今天看啥
热点:

android 上下左右都能滑动的是类似scorllview效果


上下左右都能滑动且带平滑效果的类似scorllview

代码:HVScrollView.java
package com.yqy.yqy_frame.view;

import java.util.List;

import android.content.Context;
import android.graphics.Rect;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.animation.AnimationUtils;
import android.view.animation.TranslateAnimation;
import android.widget.FrameLayout;
import android.widget.Scroller;

/**
 * 类功能描述: 具有弹性效果的全方向ScrollView,参考ScrollView与HorizontalScrollView源码
 * 
 * @author YQY
 * 
 */
public class HVScrollView extends FrameLayout {
	static final int ANIMATED_SCROLL_GAP = 250;

	static final float MAX_SCROLL_FACTOR = 0.5f;

	private long mLastScroll;

	private final Rect mTempRect = new Rect();
	private Scroller mScroller;

	/**
	 * Flag to indicate that we are moving focus ourselves. This is so the code
	 * that watches for focus changes initiated outside this ScrollView knows
	 * that it does not have to do anything.
	 */
	private boolean mScrollViewMovedFocus;

	/**
	 * Position of the last motion event.
	 */
	private float mLastMotionY;
	private float mLastMotionX;

	/**
	 * True when the layout has changed but the traversal has not come through
	 * yet. Ideally the view hierarchy would keep track of this for us.
	 */
	private boolean mIsLayoutDirty = true;

	/**
	 * The child to give focus to in the event that a child has requested focus
	 * while the layout is dirty. This prevents the scroll from being wrong if
	 * the child has not been laid out before requesting focus.
	 */
	private View mChildToScrollTo = null;

	/**
	 * True if the user is currently dragging this ScrollView around. This is
	 * not the same as 'is being flinged', which can be checked by
	 * mScroller.isFinished() (flinging begins when the user lifts his finger).
	 */
	private boolean mIsBeingDragged = false;

	/**
	 * Determines speed during touch scrolling
	 */
	private VelocityTracker mVelocityTracker;

	/**
	 * When set to true, the scroll view measure its child to make it fill the
	 * currently visible area.
	 */
	private boolean mFillViewport;

	/**
	 * Whether arrow scrolling is animated.
	 */
	private boolean mSmoothScrollingEnabled = true;

	private int mTouchSlop;
	private int mMinimumVelocity;
	private int mMaximumVelocity;

	/**
	 * ID of the active pointer. This is used to retain consistency during
	 * drags/flings if multiple pointers are used.
	 */
	private int mActivePointerId = INVALID_POINTER;

	/**
	 * Sentinel value for no current active pointer. Used by
	 * {@link #mActivePointerId}.
	 */
	private static final int INVALID_POINTER = -1;

	private boolean mFlingEnabled = true;

	public HVScrollView(Context context) {
		this(context, null);
	}

	public HVScrollView(Context context, AttributeSet attrs) {
		super(context, attrs);
		initScrollView();
	}

	@Override
	protected float getTopFadingEdgeStrength() {
		if (getChildCount() == 0) {
			return 0.0f;
		}

		final int length = getVerticalFadingEdgeLength();
		if (getScrollY() < length) {
			return getScrollY() / (float) length;
		}

		return 1.0f;
	}

	@Override
	protected float getLeftFadingEdgeStrength() {
		if (getChildCount() == 0) {
			return 0.0f;
		}

		final int length = getHorizontalFadingEdgeLength();
		if (getScrollX() < length) {
			return getScrollX() / (float) length;
		}

		return 1.0f;
	}

	@Override
	protected float getRightFadingEdgeStrength() {
		if (getChildCount() == 0) {
			return 0.0f;
		}

		final int length = getHorizontalFadingEdgeLength();
		final int rightEdge = getWidth() - getPaddingRight();
		final int span = getChildAt(0).getRight() - getScrollX() - rightEdge;
		if (span < length) {
			return span / (float) length;
		}

		return 1.0f;
	}

	@Override
	protected float getBottomFadingEdgeStrength() {
		if (getChildCount() == 0) {
			return 0.0f;
		}

		final int length = getVerticalFadingEdgeLength();
		final int bottomEdge = getHeight() - getPaddingBottom();
		final int span = getChildAt(0).getBottom() - getScrollY() - bottomEdge;
		if (span < length) {
			return span / (float) length;
		}

		return 1.0f;
	}

	/**
	 * @return The maximum amount this scroll view will scroll in response to an
	 *         arrow event.
	 */
	public int getMaxScrollAmountV() {
		return (int) (MAX_SCROLL_FACTOR * (getBottom() - getTop()));
	}

	public int getMaxScrollAmountH() {
		return (int) (MAX_SCROLL_FACTOR * (getRight() - getLeft()));
	}

	private void initScrollView() {
		mScroller = new Scroller(getContext());
		setFocusable(true);
		setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
		setWillNotDraw(false);
		setFillViewport(true);//子布局fill有效,宽高可以设置为最大
		final ViewConfiguration configuration = ViewConfiguration
				.get(getContext());
		mTouchSlop = configuration.getScaledTouchSlop();
		mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
		mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
	}

