From 36471abc904ff4aa3109bd06efbc3ed493f082b2 Mon Sep 17 00:00:00 2001 From: Allan Wang Date: Wed, 5 Jul 2017 14:47:58 -0700 Subject: Setup swipe for all directions --- .../ca/allanwang/kau/swipe/RelativeSlider.kt | 27 +- .../ca/allanwang/kau/swipe/SwipeBackHelper.kt | 3 +- .../ca/allanwang/kau/swipe/SwipeBackLayout.kt | 161 ++- .../kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt | 11 +- .../kotlin/ca/allanwang/kau/swipe/SwipeListener.kt | 4 +- .../ca/allanwang/kau/swipe/ViewDragHelper.java | 1515 ++++++++++++++++++++ .../allanwang/kau/swipe/ViewDragHelperExtras.java | 24 + core/src/main/res/values/styles.xml | 4 + 8 files changed, 1699 insertions(+), 50 deletions(-) create mode 100644 core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java create mode 100644 core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelperExtras.java (limited to 'core/src') diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt index ee86ff2..5d54134 100644 --- a/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt @@ -17,17 +17,34 @@ class RelativeSlider(var curPage: SwipeBackPage) : SwipeListener { else curPage.removeListener(this) } - override fun onScroll(percent: Float, px: Int) { + /** + * Set offset of previous page based on the edge flag and percentage scrolled + */ + override fun onScroll(percent: Float, px: Int, edgeFlag: Int) { if (offset == 0f) return //relative slider is not enabled val page = SwipeBackHelper.getPrePage(curPage) ?: return - page.swipeBackLayout.x = Math.min(-offset * Math.max(1 - percent, 0f) + DEFAULT_OFFSET, 0f) - if (percent == 0f) page.swipeBackLayout.x = 0f + if (percent == 0f) { + page.swipeBackLayout.x = 0f + page.swipeBackLayout.y = 0f + return + } + when (edgeFlag) { + SwipeBackLayout.EDGE_LEFT -> page.swipeBackLayout.x = Math.min(-offset * Math.max(1 - percent, 0f) + DEFAULT_OFFSET, 0f) + SwipeBackLayout.EDGE_RIGHT -> page.swipeBackLayout.x = Math.min(offset * Math.max(1 - percent, 0f) - DEFAULT_OFFSET, 0f) + SwipeBackLayout.EDGE_TOP -> page.swipeBackLayout.y = Math.min(-offset * Math.max(1 - percent, 0f) + DEFAULT_OFFSET, 0f) + SwipeBackLayout.EDGE_BOTTOM -> page.swipeBackLayout.y = Math.min(offset * Math.max(1 - percent, 0f) - DEFAULT_OFFSET, 0f) + } } override fun onEdgeTouch() {} - override fun onScrollToClose() { - SwipeBackHelper.getPrePage(curPage)?.swipeBackLayout?.x = 0f + /** + * Reset offsets for previous page + */ + override fun onScrollToClose(edgeFlag: Int) { + val prePage = SwipeBackHelper.getPrePage(curPage) ?: return + prePage.swipeBackLayout.x = 0f + prePage.swipeBackLayout.y = 0f } companion object { diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt index 4a8b6dc..0039687 100644 --- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt @@ -16,8 +16,8 @@ object SwipeBackHelper { fun getCurrentPage(activity: Activity): SwipeBackPage = this[activity] fun onCreate(activity: Activity) { + activity.overridePendingTransition(0, 0) pageStack.firstOrNull { it.activity === activity } ?: pageStack.push(SwipeBackPage(activity)) -// activity.window.exitTransition = } fun onPostCreate(activity: Activity) = this[activity].onPostCreate() @@ -42,4 +42,3 @@ fun Activity.kauSwipeOnCreate() = SwipeBackHelper.onCreate(this) fun Activity.kauSwipeOnPostCreate() = SwipeBackHelper.onPostCreate(this) fun Activity.kauSwipeOnDestroy() = SwipeBackHelper.onDestroy(this) fun Activity.kauSwipeFinish() = SwipeBackHelper.finish(this) - diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt index 37dde73..d668b4c 100644 --- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt @@ -5,14 +5,15 @@ import android.content.Context import android.graphics.Canvas import android.graphics.Color import android.support.v4.view.ViewCompat -import android.support.v4.widget.ViewDragHelper import android.util.AttributeSet import android.view.MotionEvent import android.view.View import android.view.ViewGroup import android.widget.FrameLayout +import ca.allanwang.kau.logging.KL import ca.allanwang.kau.utils.navigationBarColor import ca.allanwang.kau.utils.statusBarColor +import ca.allanwang.kau.utils.withAlpha import java.lang.ref.WeakReference class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyle: Int = 0 @@ -34,8 +35,8 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu set(value) { field = value if (value != null) { - statusBarAlpha = Color.alpha(value.statusBarColor) - navBarAlpha = Color.alpha(value.navigationBarColor) + statusBarAlpha = Color.alpha(value.statusBarColor) + navBarAlpha = Color.alpha(value.navigationBarColor) } } @@ -70,22 +71,21 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu invalidate() } - var statusBarAlpha: Int = 255 - var navBarAlpha: Int = 255 + private var statusBarAlpha: Int = 255 + private var navBarAlpha: Int = 255 val chromeFadeListener: SwipeListener by lazy { object : SwipeListener { - override fun onScroll(percent: Float, px: Int) { - TODO("not implemented") //To change body of created functions use File | Settings | File Templates. + override fun onScroll(percent: Float, px: Int, edgeFlag: Int) { + activity?.apply { + statusBarColor = statusBarColor.withAlpha((statusBarAlpha * (1 - percent)).toInt()) + navigationBarColor = navigationBarColor.withAlpha((navBarAlpha * (1 - percent)).toInt()) + } } - override fun onEdgeTouch() { - TODO("not implemented") //To change body of created functions use File | Settings | File Templates. - } + override fun onEdgeTouch() {} - override fun onScrollToClose() { - TODO("not implemented") //To change body of created functions use File | Settings | File Templates. - } + override fun onScrollToClose(edgeFlag: Int) {} } } @@ -98,13 +98,43 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu */ private var trackingEdge: Int = 0 + override var edgeSize: Int + get() = dragHelper.edgeSize + set(value) { + dragHelper.edgeSize = value + } + + override var edgeFlag = EDGE_LEFT + /** + * We will verify that only one axis is used at a time + */ + set(value) { + val result = if (value and EDGE_HORIZONTAL > 0) value and EDGE_HORIZONTAL else value and EDGE_VERTICAL + field = value + dragHelper.setEdgeTrackingEnabled(value) + } + + private val isHorizontal: Boolean + get() = edgeFlag and EDGE_HORIZONTAL > 0 + + private val isVertical: Boolean + get() = edgeFlag and EDGE_VERTICAL > 0 + + /** + * Specifies the edge flag that should by considered at the current moment + */ + private var edgeChangeFlag: Int = -1 + init { dragHelper = ViewDragHelper.create(this, ViewDragCallback()) val density = resources.displayMetrics.density val minVel = MIN_FLING_VELOCITY * density - setEdgeSize(resources.displayMetrics.widthPixels) + //allow touch from anywhere on the screen + edgeSize = Math.max(resources.displayMetrics.widthPixels, resources.displayMetrics.heightPixels) dragHelper.minVelocity = minVel - dragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT) + dragHelper.maxVelocity = 2 * minVel + edgeFlag = edgeFlag + addListener(chromeFadeListener) } @@ -124,13 +154,13 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu * @param swipeEdge The size of an edge in pixels */ - override fun setEdgeSize(swipeEdge: Int) { - trackingEdge = swipeEdge - } + // override fun setEdgeSize(swipeEdge: Int) { +// trackingEdge = swipeEdge +// } override fun setEdgeSizePercent(swipeEdgePercent: Float) { - trackingEdge = (resources.displayMetrics.widthPixels * swipeEdgePercent).toInt() + edgeSize = (resources.displayMetrics.widthPixels * swipeEdgePercent).toInt() } /** @@ -181,6 +211,7 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) { inLayout = true + //todo update contentView?.layout(contentOffset, 0, contentOffset + contentView!!.measuredWidth, contentView!!.measuredHeight) inLayout = false } @@ -214,9 +245,8 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu val decor = activity.window.decorView as ViewGroup var decorChild = decor.findViewById(android.R.id.content) - while (decorChild.parent !== decor) { + while (decorChild.parent !== decor) decorChild = decorChild.parent as View - } decorChild.setBackgroundResource(background) decor.removeView(decorChild) addView(decorChild) @@ -241,8 +271,11 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu private inner class ViewDragCallback : ViewDragHelper.Callback() { private var isScrollOverValid: Boolean = false + /** + * Toggles whether we may intercept the touch event + */ override fun tryCaptureView(view: View, i: Int): Boolean { - val ret = dragHelper.isEdgeTouched(ViewDragHelper.EDGE_LEFT, i) + val ret = dragHelper.isEdgeTouched(edgeFlag, i) if (ret) { listeners.forEach { it.get()?.onEdgeTouch() } isScrollOverValid = true @@ -250,47 +283,89 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu return ret } + /** + * Needs to be bigger than 0 to specify that scrolling is possible horizontally + */ override fun getViewHorizontalDragRange(child: View): Int { - return trackingEdge + return if (isHorizontal) 1 else 0 } - override fun getViewVerticalDragRange(child: View?): Int { - return 0 + /** + * Needs to be bigger than 0 to specify that scrolling is possible vertically + */ + override fun getViewVerticalDragRange(child: View): Int { + return if (isVertical) 1 else 0 } override fun onViewPositionChanged(changedView: View, left: Int, top: Int, dx: Int, dy: Int) { super.onViewPositionChanged(changedView, left, top, dx, dy) - scrollPercent = Math.abs(left.toFloat() / contentView!!.width) - contentOffset = left + //make sure that we are using the proper axis + val horizontal = (isHorizontal && (!isVertical || dy == 0)) + edgeChangeFlag = + if (horizontal) + if (left > 0) EDGE_LEFT else EDGE_RIGHT + else + if (top > 0) EDGE_BOTTOM else EDGE_TOP + + scrollPercent = Math.abs( + if (horizontal) left.toFloat() / contentView!!.width + else (top.toFloat() / contentView!!.height)) +// KL.d("horiz $horizontal scroll $scrollPercent") + contentOffset = if (horizontal) left else top invalidate() if (scrollPercent < scrollThreshold && !isScrollOverValid) isScrollOverValid = true - listeners.forEach { it.get()?.onScroll(scrollPercent, contentOffset) } + listeners.forEach { it.get()?.onScroll(scrollPercent, contentOffset, edgeChangeFlag) } if (scrollPercent >= 1) { if (!