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Android: 仿Launcher Workspace左右滑动控件

作者:zmyde2010  发布日期:2011-10-27 19:02:56
Tag标签:  Launcher  Workspace  左右滑动控件  
  • 修改Launcher的Workspace,去掉Drag相关的操作,精简为一个支持左右滑动的控件

    每屏中可以自由放置layout

     

    主要的问题是对

        @Override
        public boolean dispathTouchEvent(MotionEvent ev) {}

        @Override
        public boolean onInterceptTouchEvent(MotionEvent ev) {}

        @Override
        public boolean onTouchEvent(MotionEvent ev) {}

    的理解,不然不好控制touch事件

    代码贴上,其实没啥参考价值:

     

    <?xml version="1.0" encoding="utf-8"?>
    
        
        <com.mylauncher.Workspace	
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:launcher="http://schemas.android.com/apk/res/com.mylauncher"    
            android:id="@+id/workspace"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scrollbars="horizontal"
            android:fadeScrollbars="true"
            launcher:defaultScreen="0">
            
            <com.mylauncher.CellLayout	android:background="#ff0000ff"
            	android:id="@+id/cell1"
    	        android:layout_width="match_parent"
    	        android:layout_height="match_parent"    
    	        android:orientation="vertical"    	
            	>
                <TextView	
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"   	        
    	        android:text="@string/screen1" />
                <Button		
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"  	        
    	        android:text="@string/screen1" /> 	        
    	        
            </com.mylauncher.CellLayout>
            
            <com.mylauncher.CellLayout	android:background="#ffff0000"
            	android:id="@+id/cell2"
    	        android:layout_width="match_parent"
    	        android:layout_height="match_parent"  
    	        android:orientation="vertical"      	
            	>
                <TextView	
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"  	        
    	        android:text="@string/screen2" />     
                <Button		 
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"  	        
    	        android:text="@string/screen2" />  	 	               
            </com.mylauncher.CellLayout>    
            
            <com.mylauncher.CellLayout	android:background="#ff00ff00"
            	android:id="@+id/cell3"
    	        android:layout_width="match_parent"
    	        android:layout_height="match_parent"   
    	        android:orientation="vertical"     	
            	>
                <TextView	
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"  	        
    	        android:text="@string/screen3" />      
                <Button		 
    	        android:layout_width="fill_parent"
    	        android:layout_height="wrap_content"
    	    	android:textSize="30sp"			    		
    	    	android:textStyle="bold"  	        
    	        android:text="@string/screen3" />  	              
            </com.mylauncher.CellLayout>              
            
        </com.mylauncher.Workspace>
    package com.mylauncher;
    
    import android.app.WallpaperManager;
    import android.content.Context;
    import android.content.res.TypedArray;
    import android.graphics.Canvas;
    import android.graphics.Rect;
    import android.graphics.drawable.Drawable;
    import android.os.IBinder;
    import android.os.Parcel;
    import android.os.Parcelable;
    import android.util.AttributeSet;
    import android.util.Log;
    import android.view.MotionEvent;
    import android.view.VelocityTracker;
    import android.view.View;
    import android.view.ViewConfiguration;
    import android.view.ViewGroup;
    import android.view.ViewParent;
    import android.view.animation.Interpolator;
    import android.widget.Scroller;
    
    /**
     * The workspace is a wide area with a wallpaper and a finite number of screens. Each
     * screen contains a number of icons, folders or widgets the user can interact with.
     * A workspace is meant to be used with a fixed width only.
     */
    public class Workspace extends ViewGroup {
        @SuppressWarnings({"UnusedDeclaration"})
        private static final String TAG = "MyLauncher.Workspace";
        private static final int INVALID_SCREEN = -1;
        
        /**
         * The velocity at which a fling gesture will cause us to snap to the next screen
         */
        private static final int SNAP_VELOCITY = 600;
    
        private final WallpaperManager mWallpaperManager;
        
        private int mDefaultScreen;
    
        private boolean mFirstLayout = true;
    
        private int mCurrentScreen;
        private int mNextScreen = INVALID_SCREEN;
        private Scroller mScroller;
        private VelocityTracker mVelocityTracker;
    
    
        
