| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.systemui.recents.views; |
| |
| import android.content.Context; |
| import android.view.MotionEvent; |
| import android.view.VelocityTracker; |
| import android.view.View; |
| import android.view.ViewConfiguration; |
| import android.view.ViewParent; |
| import com.android.systemui.recents.Constants; |
| import com.android.systemui.recents.RecentsConfiguration; |
| |
| /* Handles touch events for a TaskStackView. */ |
| class TaskStackViewTouchHandler implements SwipeHelper.Callback { |
| static int INACTIVE_POINTER_ID = -1; |
| |
| RecentsConfiguration mConfig; |
| TaskStackView mSv; |
| TaskStackViewScroller mScroller; |
| VelocityTracker mVelocityTracker; |
| |
| boolean mIsScrolling; |
| |
| float mInitialP; |
| float mLastP; |
| float mTotalPMotion; |
| int mInitialMotionX, mInitialMotionY; |
| int mLastMotionX, mLastMotionY; |
| int mActivePointerId = INACTIVE_POINTER_ID; |
| TaskView mActiveTaskView = null; |
| |
| int mMinimumVelocity; |
| int mMaximumVelocity; |
| // The scroll touch slop is used to calculate when we start scrolling |
| int mScrollTouchSlop; |
| // The page touch slop is used to calculate when we start swiping |
| float mPagingTouchSlop; |
| |
| SwipeHelper mSwipeHelper; |
| boolean mInterceptedBySwipeHelper; |
| |
| public TaskStackViewTouchHandler(Context context, TaskStackView sv, |
| RecentsConfiguration config, TaskStackViewScroller scroller) { |
| ViewConfiguration configuration = ViewConfiguration.get(context); |
| mMinimumVelocity = configuration.getScaledMinimumFlingVelocity(); |
| mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); |
| mScrollTouchSlop = configuration.getScaledTouchSlop(); |
| mPagingTouchSlop = configuration.getScaledPagingTouchSlop(); |
| mSv = sv; |
| mScroller = scroller; |
| mConfig = config; |
| |
| float densityScale = context.getResources().getDisplayMetrics().density; |
| mSwipeHelper = new SwipeHelper(SwipeHelper.X, this, densityScale, mPagingTouchSlop); |
| mSwipeHelper.setMinAlpha(1f); |
| } |
| |
| /** Velocity tracker helpers */ |
| void initOrResetVelocityTracker() { |
| if (mVelocityTracker == null) { |
| mVelocityTracker = VelocityTracker.obtain(); |
| } else { |
| mVelocityTracker.clear(); |
| } |
| } |
| void initVelocityTrackerIfNotExists() { |
| if (mVelocityTracker == null) { |
| mVelocityTracker = VelocityTracker.obtain(); |
| } |
| } |
| void recycleVelocityTracker() { |
| if (mVelocityTracker != null) { |
| mVelocityTracker.recycle(); |
| mVelocityTracker = null; |
| } |
| } |
| |
| /** Returns the view at the specified coordinates */ |
| TaskView findViewAtPoint(int x, int y) { |
| int childCount = mSv.getChildCount(); |
| for (int i = childCount - 1; i >= 0; i--) { |
| TaskView tv = (TaskView) mSv.getChildAt(i); |
| if (tv.getVisibility() == View.VISIBLE) { |
| if (mSv.isTransformedTouchPointInView(x, y, tv)) { |
| return tv; |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** Constructs a simulated motion event for the current stack scroll. */ |
| MotionEvent createMotionEventForStackScroll(MotionEvent ev) { |
| MotionEvent pev = MotionEvent.obtainNoHistory(ev); |
| pev.setLocation(0, mScroller.progressToScrollRange(mScroller.getStackScroll())); |
| return pev; |
| } |
| |
