package com.sogou.sogouchat.ui;
import com.sogou.sogouchat.R;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
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.widget.Scroller;
/**
* EffectSpace
*
* @author lance
*
*/
public class SlidingMenuView extends ViewGroup
{
private static final int INVALID_SCREEN = -1;
private static final int SNAP_VELOCITY = 1000;
private int mDefaultScreen = 1;
private int mCurrentScreen;
private int mNextScreen = INVALID_SCREEN;
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
private float mLastMotionX;
private float mLastMotionY;
private final static int TOUCH_STATE_REST = 0;
private final static int TOUCH_STATE_SCROLLING = 1;
public int mTouchState = TOUCH_STATE_REST;
private boolean mAllowLongPress;
private boolean mLocked;
private int mTouchSlop;
public SlidingMenuView(Context context, AttributeSet attrs)
{
this(context, attrs, 0);
}
public SlidingMenuView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
initWorkspace();
postDelayed(new Runnable()
{
public void run()
{
scrollTo(findViewById(R.id.sliding_tab).getWidth(), 0);
}
}, 50);
}
private void initWorkspace()
{
mScroller = new Scroller(getContext());
mCurrentScreen = mDefaultScreen;
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
}
boolean isDefaultScreenShowing()
{
return mCurrentScreen == mDefaultScreen;
}
int getCurrentScreen()
{
return mCurrentScreen;
}
public void setCurrentScreen(int currentScreen)
{
mCurrentScreen = Math.max(0, Math.min(currentScreen, getChildCount() - 1));
invalidate();
}
void showDefaultScreen()
{
setCurrentScreen(mDefaultScreen);
}
@Override
public void computeScroll()
{
if (mScroller.computeScrollOffset())
{
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
}
else if (mNextScreen != INVALID_SCREEN)
{
mCurrentScreen = Math.max(0, Math.min(mNextScreen, getChildCount() - 1));
mNextScreen = INVALID_SCREEN;
clearChildrenCache();
}
}
@Override
public void scrollTo(int x, int y)
{
super.scrollTo(x, y);
postInvalidate();
}
@Override
protected void dispatchDraw(Canvas canvas)
{
final int scrollX = getScrollX();
super.dispatchDraw(canvas);
canvas.translate(scrollX, 0);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
measureViews(widthMeasureSpec, heightMeasureSpec);
}
public void measureViews(int widthMeasureSpec, int heightMeasureSpec)
{
View v1 = findViewById(R.id.sliding_tab);
v1.measure(v1.getLayoutParams().width + v1.getLeft() + v1.getRight(), heightMeasureSpec);
View v2 = findViewById(R.id.sliding_body);
v2.measure(widthMeasureSpec, heightMeasureSpec);
}
@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 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)
{
if (mLocked)
{
return true;
}
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST))
{
return true;
}
final float x = ev.getX();
final float y = ev.getY();
switch (action)
{
case MotionEvent.ACTION_MOVE:
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;
enableChildrenCache();
}
// 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:
// Remember location of down touch
mLastMotionX = x;
mLastMotionY = y;
mAllowLongPress = true;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING;
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
// Release the drag
clearChildrenCache();
mTouchState = TOUCH_STATE_REST;
mAllowLongPress = false;
break;
}
/*
* The only time we want to intercept motion events is if we are in the
* drag mode.
*/
return mTouchState != TOUCH_STATE_REST;
}
void enableChildrenCache()
{
final int count = getChildCount();
for (int i = 0; i < count; i++)
{
final View layout = (View) getChildAt(i);
layout.setDrawingCacheEnabled(true);
}
}
void clearChildrenCache()
{
final int count = getChildCount();
for (int i = 0; i < count; i++)
{
final View layout = (View) getChildAt(i);
layout.setDrawingCacheEnabled(false);
}
}
@Override
public boolean onTouchEvent(MotionEvent ev)
{
if (mLocked)
{
return true;
}
if (mVelocityTracker == null)
{
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
final float x = ev.getX();
switch (action)
{
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 = x;
break;
case MotionEvent.ACTION_MOVE:
if (mTouchState == TOUCH_STATE_SCROLLING)
{
// Scroll to follow the motion event
final int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
if (deltaX < 0)
{
if (getScrollX() > 0)
{
scrollBy(Math.max(-getScrollX(), deltaX), 0);
}
}
else if (deltaX > 0)
{
final int availableToScroll = getChildAt(getChildCount() - 1).getRight() - getScrollX()
- getWidth();
if (availableToScroll > 0)
{
scrollBy(Math.min(availableToScroll, deltaX), 0);
}
}
}
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_SCROLLING)
{
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000);
int velocityX = (int) velocityTracker.getXVelocity();
if (velocityX > SNAP_VELOCITY && mCurrentScreen > 0)
{
// Fling hard enough to move left
snapToScreen(mCurrentScreen - 1);
}
else if (velocityX < -SNAP_VELOCITY && mCurrentScreen < getChildCount() - 1)
{
// Fling hard enough to move right
snapToScreen(mCurrentScreen + 1);
}
else
{
snapToDestination();
}
if (mVelocityTracker != null)
{
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
mTouchState = TOUCH_STATE_REST;
break;
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
}
return true;
}
protected void snapToDestination()
{
final int screenWidth = findViewById(R.id.sliding_tab).getWidth();
final int whichScreen = (getScrollX() + (screenWidth / 2)) / screenWidth;
snapToScreen(whichScreen);
}
protected void snapToScreen(int whichScreen)
{
enableChildrenCache();
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
boolean changingScreens = whichScreen != mCurrentScreen;
mNextScreen = whichScreen;
View focusedChild = getFocusedChild();
if (focusedChild != null && changingScreens && focusedChild == getChildAt(mCurrentScreen))
{
focusedChild.clearFocus();
}
final int newX = whichScreen * findViewById(R.id.sliding_tab).getWidth();
final int delta = newX - getScrollX();
mScroller.startScroll(getScrollX(), 0, delta, 0, Math.abs(delta) * 2);
invalidate();
}
public void scrollLeft()
{
if (mNextScreen == INVALID_SCREEN && mCurrentScreen > 0 && mScroller.isFinished())
{
snapToScreen(mCurrentScreen - 1);
}
}
public void scrollRight()
{
if (mNextScreen == INVALID_SCREEN && mCurrentScreen < getChildCount() - 1 && mScroller.isFinished())
{
snapToScreen(mCurrentScreen + 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;
}
public void unlock()
{
mLocked = false;
}
public void lock()
{
mLocked = true;
}
void moveToDefaultScreen()
{
snapToScreen(mDefaultScreen);
getChildAt(mDefaultScreen).requestFocus();
}
@Override
protected void onFinishInflate()
{
// TODO Auto-generated method stub
super.onFinishInflate();
View child;
for (int i = 0; i < getChildCount(); i++)
{
child = getChildAt(i);
child.setFocusable(true);
child.setClickable(true);
}
}
}