Android侧滑效果简单实现代码

首先，导入包：compile files('libs/nineoldandroids-2.4.0.jar')

r然后在main中创建一个widget包。
c创建ViewDragHelper类

public class ViewDragHelper {
private static final String TAG = "ViewDragHelper";
public static final int INVALID_POINTER = -1
public static final int STATE_IDLE = 0;
public static final int STATE_DRAGGING = 1;
public static final int STATE_SETTLING = 2;
public static final int EDGE_LEFT = 1 << 0;
public static final int EDGE_RIGHT = 1 << 1
public static final int EDGE_TOP = 1 << 2;
public static final int EDGE_BOTTOM = 1 << 3
public static final int EDGE_ALL = EDGE_LEFT | EDGE_TOP | EDGE_RIGHT | EDGE_BOTTOM;
public static final int DIRECTION_HORIZONTAL = 1 << 0;
public static final int DIRECTION_VERTICAL = 1 << 1;
public static final int DIRECTION_ALL = DIRECTION_HORIZONTAL | DIRECTION_VERTICAL;
private static final int EDGE_SIZE = 20; // dp
private static final int BASE_SETTLE_DURATION = 256; // ms
private static final int MAX_SETTLE_DURATION = 600; // ms
// Current drag state; idle, dragging or settling
private int mDragState;
// Distance to travel before a drag may begin
private int mTouchSlop;
// Last known position/pointer tracking
private int mActivePointerId = INVALID_POINTER;
private float[] mInitialMotionX;
private float[] mInitialMotionY;
private float[] mLastMotionX;
private float[] mLastMotionY;
private int[] mInitialEdgesTouched;
private int[] mEdgeDragsInProgress;
private int[] mEdgeDragsLocked;
private int mPointersDown;
private VelocityTracker mVelocityTracker;
private final float mMaxVelocity;
private float mMinVelocity;
private final int mEdgeSize;
private int mTrackingEdges;
private final ScrollerCompat mScroller;
private final Callback mCallback;
private View mCapturedView;
private boolean mReleaseInProgress;
private final ViewGroup mParentView;
private static final Interpolator sInterpolator = new Interpolator() {
public float getInterpolation(float t) {
t -= 1.0f;
return t * t * t * t * t + 1.0f;
}
};
private final Runnable mSetIdleRunnable = new Runnable() {
public void run() {
setDragState(STATE_IDLE);
}
};
private ViewDragHelper(Context context, ViewGroup forParent, Callback cb) {
if (forParent == null) {
throw new IllegalArgumentException("Parent view may not be null");
}
if (cb == null) {
throw new IllegalArgumentException("Callback may not be null");
}
mParentView = forParent;
mCallback = cb;
final ViewConfiguration vc = ViewConfiguration.get(context);
final float density = context.getResources().getDisplayMetrics().density;
mEdgeSize = (int) (EDGE_SIZE * density + 0.5f);
mTouchSlop = vc.getScaledTouchSlop();
mMaxVelocity = vc.getScaledMaximumFlingVelocity();
mMinVelocity = vc.getScaledMinimumFlingVelocity();
mScroller = ScrollerCompat.create(context, sInterpolator);
}
public static abstract class Callback {
public void onViewDragStateChanged(int state) {}
public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {}
public void onViewCaptured(View capturedChild, int activePointerId) {}
public void onViewReleased(View releasedChild, float xvel, float yvel) {}
public void onEdgeTouched(int edgeFlags, int pointerId) {}
public boolean onEdgeLock(int edgeFlags) {
return false;
}
public void onEdgeDragStarted(int edgeFlags, int pointerId) {}
public int getOrderedChildIndex(int index) {
return index;
}
public int getViewHorizontalDragRange(View child) {
return 0;
}
public int getViewVerticalDragRange(View child) {
return 0;
}
public abstract boolean tryCaptureView(View child, int pointerId);
public int clampViewPositionHorizontal(View child, int left, int dx) {
return 0;
}
public int clampViewPositionVertical(View child, int top, int dy) {
return 0;
}
}
public static ViewDragHelper create(ViewGroup forParent, Callback cb) {
return new ViewDragHelper(forParent.getContext(), forParent, cb);
}
public static ViewDragHelper create(ViewGroup forParent, float sensitivity, Callback cb) {
final ViewDragHelper helper = create(forParent, cb);
helper.mTouchSlop = (int) (helper.mTouchSlop * (1 / sensitivity));
return helper;
}
public void setMinVelocity(float minVel) {
mMinVelocity = minVel;
}
public float getMinVelocity() {
return mMinVelocity;
}
public int getViewDragState() {
return mDragState;
}
public void setEdgeTrackingEnabled(int edgeFlags) {
mTrackingEdges = edgeFlags;
}
public int getEdgeSize() {
return mEdgeSize;
}
public void captureChildView(View childView, int activePointerId) {
if (childView.getParent() != mParentView) {
throw new IllegalArgumentException("captureChildView: parameter must be a descendant " +
"of the ViewDragHelper's tracked parent view (" + mParentView + ")");
}
mCapturedView = childView;