	@Override
	public void addView(View child) {
		if (getChildCount() > 0) {
			throw new IllegalStateException(
					ScrollView can host only one direct child);
		}

		super.addView(child);
	}

	@Override
	public void addView(View child, int index) {
		if (getChildCount() > 0) {
			throw new IllegalStateException(
					ScrollView can host only one direct child);
		}

		super.addView(child, index);
	}

	@Override
	public void addView(View child, ViewGroup.LayoutParams params) {
		if (getChildCount() > 0) {
			throw new IllegalStateException(
					ScrollView can host only one direct child);
		}

		super.addView(child, params);
	}

	@Override
	public void addView(View child, int index, ViewGroup.LayoutParams params) {
		if (getChildCount() > 0) {
			throw new IllegalStateException(
					ScrollView can host only one direct child);
		}

		super.addView(child, index, params);
	}

	/**
	 * @return Returns true this ScrollView can be scrolled
	 */
	private boolean canScrollV() {
		View child = getChildAt(0);
		if (child != null) {
			int childHeight = child.getHeight();
			return getHeight() < childHeight + getPaddingTop()
					+ getPaddingBottom();
		}
		return false;
	}

	private boolean canScrollH() {
		View child = getChildAt(0);
		if (child != null) {
			int childWidth = child.getWidth();
			return getWidth() < childWidth + getPaddingLeft()
					+ getPaddingRight();
		}
		return false;
	}

	/**
	 * Indicates whether this ScrollView's content is stretched to fill the
	 * viewport.
	 * 
	 * @return True if the content fills the viewport, false otherwise.
	 */
	public boolean isFillViewport() {
		return mFillViewport;
	}

	/**
	 * Indicates this ScrollView whether it should stretch its content height to
	 * fill the viewport or not.
	 * 
	 * @param fillViewport
	 *            True to stretch the content's height to the viewport's
	 *            boundaries, false otherwise.
	 */
	public void setFillViewport(boolean fillViewport) {
		if (fillViewport != mFillViewport) {
			mFillViewport = fillViewport;
			requestLayout();
		}
	}

	/**
	 * @return Whether arrow scrolling will animate its transition.
	 */
	public boolean isSmoothScrollingEnabled() {
		return mSmoothScrollingEnabled;
	}

	/**
	 * Set whether arrow scrolling will animate its transition.
	 * 
	 * @param smoothScrollingEnabled
	 *            whether arrow scrolling will animate its transition
	 */
	public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) {
		mSmoothScrollingEnabled = smoothScrollingEnabled;
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);

		if (!mFillViewport) {
			return;
		}

		final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
		final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
		if (heightMode == MeasureSpec.UNSPECIFIED
				&& widthMode == MeasureSpec.UNSPECIFIED) {
			return;
		}

		if (getChildCount() > 0) {
			final View child = getChildAt(0);
			int height = getMeasuredHeight();
			int width = getMeasuredWidth();
			if (child.getMeasuredHeight() < height
					|| child.getMeasuredWidth() < width) {
				width -= getPaddingLeft();
				width -= getPaddingRight();
				int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(width,
						MeasureSpec.EXACTLY);

				height -= getPaddingTop();
				height -= getPaddingBottom();
				int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
						height, MeasureSpec.EXACTLY);

				child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
			}
		}
	}

	@Override
	public boolean dispatchKeyEvent(KeyEvent event) {
		// Let the focused view and/or our descendants get the key first
		return super.dispatchKeyEvent(event) || executeKeyEvent(event);
	}

	/**
	 * You can call this function yourself to have the scroll view perform
	 * scrolling from a key event, just as if the event had been dispatched to
	 * it by the view hierarchy.
	 * 
	 * @param event
	 *            The key event to execute.
	 * @return Return true if the event was handled, else false.
	 */
	public boolean executeKeyEvent(KeyEvent event) {
		mTempRect.setEmpty();

		boolean handled = false;

		if (event.getAction() == KeyEvent.ACTION_DOWN) {
			switch (event.getKeyCode()) {
			case KeyEvent.KEYCODE_DPAD_LEFT:
				if (canScrollH()) {
					if (!event.isAltPressed()) {
						handled = arrowScrollH(View.FOCUS_LEFT);
					} else {
						handled = fullScrollH(View.FOCUS_LEFT);
					}
				}
				break;
			case KeyEvent.KEYCODE_DPAD_RIGHT:
				if (canScrollH()) {
					if (!event.isAltPressed()) {
						handled = arrowScrollH(View.FOCUS_RIGHT);
					} else {
						handled = fullScrollH(View.FOCUS_RIGHT);
					}
				}
				break;
			case KeyEvent.KEYCODE_DPAD_UP:
				if (canScrollV()) {
					if (!event.isAltPressed()) {
						handled = arrowScrollV(View.FOCUS_UP);
					} else {
						handled = fullScrollV(View.FOCUS_UP);
					}
				}
				break;
			case KeyEvent.KEYCODE_DPAD_DOWN:
				if (canScrollV()) {
					if (!event.isAltPressed()) {
						handled = arrowScrollV(View.FOCUS_DOWN);
					} else {
						handled = fullScrollV(View.FOCUS_DOWN);
					}
				}
				break;
			}
		}
		return handled;
	}

	private boolean inChild(int x, int y) {
		if (getChildCount() > 0) {
			final int scrollX = getScrollX();
			final int scrollY = getScrollY();
			final View child = getChildAt(0);
			return !(y < child.getTop() - scrollY
					|| y >= child.getBottom() - scrollY
					|| x < child.getLeft() - scrollX || x >= child.getRight()
					- scrollX);
		}
		return false;
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
		/*
		 * This method JUST determines whether we want to intercept the motion.
		 * If we return true, onMotionEvent will be called and we do the actual
		 * scrolling there.
		 */

		/*
		 * Shortcut the most recurring case: the user is in the dragging state
		 * and he is moving his finger. We want to intercept this motion.
		 */
		final int action = ev.getAction();
		if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) {
			return true;
		}

		switch (action & MotionEvent.ACTION_MASK) {
		case MotionEvent.ACTION_MOVE: {
			/*
			 * mIsBeingDragged == false, otherwise the shortcut would have
			 * caught it. Check whether the user has moved far enough from his
			 * original down touch.
			 */