        /**
         * Target drop area calculated during last acceptDrop call.
         */
        private int[] mTargetCell = null;
    
        private float mLastMotionX;
        private float mLastMotionY;
        
        private final static int TOUCH_STATE_REST = 0;
        private final static int TOUCH_STATE_SCROLLING = 1;
    
        private int mTouchState = TOUCH_STATE_REST;
    
        private OnLongClickListener mLongClickListener;
    
    
        
    
        
        private int[] mTempCell = new int[2];
        private int[] mTempEstimate = new int[2];
    
        private boolean mAllowLongPress = true;
    
        private int mTouchSlop;
        private int mMaximumVelocity;
        
        private static final int INVALID_POINTER = -1;
    
        private int mActivePointerId = INVALID_POINTER;
        
        private Drawable mPreviousIndicator;
        private Drawable mNextIndicator;
        
        private static final float NANOTIME_DIV = 1000000000.0f;
        private static final float SMOOTHING_SPEED = 0.75f;
        private static final float SMOOTHING_CONSTANT = (float) (0.016 / Math.log(SMOOTHING_SPEED));
        private float mSmoothingTime;
        private float mTouchX;
    
        private WorkspaceOvershootInterpolator mScrollInterpolator;
    
        private static final float BASELINE_FLING_VELOCITY = 2500.f;
        private static final float FLING_VELOCITY_INFLUENCE = 0.4f;
        
        private static class WorkspaceOvershootInterpolator implements Interpolator {
            private static final float DEFAULT_TENSION = 1.3f;
            private float mTension;
    
            public WorkspaceOvershootInterpolator() {
                mTension = DEFAULT_TENSION;
            }
            
            public void setDistance(int distance) {
                mTension = distance > 0 ? DEFAULT_TENSION / distance : DEFAULT_TENSION;
            }
    
            public void disableSettle() {
                mTension = 0.f;
            }
    
            public float getInterpolation(float t) {
                // _o(t) = t * t * ((tension + 1) * t + tension)
                // o(t) = _o(t - 1) + 1
                t -= 1.0f;
                return t * t * ((mTension + 1) * t + mTension) + 1.0f;
            }
        }
        
        /**
         * Used to inflate the Workspace from XML.
         *
         * @param context The application's context.
         * @param attrs The attribtues set containing the Workspace's customization values.
         */
        public Workspace(Context context, AttributeSet attrs) {
            this(context, attrs, 0);
        }
    
        /**
         * Used to inflate the Workspace from XML.
         *
         * @param context The application's context.
         * @param attrs The attribtues set containing the Workspace's customization values.
         * @param defStyle Unused.
         */
        public Workspace(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
    
            mWallpaperManager = WallpaperManager.getInstance(context);
            
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Workspace, defStyle, 0);
            mDefaultScreen = a.getInt(R.styleable.Workspace_defaultScreen, 1);
            a.recycle();
    
            setHapticFeedbackEnabled(false);
            initWorkspace();
        }
    
        /**
         * Initializes various states for this workspace.
         */
        private void initWorkspace() {
            Context context = getContext();
            mScrollInterpolator = new WorkspaceOvershootInterpolator();
            mScroller = new Scroller(context, mScrollInterpolator);
            mCurrentScreen = mDefaultScreen;
    
    
            final ViewConfiguration configuration = ViewConfiguration.get(getContext());
            mTouchSlop = configuration.getScaledTouchSlop();
            mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
        }
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
        boolean isDefaultScreenShowing() {
            return mCurrentScreen == mDefaultScreen;
        }
    
        /**
         * Returns the index of the currently displayed screen.
         *
         * @return The index of the currently displayed screen.
         */
        int getCurrentScreen() {
            return mCurrentScreen;
        }
    
        /**
         * Sets the current screen.
         *
         * @param currentScreen
         */
        void setCurrentScreen(int currentScreen) {
            if (!mScroller.isFinished()) mScroller.abortAnimation();
            
            mCurrentScreen = Math.max(0, Math.min(currentScreen, getChildCount() - 1));
            //mPreviousIndicator.setLevel(mCurrentScreen);
            //mNextIndicator.setLevel(mCurrentScreen);
            scrollTo(mCurrentScreen * getWidth(), 0);
    
            invalidate();
        }
    
    
    
