package com.vanco.abplayer.view;
import android.content.Context;
import android.graphics.Rect;
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.widget.Scroller;
/**
* 左边侧滑
* @author Administrator
*
*/
public class LeftSliderLayout extends ViewGroup {
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
/**
* Constant value for touch state
* TOUCH_STATE_REST : no touch
* TOUCH_STATE_SCROLLING : scrolling
*/
private static final int TOUCH_STATE_REST = 0;
private static final int TOUCH_STATE_SCROLLING = 1;
private int mTouchState = TOUCH_STATE_REST;
/**
* Distance in pixels a touch can wander before we think the user is scrolling
*/
private int mTouchSlop;
/**
* Values for saving axis of the last touch event.
*/
private float mLastMotionX;
private float mLastMotionY;
/**
* Values for VelocityTracker to compute current velocity.
* VELOCITY_UNITS in dp
* mVelocityUnits in px
*/
private static final int VELOCITY_UNITS = 1000;
private int mVelocityUnits;
/**
* The minimum velocity for determining the direction.
* MINOR_VELOCITY in dp
* mMinorVelocity in px
*/
private static final float MINOR_VELOCITY = 150.0f;
private int mMinorVelocity;
/**
* The width of Sliding distance from left.
* And it should be the same with the width of the View below SliderLayout in a FrameLayout.
* DOCK_WIDTH in dp
* mDockWidth in px
*/
private static final float SLIDING_WIDTH = 180.0f;
private int mSlidingWidth;
/**
* The default values of shadow.
* VELOCITY_UNITS in dp
* mVelocityUnits in px
*/
private static final float DEF_SHADOW_WIDTH = 10.0f;
private int mDefShadowWidth;
/**
* Value for checking a touch event is completed.
*/
private boolean mIsTouchEventDone = false;
/**
* Value for checking slider is open.
*/
private boolean mIsOpen = false;
/**
* Value for saving the last offset of scroller ’ x-axis.
*/
private int mSaveScrollX = 0;
/**
* Value for checking slider is allowed to slide.
*/
private boolean mEnableSlide = true;
private View mMainChild = null;
private OnLeftSliderLayoutStateListener mListener = null;
/**
* Instantiates a new LeftSliderLayout.
*
* @param context the associated Context
* @param attrs AttributeSet
*/
public LeftSliderLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
/**
* Instantiates a new LeftSliderLayout.
*
* @param context the associated Context
* @param attrs AttributeSet
* @param defStyle Style
*/
public LeftSliderLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mScroller = new Scroller(context);
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
/**
* Convert values in dp to values in px;
*/
final float fDensity = getResources().getDisplayMetrics().density;
mVelocityUnits = (int) (VELOCITY_UNITS * fDensity + 0.5f);
mMinorVelocity = (int) (MINOR_VELOCITY * fDensity + 0.5f);
mSlidingWidth = (int) (SLIDING_WIDTH * fDensity + 0.5f);
mDefShadowWidth = (int) (DEF_SHADOW_WIDTH * fDensity + 0.5f);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// check Measure Mode is Exactly.
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
if (widthMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException("LeftSliderLayout only canmCurScreen run at EXACTLY mode!");
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException("LeftSliderLayout only can run at EXACTLY mode!");
}
// measure child views
int nCount = getChildCount();
for (int i = 2; i < nCount; i++) {
removeViewAt(i);
}
nCount = getChildCount();
if (nCount > 0) {
if (nCount > 1) {
mMainChild = getChildAt(1);
getChildAt(0).measure(widthMeasureSpec, heightMeasureSpec);
} else {
mMainChild = getChildAt(0);
}
mMainChild.measure(widthMeasureSpec, heightMeasureSpec);
}
// Set the scrolled position
scrollTo(mSaveScrollX, 0);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int nCount = getChildCount();
if (nCount <= 0) {
return;
}
// Set the size and position of Main Child
if (mMainChild != null) {
mMainChild.layout(
l,
t,
l + mMainChild.getMeasuredWidth(),
t + mMainChild.getMeasuredHeight());
}
// Set the size and position of Shadow Child
if (nCount > 1) {
int nLeftChildWidth = 0;
View leftChild = getChildAt(0);
ViewGroup.LayoutParams layoutParams = leftChild.getLayoutParams();
if (layoutParams.width == ViewGroup.LayoutParams.FILL_PARENT
|| layoutParams.width == ViewGroup.LayoutParams.MATCH_PARENT) {
nLeftChildWidth = mDefShadowWidth;
} else {
nLeftChildWidth = layoutParams.width;
}
leftChild.layout(
l - nLeftChildWidth,
t,
l,
t + leftChild.getMeasuredHeight());
}
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int nCurScrollX = getScrollX();
// check touch point is in the rectangle of Main Child
if (mMainChild != null
&& mTouchState != TOUCH_STATE_SCROLLING
&& mIsTouchEventDone) {
Rect rect = new Rect();
mMainChild.getHitRect(rect);
if (!rect.contains((int)event.getX() + nCurScrollX, (int)event.getY())) {
return false;
}
}
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
final int action = event.getAction();
final float x = event.getX();
switch (action) {
case MotionEvent.ACTION_DOWN: {
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
mIsTouchEventDone = false;
mLastMotionX = x;
break;
}
case MotionEvent.ACTION_MOVE: {
// check slider is allowed to slide.