			/*
			 * Locally do absolute value. mLastMotionY is set to the y value of
			 * the down event.
			 */
			final int activePointerId = mActivePointerId;
			if (activePointerId == INVALID_POINTER) {
				// If we don't have a valid id, the touch down wasn't on
				// content.
				break;
			}

			final int pointerIndex = ev.findPointerIndex(activePointerId);
			final float y = ev.getY(pointerIndex);
			final int yDiff = (int) Math.abs(y - mLastMotionY);
			if (yDiff > mTouchSlop) {
				mIsBeingDragged = true;
				mLastMotionY = y;
			}
			final float x = ev.getX(pointerIndex);
			final int xDiff = (int) Math.abs(x - mLastMotionX);
			if (xDiff > mTouchSlop) {
				mIsBeingDragged = true;
				mLastMotionX = x;
			}
			break;
		}

		case MotionEvent.ACTION_DOWN: {
			final float x = ev.getX();
			final float y = ev.getY();
			if (!inChild((int) x, (int) y)) {
				mIsBeingDragged = false;
				break;
			}

			/*
			 * Remember location of down touch. ACTION_DOWN always refers to
			 * pointer index 0.
			 */
			mLastMotionY = y;
			mLastMotionX = x;
			mActivePointerId = ev.getPointerId(0);

			/*
			 * If being flinged and user touches the screen, initiate drag;
			 * otherwise don't. mScroller.isFinished should be false when being
			 * flinged.
			 */
			mIsBeingDragged = !mScroller.isFinished();
			break;
		}

		case MotionEvent.ACTION_CANCEL:
		case MotionEvent.ACTION_UP:
			/* Release the drag */
			mIsBeingDragged = false;
			mActivePointerId = INVALID_POINTER;
			break;
		case MotionEvent.ACTION_POINTER_UP:
			onSecondaryPointerUp(ev);
			break;
		}

		/*
		 * The only time we want to intercept motion events is if we are in the
		 * drag mode.
		 */
		return mIsBeingDragged;
	}

	private boolean scrollableOutsideTouch = false;

	/**
	 * 设置scroller是否可以滑动内容当触屏事件在chileview之外 default:false
	 * 
	 * @param b
	 *            true-可以,false-不可
	 */
	public void setScrollableOutsideChile(boolean b) {
		scrollableOutsideTouch = b;
	}

	private boolean flexible = true;

	/**
	 * 设置是否可有弹性效果
	 * 
	 * @param b
	 *            true-可以,false-不可
	 */
	public void setFlexible(boolean b) {
		flexible = b;
	}

	private long lastEvenTime;

	@Override
	public boolean onTouchEvent(MotionEvent ev) {

		if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
			// Don't handle edge touches immediately -- they may actually belong
			// to one of our
			// descendants.
			return false;
		}

		if (mVelocityTracker == null) {
			mVelocityTracker = VelocityTracker.obtain();
		}
		mVelocityTracker.addMovement(ev);

		final int action = ev.getAction();

		switch (action & MotionEvent.ACTION_MASK) {
		case MotionEvent.ACTION_DOWN: {
			final float x = ev.getX();
			final float y = ev.getY();
			if (!(mIsBeingDragged = inChild((int) x, (int) y))
					&& !scrollableOutsideTouch) {
				return false;
			}
			// 阻止测试人员暴力测试
			if (System.currentTimeMillis() - lastEvenTime < 200) {
				ev.setAction(MotionEvent.ACTION_CANCEL);
			}
			lastEvenTime = System.currentTimeMillis();
			/*
			 * If being flinged and user touches, stop the fling. isFinished
			 * will be false if being flinged.
			 */
			if (!mScroller.isFinished()) {
				mScroller.abortAnimation();
			}

			// Remember where the motion event started
			mLastMotionY = y;
			mLastMotionX = x;
			mActivePointerId = ev.getPointerId(0);
			break;
		}
		case MotionEvent.ACTION_MOVE:
			if (mIsBeingDragged || scrollableOutsideTouch) {
				// Scroll to follow the motion event
				final int activePointerIndex = ev
						.findPointerIndex(mActivePointerId);
				final float y = ev.getY(activePointerIndex);
				final int deltaY = (int) (mLastMotionY - y);//恢复纵向滚动
//				final int deltaY = 0;//禁止纵向滚动
				mLastMotionY = y;

				final float x = ev.getX(activePointerIndex);
//				final int deltaX = (int) (mLastMotionX - x);//恢复横向滚动
				final int deltaX = 0;//禁止横向滚动
				mLastMotionX = x;
				// 全方向滚动
				scrollBy(deltaX, deltaY);
				// 当滚动到边界时就不会再滚动,这时移动布局
				if (isNeedMove() && flexible) {
					if (normal.isEmpty()) {
						// 保存正常的布局属性
						normal.set(inner.getLeft(), inner.getTop(),
								inner.getRight(), inner.getBottom());
					}
					// 移动布局
					inner.layout(inner.getLeft() - deltaX / 2, inner.getTop()
							- deltaY / 2, inner.getRight() - deltaX / 2,
							inner.getBottom() - deltaY / 2);
				}
			}
			break;
		case MotionEvent.ACTION_UP:
			if (mIsBeingDragged || scrollableOutsideTouch) {
				if (mFlingEnabled) {
					final VelocityTracker velocityTracker = mVelocityTracker;
					velocityTracker.computeCurrentVelocity(1000,
							mMaximumVelocity);
					int initialVelocitx = (int) velocityTracker
							.getXVelocity(mActivePointerId);
					int initialVelocity = (int) velocityTracker
							.getYVelocity(mActivePointerId);

					if (getChildCount() > 0) {
						if (Math.abs(initialVelocitx) > initialVelocitx
								|| Math.abs(initialVelocity) > mMinimumVelocity) {
							fling(-initialVelocitx, -initialVelocity);
						}

