state = MOVE_TO_REST;  }  break;  case MotionEvent.ACTION_MOVE:  int last_y = (int) y;  int last_x = (int) x;  super.dispatchTouchEvent(ev);  if (!isMoved) {   if (Math.abs(last_y - start_y) > Math.abs(last_x - start_x)) {//如果Y上面移動的距離大于X上面移動的距離。   super.onTouchEvent(ev);   return true;   } else {//X移動距離大于Y   if (Math.abs(last_x - start_x) > 5) {//X移動距離大于5就被認為移動了    isMoved = true;   }   }  }  if (isMoved) {   if (this.touch_state == TOUCH_STATE_MOVING) {   if (Math.abs(last_x - start_x) > 10) {//如果移動的X距離大于10    int left = main_show_view.getView().getLeft();    Log.d("msg", "left:" + left);    Log.d("msg", "x:" + last_x);    isMoved = true;    int move_x = last_x - start_x;    if (move_x > 0 && now_state == LEFT) {//方向正確的移動才算是移動的狀態    isMoved = false;    break;    }    if (move_x < 0 && now_state == RIGHT) {//如果現在在顯示右邊，那么再向右移就不反應。    isMoved = false;    break;    }    if (move_x < 0 && now_state ==MAIN){//如果現在在主屏，向右移動也是無效的    isMoved = false;    break;    }    if (move_x > 234 && now_state ==MAIN){    isMoved = true;//設置為true那么移動還是發生了，break之后還是會在ACTIONUP中起作用    break;//break之后不會執行下面的move()語句,    }    if (move_x < -234 && now_state ==LEFT){    isMoved = true;    break;    }    move(move_x);//以移動的距離為參數調用move（）實現移動的動態顯示   }   }   return false;  }  break;  case MotionEvent.ACTION_UP://  if (this.touch_state == TOUCH_STATE_MOVING) {   if (isMoved) {   last_x = (int) x;   if (Math.abs(last_x - start_x) > min_distance) {//    if (now_state == MAIN) {    if (move_state == MOVE_TO_LEFT) {     this.moveToLeft(false);    }    } else {    this.moveToMain(false);    }   } else {  //    if (now_state == MAIN) {    this.moveToMain(false);    }    if (now_state == LEFT) {    this.moveToLeft(false);    }    if (now_state == RIGHT) {    //this.moveToRight(false);    }   }   move_state = MOVE_TO_REST;   }  else {   super.dispatchTouchEvent(ev);   this.touch_state = TOUCH_STATE_REST;   return false;//   }  }  super.onTouchEvent(ev);  this.touch_state = TOUCH_STATE_REST;  break;  }  return true; } } public boolean getIsMoved() { return isMoved; } public void moveToLeft(boolean b) { if (!b) {  int move_x = (int) (screen_w * WIDTH_RATE);  left_show_view.getView().layout(0, 0, screen_w, screen_h);  //right_show_view.getView().layout(move_x, 0, move_x * 2, screen_h);  main_show_view.getView().layout(move_x, 0, move_x + screen_w,   screen_h);  now_state = LEFT;//為什么現在又把now_state賦值為left？ }//  else {//else以及括號中的語句都是為原來的按鈕準備的。。。//  mHandler.postDelayed(new Runnable() {//一個新的可運行的函數////  @Override//  public void run() {//   int move_change = (int) (screen_w * WIDTH_RATE / 5);//五分之一要顯示的寬度//   int left = (int) (screen_w * WIDTH_RATE - main_show_view//    .getView().getLeft());//getleft()返回的是主屏左邊緣離左邊的距離//   Message msg = new Message();//   if (left > move_change) {//括號里面不懂，起什么作用？//   msg.what = 1;//   mHandler.sendMessage(msg);//   mHandler.postDelayed(this, 10);//又調用自己，基本上非要是小于關系//   } else {//   msg.what = 11;//   mHandler.sendMessage(msg);//   mHandler.removeCallbacks(this);//   }//  }//  }, 0);// } } public void moveToMain(boolean b) { if (!b) {  //right_show_view.getView().setVisibility(View.VISIBLE);  left_show_view.getView().setVisibility(View.VISIBLE);  int w = (int) (screen_w * WIDTH_RATE);  main_show_view.getView().layout(0, 0, screen_w, screen_h);  left_show_view.getView().layout(0, 0, w, screen_h);  now_state = MAIN; } } public void initScreenSize(int w, int h) { this.screen_w = w; this.screen_h = h; Log.d("screen", "screen_w:" + w); this.setKeepScreenOn(true); min_distance = (int) (screen_w / 12.0);//min_distance在這里又被初始化為屏幕的一個比例大小 initView(); initContent(); moveToMain(false); } public int getNowState() { return this.now_state; }}