(activity?.isFinishing ?: true)) { if (scrollPercent >= scrollThreshold && isScrollOverValid) { isScrollOverValid = false - listeners.forEach { it.get()?.onScrollToClose() } + listeners.forEach { it.get()?.onScrollToClose(edgeChangeFlag) } } activity?.finish() + activity?.overridePendingTransition(0, 0) } } } override fun onViewReleased(releasedChild: View, xvel: Float, yvel: Float) { - val childWidth = releasedChild.width - val top = 0 - val left = if (xvel > 0 || xvel == 0f && scrollPercent > scrollThreshold) - childWidth + OVERSCROLL_DISTANCE - else 0 - dragHelper.settleCapturedViewAt(left, top) + var result = Pair(0, 0) + if (scrollPercent <= scrollThreshold) { + //threshold not met; check velocities + if ((edgeChangeFlag == EDGE_LEFT && xvel > MIN_FLING_VELOCITY) + || (edgeChangeFlag == EDGE_RIGHT && xvel < -MIN_FLING_VELOCITY) + || (edgeChangeFlag == EDGE_TOP && yvel > MIN_FLING_VELOCITY) + || (edgeChangeFlag == EDGE_BOTTOM && yvel < -MIN_FLING_VELOCITY)) + result = exitCaptureOffsets(edgeChangeFlag, releasedChild) + } else { + //threshold met; fling to designated side + result = exitCaptureOffsets(edgeChangeFlag, releasedChild) + } + dragHelper.settleCapturedViewAt(result.first, result.second) invalidate() } + private fun exitCaptureOffsets(edgeFlag: Int, view: View): Pair { + var top: Int = 0 + var left: Int = 0 + when (edgeFlag) { + EDGE_LEFT -> left = view.width + OVERSCROLL_DISTANCE + EDGE_RIGHT -> left = -(view.width + OVERSCROLL_DISTANCE) + EDGE_TOP -> top = -(view.height + OVERSCROLL_DISTANCE) + EDGE_BOTTOM -> top = view.height + OVERSCROLL_DISTANCE + else -> KL.e("Unknown edgeChangeFlag $edgeChangeFlag") + } + return Pair(left, top) + } + override fun clampViewPositionHorizontal(child: View, left: Int, dx: Int): Int { - return Math.min(child.width, Math.max(left, 0)) + return if (isHorizontal) Math.min(child.width, Math.max(left, 0)) else 0 + } + + override fun clampViewPositionVertical(child: View, top: Int, dy: Int): Int { + return if (isVertical) Math.min(child.height, Math.max(top, 0)) else 0 } } @@ -308,5 +383,19 @@ class SwipeBackLayout @JvmOverloads constructor(context: Context, attrs: Attribu private const val DEFAULT_SCROLL_THRESHOLD = 0.3f private const val OVERSCROLL_DISTANCE = 10 + + val EDGE_LEFT = ViewDragHelper.EDGE_LEFT + + val EDGE_RIGHT = ViewDragHelper.EDGE_RIGHT + + val EDGE_TOP = ViewDragHelper.EDGE_TOP + + val EDGE_BOTTOM = ViewDragHelper.EDGE_BOTTOM + + val EDGE_HORIZONTAL = EDGE_LEFT or EDGE_RIGHT + + val EDGE_VERTICAL = EDGE_TOP or EDGE_BOTTOM + + val EDGE_ALL = EDGE_HORIZONTAL or EDGE_VERTICAL } } diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt index e9a872b..56085c8 100644 --- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt @@ -46,7 +46,7 @@ class SwipeBackPage(activity: Activity) : SwipeBackPageContract by SwipeBackLayo //触发关闭Activity百分比 fun setClosePercent(percent: Float): SwipeBackPage { - swipeBackLayout.scrollThreshold=percent + swipeBackLayout.scrollThreshold = percent return this } @@ -54,11 +54,12 @@ class SwipeBackPage(activity: Activity) : SwipeBackPageContract by SwipeBackLayo interface SwipeBackPageContract { var swipeEnabled: Boolean - var scrimColor:Int + var scrimColor: Int val swipeBackLayout: SwipeBackLayout - var scrollThreshold:Float - var disallowIntercept:Boolean - fun setEdgeSize(swipeEdge: Int) + var edgeSize: Int + var edgeFlag:Int + var scrollThreshold: Float + var disallowIntercept: Boolean fun setEdgeSizePercent(swipeEdgePercent: Float) fun addListener(listener: SwipeListener) fun removeListener(listener: SwipeListener) diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeListener.kt b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeListener.kt index 4fe9fa8..71771a8 100644 --- a/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeListener.kt +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeListener.kt @@ -1,10 +1,10 @@ package ca.allanwang.kau.swipe interface SwipeListener { - fun onScroll(percent: Float, px: Int) + fun onScroll(percent: Float, px: Int, edgeFlag: Int) fun onEdgeTouch() /** * Invoke when scroll percent over the threshold for the first time */ - fun onScrollToClose() + fun onScrollToClose(edgeFlag: Int) } \ No newline at end of file diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java new file mode 100644 index 0000000..ad17366 --- /dev/null +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java @@ -0,0 +1,1515 @@ +package ca.allanwang.kau.swipe; + +/** + * Created by Allan Wang on 2017-07-05. + */ + +import android.content.Context; +import android.support.v4.view.ViewCompat; +import android.util.Log; +import android.view.MotionEvent; +import android.view.VelocityTracker; +import android.view.View; +import android.view.ViewConfiguration; +import android.view.ViewGroup; +import android.view.animation.Interpolator; +import android.widget.OverScroller; + +import java.util.Arrays; + +/** + * ViewDragHelper is a utility class for writing custom ViewGroups. It offers a number + * of useful operations and state tracking for allowing a user to drag and reposition + * views within their parent ViewGroup. + *