mActivePointerId = activePointerId;
mCallback.onViewCaptured(childView, activePointerId);
setDragState(STATE_DRAGGING);
}
public View getCapturedView() {
return mCapturedView;
}
public int getActivePointerId() {
return mActivePointerId;
}
public int getTouchSlop() {
return mTouchSlop;
}
public void cancel() {
mActivePointerId = INVALID_POINTER;
clearMotionHistory();
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
public void abort() {
cancel();
if (mDragState == STATE_SETTLING) {
final int oldX = mScroller.getCurrX();
final int oldY = mScroller.getCurrY();
mScroller.abortAnimation();
final int newX = mScroller.getCurrX();
final int newY = mScroller.getCurrY();
mCallback.onViewPositionChanged(mCapturedView, newX, newY, newX - oldX, newY - oldY);
}
setDragState(STATE_IDLE);
}
public boolean smoothSlideViewTo(View child, int finalLeft, int finalTop) {
mCapturedView = child;
mActivePointerId = INVALID_POINTER;
boolean continueSliding = forceSettleCapturedViewAt(finalLeft, finalTop, 0, 0);
if (!continueSliding && mDragState == STATE_IDLE && mCapturedView != null) {
// If we're in an IDLE state to begin with and aren't moving anywhere, we
// end up having a non-null capturedView with an IDLE dragState
mCapturedView = null;
}
return continueSliding;
}
public boolean settleCapturedViewAt(int finalLeft, int finalTop) {
if (!mReleaseInProgress) {
throw new IllegalStateException("Cannot settleCapturedViewAt outside of a call to " +
"Callback#onViewReleased");
}
return forceSettleCapturedViewAt(finalLeft, finalTop,
(int) VelocityTrackerCompat.getXVelocity(mVelocityTracker, mActivePointerId),
(int) VelocityTrackerCompat.getYVelocity(mVelocityTracker, mActivePointerId));
}
private boolean forceSettleCapturedViewAt(int finalLeft, int finalTop, int xvel, int yvel) {
final int startLeft = mCapturedView.getLeft();
final int startTop = mCapturedView.getTop();
final int dx = finalLeft - startLeft;
final int dy = finalTop - startTop;
if (dx == 0 && dy == 0) {
// Nothing to do. Send callbacks, be done.
mScroller.abortAnimation();
setDragState(STATE_IDLE);
return false;
}
final int duration = computeSettleDuration(mCapturedView, dx, dy, xvel, yvel);
mScroller.startScroll(startLeft, startTop, dx, dy, duration);
setDragState(STATE_SETTLING);
return true;
}
private int computeSettleDuration(View child, int dx, int dy, int xvel, int yvel) {
xvel = clampMag(xvel, (int) mMinVelocity, (int) mMaxVelocity);
yvel = clampMag(yvel, (int) mMinVelocity, (int) mMaxVelocity);
final int absDx = Math.abs(dx);
final int absDy = Math.abs(dy);
final int absXVel = Math.abs(xvel);
final int absYVel = Math.abs(yvel);
final int addedVel = absXVel + absYVel;
final int addedDistance = absDx + absDy;
final float xweight = xvel != 0 ? (float) absXVel / addedVel :
(float) absDx / addedDistance;
final float yweight = yvel != 0 ? (float) absYVel / addedVel :
(float) absDy / addedDistance;
int xduration = computeAxisDuration(dx, xvel, mCallback.getViewHorizontalDragRange(child));
int yduration = computeAxisDuration(dy, yvel, mCallback.getViewVerticalDragRange(child));
return (int) (xduration * xweight + yduration * yweight);
}
private int computeAxisDuration(int delta, int velocity, int motionRange) {
if (delta == 0) {
return 0;
}
final int width = mParentView.getWidth();
final int halfWidth = width / 2;
final float distanceRatio = Math.min(1f, (float) Math.abs(delta) / width);
final float distance = halfWidth + halfWidth *
distanceInfluenceForSnapDuration(distanceRatio);
int duration;
velocity = Math.abs(velocity);
if (velocity > 0) {
duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
} else {
final float range = (float) Math.abs(delta) / motionRange;
duration = (int) ((range + 1) * BASE_SETTLE_DURATION);
}
return Math.min(duration, MAX_SETTLE_DURATION);
}
private static int clampMag(int value, int absMin, int absMax) {
final int absValue = Math.abs(value);
if (absValue < absMin) return 0;
if (absValue > absMax) return value > 0 ? absMax : -absMax;
return value;
}
private static float clampMag(float value, float absMin, float absMax) {
final float absValue = Math.abs(value);
if (absValue < absMin) return 0;
if (absValue > absMax) return value > 0 ? absMax : -absMax;
return value;
}
private static float distanceInfluenceForSnapDuration(float f) {
f -= 0.5f; // center the values about 0.
f *= 0.3f * Math.PI / 2.0f;
return (float) Math.sin(f);
}
public void flingCapturedView(int minLeft, int minTop, int maxLeft, int maxTop) {
if (!mReleaseInProgress) {
throw new IllegalStateException("Cannot flingCapturedView outside of a call to " +
"Callback#onViewReleased");
}
mScroller.fling(mCapturedView.getLeft(), mCapturedView.getTop(),
