高仿launcher和墨迹左右拖动效果

来源:互联网 发布:手机制作淘宝图片软件 编辑:程序博客网 时间:2024/05/02 01:25

           半个月前就有这样的想法,做出一个模仿launcher的效果。自己也曾从网上搜过很多资料,也思考过怎么实现,最终还是参考了别人的资料实现了此效果,也解决了我这半个多月的冥思苦想,再次感谢,今天把代码贴出来供大家学习,因为这方面做得比较好的资料缺失比较少(因为本人搜了很多资料都不能达到效果),如果大家觉得还不错,请顶起。

       

            首先自定义一个 ViewGroup:

 

public class MyScrollLayout extends ViewGroup{    private VelocityTracker mVelocityTracker;  // 用于判断甩动手势        private static final int SNAP_VELOCITY = 600;            private Scroller  mScroller;// 滑动控制器    private int mCurScreen;        private int mDefaultScreen = 0;         private float mLastMotionX;        //   private int mTouchSlop;       private OnViewChangeListener mOnViewChangeListener; public MyScrollLayout(Context context) {super(context);// TODO Auto-generated constructor stubinit(context);}public MyScrollLayout(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stubinit(context);}public MyScrollLayout(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stubinit(context);}private void init(Context context){mCurScreen = mDefaultScreen;       //   mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();                mScroller = new Scroller(context);     }@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {// TODO Auto-generated method stub if (changed) {                int childLeft = 0;                final int childCount = getChildCount();                                for (int i=0; i<childCount; i++) {                    final View childView = getChildAt(i);                    if (childView.getVisibility() != View.GONE) {                        final int childWidth = childView.getMeasuredWidth();                        childView.layout(childLeft, 0,                                 childLeft+childWidth, childView.getMeasuredHeight());                        childLeft += childWidth;                    }                }            }    }@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// TODO Auto-generated method stubsuper.onMeasure(widthMeasureSpec, heightMeasureSpec);final int width = MeasureSpec.getSize(widthMeasureSpec);           final int widthMode = MeasureSpec.getMode(widthMeasureSpec);          final int count = getChildCount();               for (int i = 0; i < count; i++) {                   getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);               }                        scrollTo(mCurScreen * width, 0);} public void snapToDestination() {            final int screenWidth = getWidth();            final int destScreen = (getScrollX()+ screenWidth/2)/screenWidth;            snapToScreen(destScreen);     }   public void snapToScreen(int whichScreen) {            // get the valid layout page            whichScreen = Math.max(0, Math.min(whichScreen, getChildCount()-1));            if (getScrollX() != (whichScreen*getWidth())) {                                final int delta = whichScreen*getWidth()-getScrollX();                      mScroller.startScroll(getScrollX(), 0,                         delta, 0, Math.abs(delta)*2);                        mCurScreen = whichScreen;                invalidate();       // Redraw the layout                            if (mOnViewChangeListener != null)            {            mOnViewChangeListener.OnViewChange(mCurScreen);            }        }        }    @Overridepublic void computeScroll() {// TODO Auto-generated method stubif (mScroller.computeScrollOffset()) {                scrollTo(mScroller.getCurrX(), mScroller.getCurrY());              postInvalidate();            }   }@Overridepublic boolean onTouchEvent(MotionEvent event) {// TODO Auto-generated method stub                               final int action = event.getAction();            final float x = event.getX();            final float y = event.getY();                        switch (action) {            case MotionEvent.ACTION_DOWN:                   Log.i("", "onTouchEvent  ACTION_DOWN");                  if (mVelocityTracker == null) {                mVelocityTracker = VelocityTracker.obtain();                mVelocityTracker.addMovement(event);     }                     if (!mScroller.isFinished()){                    mScroller.abortAnimation();                }                            mLastMotionX = x;                       break;                            case MotionEvent.ACTION_MOVE:             int deltaX = (int)(mLastMotionX - x);                      if (IsCanMove(deltaX))           {         if (mVelocityTracker != null)           {              mVelocityTracker.addMovement(event);            }                 mLastMotionX = x;                   scrollBy(deltaX, 0);           }                    break;                            case MotionEvent.ACTION_UP:                       int velocityX = 0;            if (mVelocityTracker != null)            {            mVelocityTracker.addMovement(event);             mVelocityTracker.computeCurrentVelocity(1000);              velocityX = (int) mVelocityTracker.getXVelocity();            }                                           if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {                       // Fling enough to move left                          snapToScreen(mCurScreen - 1);                   } else if (velocityX < -SNAP_VELOCITY                           && mCurScreen < getChildCount() - 1) {                       // Fling enough to move right                          snapToScreen(mCurScreen + 1);                   } else {                       snapToDestination();                   }                                          if (mVelocityTracker != null) {                       mVelocityTracker.recycle();                       mVelocityTracker = null;                   }             //      mTouchState = TOUCH_STATE_REST;            break;              }                        return true;    }private boolean IsCanMove(int deltaX){if (getScrollX() <= 0 && deltaX < 0 ){return false;}if  (getScrollX() >=  (getChildCount() - 1) * getWidth() && deltaX > 0){return false;}return true;}public void SetOnViewChangeListener(OnViewChangeListener listener){mOnViewChangeListener = listener;}}