					}
				}
				if (isNeedAnimation()) {
					animation();
				}
				mActivePointerId = INVALID_POINTER;
				mIsBeingDragged = false;

				if (mVelocityTracker != null) {
					mVelocityTracker.recycle();
					mVelocityTracker = null;
				}
			}
			break;
		case MotionEvent.ACTION_CANCEL:
			if (mIsBeingDragged && getChildCount() > 0) {
				mActivePointerId = INVALID_POINTER;
				mIsBeingDragged = false;
				if (mVelocityTracker != null) {
					mVelocityTracker.recycle();
					mVelocityTracker = null;
				}
			}
			break;
		case MotionEvent.ACTION_POINTER_UP:
			onSecondaryPointerUp(ev);
			break;
		}
		return true;
	}

	private void onSecondaryPointerUp(MotionEvent ev) {
		final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
		final int pointerId = ev.getPointerId(pointerIndex);
		if (pointerId == mActivePointerId) {
			// This was our active pointer going up. Choose a new
			// active pointer and adjust accordingly.
			final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
			mLastMotionX = ev.getX(newPointerIndex);
			mLastMotionY = ev.getY(newPointerIndex);
			mActivePointerId = ev.getPointerId(newPointerIndex);
			if (mVelocityTracker != null) {
				mVelocityTracker.clear();
			}
		}
	}

	/**
	 * 

* Finds the next focusable component that fits in the specified bounds. *

* * @param topFocus * look for a candidate is the one at the top of the bounds if * topFocus is true, or at the bottom of the bounds if topFocus * is false * @param top * the top offset of the bounds in which a focusable must be * found * @param bottom * the bottom offset of the bounds in which a focusable must be * found * @return the next focusable component in the bounds or null if none can be * found */ private View findFocusableViewInBoundsV(boolean topFocus, int top, int bottom) { List focusables = getFocusables(View.FOCUS_FORWARD); View focusCandidate = null; /* * A fully contained focusable is one where its top is below the bound's * top, and its bottom is above the bound's bottom. A partially * contained focusable is one where some part of it is within the * bounds, but it also has some part that is not within bounds. A fully * contained focusable is preferred to a partially contained focusable. */ boolean foundFullyContainedFocusable = false; int count = focusables.size(); for (int i = 0; i < count; i++) { View view = focusables.get(i); int viewTop = view.getTop(); int viewBottom = view.getBottom(); if (top < viewBottom && viewTop < bottom) { /* * the focusable is in the target area, it is a candidate for * focusing */ final boolean viewIsFullyContained = (top < viewTop) && (viewBottom < bottom); if (focusCandidate == null) { /* No candidate, take this one */ focusCandidate = view; foundFullyContainedFocusable = viewIsFullyContained; } else { final boolean viewIsCloserToBoundary = (topFocus && viewTop < focusCandidate .getTop()) || (!topFocus && viewBottom > focusCandidate .getBottom()); if (foundFullyContainedFocusable) { if (viewIsFullyContained && viewIsCloserToBoundary) { /* * We're dealing with only fully contained views, so * it has to be closer to the boundary to beat our * candidate */ focusCandidate = view; } } else { if (viewIsFullyContained) { /* * Any fully contained view beats a partially * contained view */ focusCandidate = view; foundFullyContainedFocusable = true; } else if (viewIsCloserToBoundary) { /* * Partially contained view beats another partially * contained view if it's closer */ focusCandidate = view; } } } } } return focusCandidate; } private View findFocusableViewInBoundsH(boolean leftFocus, int left, int right) { List focusables = getFocusables(View.FOCUS_FORWARD); View focusCandidate = null; /* * A fully contained focusable is one where its left is below the * bound's left, and its right is above the bound's right. A partially * contained focusable is one where some part of it is within the * bounds, but it also has some part that is not within bounds. A fully * contained focusable is preferred to a partially contained focusable. */ boolean foundFullyContainedFocusable = false; int count = focusables.size(); for (int i = 0; i < count; i++) { View view = focusables.get(i); int viewLeft = view.getLeft(); int viewRight = view.getRight(); if (left < viewRight && viewLeft < right) { /* * the focusable is in the target area, it is a candidate for * focusing */ final boolean viewIsFullyContained = (left < viewLeft) && (viewRight < right); if (focusCandidate == null) { /* No candidate, take this one */ focusCandidate = view; foundFullyContainedFocusable = viewIsFullyContained; } else { final boolean viewIsCloserToBoundary = (leftFocus && viewLeft < focusCandidate .getLeft()) || (!leftFocus && viewRight > focusCandidate .getRight()); if (foundFullyContainedFocusable) { if (viewIsFullyContained && viewIsCloserToBoundary) { /* * We're dealing with only fully contained views, so * it has to be closer to the boundary to beat our * candidate */ focusCandidate = view; } } else { if (viewIsFullyContained) { /* * Any fully contained view beats a partially * contained view */ focusCandidate = view; foundFullyContainedFocusable = true; } else if (viewIsCloserToBoundary) { /* * Partially contained view beats another partially * contained view if it's closer */ focusCandidate = view; } } } } } return focusCandidate; } /** *

* Handles scrolling in response to a home/end shortcut press. This method * will scroll the view to the top or bottom and give the focus to the * topmost/bottommost component in the new visible area. If no component is * a good candidate for focus, this scrollview reclaims the focus. *