(int) VelocityTrackerCompat.getXVelocity(mVelocityTracker, mActivePointerId),
(int) VelocityTrackerCompat.getYVelocity(mVelocityTracker, mActivePointerId),
minLeft, maxLeft, minTop, maxTop);
setDragState(STATE_SETTLING);
}
public boolean continueSettling(boolean deferCallbacks) {
if (mDragState == STATE_SETTLING) {
boolean keepGoing = mScroller.computeScrollOffset();
final int x = mScroller.getCurrX();
final int y = mScroller.getCurrY();
final int dx = x - mCapturedView.getLeft();
final int dy = y - mCapturedView.getTop();
if (dx != 0) {
mCapturedView.offsetLeftAndRight(dx);
}
if (dy != 0) {
mCapturedView.offsetTopAndBottom(dy);
}
if (dx != 0 || dy != 0) {
mCallback.onViewPositionChanged(mCapturedView, x, y, dx, dy);
}
if (keepGoing && x == mScroller.getFinalX() && y == mScroller.getFinalY()) {
// Close enough. The interpolator/scroller might think we're still moving
// but the user sure doesn't.
mScroller.abortAnimation();
keepGoing = false;
}
if (!keepGoing) {
if (deferCallbacks) {
mParentView.post(mSetIdleRunnable);
} else {
setDragState(STATE_IDLE);
}
}
}
return mDragState == STATE_SETTLING;
}
private void dispatchViewReleased(float xvel, float yvel) {
mReleaseInProgress = true;
mCallback.onViewReleased(mCapturedView, xvel, yvel);
mReleaseInProgress = false;
if (mDragState == STATE_DRAGGING) {
// onViewReleased didn't call a method that would have changed this. Go idle.
setDragState(STATE_IDLE);
}
}
private void clearMotionHistory() {
if (mInitialMotionX == null) {
return;
}
Arrays.fill(mInitialMotionX, 0);
Arrays.fill(mInitialMotionY, 0);
Arrays.fill(mLastMotionX, 0);
Arrays.fill(mLastMotionY, 0);
Arrays.fill(mInitialEdgesTouched, 0);
Arrays.fill(mEdgeDragsInProgress, 0);
Arrays.fill(mEdgeDragsLocked, 0);
mPointersDown = 0;
}
private void clearMotionHistory(int pointerId) {
if (mInitialMotionX == null) {
return;
}
mInitialMotionX[pointerId] = 0;
mInitialMotionY[pointerId] = 0;
mLastMotionX[pointerId] = 0;
mLastMotionY[pointerId] = 0;
mInitialEdgesTouched[pointerId] = 0;
mEdgeDragsInProgress[pointerId] = 0;
mEdgeDragsLocked[pointerId] = 0;
mPointersDown &= ~(1 << pointerId);
}
private void ensureMotionHistorySizeForId(int pointerId) {
if (mInitialMotionX == null || mInitialMotionX.length <= pointerId) {
float[] imx = new float[pointerId + 1];
float[] imy = new float[pointerId + 1];
float[] lmx = new float[pointerId + 1];
float[] lmy = new float[pointerId + 1];
int[] iit = new int[pointerId + 1];
int[] edip = new int[pointerId + 1];
int[] edl = new int[pointerId + 1];
if (mInitialMotionX != null) {
System.arraycopy(mInitialMotionX, 0, imx, 0, mInitialMotionX.length);
System.arraycopy(mInitialMotionY, 0, imy, 0, mInitialMotionY.length);
System.arraycopy(mLastMotionX, 0, lmx, 0, mLastMotionX.length);
System.arraycopy(mLastMotionY, 0, lmy, 0, mLastMotionY.length);
System.arraycopy(mInitialEdgesTouched, 0, iit, 0, mInitialEdgesTouched.length);
System.arraycopy(mEdgeDragsInProgress, 0, edip, 0, mEdgeDragsInProgress.length);
System.arraycopy(mEdgeDragsLocked, 0, edl, 0, mEdgeDragsLocked.length);
}
mInitialMotionX = imx;
mInitialMotionY = imy;
mLastMotionX = lmx;
mLastMotionY = lmy;
mInitialEdgesTouched = iit;
mEdgeDragsInProgress = edip;
mEdgeDragsLocked = edl;
}
}
private void saveInitialMotion(float x, float y, int pointerId) {
ensureMotionHistorySizeForId(pointerId);
mInitialMotionX[pointerId] = mLastMotionX[pointerId] = x;
mInitialMotionY[pointerId] = mLastMotionY[pointerId] = y;
mInitialEdgesTouched[pointerId] = getEdgesTouched((int) x, (int) y);
mPointersDown |= 1 << pointerId;
}
private void saveLastMotion(MotionEvent ev) {
final int pointerCount = MotionEventCompat.getPointerCount(ev);
for (int i = 0; i < pointerCount; i++) {
final int pointerId = MotionEventCompat.getPointerId(ev, i);
final float x = MotionEventCompat.getX(ev, i);
final float y = MotionEventCompat.getY(ev, i);
mLastMotionX[pointerId] = x;
mLastMotionY[pointerId] = y;
}
}
public boolean isPointerDown(int pointerId) {
return (mPointersDown & 1 << pointerId) != 0;
}
void setDragState(int state) {
mParentView.removeCallbacks(mSetIdleRunnable);
if (mDragState != state) {
mDragState = state;
mCallback.onViewDragStateChanged(state);
if (mDragState == STATE_IDLE) {
mCapturedView = null;
}
}
}
boolean tryCaptureViewForDrag(View toCapture, int pointerId) {
if (toCapture == mCapturedView && mActivePointerId == pointerId) {
// Already done!
return true;
}
if (toCapture != null && mCallback.tryCaptureView(toCapture, pointerId)) {
mActivePointerId = pointerId;
captureChildView(toCapture, pointerId);
return true;
}
return false;
}
protected boolean canScroll(View v, boolean checkV, int dx, int dy, int x, int y) {
