public NestedScrollWebView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public NestedScrollWebView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mChildHelper = new NestedScrollingChildHelper(this);
setNestedScrollingEnabled(true);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
boolean result = false;
MotionEvent trackedEvent = MotionEvent.obtain(event);
final int action = MotionEventCompat.getActionMasked(event);
if (action == MotionEvent.ACTION_DOWN) {
mNestedYOffset = 0;
}
int y = (int) event.getY();
event.offsetLocation(0, mNestedYOffset);
switch (action) {
case MotionEvent.ACTION_DOWN:
mLastMotionY = y;
startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
result = super.onTouchEvent(event);
break;
case MotionEvent.ACTION_MOVE:
int deltaY = mLastMotionY - y;
if (dispatchNestedPreScroll(0, deltaY, mScrollConsumed, mScrollOffset)) {
deltaY -= mScrollConsumed[1];
trackedEvent.offsetLocation(0, mScrollOffset[1]);
mNestedYOffset += mScrollOffset[1];
}
int oldY = getScrollY();
mLastMotionY = y - mScrollOffset[1];
int newScrollY = Math.max(0, oldY + deltaY);
deltaY -= newScrollY - oldY;
if (dispatchNestedScroll(0, newScrollY - deltaY, 0, deltaY, mScrollOffset)) {
mLastMotionY -= mScrollOffset[1];
trackedEvent.offsetLocation(0, mScrollOffset[1]);
mNestedYOffset += mScrollOffset[1];
}
if(mScrollConsumed[1]==0 && mScrollOffset[1]==0) {
trackedEvent.recycle();
result = super.onTouchEvent(trackedEvent);
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
stopNestedScroll();
result = super.onTouchEvent(event);
break;
}
return result;
}
// NestedScrollingChild
@Override
public void setNestedScrollingEnabled(boolean enabled) {
mChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(int axes) {
return mChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow) {
return mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
return mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
return mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
return mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
前端框架
前端框架太多了，真的学不动了，别慌，其实对于前端的三大马车，Angular、React、Vue 只要把其中一种框架学明白，底层原理实现，其他两个学起来不会很吃力，这也取决于你以后就职的公司要求你会哪一个框架了，当然，会的越多越好，但是往往每个人的时间是有限的，对于自学的学生，或者即将面试找工作的人，当然要选择一门框架深挖原理。
以 Vue 为例，我整理了如下的面试题。
