C# android.findPointerIndex方法代码示例

		private int findNewActiveIndex(android.view.MotionEvent ev, int otherActiveId, int
			 oldIndex)
		{
			int pointerCount = ev.getPointerCount();
			// It's ok if this isn't found and returns -1, it simply won't match.
			int otherActiveIndex = ev.findPointerIndex(otherActiveId);
			int newActiveIndex = -1;
			{
				// Pick a new id and update tracking state. Only pick pointers not on the slop edges.
				for (int i = 0; i < pointerCount; i++)
				{
					if (i != oldIndex && i != otherActiveIndex)
					{
						float edgeSlop = mEdgeSlop;
						float rightSlop = mRightSlopEdge;
						float bottomSlop = mBottomSlopEdge;
						float x = getRawX(ev, i);
						float y = getRawY(ev, i);
						if (x >= edgeSlop && y >= edgeSlop && x <= rightSlop && y <= bottomSlop)
						{
							newActiveIndex = i;
							break;
						}
					}
				}
			}
			return newActiveIndex;
		}

		private void setContext(android.view.MotionEvent curr)
		{
			if (mCurrEvent != null)
			{
				mCurrEvent.recycle();
			}
			mCurrEvent = android.view.MotionEvent.obtain(curr);
			mCurrLen = -1;
			mPrevLen = -1;
			mScaleFactor = -1;
			android.view.MotionEvent prev = mPrevEvent;
			int prevIndex0 = prev.findPointerIndex(mActiveId0);
			int prevIndex1 = prev.findPointerIndex(mActiveId1);
			int currIndex0 = curr.findPointerIndex(mActiveId0);
			int currIndex1 = curr.findPointerIndex(mActiveId1);
			if (prevIndex0 < 0 || prevIndex1 < 0 || currIndex0 < 0 || currIndex1 < 0)
			{
				mInvalidGesture = true;
				android.util.Log.e(TAG, "Invalid MotionEvent stream detected.", new System.Exception
					());
				if (mGestureInProgress)
				{
					mListener.onScaleEnd(this);
				}
				return;
			}
			float px0 = prev.getX(prevIndex0);
			float py0 = prev.getY(prevIndex0);
			float px1 = prev.getX(prevIndex1);
			float py1 = prev.getY(prevIndex1);
			float cx0 = curr.getX(currIndex0);
			float cy0 = curr.getY(currIndex0);
			float cx1 = curr.getX(currIndex1);
			float cy1 = curr.getY(currIndex1);
			float pvx = px1 - px0;
			float pvy = py1 - py0;
			float cvx = cx1 - cx0;
			float cvy = cy1 - cy0;
			mPrevFingerDiffX = pvx;
			mPrevFingerDiffY = pvy;
			mCurrFingerDiffX = cvx;
			mCurrFingerDiffY = cvy;
			mFocusX = cx0 + cvx * 0.5f;
			mFocusY = cy0 + cvy * 0.5f;
			mTimeDelta = curr.getEventTime() - prev.getEventTime();
			mCurrPressure = curr.getPressure(currIndex0) + curr.getPressure(currIndex1);
			mPrevPressure = prev.getPressure(prevIndex0) + prev.getPressure(prevIndex1);
		}

		public override bool onTouchEvent(android.view.MotionEvent ev)
		{
			initVelocityTrackerIfNotExists();
			mVelocityTracker.addMovement(ev);
			int action = ev.getAction();
			switch (action & android.view.MotionEvent.ACTION_MASK)
			{
				case android.view.MotionEvent.ACTION_DOWN:
				{
					mIsBeingDragged = getChildCount() != 0;
					if (!mIsBeingDragged)
					{
						return false;
					}
					if (!mScroller.isFinished())
					{
						mScroller.abortAnimation();
					}
					// Remember where the motion event started
					mLastMotionX = ev.getX();
					mActivePointerId = ev.getPointerId(0);
					break;
				}