if (v instanceof ViewGroup) {
final ViewGroup group = (ViewGroup) v;
final int scrollX = v.getScrollX();
final int scrollY = v.getScrollY();
final int count = group.getChildCount();
// Count backwards - let topmost views consume scroll distance first.
for (int i = count - 1; i >= 0; i--) {
// TODO: Add versioned support here for transformed views.
// This will not work for transformed views in Honeycomb+
final View child = group.getChildAt(i);
if (x + scrollX >= child.getLeft() && x + scrollX < child.getRight() &&
y + scrollY >= child.getTop() && y + scrollY < child.getBottom() &&
canScroll(child, true, dx, dy, x + scrollX - child.getLeft(),
y + scrollY - child.getTop())) {
return true;
}
}
}
return checkV && (ViewCompat.canScrollHorizontally(v, -dx) ||
ViewCompat.canScrollVertically(v, -dy));
}
public boolean shouldInterceptTouchEvent(MotionEvent ev) {
final int action = MotionEventCompat.getActionMasked(ev);
final int actionIndex = MotionEventCompat.getActionIndex(ev);
if (action == MotionEvent.ACTION_DOWN) {
// Reset things for a new event stream, just in case we didn't get
// the whole previous stream.
cancel();
}
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
switch (action) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
final int pointerId = MotionEventCompat.getPointerId(ev, 0);
saveInitialMotion(x, y, pointerId);
final View toCapture = findTopChildUnder((int) x, (int) y);
// Catch a settling view if possible.
if (toCapture == mCapturedView && mDragState == STATE_SETTLING) {
tryCaptureViewForDrag(toCapture, pointerId);
}
final int edgesTouched = mInitialEdgesTouched[pointerId];
if ((edgesTouched & mTrackingEdges) != 0) {
mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
}
break;
}
case MotionEventCompat.ACTION_POINTER_DOWN: {
final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
final float x = MotionEventCompat.getX(ev, actionIndex);
final float y = MotionEventCompat.getY(ev, actionIndex);
saveInitialMotion(x, y, pointerId);
// A ViewDragHelper can only manipulate one view at a time.
if (mDragState == STATE_IDLE) {
final int edgesTouched = mInitialEdgesTouched[pointerId];
if ((edgesTouched & mTrackingEdges) != 0) {
mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
}
} else if (mDragState == STATE_SETTLING) {
// Catch a settling view if possible.
final View toCapture = findTopChildUnder((int) x, (int) y);
if (toCapture == mCapturedView) {
tryCaptureViewForDrag(toCapture, pointerId);
}
}
break;
}
case MotionEvent.ACTION_MOVE: {
if (mInitialMotionX == null || mInitialMotionY == null) break;
// First to cross a touch slop over a draggable view wins. Also report edge drags.
final int pointerCount = MotionEventCompat.getPointerCount(ev);
for (int i = 0; i < pointerCount; i++) {
final int pointerId = MotionEventCompat.getPointerId(ev, i);
final float x = MotionEventCompat.getX(ev, i);
final float y = MotionEventCompat.getY(ev, i);
final float dx = x - mInitialMotionX[pointerId];
final float dy = y - mInitialMotionY[pointerId];
final View toCapture = findTopChildUnder((int) x, (int) y);
final boolean pastSlop = toCapture != null && checkTouchSlop(toCapture, dx, dy);
if (pastSlop) {
// check the callback's
// getView[Horizontal|Vertical]DragRange methods to know
// if you can move at all along an axis, then see if it
// would clamp to the same value. If you can't move at
// all in every dimension with a nonzero range, bail.
final int oldLeft = toCapture.getLeft();
final int targetLeft = oldLeft + (int) dx;
final int newLeft = mCallback.clampViewPositionHorizontal(toCapture,
targetLeft, (int) dx);
final int oldTop = toCapture.getTop();
final int targetTop = oldTop + (int) dy;
final int newTop = mCallback.clampViewPositionVertical(toCapture, targetTop,
(int) dy);
final int horizontalDragRange = mCallback.getViewHorizontalDragRange(
toCapture);
final int verticalDragRange = mCallback.getViewVerticalDragRange(toCapture);
if ((horizontalDragRange == 0 || horizontalDragRange > 0
&& newLeft == oldLeft) && (verticalDragRange == 0
|| verticalDragRange > 0 && newTop == oldTop)) {
break;
}
}
reportNewEdgeDrags(dx, dy, pointerId);
if (mDragState == STATE_DRAGGING) {
// Callback might have started an edge drag
break;
}
if (pastSlop && tryCaptureViewForDrag(toCapture, pointerId)) {
break;
}
}
saveLastMotion(ev);
break;
}
case MotionEventCompat.ACTION_POINTER_UP: {
final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
clearMotionHistory(pointerId);
break;
}
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
cancel();
break;
}
default:
break;
}
return mDragState == STATE_DRAGGING;
}
public void processTouchEvent(MotionEvent ev) {
