我正在尝试创建和改进现有的SlidingDrawers项目，这些项目可以适用于屏幕的所有四个边{LEFT，RIGHT，TOP，BOTTOM}。有一些库，但它们都有局限性，复杂性和错误。其中一个比较常见的是umano的AndroidSlidingUpPanel，但是，我不喜欢这个库，因为你只需要包含两个子布局，并且还需要注意主要内容的具体安排。其他库类似，或更复杂，或有错误。
我即将完成我的SlidingDrawers版本，我专注于BOTTOM引力。我需要一些帮助。单击抽屉将打开并关闭它。您也可以用手指滑动抽屉。但是，如果你扔掉抽屉，整个视图将会移动到比它应该更低或更低的位置。
我该如何解决这个问题？据我所知，我的数学是正确的。我传给动画师的翻译价值应该是正确的。以下是我完成的工作。请查看此项目https://github.com/drxeno02/CustomDrawerLayout.git。先感谢您。
对于那些想要查看问题代码外观的片段的人，我现在正在做我的手势。
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mActivePointerId = MotionEventCompat.getPointerId(event, 0);
switch (mStickTo) {
case GRAVITY_BOTTOM:
case GRAVITY_TOP:
mInitialCoordinate = event.getY();
break;
case GRAVITY_LEFT:
case GRAVITY_RIGHT:
mInitialCoordinate = event.getX();
break;
}
break;
case MotionEvent.ACTION_MOVE:
float coordinate = 0;
switch (mStickTo) {
case GRAVITY_BOTTOM:
case GRAVITY_TOP:
coordinate = event.getY();
break;
case GRAVITY_LEFT:
case GRAVITY_RIGHT:
coordinate = event.getX();
break;
}
final int diff = (int) Math.abs(coordinate - mInitialCoordinate);
// confirm that difference is enough to indicate drag action
if (diff > mTouchSlop) {
// start capturing events
Logger.d(TAG, "drag is being captured");
return true;
}
break;
case MotionEvent.ACTION_UP:
if (!FrameworkUtils.checkIfNull(mVelocityTracker)) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
break;
}
// add velocity movements
if (FrameworkUtils.checkIfNull(mVelocityTracker)) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
return super.onInterceptTouchEvent(event);
}
@Override
public boolean onTouchEvent(@NonNull MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN && event.getEdgeFlags() != 0) {
return false;
}
// add velocity movements
if (FrameworkUtils.checkIfNull(mVelocityTracker)) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
final View parent = (View) getParent();
final int coordinate;
final int distance = getDistance();
final int tapCoordinate;
switch (mStickTo) {
case GRAVITY_BOTTOM:
coordinate = (int) event.getRawY();
tapCoordinate = (int) event.getRawY();
break;
case GRAVITY_LEFT:
coordinate = parent.getWidth() - (int) event.getRawX();
tapCoordinate = (int) event.getRawX();
break;
case GRAVITY_RIGHT:
coordinate = (int) event.getRawX();
tapCoordinate = (int) event.getRawX();
break;
case GRAVITY_TOP:
coordinate = getRawDisplayHeight(getContext()) - (int) event.getRawY();
tapCoordinate = (int) event.getRawY();
break;
// if view position is not initialized throw an error
default:
throw new IllegalStateException("Failed to initialize coordinates");
}
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
/*
* Return the pointer identifier associated with a particular pointer data index is
* this event. The identifier tells you the actual pointer number associated with
* the data, accounting for individual pointers going up and down since the start
* of the current gesture.