* * @param direction * the scroll direction: {@link android.view.View#FOCUS_UP} to go * the top of the view or {@link android.view.View#FOCUS_DOWN} to * go the bottom * @return true if the key event is consumed by this method, false otherwise */ public boolean fullScrollV(int direction) { boolean down = direction == View.FOCUS_DOWN; int height = getHeight(); mTempRect.top = 0; mTempRect.bottom = height; if (down) { int count = getChildCount(); if (count > 0) { View view = getChildAt(count - 1); mTempRect.bottom = view.getBottom(); mTempRect.top = mTempRect.bottom - height; } } return scrollAndFocusV(direction, mTempRect.top, mTempRect.bottom); } public boolean fullScrollH(int direction) { boolean right = direction == View.FOCUS_RIGHT; int width = getWidth(); mTempRect.left = 0; mTempRect.right = width; if (right) { int count = getChildCount(); if (count > 0) { View view = getChildAt(0); mTempRect.right = view.getRight(); mTempRect.left = mTempRect.right - width; } } return scrollAndFocusH(direction, mTempRect.left, mTempRect.right); } /** *

* Scrolls the view to make the area defined by top and * bottom visible. This method attempts to give the focus to a * component visible in this area. If no component can be focused in the new * visible area, the focus is reclaimed by this scrollview. *

* * @param direction * the scroll direction: {@link android.view.View#FOCUS_UP} to go * upward {@link android.view.View#FOCUS_DOWN} to downward * @param top * the top offset of the new area to be made visible * @param bottom * the bottom offset of the new area to be made visible * @return true if the key event is consumed by this method, false otherwise */ private boolean scrollAndFocusV(int direction, int top, int bottom) { boolean handled = true; int height = getHeight(); int containerTop = getScrollY(); int containerBottom = containerTop + height; boolean up = direction == View.FOCUS_UP; View newFocused = findFocusableViewInBoundsV(up, top, bottom); if (newFocused == null) { newFocused = this; } if (top >= containerTop && bottom <= containerBottom) { handled = false; } else { int delta = up ? (top - containerTop) : (bottom - containerBottom); doScrollY(delta); } if (newFocused != findFocus() && newFocused.requestFocus(direction)) { mScrollViewMovedFocus = true; mScrollViewMovedFocus = false; } return handled; } private boolean scrollAndFocusH(int direction, int left, int right) { boolean handled = true; int width = getWidth(); int containerLeft = getScrollX(); int containerRight = containerLeft + width; boolean goLeft = direction == View.FOCUS_LEFT; View newFocused = findFocusableViewInBoundsH(goLeft, left, right); if (newFocused == null) { newFocused = this; } if (left >= containerLeft && right <= containerRight) { handled = false; } else { int delta = goLeft ? (left - containerLeft) : (right - containerRight); doScrollX(delta); } if (newFocused != findFocus() && newFocused.requestFocus(direction)) { mScrollViewMovedFocus = true; mScrollViewMovedFocus = false; } return handled; } /** * Handle scrolling in response to an up or down arrow click. * * @param direction * The direction corresponding to the arrow key that was pressed * @return True if we consumed the event, false otherwise */ public boolean arrowScrollV(int direction) { View currentFocused = findFocus(); if (currentFocused == this) currentFocused = null; View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction); final int maxJump = getMaxScrollAmountV(); if (nextFocused != null && isWithinDeltaOfScreenV(nextFocused, maxJump, getHeight())) { nextFocused.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(nextFocused, mTempRect); int scrollDelta = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); doScrollY(scrollDelta); nextFocused.requestFocus(direction); } else { // no new focus int scrollDelta = maxJump; if (direction == View.FOCUS_UP && getScrollY() < scrollDelta) { scrollDelta = getScrollY(); } else if (direction == View.FOCUS_DOWN) { if (getChildCount() > 0) { int daBottom = getChildAt(0).getBottom(); int screenBottom = getScrollY() + getHeight(); if (daBottom - screenBottom < maxJump) { scrollDelta = daBottom - screenBottom; } } } if (scrollDelta == 0) { return false; } doScrollY(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta); } if (currentFocused != null && currentFocused.isFocused() && isOffScreenV(currentFocused)) { // previously focused item still has focus and is off screen, give // it up (take it back to ourselves) // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we // are sure to get it) final int descendantFocusability = getDescendantFocusability(); // save setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); requestFocus(); setDescendantFocusability(descendantFocusability); // restore } return true; } public boolean arrowScrollH(int direction) { View currentFocused = findFocus(); if (currentFocused == this) currentFocused = null; View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction); final int maxJump = getMaxScrollAmountH(); if (nextFocused != null && isWithinDeltaOfScreenH(nextFocused, maxJump)) { nextFocused.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(nextFocused, mTempRect); int scrollDelta = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); doScrollX(scrollDelta); nextFocused.requestFocus(direction); } else { // no new focus int scrollDelta = maxJump; if (direction == View.FOCUS_LEFT && getScrollX() < scrollDelta) { scrollDelta = getScrollX(); } else if (direction == View.FOCUS_RIGHT && getChildCount() > 0) { int daRight = getChildAt(0).getRight(); int screenRight = getScrollX() + getWidth(); if (daRight - screenRight < maxJump) { scrollDelta = daRight - screenRight; } } if (scrollDelta == 0) { return false; } doScrollX(direction == View.FOCUS_RIGHT ? scrollDelta : -scrollDelta); } if (currentFocused != null && currentFocused.isFocused() && isOffScreenH(currentFocused)) { // previously focused item still has focus and is off screen, give // it up (take it back to ourselves) // (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we // are sure to get it) final int descendantFocusability = getDescendantFocusability(); // save setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS); requestFocus(); setDescendantFocusability(descendantFocusability); // restore } return true; } /** * @return whether the descendant of this scroll view is scrolled off * screen. */ private boolean isOffScreenV(View descendant) { return !isWithinDeltaOfScreenV(descendant, 0, getHeight()); } private boolean isOffScreenH(View descendant) { return !isWithinDeltaOfScreenH(descendant, 0); } /** * @return whether the descendant of this scroll view is within delta pixels * of being on the screen. */ private boolean isWithinDeltaOfScreenV(View descendant, int delta, int height) { descendant.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(descendant, mTempRect); return (mTempRect.bottom + delta) >= getScrollY() && (mTempRect.top - delta) <= (getScrollY() + height); } private boolean isWithinDeltaOfScreenH(View descendant, int delta) { descendant.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(descendant, mTempRect); return (mTempRect.right + delta) >= getScrollX() && (mTempRect.left - delta) <= (getScrollX() + getWidth()); } /** * Smooth scroll by a Y delta * * @param delta * the number of pixels to scroll by on the Y axis */ private void doScrollY(int delta) { if (delta != 0) { if (mSmoothScrollingEnabled) { smoothScrollBy(0, delta); } else { scrollBy(0, delta); } } } private void doScrollX(int delta) { if (delta != 0) { if (mSmoothScrollingEnabled) { smoothScrollBy(delta, 0); } else { scrollBy(delta, 0); } } } /** * Like {@link View#scrollBy}, but scroll smoothly instead of immediately. * * @param dx * the number of pixels to scroll by on the X axis * @param dy * the number of pixels to scroll by on the Y axis */ public void smoothScrollBy(int dx, int dy) { if (getChildCount() == 0) { // Nothing to do. return; } long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll; if (duration > ANIMATED_SCROLL_GAP) { final int height = getHeight() - getPaddingBottom() - getPaddingTop(); final int bottom = getChildAt(0).getHeight(); final int maxY = Math.max(0, bottom - height); final int scrollY = getScrollY(); dy = Math.max(0, Math.min(scrollY + dy, maxY)) - scrollY; final int width = getWidth() - getPaddingRight() - getPaddingLeft(); final int right = getChildAt(0).getWidth(); final int maxX = Math.max(0, right - width); final int scrollX = getScrollX(); dx = Math.max(0, Math.min(scrollX + dx, maxX)) - scrollX; mScroller.startScroll(scrollX, scrollY, dx, dy); invalidate(); } else { if (!mScroller.isFinished()) { mScroller.abortAnimation(); } scrollBy(dx, dy); } mLastScroll = AnimationUtils.currentAnimationTimeMillis(); } /** * Like {@link #scrollTo}, but scroll smoothly instead of immediately. * * @param x * the position where to scroll on the X axis * @param y * the position where to scroll on the Y axis */ public final void smoothScrollTo(int x, int y) { smoothScrollBy(x - getScrollX(), y - getScrollY()); } /** *