				case android.view.MotionEvent.ACTION_MOVE:
				{
					if (mIsBeingDragged)
					{
						// Scroll to follow the motion event
						int activePointerIndex = ev.findPointerIndex(mActivePointerId);
						float x = ev.getX(activePointerIndex);
						int deltaX = (int)(mLastMotionX - x);
						mLastMotionX = x;
						int oldX = mScrollX;
						int oldY = mScrollY;
						int range = getScrollRange();
						int overscrollMode = getOverScrollMode();
						bool canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS || (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS
							 && range > 0);
						if (overScrollBy(deltaX, 0, mScrollX, 0, range, 0, mOverscrollDistance, 0, true))
						{
							// Break our velocity if we hit a scroll barrier.
							mVelocityTracker.clear();
						}
						onScrollChanged(mScrollX, mScrollY, oldX, oldY);
						if (canOverscroll)
						{
							int pulledToX = oldX + deltaX;
							if (pulledToX < 0)
							{
								mEdgeGlowLeft.onPull((float)deltaX / getWidth());
								if (!mEdgeGlowRight.isFinished())
								{
									mEdgeGlowRight.onRelease();
								}
							}
							else
							{
								if (pulledToX > range)
								{
									mEdgeGlowRight.onPull((float)deltaX / getWidth());
									if (!mEdgeGlowLeft.isFinished())
									{
										mEdgeGlowLeft.onRelease();
									}
								}
							}
							if (mEdgeGlowLeft != null && (!mEdgeGlowLeft.isFinished() || !mEdgeGlowRight.isFinished
								()))
							{
								invalidate();
							}
						}
					}
					break;
				}

				case android.view.MotionEvent.ACTION_UP:
				{
					if (mIsBeingDragged)
					{
						android.view.VelocityTracker velocityTracker = mVelocityTracker;
						velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
						int initialVelocity = (int)velocityTracker.getXVelocity(mActivePointerId);
						if (getChildCount() > 0)
						{
							if ((System.Math.Abs(initialVelocity) > mMinimumVelocity))
							{
								fling(-initialVelocity);
							}
							else
							{
								if (mScroller.springBack(mScrollX, mScrollY, 0, getScrollRange(), 0, 0))
								{
									invalidate();
								}
							}
						}
						mActivePointerId = INVALID_POINTER;
						mIsBeingDragged = false;
//.........这里部分代码省略.........

		public virtual bool onTouchEvent(android.view.MotionEvent @event)
		{
			if (mInputEventConsistencyVerifier != null)
			{
				mInputEventConsistencyVerifier.onTouchEvent(@event, 0);
			}
			int action = @event.getActionMasked();
			if (action == android.view.MotionEvent.ACTION_DOWN)
			{
				reset();
			}
			// Start fresh
			bool handled = true;
			if (mInvalidGesture)
			{
				handled = false;
			}
			else
			{
				if (!mGestureInProgress)
				{
					switch (action)
					{
						case android.view.MotionEvent.ACTION_DOWN:
						{
							mActiveId0 = @event.getPointerId(0);
							mActive0MostRecent = true;
							break;
						}

						case android.view.MotionEvent.ACTION_UP:
						{
							reset();
							break;
						}

						case android.view.MotionEvent.ACTION_POINTER_DOWN:
						{
							// We have a new multi-finger gesture
							// as orientation can change, query the metrics in touch down
							android.util.DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
							mRightSlopEdge = metrics.widthPixels - mEdgeSlop;
							mBottomSlopEdge = metrics.heightPixels - mEdgeSlop;
							if (mPrevEvent != null)
							{
								mPrevEvent.recycle();
							}
							mPrevEvent = android.view.MotionEvent.obtain(@event);
							mTimeDelta = 0;
							int index1 = @event.getActionIndex();
							int index0 = @event.findPointerIndex(mActiveId0);
							mActiveId1 = @event.getPointerId(index1);
							if (index0 < 0 || index0 == index1)
							{
								// Probably someone sending us a broken event stream.
								index0 = findNewActiveIndex(@event, index0 == index1 ? -1 : mActiveId1, index0);
								mActiveId0 = @event.getPointerId(index0);
							}
							mActive0MostRecent = false;
							setContext(@event);
							// Check if we have a sloppy gesture. If so, delay
							// the beginning of the gesture until we're sure that's
							// what the user wanted. Sloppy gestures can happen if the
							// edge of the user's hand is touching the screen, for example.
							float edgeSlop = mEdgeSlop;
							float rightSlop = mRightSlopEdge;
							float bottomSlop = mBottomSlopEdge;
							float x0 = getRawX(@event, index0);
							float y0 = getRawY(@event, index0);
							float x1 = getRawX(@event, index1);
							float y1 = getRawY(@event, index1);
							bool p0sloppy = x0 < edgeSlop || y0 < edgeSlop || x0 > rightSlop || y0 > bottomSlop;
							bool p1sloppy = x1 < edgeSlop || y1 < edgeSlop || x1 > rightSlop || y1 > bottomSlop;
							if (p0sloppy && p1sloppy)
							{
								mFocusX = -1;
								mFocusY = -1;
								mSloppyGesture = true;
							}
							else
							{
								if (p0sloppy)
								{
									mFocusX = @event.getX(index1);
									mFocusY = @event.getY(index1);
									mSloppyGesture = true;
								}
								else
								{
									if (p1sloppy)
									{
										mFocusX = @event.getX(index0);
										mFocusY = @event.getY(index0);
										mSloppyGesture = true;
									}
									else
									{
										mSloppyGesture = false;
										mGestureInProgress = mListener.onScaleBegin(this);
									}
//.........这里部分代码省略.........