*/
mActivePointerId = event.getPointerId(0);
switch (mStickTo) {
case GRAVITY_BOTTOM:
mDelta = coordinate - ((RelativeLayout.LayoutParams) getLayoutParams()).topMargin;
break;
case GRAVITY_LEFT:
mDelta = coordinate - ((RelativeLayout.LayoutParams) getLayoutParams()).rightMargin;
break;
case GRAVITY_RIGHT:
mDelta = coordinate - ((RelativeLayout.LayoutParams) getLayoutParams()).leftMargin;
break;
case GRAVITY_TOP:
mDelta = coordinate - ((RelativeLayout.LayoutParams) getLayoutParams()).bottomMargin;
break;
}
mLastCoordinate = coordinate;
mPressStartTime = System.currentTimeMillis();
break;
case MotionEvent.ACTION_MOVE:
RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) getLayoutParams();
final int farMargin = coordinate - mDelta;
final int closeMargin = distance - farMargin;
switch (mStickTo) {
case GRAVITY_BOTTOM:
if (farMargin > distance && closeMargin > mOffsetHeight - getHeight()) {
layoutParams.bottomMargin = closeMargin;
layoutParams.topMargin = farMargin;
}
break;
case GRAVITY_LEFT:
if (farMargin > distance && closeMargin > mOffsetHeight - getWidth()) {
layoutParams.leftMargin = closeMargin;
layoutParams.rightMargin = farMargin;
}
break;
case GRAVITY_RIGHT:
if (farMargin > distance && closeMargin > mOffsetHeight - getWidth()) {
layoutParams.rightMargin = closeMargin;
layoutParams.leftMargin = farMargin;
}
break;
case GRAVITY_TOP:
if (farMargin > distance && closeMargin > mOffsetHeight - getHeight()) {
layoutParams.topMargin = closeMargin;
layoutParams.bottomMargin = farMargin;
}
break;
}
setLayoutParams(layoutParams);
break;
case MotionEvent.ACTION_UP:
final int diff = coordinate - mLastCoordinate;
final long pressDuration = System.currentTimeMillis() - mPressStartTime;
switch (mStickTo) {
case GRAVITY_BOTTOM:
// determine if fling
int relativeVelocity;
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
final int initialVelocityY = (int) VelocityTrackerCompat.getYVelocity(
velocityTracker, mActivePointerId);
relativeVelocity = initialVelocityY * -1;
// take absolute value to have positive values
final int absoluteVelocity = Math.abs(relativeVelocity);
if (Math.abs(diff) > mFlingDistance && absoluteVelocity > mMinimumVelocity) {
if (tapCoordinate > parent.getHeight() - mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_CLOSED) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, parent.getHeight() - mOffsetHeight, true);
} else if (Math.abs(getRawDisplayHeight(getContext()) -
tapCoordinate - getHeight()) < mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_OPEN) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_CLOSED, parent.getHeight() - mOffsetHeight, true);
}
} else {
if (isClicked(getContext(), diff, pressDuration)) {
if (tapCoordinate > parent.getHeight() - mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_CLOSED) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, parent.getHeight() - mOffsetHeight, true);
} else if (Math.abs(getRawDisplayHeight(getContext()) -
tapCoordinate - getHeight()) < mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_OPEN) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_CLOSED, parent.getHeight() - mOffsetHeight, true);
}
} else {
smoothScrollToAndNotify(diff);
}
}
break;
case GRAVITY_TOP:
if (isClicked(getContext(), diff, pressDuration)) {
final int y = getLocationInYAxis(this);
if (tapCoordinate - Math.abs(y) <= mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_CLOSED) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, parent.getHeight() - mOffsetHeight, true);
} else if (getHeight() - (tapCoordinate - Math.abs(y)) < mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_OPEN) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_CLOSED, parent.getHeight() - mOffsetHeight, true);
}
} else {
smoothScrollToAndNotify(diff);
}
break;
case GRAVITY_LEFT:
if (isClicked(getContext(), diff, pressDuration)) {
if (tapCoordinate <= mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_CLOSED) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, getWidth() - mOffsetHeight, true);
} else if (tapCoordinate > getWidth() - mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_OPEN) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_CLOSED, getWidth() - mOffsetHeight, true);
}
} else {
smoothScrollToAndNotify(diff);
}
break;
case GRAVITY_RIGHT:
if (isClicked(getContext(), diff, pressDuration)) {
if (parent.getWidth() - tapCoordinate <= mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_CLOSED) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, getWidth() - mOffsetHeight, true);
} else if (parent.getWidth() - tapCoordinate > getWidth() - mOffsetHeight &&