+ * This is an extension of {@link android.support.v4.widget.ViewDragHelper} + * Along with additional methods defined in + */ +public class ViewDragHelper implements ViewDragHelperExtras { + private static final String TAG = "ViewDragHelper"; + + /** + * A null/invalid pointer ID. + */ + public static final int INVALID_POINTER = -1; + + /** + * A view is not currently being dragged or animating as a result of a fling/snap. + */ + public static final int STATE_IDLE = 0; + + /** + * A view is currently being dragged. The position is currently changing as a result + * of user input or simulated user input. + */ + public static final int STATE_DRAGGING = 1; + + /** + * A view is currently settling into place as a result of a fling or + * predefined non-interactive motion. + */ + public static final int STATE_SETTLING = 2; + + /** + * Edge flag indicating that the left edge should be affected. + */ + public static final int EDGE_LEFT = 1 << 0; + + /** + * Edge flag indicating that the right edge should be affected. + */ + public static final int EDGE_RIGHT = 1 << 1; + + /** + * Edge flag indicating that the top edge should be affected. + */ + public static final int EDGE_TOP = 1 << 2; + + /** + * Edge flag indicating that the bottom edge should be affected. + */ + public static final int EDGE_BOTTOM = 1 << 3; + + /** + * Edge flag set indicating all edges should be affected. + */ + public static final int EDGE_ALL = EDGE_LEFT | EDGE_TOP | EDGE_RIGHT | EDGE_BOTTOM; + + /** + * Indicates that a check should occur along the horizontal axis + */ + public static final int DIRECTION_HORIZONTAL = 1 << 0; + + /** + * Indicates that a check should occur along the vertical axis + */ + public static final int DIRECTION_VERTICAL = 1 << 1; + + /** + * Indicates that a check should occur along all axes + */ + 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 float mMaxVelocity; + private float mMinVelocity; + + private int mEdgeSize; + private int mTrackingEdges; + + private OverScroller mScroller; + + private final ViewDragHelper.Callback mCallback; + + private View mCapturedView; + private boolean mReleaseInProgress; + + private final ViewGroup mParentView; + + /** + * A Callback is used as a communication channel with the ViewDragHelper back to the + * parent view using it. on*methods are invoked on siginficant events and several + * accessor methods are expected to provide the ViewDragHelper with more information + * about the state of the parent view upon request. The callback also makes decisions + * governing the range and draggability of child views. + */ + public abstract static class Callback { + /** + * Called when the drag state changes. See the STATE_* constants + * for more information. + * + * @param state The new drag state + * @see #STATE_IDLE + * @see #STATE_DRAGGING + * @see #STATE_SETTLING + */ + public void onViewDragStateChanged(int state) { + } + + /** + * Called when the captured view's position changes as the result of a drag or settle. + * + * @param changedView View whose position changed + * @param left New X coordinate of the left edge of the view + * @param top New Y coordinate of the top edge of the view + * @param dx Change in X position from the last call + * @param dy Change in Y position from the last call + */ + public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) { + } + + /** + * Called when a child view is captured for dragging or settling. The ID of the pointer + * currently dragging the captured view is supplied. If activePointerId is + * identified as {@link #INVALID_POINTER} the capture is programmatic instead of + * pointer-initiated. + * + * @param capturedChild Child view that was captured + * @param activePointerId Pointer id tracking the child capture + */ + public void onViewCaptured(View capturedChild, int activePointerId) { + } + + /** + * Called when the child view is no longer being actively dragged. + * The fling velocity is also supplied, if relevant. The velocity values may + * be clamped to system minimums or maximums. + *