final int action = MotionEventCompat.getActionMasked(ev);
final int actionIndex = MotionEventCompat.getActionIndex(ev);
if (action == MotionEvent.ACTION_DOWN) {
// Reset things for a new event stream, just in case we didn't get
// the whole previous stream.
cancel();
}
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
switch (action) {
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
final int pointerId = MotionEventCompat.getPointerId(ev, 0);
final View toCapture = findTopChildUnder((int) x, (int) y);
saveInitialMotion(x, y, pointerId);
// Since the parent is already directly processing this touch event,
// there is no reason to delay for a slop before dragging.
// Start immediately if possible.
tryCaptureViewForDrag(toCapture, pointerId);
final int edgesTouched = mInitialEdgesTouched[pointerId];
if ((edgesTouched & mTrackingEdges) != 0) {
mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
}
break;
}
case MotionEventCompat.ACTION_POINTER_DOWN: {
final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
final float x = MotionEventCompat.getX(ev, actionIndex);
final float y = MotionEventCompat.getY(ev, actionIndex);
saveInitialMotion(x, y, pointerId);
// A ViewDragHelper can only manipulate one view at a time.
if (mDragState == STATE_IDLE) {
// If we're idle we can do anything! Treat it like a normal down event.
final View toCapture = findTopChildUnder((int) x, (int) y);
tryCaptureViewForDrag(toCapture, pointerId);
final int edgesTouched = mInitialEdgesTouched[pointerId];
if ((edgesTouched & mTrackingEdges) != 0) {
mCallback.onEdgeTouched(edgesTouched & mTrackingEdges, pointerId);
}
} else if (isCapturedViewUnder((int) x, (int) y)) {
// We're still tracking a captured view. If the same view is under this
// point, we'll swap to controlling it with this pointer instead.
// (This will still work if we're "catching" a settling view.)
tryCaptureViewForDrag(mCapturedView, pointerId);
}
break;
}
case MotionEvent.ACTION_MOVE: {
if (mDragState == STATE_DRAGGING) {
final int index = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
final float x = MotionEventCompat.getX(ev, index);
final float y = MotionEventCompat.getY(ev, index);
final int idx = (int) (x - mLastMotionX[mActivePointerId]);
final int idy = (int) (y - mLastMotionY[mActivePointerId]);
dragTo(mCapturedView.getLeft() + idx, mCapturedView.getTop() + idy, idx, idy);
saveLastMotion(ev);
} else {
// Check to see if any pointer is now over a draggable view.
final int pointerCount = MotionEventCompat.getPointerCount(ev);
for (int i = 0; i < pointerCount; i++) {
final int pointerId = MotionEventCompat.getPointerId(ev, i);
final float x = MotionEventCompat.getX(ev, i);
final float y = MotionEventCompat.getY(ev, i);
final float dx = x - mInitialMotionX[pointerId];
final float dy = y - mInitialMotionY[pointerId];
reportNewEdgeDrags(dx, dy, pointerId);
if (mDragState == STATE_DRAGGING) {
// Callback might have started an edge drag.
break;
}
final View toCapture = findTopChildUnder((int) x, (int) y);
if (checkTouchSlop(toCapture, dx, dy) &&
tryCaptureViewForDrag(toCapture, pointerId)) {
break;
}
}
saveLastMotion(ev);
}
break;
}
case MotionEventCompat.ACTION_POINTER_UP: {
final int pointerId = MotionEventCompat.getPointerId(ev, actionIndex);
if (mDragState == STATE_DRAGGING && pointerId == mActivePointerId) {
// Try to find another pointer that's still holding on to the captured view.
int newActivePointer = INVALID_POINTER;
final int pointerCount = MotionEventCompat.getPointerCount(ev);
for (int i = 0; i < pointerCount; i++) {
final int id = MotionEventCompat.getPointerId(ev, i);
if (id == mActivePointerId) {
// This one's going away, skip.
continue;
}
final float x = MotionEventCompat.getX(ev, i);
final float y = MotionEventCompat.getY(ev, i);
if (findTopChildUnder((int) x, (int) y) == mCapturedView &&
tryCaptureViewForDrag(mCapturedView, id)) {
newActivePointer = mActivePointerId;
break;
}
}
if (newActivePointer == INVALID_POINTER) {
// We didn't find another pointer still touching the view, release it.
releaseViewForPointerUp();
}
}
clearMotionHistory(pointerId);
break;
}
case MotionEvent.ACTION_UP: {
if (mDragState == STATE_DRAGGING) {
releaseViewForPointerUp();
}
cancel();
break;
}
case MotionEvent.ACTION_CANCEL: {
if (mDragState == STATE_DRAGGING) {
dispatchViewReleased(0, 0);
}
cancel();
break;
}
default:
break;
}
}
private void reportNewEdgeDrags(float dx, float dy, int pointerId) {
int dragsStarted = 0;
if (checkNewEdgeDrag(dx, dy, pointerId, EDGE_LEFT)) {
dragsStarted |= EDGE_LEFT;
}
if (checkNewEdgeDrag(dy, dx, pointerId, EDGE_TOP)) {
dragsStarted |= EDGE_TOP;
}