* The scroll range of a scroll view is the overall height of all of its * children. *

*/ @Override protected int computeVerticalScrollRange() { final int count = getChildCount(); final int contentHeight = getHeight() - getPaddingBottom() - getPaddingTop(); if (count == 0) { return contentHeight; } return getChildAt(0).getBottom(); } @Override protected int computeHorizontalScrollRange() { final int count = getChildCount(); final int contentWidth = getWidth() - getPaddingLeft() - getPaddingRight(); if (count == 0) { return contentWidth; } return getChildAt(0).getRight(); } @Override protected int computeVerticalScrollOffset() { return Math.max(0, super.computeVerticalScrollOffset()); } @Override protected int computeHorizontalScrollOffset() { return Math.max(0, super.computeHorizontalScrollOffset()); } @Override protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) { int childWidthMeasureSpec; int childHeightMeasureSpec; childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); child.measure(childWidthMeasureSpec, childHeightMeasureSpec); } @Override protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed) { final MarginLayoutParams lp = (MarginLayoutParams) child .getLayoutParams(); final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec( lp.leftMargin + lp.rightMargin, MeasureSpec.UNSPECIFIED); final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec( lp.topMargin + lp.bottomMargin, MeasureSpec.UNSPECIFIED); child.measure(childWidthMeasureSpec, childHeightMeasureSpec); } @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { // This is called at drawing time by ViewGroup. We don't want to // re-show the scrollbars at this point, which scrollTo will do, // so we replicate most of scrollTo here. // // It's a little odd to call onScrollChanged from inside the // drawing. // // It is, except when you remember that computeScroll() is used to // animate scrolling. So unless we want to defer the // onScrollChanged() // until the end of the animated scrolling, we don't really have a // choice here. // // I agree. The alternative, which I think would be worse, is to // post // something and tell the subclasses later. This is bad because // there // will be a window where mScrollX/Y is different from what the app // thinks it is. // int x = mScroller.getCurrX(); int y = mScroller.getCurrY(); if (getChildCount() > 0) { View child = getChildAt(0); x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth()); y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight()); super.scrollTo(x, y); // getHeight()- child.getHeight()=y ->底部 y=0 ->顶端 // 惯性强度 mScroller.getDuration() } awakenScrollBars(); // Keep on drawing until the animation has finished. postInvalidate(); } } /** * Scrolls the view to the given child. * * @param child * the View to scroll to */ private void scrollToChild(View child) { child.getDrawingRect(mTempRect); /* Offset from child's local coordinates to ScrollView coordinates */ offsetDescendantRectToMyCoords(child, mTempRect); int scrollDeltaV = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); int scrollDeltaH = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); if (scrollDeltaH != 0 || scrollDeltaV != 0) { scrollBy(scrollDeltaH, scrollDeltaV); } } /** * If rect is off screen, scroll just enough to get it (or at least the * first screen size chunk of it) on screen. * * @param rect * The rectangle. * @param immediate * True to scroll immediately without animation * @return true if scrolling was performed */ private boolean scrollToChildRect(Rect rect, boolean immediate) { final int deltaV = computeScrollDeltaToGetChildRectOnScreenV(rect); final int deltaH = computeScrollDeltaToGetChildRectOnScreenH(rect); final boolean scroll = deltaH != 0 || deltaV != 0; if (scroll) { if (immediate) { scrollBy(deltaH, deltaV); } else { smoothScrollBy(deltaH, deltaV); } } return scroll; } /** * Compute the amount to scroll in the Y direction in order to get a * rectangle completely on the screen (or, if taller than the screen, at * least the first screen size chunk of it). * * @param rect * The rect. * @return The scroll delta. */ protected int computeScrollDeltaToGetChildRectOnScreenV(Rect rect) { if (getChildCount() == 0) return 0; int height = getHeight(); int screenTop = getScrollY(); int screenBottom = screenTop + height; int fadingEdge = getVerticalFadingEdgeLength(); // leave room for top fading edge as long as rect isn't at very top if (rect.top > 0) { screenTop += fadingEdge; } // leave room for bottom fading edge as long as rect isn't at very // bottom if (rect.bottom < getChildAt(0).getHeight()) { screenBottom -= fadingEdge; } int scrollYDelta = 0; if (rect.bottom > screenBottom && rect.top > screenTop) { // need to move down to get it in view: move down just enough so // that the entire rectangle is in view (or at least the first // screen size chunk). if (rect.height() > height) { // just enough to get screen size chunk on scrollYDelta += (rect.top - screenTop); } else { // get entire rect at bottom of screen scrollYDelta += (rect.bottom - screenBottom); } // make sure we aren't scrolling beyond the end of our content int bottom = getChildAt(0).getBottom(); int distanceToBottom = bottom - screenBottom; scrollYDelta = Math.min(scrollYDelta, distanceToBottom); } else if (rect.top < screenTop && rect.bottom < screenBottom) { // need to move up to get it in view: move up just enough so that // entire rectangle is in view (or at least the first screen // size chunk of it). if (rect.height() > height) { // screen size chunk scrollYDelta -= (screenBottom - rect.bottom); } else { // entire rect at top scrollYDelta -= (screenTop - rect.top); } // make sure we aren't scrolling any further than the top our // content scrollYDelta = Math.max(scrollYDelta, -getScrollY()); } return scrollYDelta; } protected int computeScrollDeltaToGetChildRectOnScreenH(Rect