    
        /**
         * Registers the specified listener on each screen contained in this workspace.
         *
         * @param l The listener used to respond to long clicks.
         */
        @Override
        public void setOnLongClickListener(OnLongClickListener l) {
            mLongClickListener = l;
            final int count = getChildCount();
            for (int i = 0; i < count; i++) {
                getChildAt(i).setOnLongClickListener(l);
            }
        }
    
    
    
        private void updateWallpaperOffset(int scrollRange) {
            IBinder token = getWindowToken();
            if (token != null) {
                mWallpaperManager.setWallpaperOffsetSteps(1.0f / (getChildCount() - 1), 0 );
                mWallpaperManager.setWallpaperOffsets(getWindowToken(),
                        Math.max(0.f, Math.min(mScrollX/(float)scrollRange, 1.f)), 0);
            }
        }
        
        @Override
        public void scrollTo(int x, int y) {
            super.scrollTo(x, y);
            mTouchX = x;
            mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
        }
        
        @Override
        public void computeScroll() {
            if (mScroller.computeScrollOffset()) {
                mTouchX = mScrollX = mScroller.getCurrX();
                mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                mScrollY = mScroller.getCurrY();
                
                postInvalidate();
            } else if (mNextScreen != INVALID_SCREEN) {
                mCurrentScreen = Math.max(0, Math.min(mNextScreen, getChildCount() - 1));
                //mPreviousIndicator.setLevel(mCurrentScreen);
                //mNextIndicator.setLevel(mCurrentScreen);
    
                mNextScreen = INVALID_SCREEN;
                //clearChildrenCache();
            } else if (mTouchState == TOUCH_STATE_SCROLLING) {
                final float now = System.nanoTime() / NANOTIME_DIV;
                final float e = (float) Math.exp((now - mSmoothingTime) / SMOOTHING_CONSTANT);
                final float dx = mTouchX - mScrollX;
                mScrollX += dx * e;
                mSmoothingTime = now;
    
                // Keep generating points as long as we're more than 1px away from the target
                if (dx > 1.f || dx < -1.f) {
                    
                    postInvalidate();
                }
            }
        }
    
        @Override
        protected void dispatchDraw(Canvas canvas) {
            boolean restore = false;
            int restoreCount = 0;
    
            // ViewGroup.dispatchDraw() supports many features we don't need:
            // clip to padding, layout animation, animation listener, disappearing
            // children, etc. The following implementation attempts to fast-track
            // the drawing dispatch by drawing only what we know needs to be drawn.
    
            boolean fastDraw = mTouchState != TOUCH_STATE_SCROLLING && mNextScreen == INVALID_SCREEN;
            // If we are not scrolling or flinging, draw only the current screen
            if (fastDraw) {
                drawChild(canvas, getChildAt(mCurrentScreen), getDrawingTime());
            } else {
                final long drawingTime = getDrawingTime();
                final float scrollPos = (float) mScrollX / getWidth();
                final int leftScreen = (int) scrollPos;
                final int rightScreen = leftScreen + 1;
                if (leftScreen >= 0) {
                    drawChild(canvas, getChildAt(leftScreen), drawingTime);
                }
                if (scrollPos != leftScreen && rightScreen < getChildCount()) {
                    drawChild(canvas, getChildAt(rightScreen), drawingTime);
                }
            }
    
            if (restore) {
                canvas.restoreToCount(restoreCount);
            }
        }
    
        protected void onAttachedToWindow() {
            super.onAttachedToWindow();
            computeScroll();
    
        }
    
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    
            final int width = MeasureSpec.getSize(widthMeasureSpec);
            final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
            if (widthMode != MeasureSpec.EXACTLY) {
                throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
            }
    
            final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
            if (heightMode != MeasureSpec.EXACTLY) {
                throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
            }
    
            // The children are given the same width and height as the workspace
            final int count = getChildCount();
            for (int i = 0; i < count; i++) {
                getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
            }
    
    
            if (mFirstLayout) {
                setHorizontalScrollBarEnabled(false);
                scrollTo(mCurrentScreen * width, 0);
                setHorizontalScrollBarEnabled(true);
                updateWallpaperOffset(width * (getChildCount() - 1));
                mFirstLayout = false;
            }
        }
    
