From fae2ddd6bf9b9b60e665c0e995864845ac7231db Mon Sep 17 00:00:00 2001 From: kunfei Date: Sun, 22 Sep 2019 10:03:34 +0800 Subject: [PATCH] up --- .../app/ui/widget/page/ContentTextView.kt | 190 ++++++++++++++++++ 1 file changed, 190 insertions(+) diff --git a/app/src/main/java/io/legado/app/ui/widget/page/ContentTextView.kt b/app/src/main/java/io/legado/app/ui/widget/page/ContentTextView.kt index 485895497..c2a9632ba 100644 --- a/app/src/main/java/io/legado/app/ui/widget/page/ContentTextView.kt +++ b/app/src/main/java/io/legado/app/ui/widget/page/ContentTextView.kt @@ -1,8 +1,16 @@ package io.legado.app.ui.widget.page +import android.annotation.SuppressLint import android.content.Context import android.util.AttributeSet +import android.view.MotionEvent +import android.view.VelocityTracker +import android.view.ViewConfiguration +import android.view.animation.Interpolator +import android.widget.OverScroller import androidx.appcompat.widget.AppCompatTextView +import androidx.core.view.ViewCompat +import kotlin.math.abs class ContentTextView : AppCompatTextView { @@ -13,6 +21,34 @@ class ContentTextView : AppCompatTextView { constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr) + private val INVALID_POINTER = -1 + private val SCROLL_STATE_IDLE = 0 + private val SCROLL_STATE_DRAGGING = 1 + val SCROLL_STATE_SETTLING = 2 + + private var velocityTracker: VelocityTracker? = null + private var mScrollState = SCROLL_STATE_IDLE + private var mScrollPointerId = INVALID_POINTER + private var mLastTouchY: Int = 0 + private var mTouchSlop: Int = 0 + private var mMinFlingVelocity: Int = 0 + private var mMaxFlingVelocity: Int = 0 + private val mViewFling = ViewFling() + + //f(x) = (x-1)^5 + 1 + private val sQuinticInterpolator = Interpolator { + var t = it + t -= 1.0f + t * t * t * t * t + 1.0f + } + + init { + val vc = ViewConfiguration.get(context) + mTouchSlop = vc.scaledTouchSlop + mMinFlingVelocity = vc.scaledMinimumFlingVelocity + mMaxFlingVelocity = vc.scaledMaximumFlingVelocity + } + /** * 获取当前页总字数 */ @@ -27,4 +63,158 @@ class ContentTextView : AppCompatTextView { val topOfLastLine = height - paddingTop - paddingBottom - lineHeight return layout?.getLineForVertical(topOfLastLine) ?: 0 } + + @SuppressLint("ClickableViewAccessibility") + override fun onTouchEvent(event: MotionEvent?): Boolean { + event?.let { + val action = event.action + val actionIndex = event.actionIndex + val vtEvent = MotionEvent.obtain(event) + + if (velocityTracker == null) { + velocityTracker = VelocityTracker.obtain() + } + velocityTracker?.addMovement(it) + when (action) { + MotionEvent.ACTION_DOWN -> { + setScrollState(SCROLL_STATE_IDLE) + mScrollPointerId = event.getPointerId(0) + mLastTouchY = (event.y + 0.5f).toInt() + } + MotionEvent.ACTION_POINTER_DOWN -> { + mScrollPointerId = event.getPointerId(actionIndex) + mLastTouchY = (event.getY(actionIndex) + 0.5f).toInt() + } + MotionEvent.ACTION_MOVE -> { + val index = event.findPointerIndex(mScrollPointerId) + if (index < 0) { + return false + } + + val y = (event.getY(index) + 0.5f).toInt() + var dy = mLastTouchY - y + + if (mScrollState != SCROLL_STATE_DRAGGING) { + var startScroll = false + + if (abs(dy) > mTouchSlop) { + if (dy > 0) { + dy -= mTouchSlop + } else { + dy += mTouchSlop + } + startScroll = true + } + if (startScroll) { + setScrollState(SCROLL_STATE_DRAGGING) + } + } + + if (mScrollState == SCROLL_STATE_DRAGGING) { + mLastTouchY = y + } + } + MotionEvent.ACTION_POINTER_UP -> { + if (event.getPointerId(actionIndex) == mScrollPointerId) { + // Pick a new pointer to pick up the slack. + val newIndex = if (actionIndex == 0) 1 else 0 + mScrollPointerId = event.getPointerId(newIndex) + mLastTouchY = (event.getY(newIndex) + 0.5f).toInt() + } + } + MotionEvent.ACTION_UP -> { + velocityTracker?.computeCurrentVelocity(1000, mMaxFlingVelocity.toFloat()) + val yVelocity = velocityTracker?.getXVelocity(mScrollPointerId) ?: 0f + if (abs(yVelocity) > mMinFlingVelocity) { + mViewFling.fling(yVelocity.toInt()) + } else { + setScrollState(SCROLL_STATE_IDLE) + } + resetTouch() + } + MotionEvent.ACTION_CANCEL -> { + resetTouch() + } + } + vtEvent.recycle() + } + return super.onTouchEvent(event) + } + + private fun resetTouch() { + velocityTracker?.clear() + } + + private fun setScrollState(state: Int) { + if (state == mScrollState) { + return + } + mScrollState = state + if (state != SCROLL_STATE_SETTLING) { + mViewFling.stop() + } + } + + private inner class ViewFling : Runnable { + + private var mLastFlingY = 0 + private val mScroller: OverScroller = OverScroller(context, sQuinticInterpolator) + private var mEatRunOnAnimationRequest = false + private var mReSchedulePostAnimationCallback = false + + override fun run() { + disableRunOnAnimationRequests() + val scroller = mScroller + if (scroller.computeScrollOffset()) { + val y = scroller.currY + val dy = y - mLastFlingY + mLastFlingY = y + this@ContentTextView.scrollBy(0, dy) + postOnAnimation() + } + enableRunOnAnimationRequests() + } + + fun fling(velocityY: Int) { + mLastFlingY = 0 + setScrollState(SCROLL_STATE_SETTLING) + mScroller.fling( + 0, + 0, + 0, + velocityY, + Integer.MIN_VALUE, + Integer.MAX_VALUE, + Integer.MIN_VALUE, + Integer.MAX_VALUE + ) + postOnAnimation() + } + + fun stop() { + removeCallbacks(this) + mScroller.abortAnimation() + } + + private fun disableRunOnAnimationRequests() { + mReSchedulePostAnimationCallback = false + mEatRunOnAnimationRequest = true + } + + private fun enableRunOnAnimationRequests() { + mEatRunOnAnimationRequest = false + if (mReSchedulePostAnimationCallback) { + postOnAnimation() + } + } + + internal fun postOnAnimation() { + if (mEatRunOnAnimationRequest) { + mReSchedulePostAnimationCallback = true + } else { + removeCallbacks(this) + ViewCompat.postOnAnimation(this@ContentTextView, this) + } + } + } }