+ *

Calling code may decide to fling or otherwise release the view to let it + * settle into place. It should do so using {@link #settleCapturedViewAt(int, int)} + * or {@link #flingCapturedView(int, int, int, int)}. If the Callback invokes + * one of these methods, the ViewDragHelper will enter {@link #STATE_SETTLING} + * and the view capture will not fully end until it comes to a complete stop. + * If neither of these methods is invoked before onViewReleased returns, + * the view will stop in place and the ViewDragHelper will return to + * {@link #STATE_IDLE}.

+ * + * @param releasedChild The captured child view now being released + * @param xvel X velocity of the pointer as it left the screen in pixels per second. + * @param yvel Y velocity of the pointer as it left the screen in pixels per second. + */ + public void onViewReleased(View releasedChild, float xvel, float yvel) { + } + + /** + * Called when one of the subscribed edges in the parent view has been touched + * by the user while no child view is currently captured. + * + * @param edgeFlags A combination of edge flags describing the edge(s) currently touched + * @param pointerId ID of the pointer touching the described edge(s) + * @see #EDGE_LEFT + * @see #EDGE_TOP + * @see #EDGE_RIGHT + * @see #EDGE_BOTTOM + */ + public void onEdgeTouched(int edgeFlags, int pointerId) { + } + + /** + * Called when the given edge may become locked. This can happen if an edge drag + * was preliminarily rejected before beginning, but after {@link #onEdgeTouched(int, int)} + * was called. This method should return true to lock this edge or false to leave it + * unlocked. The default behavior is to leave edges unlocked. + * + * @param edgeFlags A combination of edge flags describing the edge(s) locked + * @return true to lock the edge, false to leave it unlocked + */ + public boolean onEdgeLock(int edgeFlags) { + return false; + } + + /** + * Called when the user has started a deliberate drag away from one + * of the subscribed edges in the parent view while no child view is currently captured. + * + * @param edgeFlags A combination of edge flags describing the edge(s) dragged + * @param pointerId ID of the pointer touching the described edge(s) + * @see #EDGE_LEFT + * @see #EDGE_TOP + * @see #EDGE_RIGHT + * @see #EDGE_BOTTOM + */ + public void onEdgeDragStarted(int edgeFlags, int pointerId) { + } + + /** + * Called to determine the Z-order of child views. + * + * @param index the ordered position to query for + * @return index of the view that should be ordered at position index + */ + public int getOrderedChildIndex(int index) { + return index; + } + + /** + * Return the magnitude of a draggable child view's horizontal range of motion in pixels. + * This method should return 0 for views that cannot move horizontally. + * + * @param child Child view to check + * @return range of horizontal motion in pixels + */ + public int getViewHorizontalDragRange(View child) { + return 0; + } + + /** + * Return the magnitude of a draggable child view's vertical range of motion in pixels. + * This method should return 0 for views that cannot move vertically. + * + * @param child Child view to check + * @return range of vertical motion in pixels + */ + public int getViewVerticalDragRange(View child) { + return 0; + } + + /** + * Called when the user's input indicates that they want to capture the given child view + * with the pointer indicated by pointerId. The callback should return true if the user + * is permitted to drag the given view with the indicated pointer. + *

+ *

ViewDragHelper may call this method multiple times for the same view even if + * the view is already captured; this indicates that a new pointer is trying to take + * control of the view.

+ *

+ *

If this method returns true, a call to {@link #onViewCaptured(android.view.View, int)} + * will follow if the capture is successful.