if (!mEnableSlide) {
break;
}
// compute the x-axis offset from last point to current point
int deltaX = (int) (mLastMotionX - x);
if (nCurScrollX + deltaX < getMinScrollX()) {
deltaX = getMinScrollX() - nCurScrollX;
mLastMotionX = mLastMotionX - deltaX;
} else if (nCurScrollX + deltaX > getMaxScrollX()) {
deltaX = getMaxScrollX() - nCurScrollX;
mLastMotionX = mLastMotionX - deltaX;
} else {
mLastMotionX = x;
}
// Move view to the current point
if (deltaX != 0) {
scrollBy(deltaX, 0);
}
// Save the scrolled position
mSaveScrollX = getScrollX();
break;
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP: {
// check slider is allowed to slide.
if (!mEnableSlide) {
break;
}
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(mVelocityUnits);
// Set open or close state, when get ACTION_UP or ACTION_CANCEL event.
if (nCurScrollX < 0) {
int velocityX = (int) velocityTracker.getXVelocity();
if (velocityX > mMinorVelocity) {
scrollByWithAnim(getMinScrollX() - nCurScrollX);
setState(true);
}
else if (velocityX < -mMinorVelocity) {
scrollByWithAnim(-nCurScrollX);
setState(false);
} else {
if (nCurScrollX >= getMinScrollX() / 2) {
scrollByWithAnim(- nCurScrollX);
setState(false);
} else {
scrollByWithAnim(getMinScrollX() - nCurScrollX);
setState(true);
}
}
} else {
if (nCurScrollX > 0) {
scrollByWithAnim(-nCurScrollX);
}
setState(false);
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
mTouchState = TOUCH_STATE_REST;
mIsTouchEventDone = true;
break;
}
}
return true;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
if (mListener != null && !mListener.OnLeftSliderLayoutInterceptTouch(ev)) {
return false;
}
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_DOWN:
mLastMotionX = x;
mLastMotionY = y;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING;
break;
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(mLastMotionX - x);
if (xDiff > mTouchSlop) {
if (Math.abs(mLastMotionY - y) / Math.abs(mLastMotionX - x) < 1)
mTouchState = TOUCH_STATE_SCROLLING;
}
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
mTouchState = TOUCH_STATE_REST;
break;
}
return mTouchState != TOUCH_STATE_REST;
}
/**
* With the horizontal scroll of the animation
*
* @param nDx x-axis offset
*/
void scrollByWithAnim(int nDx) {
if (nDx == 0) {
return;
}
mScroller.startScroll(getScrollX(), 0, nDx, 0,
Math.abs(nDx));
invalidate();
}
/**
* Get distance of the maximum horizontal scroll
*
* @return distance in px
*/
private int getMaxScrollX() {
return 0;
}
/**
* Get distance of the minimum horizontal scroll
* @return distance in px
*/
private int getMinScrollX() {
return -mSlidingWidth;
}
/**
* Open LeftSlideLayout
*/
public void open() {
if (mEnableSlide) {
scrollByWithAnim(getMinScrollX() - getScrollX());
setState(true);
}
}
/**
* Close LeftSlideLayout
*/
public void close() {
if (mEnableSlide) {
scrollByWithAnim((-1) * getScrollX());
setState(false);
}
}
/**
* Determine whether LeftSlideLayout is open
*
* @return true-open，false-close
*/
public boolean isOpen() {
return mIsOpen;
}
/**
* Set state of LeftSliderLayout
*
* @param bIsOpen the new state
*/
private void setState(boolean bIsOpen) {
boolean bStateChanged = false;
if (mIsOpen && !bIsOpen) {
bStateChanged = true;
} else if (!mIsOpen && bIsOpen) {
bStateChanged = true;
}
mIsOpen = bIsOpen;
if (bIsOpen) {
mSaveScrollX = getMaxScrollX();
} else {
mSaveScrollX = 0;
}
if (bStateChanged && mListener != null) {
mListener.OnLeftSliderLayoutStateChanged(bIsOpen);
}
}
/**
* enable slide action of LeftSliderLayout
*
* @param bEnable
*/
public void enableSlide(boolean bEnable) {
mEnableSlide = bEnable;
}
/**
* Set listener to LeftSliderLayout
*/
public void setOnLeftSliderLayoutListener(OnLeftSliderLayoutStateListener listener) {
mListener = listener;
}
/**
* LeftSliderLayout Listener
*
*/
public interface OnLeftSliderLayoutStateListener {
/**
* Called when LeftSliderLayout’s state has been changed.
*
* @param bIsOpen the new state
*/
public void OnLeftSliderLayoutStateChanged(boolean bIsOpen);
/**
* Called when LeftSliderLayout has got onInterceptTouchEvent.
*
* @param ev Touch Event
* @return true - LeftSliderLayout need to manage the InterceptTouchEvent.
* false - LeftSliderLayout don't need to manage the InterceptTouchEvent.
*/
public boolean OnLeftSliderLayoutInterceptTouch(MotionEvent ev);
}
}