        @Override
        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
            int childLeft = 0;
    
            final int count = getChildCount();
            for (int i = 0; i < count; i++) {
                final View child = getChildAt(i);
                if (child.getVisibility() != View.GONE) {
                    final int childWidth = child.getMeasuredWidth();
                    child.layout(childLeft, 0, childLeft + childWidth, child.getMeasuredHeight());
                    childLeft += childWidth;
                }
            }
        }
    
        @Override
        public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
            int screen = indexOfChild(child);
            if (screen != mCurrentScreen || !mScroller.isFinished()) {
                snapToScreen(screen);
                return true;
            }
            return false;
        }
    
    
    
    
        @Override
        public boolean dispatchUnhandledMove(View focused, int direction) {
            if (direction == View.FOCUS_LEFT) {
                if (getCurrentScreen() > 0) {
                    snapToScreen(getCurrentScreen() - 1);
                    return true;
                }
            } else if (direction == View.FOCUS_RIGHT) {
                if (getCurrentScreen() < getChildCount() - 1) {
                    snapToScreen(getCurrentScreen() + 1);
                    return true;
                }
            }
            return super.dispatchUnhandledMove(focused, direction);
        }
    
    
    
    
        @Override
        public boolean onInterceptTouchEvent(MotionEvent ev) {
    
    
            /*
             * This method JUST determines whether we want to intercept the motion.
             * If we return true, onTouchEvent will be called and we do the actual
             * scrolling there.
             */
    
            /*
             * Shortcut the most recurring case: the user is in the dragging
             * state and he is moving his finger.  We want to intercept this
             * motion.
             */
             
            final int action = ev.getAction();
                   
            
            Log.d(TAG, "onInterceptTouchEvent, action: " + action + " mTouchState: " + mTouchState);
            
            if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST)) {
            	Log.d(TAG, "onInterceptTouchEvent, MotionEvent.ACTION_MOVE mTouchState: " + mTouchState);
                return true;
            }
    
            acquireVelocityTrackerAndAddMovement(ev);
            
            switch (action & MotionEvent.ACTION_MASK) {
                case MotionEvent.ACTION_MOVE: {
                	Log.d(TAG, "onInterceptTouchEvent.ACTION_MOVE.................");
                    /*
                     * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
                     * whether the user has moved far enough from his original down touch.
                     */
    
                    /*
                     * Locally do absolute value. mLastMotionX is set to the y value
                     * of the down event.
                     */
                    final int pointerIndex = ev.findPointerIndex(mActivePointerId);
                    final float x = ev.getX(pointerIndex);
                    final float y = ev.getY(pointerIndex);
                    final int xDiff = (int) Math.abs(x - mLastMotionX);
                    final int yDiff = (int) Math.abs(y - mLastMotionY);
    
                    final int touchSlop = mTouchSlop;
                    boolean xMoved = xDiff > touchSlop;
                    boolean yMoved = yDiff > touchSlop;
                    
                    if (xMoved || yMoved) {
                        
                        if (xMoved) {
                        	Log.d(TAG, "onInterceptTouchEvent.ACTION_MOVE.TOUCH_STATE_SCROLLING................");
                            // Scroll if the user moved far enough along the X axis
                            mTouchState = TOUCH_STATE_SCROLLING;
                            mLastMotionX = x;
                            mTouchX = getScrollX();
                            mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                            //enableChildrenCache(mCurrentScreen - 1, mCurrentScreen + 1);
                        }
                        // Either way, cancel any pending longpress
                        if (mAllowLongPress) {
                            mAllowLongPress = false;
                            // Try canceling the long press. It could also have been scheduled
                            // by a distant descendant, so use the mAllowLongPress flag to block
                            // everything
                            final View currentScreen = getChildAt(mCurrentScreen);
                            currentScreen.cancelLongPress();
                        }
                    }
                    break;
                }
    
                case MotionEvent.ACTION_DOWN: {
                	Log.d(TAG, "onInterceptTouchEvent.ACTION_DOWN.................");
                    final float x = ev.getX();
                    final float y = ev.getY();
                    // Remember location of down touch
                    mLastMotionX = x;
                    mLastMotionY = y;
                    mActivePointerId = ev.getPointerId(0);
                    mAllowLongPress = true;
    