		public override bool onInterceptTouchEvent(android.view.MotionEvent ev)
		{
			int action = ev.getAction();
			if ((action == android.view.MotionEvent.ACTION_MOVE) && (mIsBeingDragged))
			{
				return true;
			}
			switch (action & android.view.MotionEvent.ACTION_MASK)
			{
				case android.view.MotionEvent.ACTION_MOVE:
				{
					int activePointerId = mActivePointerId;
					if (activePointerId == INVALID_POINTER)
					{
						// If we don't have a valid id, the touch down wasn't on content.
						break;
					}
					int pointerIndex = ev.findPointerIndex(activePointerId);
					float x = ev.getX(pointerIndex);
					int xDiff = (int)System.Math.Abs(x - mLastMotionX);
					if (xDiff > mTouchSlop)
					{
						mIsBeingDragged = true;
						mLastMotionX = x;
						initVelocityTrackerIfNotExists();
						mVelocityTracker.addMovement(ev);
						if (mParent != null)
						{
							mParent.requestDisallowInterceptTouchEvent(true);
						}
					}
					break;
				}

				case android.view.MotionEvent.ACTION_DOWN:
				{
					float x = ev.getX();
					if (!inChild((int)x, (int)ev.getY()))
					{
						mIsBeingDragged = false;
						recycleVelocityTracker();
						break;
					}
					mLastMotionX = x;
					mActivePointerId = ev.getPointerId(0);
					initOrResetVelocityTracker();
					mVelocityTracker.addMovement(ev);
					mIsBeingDragged = !mScroller.isFinished();
					break;
				}

				case android.view.MotionEvent.ACTION_CANCEL:
				case android.view.MotionEvent.ACTION_UP:
				{
					mIsBeingDragged = false;
					mActivePointerId = INVALID_POINTER;
					if (mScroller.springBack(mScrollX, mScrollY, 0, getScrollRange(), 0, 0))
					{
						invalidate();
					}
					break;
				}

				case android.view.MotionEvent.ACTION_POINTER_DOWN:
				{
					int index = ev.getActionIndex();
					mLastMotionX = ev.getX(index);
					mActivePointerId = ev.getPointerId(index);
					break;
				}

				case android.view.MotionEvent.ACTION_POINTER_UP:
				{
					onSecondaryPointerUp(ev);
					mLastMotionX = ev.getX(ev.findPointerIndex(mActivePointerId));
					break;
				}
			}
			return mIsBeingDragged;
		}