if (checkNewEdgeDrag(dx, dy, pointerId, EDGE_RIGHT)) {
dragsStarted |= EDGE_RIGHT;
}
if (checkNewEdgeDrag(dy, dx, pointerId, EDGE_BOTTOM)) {
dragsStarted |= EDGE_BOTTOM;
}
if (dragsStarted != 0) {
mEdgeDragsInProgress[pointerId] |= dragsStarted;
mCallback.onEdgeDragStarted(dragsStarted, pointerId);
}
}
private boolean checkNewEdgeDrag(float delta, float odelta, int pointerId, int edge) {
final float absDelta = Math.abs(delta);
final float absODelta = Math.abs(odelta);
if ((mInitialEdgesTouched[pointerId] & edge) != edge || (mTrackingEdges & edge) == 0 ||
(mEdgeDragsLocked[pointerId] & edge) == edge ||
(mEdgeDragsInProgress[pointerId] & edge) == edge ||
(absDelta <= mTouchSlop && absODelta <= mTouchSlop)) {
return false;
}
if (absDelta < absODelta * 0.5f && mCallback.onEdgeLock(edge)) {
mEdgeDragsLocked[pointerId] |= edge;
return false;
}
return (mEdgeDragsInProgress[pointerId] & edge) == 0 && absDelta > mTouchSlop;
}
private boolean checkTouchSlop(View child, float dx, float dy) {
if (child == null) {
return false;
}
final boolean checkHorizontal = mCallback.getViewHorizontalDragRange(child) > 0;
final boolean checkVertical = mCallback.getViewVerticalDragRange(child) > 0;
if (checkHorizontal && checkVertical) {
return dx * dx + dy * dy > mTouchSlop * mTouchSlop;
} else if (checkHorizontal) {
return Math.abs(dx) > mTouchSlop;
} else if (checkVertical) {
return Math.abs(dy) > mTouchSlop;
}
return false;
}
public boolean checkTouchSlop(int directions) {
final int count = mInitialMotionX.length;
for (int i = 0; i < count; i++) {
if (checkTouchSlop(directions, i)) {
return true;
}
}
return false;
}
public boolean checkTouchSlop(int directions, int pointerId) {
if (!isPointerDown(pointerId)) {
return false;
}
final boolean checkHorizontal = (directions & DIRECTION_HORIZONTAL) == DIRECTION_HORIZONTAL;
final boolean checkVertical = (directions & DIRECTION_VERTICAL) == DIRECTION_VERTICAL;
final float dx = mLastMotionX[pointerId] - mInitialMotionX[pointerId];
final float dy = mLastMotionY[pointerId] - mInitialMotionY[pointerId];
if (checkHorizontal && checkVertical) {
return dx * dx + dy * dy > mTouchSlop * mTouchSlop;
} else if (checkHorizontal) {
return Math.abs(dx) > mTouchSlop;
} else if (checkVertical) {
return Math.abs(dy) > mTouchSlop;
}
return false;
}
public boolean isEdgeTouched(int edges) {
final int count = mInitialEdgesTouched.length;
for (int i = 0; i < count; i++) {
if (isEdgeTouched(edges, i)) {
return true;
}
}
return false;
}
public boolean isEdgeTouched(int edges, int pointerId) {
return isPointerDown(pointerId) && (mInitialEdgesTouched[pointerId] & edges) != 0;
}
private void releaseViewForPointerUp() {
mVelocityTracker.computeCurrentVelocity(1000, mMaxVelocity);
final float xvel = clampMag(
VelocityTrackerCompat.getXVelocity(mVelocityTracker, mActivePointerId),
mMinVelocity, mMaxVelocity);
final float yvel = clampMag(
VelocityTrackerCompat.getYVelocity(mVelocityTracker, mActivePointerId),
mMinVelocity, mMaxVelocity);
dispatchViewReleased(xvel, yvel);
}
private void dragTo(int left, int top, int dx, int dy) {
int clampedX = left;
int clampedY = top;
final int oldLeft = mCapturedView.getLeft();
final int oldTop = mCapturedView.getTop();
if (dx != 0) {
clampedX = mCallback.clampViewPositionHorizontal(mCapturedView, left, dx);
mCapturedView.offsetLeftAndRight(clampedX - oldLeft);
}
if (dy != 0) {
clampedY = mCallback.clampViewPositionVertical(mCapturedView, top, dy);
mCapturedView.offsetTopAndBottom(clampedY - oldTop);
}
if (dx != 0 || dy != 0) {
final int clampedDx = clampedX - oldLeft;
final int clampedDy = clampedY - oldTop;
mCallback.onViewPositionChanged(mCapturedView, clampedX, clampedY,
clampedDx, clampedDy);
}
}
public boolean isCapturedViewUnder(int x, int y) {
return isViewUnder(mCapturedView, x, y);
}
public boolean isViewUnder(View view, int x, int y) {
if (view == null) {
return false;
}
return x >= view.getLeft() &&
x < view.getRight() &&
y >= view.getTop() &&
y < view.getBottom();
}
public View findTopChildUnder(int x, int y) {
final int childCount = mParentView.getChildCount();
for (int i = childCount - 1; i >= 0; i--) {
final View child = mParentView.getChildAt(mCallback.getOrderedChildIndex(i));
if (x >= child.getLeft() && x < child.getRight() &&
y >= child.getTop() && y < child.getBottom()) {
return child;
}
}
return null;
}
private int getEdgesTouched(int x, int y) {
int result = 0;
if (x < mParentView.getLeft() + mEdgeSize) result |= EDGE_LEFT;
if (y < mParentView.getTop() + mEdgeSize) result |= EDGE_TOP;
if (x > mParentView.getRight() - mEdgeSize) result |= EDGE_RIGHT;
if (y > mParentView.getBottom() - mEdgeSize) result |= EDGE_BOTTOM;
return result;
}
}