                    /*
                     * If being flinged and user touches the screen, initiate drag;
                     * otherwise don't.  mScroller.isFinished should be false when
                     * being flinged.
                     */
                    Log.d(TAG, "mScroller.isFinished()................." + mScroller.isFinished());
                    mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING;
                    break;
                }
    
                case MotionEvent.ACTION_CANCEL:
                case MotionEvent.ACTION_UP:
                    Log.d(TAG, "onInterceptTouchEvent.ACTION_UP.................");
    
                    
                    // Release the drag
                    //clearChildrenCache();
                    mTouchState = TOUCH_STATE_REST;
                    mActivePointerId = INVALID_POINTER;
                    mAllowLongPress = false;
                    releaseVelocityTracker();
                    break;
                    
                case MotionEvent.ACTION_POINTER_UP:
    				Log.d(TAG, "onInterceptTouchEvent.ACTION_POINTER_UP.................");
                    onSecondaryPointerUp(ev);
                    break;
            }
    
            /*
             * The only time we want to intercept motion events is if we are in the
             * drag mode.
             */
            Log.d(TAG, "onInterceptTouchEvent.mTouchState != TOUCH_STATE_REST................." + (mTouchState != TOUCH_STATE_REST));  
            return mTouchState != TOUCH_STATE_REST;
        }
        
        private void onSecondaryPointerUp(MotionEvent ev) {
            final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
                    MotionEvent.ACTION_POINTER_INDEX_SHIFT;
            final int pointerId = ev.getPointerId(pointerIndex);
            if (pointerId == mActivePointerId) {
                // This was our active pointer going up. Choose a new
                // active pointer and adjust accordingly.
                // TODO: Make this decision more intelligent.
                final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                mLastMotionX = ev.getX(newPointerIndex);
                mLastMotionY = ev.getY(newPointerIndex);
                mActivePointerId = ev.getPointerId(newPointerIndex);
                if (mVelocityTracker != null) {
                    mVelocityTracker.clear();
                }
            }
        }
    
        /**
         * If one of our descendant views decides that it could be focused now, only
         * pass that along if it's on the current screen.
         *
         * This happens when live folders requery, and if they're off screen, they
         * end up calling requestFocus, which pulls it on screen.
         */
        @Override
        public void focusableViewAvailable(View focused) {
            View current = getChildAt(mCurrentScreen);
            View v = focused;
            while (true) {
                if (v == current) {
                    super.focusableViewAvailable(focused);
                    return;
                }
                if (v == this) {
                    return;
                }
                ViewParent parent = v.getParent();
                if (parent instanceof View) {
                    v = (View)v.getParent();
                } else {
                    return;
                }
            }
        }
    
    
    
    
        @Override
        public boolean onTouchEvent(MotionEvent ev) {
            
    
    
            acquireVelocityTrackerAndAddMovement(ev);
    
            final int action = ev.getAction();
    
            switch (action & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
            	Log.d(TAG, "onTouchEvent.ACTION_DOWN.................");
                /*
                 * If being flinged and user touches, stop the fling. isFinished
                 * will be false if being flinged.
                 */
                if (!mScroller.isFinished()) {
                    mScroller.abortAnimation();
                }
    
                // Remember where the motion event started
                mLastMotionX = ev.getX();
                mActivePointerId = ev.getPointerId(0);
                if (mTouchState == TOUCH_STATE_SCROLLING) {
                    //enableChildrenCache(mCurrentScreen - 1, mCurrentScreen + 1);
                }
                break;
            case MotionEvent.ACTION_MOVE:
            	Log.d(TAG, "onTouchEvent.ACTION_MOVE.................");
                if (mTouchState == TOUCH_STATE_SCROLLING) {
                	Log.d(TAG, "onTouchEvent.ACTION_MOVE.TOUCH_STATE_SCROLLING................");
                    // Scroll to follow the motion event
                    final int pointerIndex = ev.findPointerIndex(mActivePointerId);
                    final float x = ev.getX(pointerIndex);
                    final float deltaX = mLastMotionX - x;
                    mLastMotionX = x;
    