		private void handlePointerUp(android.view.MotionEvent ev)
		{
			int pointerIndex = ev.findPointerIndex(mActivePointerId);
			float newY = ev.getY(pointerIndex);
			int deltaY = (int)(newY - mInitialY);
			mLastInteractionTime = Sharpen.Util.CurrentTimeMillis;
			if (mVelocityTracker != null)
			{
				mVelocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
				mYVelocity = (int)mVelocityTracker.getYVelocity(mActivePointerId);
			}
			if (mVelocityTracker != null)
			{
				mVelocityTracker.recycle();
				mVelocityTracker = null;
			}
			if (deltaY > mSwipeThreshold && mSwipeGestureType == GESTURE_SLIDE_DOWN && mStackSlider
				.mMode == android.widget.StackView.StackSlider.NORMAL_MODE)
			{
				// We reset the gesture variable, because otherwise we will ignore showPrevious() /
				// showNext();
				mSwipeGestureType = GESTURE_NONE;
				// Swipe threshold exceeded, swipe down
				if (mStackMode == ITEMS_SLIDE_UP)
				{
					showPrevious();
				}
				else
				{
					showNext();
				}
				mHighlight.bringToFront();
			}
			else
			{
				if (deltaY < -mSwipeThreshold && mSwipeGestureType == GESTURE_SLIDE_UP && mStackSlider
					.mMode == android.widget.StackView.StackSlider.NORMAL_MODE)
				{
					// We reset the gesture variable, because otherwise we will ignore showPrevious() /
					// showNext();
					mSwipeGestureType = GESTURE_NONE;
					// Swipe threshold exceeded, swipe up
					if (mStackMode == ITEMS_SLIDE_UP)
					{
						showNext();
					}
					else
					{
						showPrevious();
					}
					mHighlight.bringToFront();
				}
				else
				{
					if (mSwipeGestureType == GESTURE_SLIDE_UP)
					{
						// Didn't swipe up far enough, snap back down
						int duration;
						float finalYProgress = (mStackMode == ITEMS_SLIDE_DOWN) ? 1 : 0;
						if (mStackMode == ITEMS_SLIDE_UP || mStackSlider.mMode != android.widget.StackView
							.StackSlider.NORMAL_MODE)
						{
							duration = Sharpen.Util.Round(mStackSlider.getDurationForNeutralPosition());
						}
						else
						{
							duration = Sharpen.Util.Round(mStackSlider.getDurationForOffscreenPosition());
						}
						android.widget.StackView.StackSlider animationSlider = new android.widget.StackView
							.StackSlider(this, mStackSlider);
						android.animation.PropertyValuesHolder snapBackY = android.animation.PropertyValuesHolder
							.ofFloat("YProgress", finalYProgress);
						android.animation.PropertyValuesHolder snapBackX = android.animation.PropertyValuesHolder
							.ofFloat("XProgress", 0.0f);
						android.animation.ObjectAnimator pa = android.animation.ObjectAnimator.ofPropertyValuesHolder
							(animationSlider, snapBackX, snapBackY);
						pa.setDuration(duration);
						pa.setInterpolator(new android.view.animation.LinearInterpolator());
						pa.start();
					}
					else
					{
						if (mSwipeGestureType == GESTURE_SLIDE_DOWN)
						{
							// Didn't swipe down far enough, snap back up
							float finalYProgress = (mStackMode == ITEMS_SLIDE_DOWN) ? 0 : 1;
							int duration;
							if (mStackMode == ITEMS_SLIDE_DOWN || mStackSlider.mMode != android.widget.StackView
								.StackSlider.NORMAL_MODE)
							{
								duration = Sharpen.Util.Round(mStackSlider.getDurationForNeutralPosition());
							}
							else
							{
								duration = Sharpen.Util.Round(mStackSlider.getDurationForOffscreenPosition());
							}
							android.widget.StackView.StackSlider animationSlider = new android.widget.StackView
								.StackSlider(this, mStackSlider);
							android.animation.PropertyValuesHolder snapBackY = android.animation.PropertyValuesHolder
								.ofFloat("YProgress", finalYProgress);
//.........这里部分代码省略.........

		public override bool onTouchEvent(android.view.MotionEvent ev)
		{
			base.onTouchEvent(ev);
			int action = ev.getAction();
			int pointerIndex = ev.findPointerIndex(mActivePointerId);
			if (pointerIndex == INVALID_POINTER)
			{
				// no data for our primary pointer, this shouldn't happen, log it
				android.util.Log.d(TAG, "Error: No data for our primary pointer.");
				return false;
			}
			float newY = ev.getY(pointerIndex);
			float newX = ev.getX(pointerIndex);
			float deltaY = newY - mInitialY;
			float deltaX = newX - mInitialX;
			if (mVelocityTracker == null)
			{
				mVelocityTracker = android.view.VelocityTracker.obtain();
			}
			mVelocityTracker.addMovement(ev);
			switch (action & android.view.MotionEvent.ACTION_MASK)
			{
				case android.view.MotionEvent.ACTION_MOVE:
				{
					beginGestureIfNeeded(deltaY);
					float rx = deltaX / (mSlideAmount * 1.0f);
					if (mSwipeGestureType == GESTURE_SLIDE_DOWN)
					{
						float r = (deltaY - mTouchSlop * 1.0f) / mSlideAmount * 1.0f;
						if (mStackMode == ITEMS_SLIDE_DOWN)
						{
							r = 1 - r;
						}
						mStackSlider.setYProgress(1 - r);
						mStackSlider.setXProgress(rx);
						return true;
					}
					else
					{
						if (mSwipeGestureType == GESTURE_SLIDE_UP)
						{
							float r = -(deltaY + mTouchSlop * 1.0f) / mSlideAmount * 1.0f;
							if (mStackMode == ITEMS_SLIDE_DOWN)
							{
								r = 1 - r;
							}
							mStackSlider.setYProgress(r);
							mStackSlider.setXProgress(rx);
							return true;
						}
					}
					break;
				}