+ * + * @param child Child the user is attempting to capture + * @param pointerId ID of the pointer attempting the capture + * @return true if capture should be allowed, false otherwise + */ + public abstract boolean tryCaptureView(View child, int pointerId); + + /** + * Restrict the motion of the dragged child view along the horizontal axis. + * The default implementation does not allow horizontal motion; the extending + * class must override this method and provide the desired clamping. + * + * @param child Child view being dragged + * @param left Attempted motion along the X axis + * @param dx Proposed change in position for left + * @return The new clamped position for left + */ + public int clampViewPositionHorizontal(View child, int left, int dx) { + return 0; + } + + /** + * Restrict the motion of the dragged child view along the vertical axis. + * The default implementation does not allow vertical motion; the extending + * class must override this method and provide the desired clamping. + * + * @param child Child view being dragged + * @param top Attempted motion along the Y axis + * @param dy Proposed change in position for top + * @return The new clamped position for top + */ + public int clampViewPositionVertical(View child, int top, int dy) { + return 0; + } + } + + /** + * Interpolator defining the animation curve for mScroller + */ + private static final Interpolator sInterpolator = new Interpolator() { + @Override + public float getInterpolation(float t) { + t -= 1.0f; + return t * t * t * t * t + 1.0f; + } + }; + + private final Runnable mSetIdleRunnable = new Runnable() { + @Override + public void run() { + setDragState(STATE_IDLE); + } + }; + + /** + * Factory method to create a new ViewDragHelper. + * + * @param forParent Parent view to monitor + * @param cb Callback to provide information and receive events + * @return a new ViewDragHelper instance + */ + public static ViewDragHelper create(ViewGroup forParent, ViewDragHelper.Callback cb) { + return new ViewDragHelper(forParent.getContext(), forParent, cb); + } + + /** + * Factory method to create a new ViewDragHelper. + * + * @param forParent Parent view to monitor + * @param sensitivity Multiplier for how sensitive the helper should be about detecting + * the start of a drag. Larger values are more sensitive. 1.0f is normal. + * @param cb Callback to provide information and receive events + * @return a new ViewDragHelper instance + */ + public static ViewDragHelper create(ViewGroup forParent, float sensitivity, ViewDragHelper.Callback cb) { + final ViewDragHelper helper = create(forParent, cb); + helper.mTouchSlop = (int) (helper.mTouchSlop * (1 / sensitivity)); + return helper; + } + + /** + * Apps should use ViewDragHelper.create() to get a new instance. + * This will allow VDH to use internal compatibility implementations for different + * platform versions. + * + * @param context Context to initialize config-dependent params from + * @param forParent Parent view to monitor + */ + private ViewDragHelper(Context context, ViewGroup forParent, ViewDragHelper.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 = new OverScroller(context, sInterpolator); + } + + /** + * Set the minimum velocity that will be detected as having a magnitude greater than zero + * in pixels per second. Callback methods accepting a velocity will be clamped appropriately. + * + * @param minVel Minimum velocity to detect + */ + public void setMinVelocity(float minVel) { + mMinVelocity = minVel; + } + + /** + * Return the currently configured minimum velocity. Any flings with a magnitude less + * than this value in pixels per second. Callback methods accepting a velocity will receive + * zero as a velocity value if the real detected velocity was below this threshold. + * + * @return the minimum velocity that will be detected + */ + public float getMinVelocity() { + return mMinVelocity; + } + + @Override + public void setMaxVelocity(float maxVel) { + mMaxVelocity = maxVel; + } + + @Override + public float getMaxVelocity() { + return mMaxVelocity; + } + + /** + * Retrieve the current drag state of this helper. This will return one of + * {@link #STATE_IDLE}, {@link #STATE_DRAGGING} or {@link #STATE_SETTLING}. + * + * @return The current drag state + */ + public int getViewDragState() { + return mDragState; + } + + /** + * Enable edge tracking for the selected edges of the parent view. + * The callback's {@link ViewDragHelper.Callback#onEdgeTouched(int, int)} and + * {@link ViewDragHelper.Callback#onEdgeDragStarted(int, int)} methods will only be invoked + * for edges for which edge tracking has been enabled. + * + * @param edgeFlags Combination of edge flags describing the edges to watch + * @see #EDGE_LEFT + * @see #EDGE_TOP + * @see #EDGE_RIGHT + * @see #EDGE_BOTTOM + */ + public void setEdgeTrackingEnabled(int edgeFlags) { + mTrackingEdges = edgeFlags; + } + + /** + * Return the size of an edge. This is the range in pixels along the edges of this view + * that will actively detect edge touches or drags if edge tracking is enabled. + * + * @return The size of an edge in pixels + * @see #setEdgeTrackingEnabled(int) + */ + public int getEdgeSize() { + return mEdgeSize; + } + + @Override + public void setEdgeSize(int size) { + mEdgeSize = size; + } + + /** + * Capture a specific child view for dragging within the parent. The callback will be notified + * but {@link ViewDragHelper.Callback#tryCaptureView(android.view.View, int)} will not be asked permission to + * capture this view. + * + * @param childView Child view to capture + * @param activePointerId ID of the pointer that is dragging the captured child view + */ + 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); + } + + /** + * @return The currently captured view, or null if no view has been captured. + */ + public View getCapturedView() { + return mCapturedView; + } + + /** + * @return The ID of the pointer currently dragging the captured view, + * or {@link #INVALID_POINTER}. + */ + public int getActivePointerId() { + return mActivePointerId; + } + + /** + * @return The minimum distance in pixels that the user must travel to initiate a drag + */ + public int getTouchSlop() { + return mTouchSlop; + } + + /** + * The result of a call to this method is equivalent to + * {@link #processTouchEvent(android.view.MotionEvent)} receiving an ACTION_CANCEL event. + */ + public void cancel() { + mActivePointerId = INVALID_POINTER; + clearMotionHistory(); + + if (mVelocityTracker != null) { + mVelocityTracker.recycle(); + mVelocityTracker = null; + } + } + + /** + * {@link #cancel()}, but also abort all motion in progress and snap to the end of any + * animation. + */ + 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); + } + + /** + * Animate the view child to the given (left, top) position. + * If this method returns true, the caller should invoke {@link #continueSettling(boolean)} + * on each subsequent frame to continue the motion until it returns false. If this method + * returns false there is no further work to do to complete the movement. + *

+ *

This operation does not count as a capture event, though {@link #getCapturedView()} + * will still report the sliding view while the slide is in progress.