                    if (deltaX < 0) {
                        if (mTouchX > 0) {
                            mTouchX += Math.max(-mTouchX, deltaX);
                            mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                            invalidate();
                        }
                    } else if (deltaX > 0) {
                        final float availableToScroll = getChildAt(getChildCount() - 1).getRight() -
                                mTouchX - getWidth();
                        if (availableToScroll > 0) {
                            mTouchX += Math.min(availableToScroll, deltaX);
                            mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                            invalidate();
                        }
                    } else {
                        awakenScrollBars();
                    }
                }
                break;
            case MotionEvent.ACTION_UP:
            	Log.d(TAG, "onTouchEvent.ACTION_UP.................");
                if (mTouchState == TOUCH_STATE_SCROLLING) {
                    final VelocityTracker velocityTracker = mVelocityTracker;
                    velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                    final int velocityX = (int) velocityTracker.getXVelocity(mActivePointerId);
                    
                    final int screenWidth = getWidth();
                    final int whichScreen = (getScrollX() + (screenWidth / 2)) / screenWidth;
                    final float scrolledPos = (float) getScrollX() / screenWidth;
                    
                    if (velocityX > SNAP_VELOCITY && mCurrentScreen > 0) {
                        // Fling hard enough to move left.
                        // Don't fling across more than one screen at a time.
                        final int bound = scrolledPos < whichScreen ?
                                mCurrentScreen - 1 : mCurrentScreen;
                        snapToScreen(Math.min(whichScreen, bound), velocityX, true);
                    } else if (velocityX < -SNAP_VELOCITY && mCurrentScreen < getChildCount() - 1) {
                        // Fling hard enough to move right
                        // Don't fling across more than one screen at a time.
                        final int bound = scrolledPos > whichScreen ?
                                mCurrentScreen + 1 : mCurrentScreen;
                        snapToScreen(Math.max(whichScreen, bound), velocityX, true);
                    } else {
                        snapToScreen(whichScreen, 0, true);
                    }
                }
                mTouchState = TOUCH_STATE_REST;
                mActivePointerId = INVALID_POINTER;
                releaseVelocityTracker();
                break;
            case MotionEvent.ACTION_CANCEL:
                if (mTouchState == TOUCH_STATE_SCROLLING) {
                    final int screenWidth = getWidth();
                    final int whichScreen = (getScrollX() + (screenWidth / 2)) / screenWidth;
                    snapToScreen(whichScreen, 0, true);
                }
                mTouchState = TOUCH_STATE_REST;
                mActivePointerId = INVALID_POINTER;
                releaseVelocityTracker();
                break;
            case MotionEvent.ACTION_POINTER_UP:
            	Log.d(TAG, "onTouchEvent.ACTION_POINTER_UP.................");
                onSecondaryPointerUp(ev);
                break;
            }
    
            return true;
        }
        
        private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
            if (mVelocityTracker == null) {
                mVelocityTracker = VelocityTracker.obtain();
            }
            mVelocityTracker.addMovement(ev);
        }
    
        private void releaseVelocityTracker() {
            if (mVelocityTracker != null) {
                mVelocityTracker.recycle();
                mVelocityTracker = null;
            }
        }
    
        void snapToScreen(int whichScreen) {
            snapToScreen(whichScreen, 0, false);
        }
    
        private void snapToScreen(int whichScreen, int velocity, boolean settle) {
            //if (!mScroller.isFinished()) return;
    
            whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
            
    
            //enableChildrenCache(mCurrentScreen, whichScreen);
    
            mNextScreen = whichScreen;
    
            //mPreviousIndicator.setLevel(mNextScreen);
            //mNextIndicator.setLevel(mNextScreen);
    
            View focusedChild = getFocusedChild();
            if (focusedChild != null && whichScreen != mCurrentScreen &&
                    focusedChild == getChildAt(mCurrentScreen)) {
                focusedChild.clearFocus();
            }
            
            final int screenDelta = Math.max(1, Math.abs(whichScreen - mCurrentScreen));
            final int newX = whichScreen * getWidth();
            final int delta = newX - mScrollX;
            int duration = (screenDelta + 1) * 100;
    
            if (!mScroller.isFinished()) {
                mScroller.abortAnimation();
            }
            
            if (settle) {
                mScrollInterpolator.setDistance(screenDelta);
            } else {
                mScrollInterpolator.disableSettle();
            }
            
            velocity = Math.abs(velocity);
            if (velocity > 0) {
                duration += (duration / (velocity / BASELINE_FLING_VELOCITY))
                        * FLING_VELOCITY_INFLUENCE;
            } else {
                duration += 100;
            }
    
            awakenScrollBars(duration);
            mScroller.startScroll(mScrollX, 0, delta, 0, duration);
            invalidate();
        }
    