				case android.view.MotionEvent.ACTION_UP:
				{
					handlePointerUp(ev);
					break;
				}

				case android.view.MotionEvent.ACTION_POINTER_UP:
				{
					onSecondaryPointerUp(ev);
					break;
				}

				case android.view.MotionEvent.ACTION_CANCEL:
				{
					mActivePointerId = INVALID_POINTER;
					mSwipeGestureType = GESTURE_NONE;
					break;
				}
			}
			return true;
		}

		public override bool onInterceptTouchEvent(android.view.MotionEvent ev)
		{
			int action = ev.getAction();
			switch (action & android.view.MotionEvent.ACTION_MASK)
			{
				case android.view.MotionEvent.ACTION_DOWN:
				{
					if (mActivePointerId == INVALID_POINTER)
					{
						mInitialX = ev.getX();
						mInitialY = ev.getY();
						mActivePointerId = ev.getPointerId(0);
					}
					break;
				}

				case android.view.MotionEvent.ACTION_MOVE:
				{
					int pointerIndex = ev.findPointerIndex(mActivePointerId);
					if (pointerIndex == INVALID_POINTER)
					{
						// no data for our primary pointer, this shouldn't happen, log it
						android.util.Log.d(TAG, "Error: No data for our primary pointer.");
						return false;
					}
					float newY = ev.getY(pointerIndex);
					float deltaY = newY - mInitialY;
					beginGestureIfNeeded(deltaY);
					break;
				}

				case android.view.MotionEvent.ACTION_POINTER_UP:
				{
					onSecondaryPointerUp(ev);
					break;
				}

				case android.view.MotionEvent.ACTION_UP:
				case android.view.MotionEvent.ACTION_CANCEL:
				{
					mActivePointerId = INVALID_POINTER;
					mSwipeGestureType = GESTURE_NONE;
					break;
				}
			}
			return mSwipeGestureType != GESTURE_NONE;
		}

		public override bool onInterceptTouchEvent(android.view.MotionEvent ev)
		{
			int action = ev.getAction();
			if ((action == android.view.MotionEvent.ACTION_MOVE) && (mIsBeingDragged))
			{
				return true;
			}
			switch (action & android.view.MotionEvent.ACTION_MASK)
			{
				case android.view.MotionEvent.ACTION_MOVE:
				{
					int activePointerId = mActivePointerId;
					if (activePointerId == INVALID_POINTER)
					{
						// If we don't have a valid id, the touch down wasn't on content.
						break;
					}
					int pointerIndex = ev.findPointerIndex(activePointerId);
					float y = ev.getY(pointerIndex);
					int yDiff = (int)System.Math.Abs(y - mLastMotionY);
					if (yDiff > mTouchSlop)
					{
						mIsBeingDragged = true;
						mLastMotionY = y;
						initVelocityTrackerIfNotExists();
						mVelocityTracker.addMovement(ev);
						if (mScrollStrictSpan == null)
						{
							mScrollStrictSpan = android.os.StrictMode.enterCriticalSpan("ScrollView-scroll");
						}
					}
					break;
				}

				case android.view.MotionEvent.ACTION_DOWN:
				{
					float y = ev.getY();
					if (!inChild((int)ev.getX(), (int)y))
					{
						mIsBeingDragged = false;
						recycleVelocityTracker();
						break;
					}
					mLastMotionY = y;
					mActivePointerId = ev.getPointerId(0);
					initOrResetVelocityTracker();
					mVelocityTracker.addMovement(ev);
					mIsBeingDragged = !mScroller.isFinished();
					if (mIsBeingDragged && mScrollStrictSpan == null)
					{
						mScrollStrictSpan = android.os.StrictMode.enterCriticalSpan("ScrollView-scroll");
					}
					break;
				}

				case android.view.MotionEvent.ACTION_CANCEL:
				case android.view.MotionEvent.ACTION_UP:
				{
					mIsBeingDragged = false;
					mActivePointerId = INVALID_POINTER;
					recycleVelocityTracker();
					if (mScroller.springBack(mScrollX, mScrollY, 0, 0, 0, getScrollRange()))
					{
						invalidate();
					}
					break;
				}

				case android.view.MotionEvent.ACTION_POINTER_UP:
				{
					onSecondaryPointerUp(ev);
					break;
				}
			}
			return mIsBeingDragged;
		}