update ui layout

[freespace.git] / weibosrc / com / weibo / view / Workspace.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.weibo.view;

import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
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.animation.Interpolator;
import android.widget.Scroller;
import android.widget.TextView;

import com.weibo.sina.TimeLineView;
import com.weibo.sina.R;

/**
 * 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 = "TimeLineView.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 Drawable mPreviousIndicator;
    private Drawable mNextIndicator;
    
    private int mDefaultScreen;

    private boolean mFirstLayout = true;

    private int mCurrentScreen;
    private int mNextScreen = INVALID_SCREEN;
    private Scroller mScroller;
    private VelocityTracker mVelocityTracker;
    private TextView mTitle;
    /**
     * CellInfo for the cell that is currently being dragged
     */
    
    /**
     * Target drop area calculated during last acceptDrop call.
     */

    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;


    public TimeLineView mLauncher;
    
    /**
     * Cache of vacant cells, used during drag events and invalidated as needed.
     */
    

    private boolean mAllowLongPress = true;

    private int mTouchSlop;
    private int mMaximumVelocity;
    
    private static final int INVALID_POINTER = -1;

    private int mActivePointerId = INVALID_POINTER;
    
    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 int[] mPages;
    private int[] mTitles;
    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);

        mDefaultScreen = 2;

        setHapticFeedbackEnabled(false);
        initWorkspace();
    }

    /**
     * Initializes various states for this workspace.
     */
    private void initWorkspace() {
        
        mPages=new int[]{R.id.page0,R.id.page1,R.id.page2,R.id.page3,R.id.page4};
        mTitles = new int[]{R.string.my_post,R.string.news,R.string.my_index,R.string.funny,R.string.my_post};
        
        Log.e(TAG,"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();
    }

 
    /**
     * Returns the index of the currently displayed screen.
     *
     * @return The index of the currently displayed screen.
     */
   public int getCurrentScreen() {
        return mCurrentScreen;
    }

 
  
  
  
    
    @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));
            mNextScreen = INVALID_SCREEN;
            //mTitle.setText(mTitles[mCurrentScreen]);
            
        } 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();
            }
        }
    }



    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);
            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()) {
           
            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 dispatchTouchEvent(MotionEvent ev) {
        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
            
        }
        return super.dispatchTouchEvent(ev);
    }

    @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();
        if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST)) {
            return true;
        }

        if (mVelocityTracker == null) {
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(ev);
        
        switch (action & MotionEvent.ACTION_MASK) {
            case MotionEvent.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) {
                        // Scroll if the user moved far enough along the X axis
                        mTouchState = TOUCH_STATE_SCROLLING;
                        mLastMotionX = x;
                        mTouchX = mScrollX;
                        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: {
                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.
                 */
                mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING;
                break;
            }

            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                
                if (mTouchState != TOUCH_STATE_SCROLLING) {
                    //final CellLayout currentScreen = (CellLayout)getChildAt(mCurrentScreen);
//                    if (!currentScreen.lastDownOnOccupiedCell()) {
//                        getLocationOnScreen(mTempCell);
//                        // Send a tap to the wallpaper if the last down was on empty space
//                        final int pointerIndex = ev.findPointerIndex(mActivePointerId);
//                        mWallpaperManager.sendWallpaperCommand(getWindowToken(), 
//                                "android.wallpaper.tap",
//                                mTempCell[0] + (int) ev.getX(pointerIndex),
//                                mTempCell[1] + (int) ev.getY(pointerIndex), 0, null);
//                    }
                }
             
                mTouchState = TOUCH_STATE_REST;
                mActivePointerId = INVALID_POINTER;
                mAllowLongPress = false;
                
                if (mVelocityTracker != null) {
                    mVelocityTracker.recycle();
                    mVelocityTracker = null;
                }

                break;
                
            case MotionEvent.ACTION_POINTER_UP:
                onSecondaryPointerUp(ev);
                break;
        }

        /*
         * The only time we want to intercept motion events is if we are in the
         * drag mode.
         */
        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 boolean onTouchEvent(MotionEvent ev) {
//        if (mLauncher.isWorkspaceLocked()) {
//            return false; // We don't want the events.  Let them fall through to the all apps view.
//        }
//       

        if (mVelocityTracker == null) {
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(ev);

        final int action = ev.getAction();

        switch (action & MotionEvent.ACTION_MASK) {
        case MotionEvent.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:
            if (mTouchState == 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();
                }
            }
            mTouchState = TOUCH_STATE_SCROLLING;
            break;
        case MotionEvent.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 = (mScrollX + (screenWidth / 2)) / screenWidth;
                final float scrolledPos = (float) mScrollX / 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);
                }

                if (mVelocityTracker != null) {
                    mVelocityTracker.recycle();
                    mVelocityTracker = null;
                }
            }
            mTouchState = TOUCH_STATE_REST;
            mActivePointerId = INVALID_POINTER;
            break;
        case MotionEvent.ACTION_CANCEL:
            mTouchState = TOUCH_STATE_REST;
            mActivePointerId = INVALID_POINTER;
            break;
        case MotionEvent.ACTION_POINTER_UP:
            onSecondaryPointerUp(ev);
            break;
        }

        return true;
    }
    
    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));
        

        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();
        }
        
      
        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();
    }

   
  
    /**
     * {@inheritDoc}
     */
       public void scrollLeft() {
        if (mScroller.isFinished()) {
            if (mCurrentScreen > 0) snapToScreen(mCurrentScreen - 1);
        } else {
            if (mNextScreen > 0) snapToScreen(mNextScreen - 1);            
        }
    }

    public void scrollRight() {
        if (mScroller.isFinished()) {
            if (mCurrentScreen < getChildCount() -1) snapToScreen(mCurrentScreen + 1);
        } else {
            if (mNextScreen < getChildCount() -1) snapToScreen(mNextScreen + 1);            
        }
    }

  
    public void setIndicators(Drawable previous, Drawable next,TextView title) {
        mPreviousIndicator = previous;
        mNextIndicator = next;
        previous.setLevel(mCurrentScreen);
        next.setLevel(mCurrentScreen);
        mTitle = title;
        mTitle.setText(mTitles[mCurrentScreen]);
    }
    
    public int getPage(int currentScreen){
        return mPages[currentScreen];
    }

  
   
  
}