rect) { if (getChildCount() == 0) return 0; int width = getWidth(); int screenLeft = getScrollX(); int screenRight = screenLeft + width; int fadingEdge = getHorizontalFadingEdgeLength(); // leave room for left fading edge as long as rect isn't at very left if (rect.left > 0) { screenLeft += fadingEdge; } // leave room for right fading edge as long as rect isn't at very right if (rect.right < getChildAt(0).getWidth()) { screenRight -= fadingEdge; } int scrollXDelta = 0; if (rect.right > screenRight && rect.left > screenLeft) { // need to move right to get it in view: move right just enough so // that the entire rectangle is in view (or at least the first // screen size chunk). if (rect.width() > width) { // just enough to get screen size chunk on scrollXDelta += (rect.left - screenLeft); } else { // get entire rect at right of screen scrollXDelta += (rect.right - screenRight); } // make sure we aren't scrolling beyond the end of our content int right = getChildAt(0).getRight(); int distanceToRight = right - screenRight; scrollXDelta = Math.min(scrollXDelta, distanceToRight); } else if (rect.left < screenLeft && rect.right < screenRight) { // need to move right to get it in view: move right just enough so // that // entire rectangle is in view (or at least the first screen // size chunk of it). if (rect.width() > width) { // screen size chunk scrollXDelta -= (screenRight - rect.right); } else { // entire rect at left scrollXDelta -= (screenLeft - rect.left); } // make sure we aren't scrolling any further than the left our // content scrollXDelta = Math.max(scrollXDelta, -getScrollX()); } return scrollXDelta; } @Override public void requestChildFocus(View child, View focused) { if (!mScrollViewMovedFocus) { if (!mIsLayoutDirty) { scrollToChild(focused); } else { // The child may not be laid out yet, we can't compute the // scroll yet mChildToScrollTo = focused; } } super.requestChildFocus(child, focused); } /** * When looking for focus in children of a scroll view, need to be a little * more careful not to give focus to something that is scrolled off screen. * * This is more expensive than the default {@link android.view.ViewGroup} * implementation, otherwise this behavior might have been made the default. */ @Override protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) { // convert from forward / backward notation to up / down / left / right // (ugh). // if (direction == View.FOCUS_FORWARD) { // direction = View.FOCUS_RIGHT; // } else if (direction == View.FOCUS_BACKWARD) { // direction = View.FOCUS_LEFT; // } final View nextFocus = previouslyFocusedRect == null ? FocusFinder .getInstance().findNextFocus(this, null, direction) : FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction); if (nextFocus == null) { return false; } // if (isOffScreenH(nextFocus)) { // return false; // } return nextFocus.requestFocus(direction, previouslyFocusedRect); } @Override public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) { // offset into coordinate space of this scroll view rectangle.offset(child.getLeft() - child.getScrollX(), child.getTop() - child.getScrollY()); return scrollToChildRect(rectangle, immediate); } @Override public void requestLayout() { mIsLayoutDirty = true; super.requestLayout(); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mIsLayoutDirty = false; // Give a child focus if it needs it if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) { scrollToChild(mChildToScrollTo); } mChildToScrollTo = null; // Calling this with the present values causes it to re-clam them scrollTo(getScrollX(), getScrollY()); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); View currentFocused = findFocus(); if (null == currentFocused || this == currentFocused) return; // If the currently-focused view was visible on the screen when the // screen was at the old height, then scroll the screen to make that // view visible with the new screen height. if (isWithinDeltaOfScreenV(currentFocused, 0, oldh)) { currentFocused.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(currentFocused, mTempRect); int scrollDelta = computeScrollDeltaToGetChildRectOnScreenV(mTempRect); doScrollY(scrollDelta); } final int maxJump = getRight() - getLeft(); if (isWithinDeltaOfScreenH(currentFocused, maxJump)) { currentFocused.getDrawingRect(mTempRect); offsetDescendantRectToMyCoords(currentFocused, mTempRect); int scrollDelta = computeScrollDeltaToGetChildRectOnScreenH(mTempRect); doScrollX(scrollDelta); } } /** * Return true if child is an descendant of parent, (or equal to the * parent). */ private boolean isViewDescendantOf(View child, View parent) { if (child == parent) { return true; } final ViewParent theParent = child.getParent(); return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent); } /** * Fling the scroll view * * @param velocityY * The initial velocity in the Y direction. Positive numbers mean * that the finger/cursor is moving down the screen, which means * we want to scroll towards the top. */ public void fling(int velocityX, int velocityY) { if (getChildCount() > 0) { int width = getWidth() - getPaddingRight() - getPaddingLeft(); int right = getChildAt(0).getWidth(); int height = getHeight() - getPaddingBottom() - getPaddingTop(); int bottom = getChildAt(0).getHeight(); mScroller.fling(getScrollX(), getScrollY(), velocityX, velocityY, 0, Math.max(0, right - width), 0, Math.max(0, bottom - height)); // final boolean movingDown = velocityX > 0 || velocityY > 0; // // View newFocused = // findFocusableViewInMyBoundsV(movingDown, mScroller.getFinalY(), // findFocus()); // if (newFocused == null) { // newFocused = this; // } // // if (newFocused != findFocus() // && newFocused.requestFocus(movingDown ? View.FOCUS_DOWN : // View.FOCUS_UP)) { // mScrollViewMovedFocus = true; // mScrollViewMovedFocus = false; // } invalidate(); } } /** * {@inheritDoc} * *