| /** Touch preprocessing for handling below */ |
| public boolean onInterceptTouchEvent(MotionEvent ev) { |
| // Return early if we have no children |
| boolean hasChildren = (mSv.getChildCount() > 0); |
| if (!hasChildren) { |
| return false; |
| } |
| |
| // Pass through to swipe helper if we are swiping |
| mInterceptedBySwipeHelper = mSwipeHelper.onInterceptTouchEvent(ev); |
| if (mInterceptedBySwipeHelper) { |
| return true; |
| } |
| |
| boolean wasScrolling = mScroller.isScrolling() || |
| (mScroller.mScrollAnimator != null && mScroller.mScrollAnimator.isRunning()); |
| int action = ev.getAction(); |
| switch (action & MotionEvent.ACTION_MASK) { |
| case MotionEvent.ACTION_DOWN: { |
| // Save the touch down info |
| mInitialMotionX = mLastMotionX = (int) ev.getX(); |
| mInitialMotionY = mLastMotionY = (int) ev.getY(); |
| mInitialP = mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| mActivePointerId = ev.getPointerId(0); |
| mActiveTaskView = findViewAtPoint(mLastMotionX, mLastMotionY); |
| // Stop the current scroll if it is still flinging |
| mScroller.stopScroller(); |
| mScroller.stopBoundScrollAnimation(); |
| // Initialize the velocity tracker |
| initOrResetVelocityTracker(); |
| mVelocityTracker.addMovement(createMotionEventForStackScroll(ev)); |
| // Check if the scroller is finished yet |
| mIsScrolling = mScroller.isScrolling(); |
| break; |
| } |
| case MotionEvent.ACTION_MOVE: { |
| if (mActivePointerId == INACTIVE_POINTER_ID) break; |
| |
| int activePointerIndex = ev.findPointerIndex(mActivePointerId); |
| int y = (int) ev.getY(activePointerIndex); |
| int x = (int) ev.getX(activePointerIndex); |
| if (Math.abs(y - mInitialMotionY) > mScrollTouchSlop) { |
| // Save the touch move info |
| mIsScrolling = true; |
| // Initialize the velocity tracker if necessary |
| initVelocityTrackerIfNotExists(); |
| mVelocityTracker.addMovement(createMotionEventForStackScroll(ev)); |
| // Disallow parents from intercepting touch events |
| final ViewParent parent = mSv.getParent(); |
| if (parent != null) { |
| parent.requestDisallowInterceptTouchEvent(true); |
| } |
| } |
| |
| mLastMotionX = x; |
| mLastMotionY = y; |
| mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| break; |
| } |
| case MotionEvent.ACTION_CANCEL: |
| case MotionEvent.ACTION_UP: { |
| // Animate the scroll back if we've cancelled |
| mScroller.animateBoundScroll(); |
| // Reset the drag state and the velocity tracker |
| mIsScrolling = false; |
| mActivePointerId = INACTIVE_POINTER_ID; |
| mActiveTaskView = null; |
| mTotalPMotion = 0; |
| recycleVelocityTracker(); |
| break; |
| } |
| } |
| |
| return wasScrolling || mIsScrolling; |
| } |
| |
| /** Handles touch events once we have intercepted them */ |
| public boolean onTouchEvent(MotionEvent ev) { |
| |
| // Short circuit if we have no children |
| boolean hasChildren = (mSv.getChildCount() > 0); |
| if (!hasChildren) { |
| return false; |
| } |
| |
| // Pass through to swipe helper if we are swiping |
| if (mInterceptedBySwipeHelper && mSwipeHelper.onTouchEvent(ev)) { |
| return true; |
| } |
| |
| // Update the velocity tracker |
| initVelocityTrackerIfNotExists(); |
| |
| int action = ev.getAction(); |
| switch (action & MotionEvent.ACTION_MASK) { |
| case MotionEvent.ACTION_DOWN: { |