DragLayout布局继承FrameLayout：

public class DragLayout extends FrameLayout {
private static final boolean IS_SHOW_SHADOW = true;
//手势处理类
private GestureDetectorCompat gestureDetector;
//视图拖拽移动帮助类
private ViewDragHelper dragHelper;
//滑动监听器
private DragListener dragListener;
//水平拖拽的距离
private int range;
//宽度
private int width;
//高度
private int height;
//main视图距离在ViewGroup距离左边的距离
private int mainLeft;
private Context context;
private ImageView ivShadow;
//左侧布局
private RelativeLayout vgLeft;
//右侧(主界面布局)
private CustomRelativeLayout vgMain;
//页面状态 默认为关闭
private Status status = Status.CLOSE;
private final ViewDragHelper.Callback dragHelperCallback = new ViewDragHelper.Callback() {
@Override
public int clampViewPositionHorizontal(View child, int left, int dx) {
if (mainLeft + dx < 0) {
return 0;
} else if (mainLeft + dx > range) {
return range;
} else {
return left;
}
}
@Override
public boolean tryCaptureView(View child, int pointerId) {
return true;
}
@Override
public int getViewHorizontalDragRange(View child) {
return width;
}
@Override
public void onViewReleased(View releasedChild, float xvel, float yvel) {
super.onViewReleased(releasedChild, xvel, yvel);
if (xvel > 0) {
open();
} else if (xvel < 0) {
close();
} else if (releasedChild == vgMain && mainLeft > range * 0.3) {
open();
} else if (releasedChild == vgLeft && mainLeft > range * 0.7) {
open();
} else {
close();
}
}
@Override
public void onViewPositionChanged(View changedView, int left, int top,
int dx, int dy) {
if (changedView == vgMain) {
mainLeft = left;
} else {
mainLeft = mainLeft + left;
}
if (mainLeft < 0) {
mainLeft = 0;
} else if (mainLeft > range) {
mainLeft = range;
}
if (IS_SHOW_SHADOW) {
ivShadow.layout(mainLeft, 0, mainLeft + width, height);
}
if (changedView == vgLeft) {
vgLeft.layout(0, 0, width, height);
vgMain.layout(mainLeft, 0, mainLeft + width, height);
}
dispatchDragEvent(mainLeft);
}
};
public DragLayout(Context context) {
this(context, null);
}
public DragLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
this.context = context;
}
public DragLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
gestureDetector = new GestureDetectorCompat(context, new YScrollDetector());
dragHelper = ViewDragHelper.create(this, dragHelperCallback);
}
class YScrollDetector extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float dx, float dy) {
return Math.abs(dy) <= Math.abs(dx);
}
}
/**
* 滑动相关回调接口
*/
public interface DragListener {
//界面打开
public void onOpen();
//界面关闭
public void onClose();
//界面滑动过程中
public void onDrag(float percent);
}
public void setDragListener(DragListener dragListener) {
this.dragListener = dragListener;
}
/**
* 布局加载完成回调
* 做一些初始化的操作
*/
@Override
protected void onFinishInflate() {
super.onFinishInflate();
if (IS_SHOW_SHADOW) {
ivShadow = new ImageView(context);
ivShadow.setImageResource(R.mipmap.shadow);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
addView(ivShadow, 1, lp);
}
//左侧界面
vgLeft = (RelativeLayout) getChildAt(0);
//右侧(主)界面
vgMain = (CustomRelativeLayout) getChildAt(IS_SHOW_SHADOW ? 2 : 1);
vgMain.setDragLayout(this);
vgLeft.setClickable(true);
vgMain.setClickable(true);
}
public ViewGroup getVgMain() {
return vgMain;
}
public ViewGroup getVgLeft() {
return vgLeft;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = vgLeft.getMeasuredWidth();
height = vgLeft.getMeasuredHeight();
//可以水平拖拽滑动的距离 一共为屏幕宽度的80%
range = (int) (width * 0.8f);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
vgLeft.layout(0, 0, width, height);
vgMain.layout(mainLeft, 0, mainLeft + width, height);
}
/**
* 拦截触摸事件
* @param ev
* @return
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return dragHelper.shouldInterceptTouchEvent(ev) && gestureDetector.onTouchEvent(ev);
}
/**
* 将拦截的到事件给ViewDragHelper进行处理
* @param e
* @return
*/
@Override
public boolean onTouchEvent(MotionEvent e) {
try {
dragHelper.processTouchEvent(e);
} catch (Exception ex) {
ex.printStackTrace();
}
return false;
}
/**
* 进行处理拖拽事件
* @param mainLeft
*/
private void dispatchDragEvent(int mainLeft) {
if (dragListener == null) {
return;
}
float percent = mainLeft / (float) range;
//滑动动画效果
animateView(percent);
//进行回调滑动的百分比
dragListener.onDrag(percent);
Status lastStatus = status;
if (lastStatus != getStatus() && status == Status.CLOSE) {
dragListener.onClose();
} else if (lastStatus != getStatus() && status == Status.OPEN) {
dragListener.onOpen();
}
}
/**
* 根据滑动的距离的比例,进行平移动画
* @param percent
*/
private void animateView(float percent) {
float f1 = 1 - percent * 0.5f;
ViewHelper.setTranslationX(vgLeft, -vgLeft.getWidth() / 2.5f + vgLeft.getWidth() / 2.5f * percent);
if (IS_SHOW_SHADOW) {
//阴影效果视图大小进行缩放
ViewHelper.setScaleX(ivShadow, f1 * 1.2f * (1 - percent * 0.10f));
ViewHelper.setScaleY(ivShadow, f1 * 1.85f * (1 - percent * 0.10f));
}
}
/**
* 有加速度,当我们停止滑动的时候，该不会立即停止动画效果
*/
@Override
public void computeScroll() {
if (dragHelper.continueSettling(true)) {
ViewCompat.postInvalidateOnAnimation(this);
}
}
/**
* 页面状态(滑动,打开,关闭)
*/
public enum Status {
DRAG, OPEN, CLOSE
}
/**
* 页面状态设置
* @return
*/
public Status getStatus() {
if (mainLeft == 0) {
status = Status.CLOSE;
} else if (mainLeft == range) {
status = Status.OPEN;
} else {
status = Status.DRAG;
}
return status;
}
public void open() {
open(true);
}
public void open(boolean animate) {
if (animate) {
//继续滑动
if (dragHelper.smoothSlideViewTo(vgMain, range, 0)) {
ViewCompat.postInvalidateOnAnimation(this);
}
} else {
vgMain.layout(range, 0, range * 2, height);
dispatchDragEvent(range);
}
}
public void close() {
close(true);
}
public void close(boolean animate) {
if (animate) {
//继续滑动
if (dragHelper.smoothSlideViewTo(vgMain, 0, 0)) {
ViewCompat.postInvalidateOnAnimation(this);
}
} else {
vgMain.layout(0, 0, width, height);
dispatchDragEvent(0);
}
}
}