* This version also clamps the scrolling to the bounds of our child. */ @Override public void scrollTo(int x, int y) { // we rely on the fact the View.scrollBy calls scrollTo. if (getChildCount() > 0) { View child = getChildAt(0); x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth()); y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight()); if (x != getScrollX() || y != getScrollY()) { super.scrollTo(x, y); } } } private int clamp(int n, int my, int child) { if (my >= child || n < 0) { /* * my >= child is this case: |--------------- me ---------------| * |------ child ------| or |--------------- me ---------------| * |------ child ------| or |--------------- me ---------------| * |------ child ------| n < 0 is this case: |------ me ------| * |-------- child --------| |-- mScrollX --| */ return 0; } if ((my + n) > child) { /* * this case: |------ me ------| |------ child ------| |-- mScrollX * --| */ return child - my; } return n; } public boolean isFlingEnabled() { return mFlingEnabled; } public void setFlingEnabled(boolean flingEnabled) { this.mFlingEnabled = flingEnabled; } /** scrollview内容与属性记录 */ private View inner; private Rect normal = new Rect(); @Override protected void onFinishInflate() { if (getChildCount() > 0) { inner = getChildAt(0); } } // 是否需要开启动画 public boolean isNeedAnimation() { return !normal.isEmpty(); } // 开启动画移动 public void animation() { // 开启移动动画 TranslateAnimation ta = new TranslateAnimation(0, -inner.getLeft(), 0, -inner.getTop()); ta.setDuration(200); inner.startAnimation(ta); // 设置回到正常的布局位置 new Handler().postDelayed(new Runnable() { public void run() { inner.clearAnimation(); inner.layout(normal.left, normal.top, normal.right, normal.bottom); normal.setEmpty(); } }, 200); } // 是否需要移动布局 public boolean isNeedMove() { int offsetX = inner.getMeasuredWidth() - getWidth(); int scrollX = getScrollX(); if (scrollX == 0 || scrollX == offsetX) { return true; } int offsetY = inner.getMeasuredHeight() - getHeight(); int scrollY = getScrollY(); if (scrollY == 0 || scrollY == offsetY) { return true; } return false; } }



上面代码是只是进行上下平滑滑动反弹效果
onTouchEvent这个方法有如下代码:

final int deltaY = (int) (mLastMotionY - y);//恢复纵向滚动
//final int deltaY = 0;//禁止纵向滚动

//final int deltaX = (int) (mLastMotionX - x);//恢复横向滚动
final int deltaX = 0;//禁止横向滚动

通过上面代码的注释反注释,你就可以为所欲为了!!!


 

www.bkjia.comtruehttp://www.bkjia.com/Androidjc/998792.htmlTechArticleandroid 上下左右都能滑动的是类似scorllview效果 上下左右都能滑动且带平滑效果的类似scorllview 代码:HVScrollView.java package com.yqy.yqy_frame.view...

相关文章

相关搜索: 效果

帮客评论

视觉看点