+ * + * @param child Child view to capture and animate + * @param finalLeft Final left position of child + * @param finalTop Final top position of child + * @return true if animation should continue through {@link #continueSettling(boolean)} calls + */ + 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; + } + + /** + * Settle the captured view at the given (left, top) position. + * The appropriate velocity from prior motion will be taken into account. + * If this method returns true, the caller should invoke {@link #continueSettling(boolean)} + * on each subsequent frame to continue the motion until it returns false. If this method + * returns false there is no further work to do to complete the movement. + * + * @param finalLeft Settled left edge position for the captured view + * @param finalTop Settled top edge position for the captured view + * @return true if animation should continue through {@link #continueSettling(boolean)} calls + */ + 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) mVelocityTracker.getXVelocity(mActivePointerId), + (int) mVelocityTracker.getYVelocity(mActivePointerId)); + } + + /** + * Settle the captured view at the given (left, top) position. + * + * @param finalLeft Target left position for the captured view + * @param finalTop Target top position for the captured view + * @param xvel Horizontal velocity + * @param yvel Vertical velocity + * @return true if animation should continue through {@link #continueSettling(boolean)} calls + */ + 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); + } + + /** + * Clamp the magnitude of value for absMin and absMax. + * If the value is below the minimum, it will be clamped to zero. + * If the value is above the maximum, it will be clamped to the maximum. + * + * @param value Value to clamp + * @param absMin Absolute value of the minimum significant value to return + * @param absMax Absolute value of the maximum value to return + * @return The clamped value with the same sign as value + */ + private 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; + } + + /** + * Clamp the magnitude of value for absMin and absMax. + * If the value is below the minimum, it will be clamped to zero. + * If the value is above the maximum, it will be clamped to the maximum. + * + * @param value Value to clamp + * @param absMin Absolute value of the minimum significant value to return + * @param absMax Absolute value of the maximum value to return + * @return The clamped value with the same sign as value + */ + private 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 float distanceInfluenceForSnapDuration(float f) { + f -= 0.5f; // center the values about 0. + f *= 0.3f * (float) Math.PI / 2.0f; + return (float) Math.sin(f); + } + + /** + * Settle the captured view based on standard free-moving fling behavior. + * The caller should invoke {@link #continueSettling(boolean)} on each subsequent frame + * to continue the motion until it returns false. + * + * @param minLeft Minimum X position for the view's left edge + * @param minTop Minimum Y position for the view's top edge + * @param maxLeft Maximum X position for the view's left edge + * @param maxTop Maximum Y position for the view's top edge + */ + 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) mVelocityTracker.getXVelocity(mActivePointerId), + (int) mVelocityTracker.getYVelocity(mActivePointerId), + minLeft, maxLeft, minTop, maxTop); + + setDragState(STATE_SETTLING); + } + + /** + * Move the captured settling view by the appropriate amount for the current time. + * If continueSettling returns true, the caller should call it again + * on the next frame to continue. + * + * @param deferCallbacks true if state callbacks should be deferred via posted message. + * Set this to true if you are calling this method from + * {@link android.view.View#computeScroll()} or similar methods + * invoked as part of layout or drawing. + * @return true if settle is still in progress + */ + 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) { + ViewCompat.offsetLeftAndRight(mCapturedView, dx); + } + if (dy != 0) { + ViewCompat.offsetTopAndBottom(mCapturedView, 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; + } + + /** + * Like all callback events this must happen on the UI thread, but release + * involves some extra semantics. During a release (mReleaseInProgress) + * is the only time it is valid to call {@link #settleCapturedViewAt(int, int)} + * or {@link #flingCapturedView(int, int, int, int)}. + */ + 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 || !isPointerDown(pointerId)) { + 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 = ev.getPointerCount(); + for (int i = 0; i < pointerCount; i++) { + final int pointerId = ev.getPointerId(i); + // If pointer is invalid then skip saving on ACTION_MOVE. + if (!isValidPointerForActionMove(pointerId)) { + continue; + } + final float x = ev.getX(i); + final float y = ev.getY(i); + mLastMotionX[pointerId] = x; + mLastMotionY[pointerId] = y; + } + } + + /** + * Check if the given pointer ID represents a pointer that is currently down (to the best + * of the ViewDragHelper's knowledge). + *

+ *

The state used to report this information is populated by the methods + * {@link #shouldInterceptTouchEvent(android.view.MotionEvent)} or + * {@link #processTouchEvent(android.view.MotionEvent)}. If one of these methods has not + * been called for all relevant MotionEvents to track, the information reported + * by this method may be stale or incorrect.