CustomRelativeLayout：

public class CustomRelativeLayout extends RelativeLayout {
private DragLayout dl;
public CustomRelativeLayout(Context context) {
super(context);
}
public CustomRelativeLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void setDragLayout(DragLayout dl) {
this.dl = dl;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (dl.getStatus() != DragLayout.Status.CLOSE) {
return true;
}
return super.onInterceptTouchEvent(event);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (dl.getStatus() != DragLayout.Status.CLOSE) {
if (event.getAction() == MotionEvent.ACTION_UP) {
dl.close();
}
return true;
}
return super.onTouchEvent(event);
}
}

c沉浸式状态栏：BaseActivity：

public class BaseActivity extends FragmentActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
//透明状态栏
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
//透明导航栏
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION);
}
}
/**
* 设置沉浸式状态栏
*/
protected void setStatusBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
final ViewGroup linear_bar = (ViewGroup) findViewById(R.id.rl_title);
final int statusHeight = getStatusBarHeight();
linear_bar.post(new Runnable() {
@Override
public void run() {
int titleHeight = linear_bar.getHeight();
android.widget.LinearLayout.LayoutParams params = (android.widget.LinearLayout.LayoutParams) linear_bar.getLayoutParams();
params.height = statusHeight + titleHeight;
linear_bar.setLayoutParams(params);
}
});
}
}
/**
* 获取状态栏的高度
* @return
*/
protected int getStatusBarHeight(){
try
{
Class<?> c=Class.forName("com.android.internal.R$dimen");
Object obj=c.newInstance();
Field field=c.getField("status_bar_height");
int x=Integer.parseInt(field.get(obj).toString());
return getResources().getDimensionPixelSize(x);
}catch(Exception e){
e.printStackTrace();
}
return 0;
}
}

MainActivity：

public class MainActivity extends BaseActivity {
private DragLayout dl;
private LinearLayout linearLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initDragLayout();
}
private void initDragLayout() {
dl = (DragLayout) findViewById(R.id.dl);
linearLayout =(LinearLayout) findViewById(R.id.aaa);
dl.setDragListener(new DragLayout.DragListener() {
//界面打开的时候
@Override
public void onOpen() {
}
//界面关闭的时候
@Override
public void onClose() {
}
//界面滑动的时候
@Override
public void onDrag(float percent) {
}
});
}
}

OneFragment：

public class OneFragment extends Fragment {
private View mView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if(mView==null){
mView=inflater.inflate(R.layout.one_frag_layout,container,false);
}
return mView;
}
}

b布局文件：
one_frag_layout.xml
LinearLayout布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:id="@+id/aaa"
>
<TextView
android:text="界面"
android:layout_gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>

one_frag_layout1.xml:
RelativeLayout布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
>
<TextView
android:text="主界面"
android:layout_gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>

activity.main.xml:

<com.包名.myapplication.widget.DragLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/dl"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/transparent"
>
<!--下层 左边的布局 这个布局不能省去-->
<include layout="@layout/one_frag_layout1"/>
<!--上层 右边的主布局-->
<com.包名.myapplication.widget.CustomRelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<RelativeLayout
android:id="@+id/rl_title"
android:layout_width="match_parent"
android:layout_height="49dp"
android:gravity="bottom"
android:background="#2aaced"
>
<include layout="@layout/one_frag_layout"/>
</RelativeLayout>
<!--中间内容后面放入Fragment-->
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<fragment
android:id="@+id/main_info_fragment"
class="com.mieasy.myapplication.OneFragment"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</FrameLayout>
</LinearLayout>
</com.包名.myapplication.widget.CustomRelativeLayout>
</com.包名.myapplication.widget.DragLayout>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

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