| // Save the touch down info |
| mInitialMotionX = mLastMotionX = (int) ev.getX(); |
| mInitialMotionY = mLastMotionY = (int) ev.getY(); |
| mInitialP = mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| mActivePointerId = ev.getPointerId(0); |
| mActiveTaskView = findViewAtPoint(mLastMotionX, mLastMotionY); |
| // Stop the current scroll if it is still flinging |
| mScroller.stopScroller(); |
| mScroller.stopBoundScrollAnimation(); |
| // Initialize the velocity tracker |
| initOrResetVelocityTracker(); |
| mVelocityTracker.addMovement(createMotionEventForStackScroll(ev)); |
| // Disallow parents from intercepting touch events |
| final ViewParent parent = mSv.getParent(); |
| if (parent != null) { |
| parent.requestDisallowInterceptTouchEvent(true); |
| } |
| break; |
| } |
| case MotionEvent.ACTION_POINTER_DOWN: { |
| final int index = ev.getActionIndex(); |
| mActivePointerId = ev.getPointerId(index); |
| mLastMotionX = (int) ev.getX(index); |
| mLastMotionY = (int) ev.getY(index); |
| mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| break; |
| } |
| case MotionEvent.ACTION_MOVE: { |
| if (mActivePointerId == INACTIVE_POINTER_ID) break; |
| |
| int activePointerIndex = ev.findPointerIndex(mActivePointerId); |
| int x = (int) ev.getX(activePointerIndex); |
| int y = (int) ev.getY(activePointerIndex); |
| int yTotal = Math.abs(y - mInitialMotionY); |
| float curP = mSv.mLayoutAlgorithm.screenYToCurveProgress(y); |
| float deltaP = mLastP - curP; |
| if (!mIsScrolling) { |
| if (yTotal > mScrollTouchSlop) { |
| mIsScrolling = true; |
| // Initialize the velocity tracker |
| initOrResetVelocityTracker(); |
| mVelocityTracker.addMovement(createMotionEventForStackScroll(ev)); |
| // Disallow parents from intercepting touch events |
| final ViewParent parent = mSv.getParent(); |
| if (parent != null) { |
| parent.requestDisallowInterceptTouchEvent(true); |
| } |
| } |
| } |
| if (mIsScrolling) { |
| float curStackScroll = mScroller.getStackScroll(); |
| float overScrollAmount = mScroller.getScrollAmountOutOfBounds(curStackScroll + deltaP); |
| if (Float.compare(overScrollAmount, 0f) != 0) { |
| // Bound the overscroll to a fixed amount, and inversely scale the y-movement |
| // relative to how close we are to the max overscroll |
| float maxOverScroll = mConfig.taskStackOverscrollPct; |
| deltaP *= (1f - (Math.min(maxOverScroll, overScrollAmount) |
| / maxOverScroll)); |
| } |
| mScroller.setStackScroll(curStackScroll + deltaP); |
| if (mScroller.isScrollOutOfBounds()) { |
| mVelocityTracker.clear(); |
| } else { |
| mVelocityTracker.addMovement(createMotionEventForStackScroll(ev)); |
| } |
| } |
| mLastMotionX = x; |
| mLastMotionY = y; |
| mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| mTotalPMotion += Math.abs(deltaP); |
| break; |
| } |
| case MotionEvent.ACTION_UP: { |
| final VelocityTracker velocityTracker = mVelocityTracker; |
| velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); |
| int velocity = (int) velocityTracker.getYVelocity(mActivePointerId); |
| if (mIsScrolling && (Math.abs(velocity) > mMinimumVelocity)) { |
| int overscrollRange = (int) (Math.min(1f, |
| Math.abs((float) velocity / mMaximumVelocity)) * |
| Constants.Values.TaskStackView.TaskStackOverscrollRange); |
| // Fling scroll |