    
    
        @Override
        protected Parcelable onSaveInstanceState() {
            final SavedState state = new SavedState(super.onSaveInstanceState());
            state.currentScreen = mCurrentScreen;
            return state;
        }
    
        @Override
        protected void onRestoreInstanceState(Parcelable state) {
            SavedState savedState = (SavedState) state;
            super.onRestoreInstanceState(savedState.getSuperState());
            if (savedState.currentScreen != -1) {
                mCurrentScreen = savedState.currentScreen;
    
            }
        }
    
    
        public void scrollLeft() {
        	Log.d(TAG, "scrollLeft.................");
           
            if (mScroller.isFinished()) {
                if (mCurrentScreen > 0) snapToScreen(mCurrentScreen - 1);
            } else {
                if (mNextScreen > 0) snapToScreen(mNextScreen - 1);            
            }
        }
    
        public void scrollRight() {
        	Log.d(TAG, "scrollRight.................");
    
            if (mScroller.isFinished()) {
                if (mCurrentScreen < getChildCount() -1) snapToScreen(mCurrentScreen + 1);
            } else {
                if (mNextScreen < getChildCount() -1) snapToScreen(mNextScreen + 1);            
            }
        }
    
        public int getScreenForView(View v) {
            int result = -1;
            if (v != null) {
                ViewParent vp = v.getParent();
                int count = getChildCount();
                for (int i = 0; i < count; i++) {
                    if (vp == getChildAt(i)) {
                        return i;
                    }
                }
            }
            return result;
        }
    
    
        /**
         * @return True is long presses are still allowed for the current touch
         */
        public boolean allowLongPress() {
            return mAllowLongPress;
        }
        
        /**
         * Set true to allow long-press events to be triggered, usually checked by
         * {@link Launcher} to accept or block dpad-initiated long-presses.
         */
        public void setAllowLongPress(boolean allowLongPress) {
            mAllowLongPress = allowLongPress;
        }
    
       
    
        void moveToDefaultScreen(boolean animate) {
            if (animate) {
                snapToScreen(mDefaultScreen);
            } else {
                setCurrentScreen(mDefaultScreen);
            }
            getChildAt(mDefaultScreen).requestFocus();
        }
    
    //    void setIndicators(Drawable previous, Drawable next) {
    //        mPreviousIndicator = previous;
    //        mNextIndicator = next;
    //        previous.setLevel(mCurrentScreen);
    //        next.setLevel(mCurrentScreen);
    //    }
    
        public static class SavedState extends BaseSavedState {
            int currentScreen = -1;
    
            SavedState(Parcelable superState) {
                super(superState);
            }
    
            private SavedState(Parcel in) {
                super(in);
                currentScreen = in.readInt();
            }
    
            @Override
            public void writeToParcel(Parcel out, int flags) {
                super.writeToParcel(out, flags);
                out.writeInt(currentScreen);
            }
    
            public static final Parcelable.Creator<SavedState> CREATOR =
                    new Parcelable.Creator<SavedState>() {
                public SavedState createFromParcel(Parcel in) {
                    return new SavedState(in);
                }
    
                public SavedState[] newArray(int size) {
                    return new SavedState[size];
                }
            };
        }
    }
    package com.mylauncher;
    
    import android.content.Context;
    import android.util.AttributeSet;
    import android.view.View;
    import android.widget.LinearLayout;
    import android.view.MotionEvent;
    import android.util.Log;
    
    public class CellLayout extends LinearLayout {
    	private static final String TAG = "MyLauncher.CellLayout";
        public CellLayout(Context context, AttributeSet attrs) {
    		super(context, attrs);
    		// TODO Auto-generated constructor stub
    	}
    
        @Override
        public boolean onInterceptTouchEvent(MotionEvent ev) {
        	Log.d(TAG, "onInterceptTouchEvent, action=" + ev.getAction());
        	return true;
        }
        
        @Override
        public boolean onTouchEvent(MotionEvent ev) {
        	Log.d(TAG, "onTouchEvent, action=" + ev.getAction());
        	return true;
        }    
        
    }
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