mLockMode == LockMode.LOCK_MODE_OPEN) {
notifyActionAndAnimateForState(LockMode.LOCK_MODE_CLOSED, getWidth() - mOffsetHeight, true);
}
} else {
smoothScrollToAndNotify(diff);
}
break;
}
break;
}
return true;
}
/**
* Method is used to animate the view to the given position
*
* @param diff
*/
private void smoothScrollToAndNotify(int diff) {
int length = getLength();
LockMode stateToApply;
if (diff > 0) {
if (diff > length / 2.5) {
stateToApply = LockMode.LOCK_MODE_CLOSED;
notifyActionAndAnimateForState(stateToApply, getTranslationFor(stateToApply), true);
} else if (mLockMode == LockMode.LOCK_MODE_OPEN) {
stateToApply = LockMode.LOCK_MODE_OPEN;
notifyActionAndAnimateForState(stateToApply, getTranslationFor(stateToApply), false);
}
} else {
if (Math.abs(diff) > length / 2.5) {
stateToApply = LockMode.LOCK_MODE_OPEN;
notifyActionAndAnimateForState(stateToApply, getTranslationFor(stateToApply), true);
} else if (mLockMode == LockMode.LOCK_MODE_CLOSED) {
stateToApply = LockMode.LOCK_MODE_CLOSED;
notifyActionAndAnimateForState(stateToApply, getTranslationFor(stateToApply), false);
}
}
}
/**
* Method is used to retrieve dimensions meant for translation
*
* @param stateToApply
* @return
*/
private int getTranslationFor(LockMode stateToApply) {
switch (mStickTo) {
case GRAVITY_BOTTOM:
switch (stateToApply) {
case LOCK_MODE_OPEN:
return getHeight() - (getRawDisplayHeight(getContext()) - getLocationInYAxis(this));
case LOCK_MODE_CLOSED:
return getRawDisplayHeight(getContext()) - getLocationInYAxis(this) - mOffsetHeight;
}
break;
case GRAVITY_TOP:
final int actionBarDiff = getRawDisplayHeight(getContext()) - ((View) getParent()).getHeight();
final int y = getLocationInYAxis(this) + getHeight();
switch (stateToApply) {
case LOCK_MODE_OPEN:
return getHeight() - y + actionBarDiff;
case LOCK_MODE_CLOSED:
return y - mOffsetHeight - actionBarDiff;
}
break;
case GRAVITY_LEFT:
final int x = getLocationInXAxis(this) + getWidth();
switch (stateToApply) {
case LOCK_MODE_OPEN:
return getWidth() - x;
case LOCK_MODE_CLOSED:
return x - mOffsetHeight;
}
break;
case GRAVITY_RIGHT:
switch (stateToApply) {
case LOCK_MODE_OPEN:
return getWidth() - (getRawDisplayWidth(getContext()) - getLocationInXAxis(this));
case LOCK_MODE_CLOSED:
return getRawDisplayWidth(getContext()) - getLocationInXAxis(this) - mOffsetHeight;
}
break;
}
throw new IllegalStateException("Failed to return translation for drawer");
}
/**
* Method is used to perform the animations
*
* @param stateToApply
* @param translation
* @param notify
*/
private void notifyActionAndAnimateForState(final LockMode stateToApply,
final int translation, final boolean notify) {
switch (mStickTo) {
case GRAVITY_BOTTOM:
switch (stateToApply) {
case LOCK_MODE_OPEN:
animate().translationY(-translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationY(0);
}
});
break;
case LOCK_MODE_CLOSED:
animate().translationY(translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationY(0);
}
});
break;
}
break;
case GRAVITY_TOP:
switch (stateToApply) {
case LOCK_MODE_OPEN:
animate().translationY(translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationY(0);
}
});
break;
case LOCK_MODE_CLOSED:
animate().translationY(-translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationY(0);
}
});
break;
}
break;
case GRAVITY_LEFT:
switch (stateToApply) {
case LOCK_MODE_OPEN:
animate().translationX(translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationX(0);
}
});
break;
case LOCK_MODE_CLOSED:
animate().translationX(-translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationX(0);
}
});
break;
}
break;
case GRAVITY_RIGHT:
switch (stateToApply) {
case LOCK_MODE_OPEN:
animate().translationX(-translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationX(0);
}
});
break;
case LOCK_MODE_CLOSED:
animate().translationX(translation)
.setDuration(TRANSLATION_ANIM_DURATION)
.setInterpolator(new DecelerateInterpolator())
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
notifyActionForState(stateToApply, notify);
setTranslationX(0);
}
});
break;
}
break;
}
}
附加说明： 我对这个问题有进一步的了解。我注释掉了ACTION_MOVE以消除在投掷动作之前移动的抽屉的位置。动画效果很好。我相信我的想法是正确的。为了获得“开放”的翻译，我做了
getHeight() - (getRawDisplayHeight(getContext()) - getLocationInYAxis(this))
所以剩下的就是翻译所需的距离。然而，一旦抽屉被拖动x距离，我期待getLocationInYAxis（this）将返回拖动位置。但计算结束了。
答案 0 :(得分：2)
似乎您应该使用getTranslationFor函数来计算州的新翻译。
您目前仅考虑高度和偏移量，但是从getTranslationFor代码中您似乎也应该考虑 getLocationInYAxis 。
所以，而不是这一行：
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, parent.getHeight() - mOffsetHeight, true);
试试这一行：
notifyActionAndAnimateForState(LockMode.LOCK_MODE_OPEN, getTranslationFor(LockMode.LOCK_MODE_OPEN), true);