| mScroller.mScroller.fling(0, mScroller.progressToScrollRange(mScroller.getStackScroll()), |
| 0, velocity, |
| 0, 0, |
| mScroller.progressToScrollRange(mSv.mLayoutAlgorithm.mMinScrollP), |
| mScroller.progressToScrollRange(mSv.mLayoutAlgorithm.mMaxScrollP), |
| 0, overscrollRange); |
| // Invalidate to kick off computeScroll |
| mSv.invalidate(); |
| } else if (mScroller.isScrollOutOfBounds()) { |
| // Animate the scroll back into bounds |
| mScroller.animateBoundScroll(); |
| } |
| |
| mActivePointerId = INACTIVE_POINTER_ID; |
| mIsScrolling = false; |
| mTotalPMotion = 0; |
| recycleVelocityTracker(); |
| break; |
| } |
| case MotionEvent.ACTION_POINTER_UP: { |
| int pointerIndex = ev.getActionIndex(); |
| int pointerId = ev.getPointerId(pointerIndex); |
| if (pointerId == mActivePointerId) { |
| // Select a new active pointer id and reset the motion state |
| final int newPointerIndex = (pointerIndex == 0) ? 1 : 0; |
| mActivePointerId = ev.getPointerId(newPointerIndex); |
| mLastMotionX = (int) ev.getX(newPointerIndex); |
| mLastMotionY = (int) ev.getY(newPointerIndex); |
| mLastP = mSv.mLayoutAlgorithm.screenYToCurveProgress(mLastMotionY); |
| mVelocityTracker.clear(); |
| } |
| break; |
| } |
| case MotionEvent.ACTION_CANCEL: { |
| if (mScroller.isScrollOutOfBounds()) { |
| // Animate the scroll back into bounds |
| mScroller.animateBoundScroll(); |
| } |
| mActivePointerId = INACTIVE_POINTER_ID; |
| mIsScrolling = false; |
| mTotalPMotion = 0; |
| recycleVelocityTracker(); |
| break; |
| } |
| } |
| return true; |
| } |
| |
| /**** SwipeHelper Implementation ****/ |
| |
| @Override |
| public View getChildAtPosition(MotionEvent ev) { |
| return findViewAtPoint((int) ev.getX(), (int) ev.getY()); |
| } |
| |
| @Override |
| public boolean canChildBeDismissed(View v) { |
| return true; |
| } |
| |
| @Override |
| public void onBeginDrag(View v) { |
| TaskView tv = (TaskView) v; |
| // Disable clipping with the stack while we are swiping |
| tv.setClipViewInStack(false); |
| // Disallow touch events from this task view |
| tv.setTouchEnabled(false); |
| // Hide the footer |
| tv.animateFooterVisibility(false, mSv.mConfig.taskViewLockToAppShortAnimDuration); |
| // Disallow parents from intercepting touch events |
| final ViewParent parent = mSv.getParent(); |
| if (parent != null) { |
| parent.requestDisallowInterceptTouchEvent(true); |
| } |
| } |
| |
| @Override |
| public void onSwipeChanged(View v, float delta) { |
| // Do nothing |
| } |
| |
| @Override |
| public void onChildDismissed(View v) { |
| TaskView tv = (TaskView) v; |
| // Re-enable clipping with the stack (we will reuse this view) |
| tv.setClipViewInStack(true); |
| // Re-enable touch events from this task view |
| tv.setTouchEnabled(true); |
| // Remove the task view from the stack |
| mSv.onTaskViewDismissed(tv); |
| } |
| |
| @Override |
| public void onSnapBackCompleted(View v) { |
| TaskView tv = (TaskView) v; |
| // Re-enable clipping with the stack |
| tv.setClipViewInStack(true); |
| // Re-enable touch events from this task view |
| tv.setTouchEnabled(true); |
| // Restore the footer |
| tv.animateFooterVisibility(true, mSv.mConfig.taskViewLockToAppShortAnimDuration); |
| } |
| |
| @Override |
| public void onDragCancelled(View v) { |
| // Do nothing |
| } |
| } |