public class SwitchViewDemoActivity extends Activity implements OnViewChangeListener, OnClickListener{    /** Called when the activity is first created. */private MyScrollLayout mScrollLayout;private ImageView[] mImageViews;private int mViewCount;private int mCurSel;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                init();            }        private void init()    {    mScrollLayout = (MyScrollLayout) findViewById(R.id.ScrollLayout);     LinearLayout linearLayout = (LinearLayout) findViewById(R.id.llayout);    //动态添加一个layout控件    LinearLayout layout=new LinearLayout(this);    layout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));    layout.setBackgroundResource(R.drawable.guide01);    mScrollLayout.addView(layout);    //动态添加一个imageView控件            ImageView imageView=new ImageView(this);    imageView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));    imageView.setPadding(15, 15, 15, 15);    imageView.setImageResource(R.drawable.guide_round);    linearLayout.addView(imageView);        mViewCount = mScrollLayout.getChildCount();    mImageViews = new ImageView[mViewCount];       for(int i = 0; i < mViewCount; i++)    {    mImageViews[i] = (ImageView) linearLayout.getChildAt(i);    mImageViews[i].setEnabled(true);    mImageViews[i].setOnClickListener(this);    mImageViews[i].setTag(i);    }        mCurSel = 0;    mImageViews[mCurSel].setEnabled(false);        mScrollLayout.SetOnViewChangeListener(this);        }    private void setCurPoint(int index)    {    if (index < 0 || index > mViewCount - 1 || mCurSel == index)    {    return ;    }        mImageViews[mCurSel].setEnabled(true);    mImageViews[index].setEnabled(false);        mCurSel = index;    }    @Overridepublic void OnViewChange(int view) {// TODO Auto-generated method stubsetCurPoint(view);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubint pos = (Integer)(v.getTag());setCurPoint(pos);mScrollLayout.snapToScreen(pos);}}

最后是布局文件 :

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent" >    <cn.com.karl.scroll.MyScrollLayout        xmlns:android="http://schemas.android.com/apk/res/android"        android:id="@+id/ScrollLayout"        android:layout_width="fill_parent"        android:layout_height="fill_parent" >        <LinearLayout            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:background="@drawable/guide01" >        </LinearLayout>        <LinearLayout            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:background="@drawable/guide02" >        </LinearLayout>        <LinearLayout            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:background="@drawable/guide03" >        </LinearLayout>        <LinearLayout            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:background="@drawable/guide04" >        </LinearLayout>        <LinearLayout            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:background="@drawable/guide05" >        </LinearLayout>    </cn.com.karl.scroll.MyScrollLayout>    <LinearLayout        android:id="@+id/llayout"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true"        android:layout_centerHorizontal="true"        android:layout_marginBottom="24.0dip"        android:orientation="horizontal" >        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center_vertical"            android:clickable="true"            android:padding="15.0dip"            android:src="@drawable/guide_round" />        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center_vertical"            android:clickable="true"            android:padding="15.0dip"            android:src="@drawable/guide_round" />        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center_vertical"            android:clickable="true"            android:padding="15.0dip"            android:src="@drawable/guide_round" />        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center_vertical"            android:clickable="true"            android:padding="15.0dip"            android:src="@drawable/guide_round" />        <ImageView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center_vertical"            android:clickable="true"            android:padding="15.0dip"            android:src="@drawable/guide_round" />    </LinearLayout></RelativeLayout>

看看运行后的效果到底怎么样吧!


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