+ * + * @param pointerId pointer ID to check; corresponds to IDs provided by MotionEvent + * @return true if the pointer with the given ID is still down + */ + 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; + } + } + } + + /** + * Attempt to capture the view with the given pointer ID. The callback will be involved. + * This will put us into the "dragging" state. If we've already captured this view with + * this pointer this method will immediately return true without consulting the callback. + * + * @param toCapture View to capture + * @param pointerId Pointer to capture with + * @return true if capture was successful + */ + 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; + } + + /** + * Tests scrollability within child views of v given a delta of dx. + * + * @param v View to test for horizontal scrollability + * @param checkV Whether the view v passed should itself be checked for scrollability (true), + * or just its children (false). + * @param dx Delta scrolled in pixels along the X axis + * @param dy Delta scrolled in pixels along the Y axis + * @param x X coordinate of the active touch point + * @param y Y coordinate of the active touch point + * @return true if child views of v can be scrolled by delta of dx. + */ + 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 && (v.canScrollHorizontally(-dx) || v.canScrollVertically(-dy)); + } + + /** + * Check if this event as provided to the parent view's onInterceptTouchEvent should + * cause the parent to intercept the touch event stream. + * + * @param ev MotionEvent provided to onInterceptTouchEvent + * @return true if the parent view should return true from onInterceptTouchEvent + */ + public boolean shouldInterceptTouchEvent(MotionEvent ev) { + final int action = ev.getActionMasked(); + final int actionIndex = ev.getActionIndex(); + + 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 = ev.getPointerId(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 MotionEvent.ACTION_POINTER_DOWN: { + final int pointerId = ev.getPointerId(actionIndex); + final float x = ev.getX(actionIndex); + final float y = ev.getY(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 = ev.getPointerCount(); + for (int i = 0; i < pointerCount; i++) { + final int pointerId = ev.getPointerId(i); + + // If pointer is invalid then skip the ACTION_MOVE. + if (!isValidPointerForActionMove(pointerId)) continue; + + final float x = ev.getX(i); + final float y = ev.getY(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 hDragRange = mCallback.getViewHorizontalDragRange(toCapture); + final int vDragRange = mCallback.getViewVerticalDragRange(toCapture); + if ((hDragRange == 0 || (hDragRange > 0 && newLeft == oldLeft)) + && (vDragRange == 0 || (vDragRange > 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 MotionEvent.ACTION_POINTER_UP: { + final int pointerId = ev.getPointerId(actionIndex); + clearMotionHistory(pointerId); + break; + } + + case MotionEvent.ACTION_UP: + case MotionEvent.ACTION_CANCEL: { + cancel(); + break; + } + } + + return mDragState == STATE_DRAGGING; + } + + /** + * Process a touch event received by the parent view. This method will dispatch callback events + * as needed before returning. The parent view's onTouchEvent implementation should call this. + * + * @param ev The touch event received by the parent view + */ + public void processTouchEvent(MotionEvent ev) { + final int action = ev.getActionMasked(); + final int actionIndex = ev.getActionIndex(); + + 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 = ev.getPointerId(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 MotionEvent.ACTION_POINTER_DOWN: { + final int pointerId = ev.getPointerId(actionIndex); + final float x = ev.getX(actionIndex); + final float y = ev.getY(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) { + // If pointer is invalid then skip the ACTION_MOVE. + if (!isValidPointerForActionMove(mActivePointerId)) break; + + final int index = ev.findPointerIndex(mActivePointerId); + final float x = ev.getX(index); + final float y = ev.getY(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 = ev.getPointerCount(); + for (int i = 0; i < pointerCount; i++) { + final int pointerId = ev.getPointerId(i); + + // If pointer is invalid then skip the ACTION_MOVE. + if (!isValidPointerForActionMove(pointerId)) continue; + + final float x = ev.getX(i); + final float y = ev.getY(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 MotionEvent.ACTION_POINTER_UP: { + final int pointerId = ev.getPointerId(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 = ev.getPointerCount(); + for (int i = 0; i < pointerCount; i++) { + final int id = ev.getPointerId(i); + if (id == mActivePointerId) { + // This one's going away, skip. + continue; + } + + final float x = ev.getX(i); + final float y = ev.getY(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; + } + } + } + + 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; + } + + /** + * Check if we've crossed a reasonable touch slop for the given child view. + * If the child cannot be dragged along the horizontal or vertical axis, motion + * along that axis will not count toward the slop check. + * + * @param child Child to check + * @param dx Motion since initial position along X axis + * @param dy Motion since initial position along Y axis + * @return true if the touch slop has been crossed + */ + 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; + } + + /** + * Check if any pointer tracked in the current gesture has crossed + * the required slop threshold. + *

+ *

This depends on internal state populated by + * {@link #shouldInterceptTouchEvent(android.view.MotionEvent)} or + * {@link #processTouchEvent(android.view.MotionEvent)}. You should only rely on + * the results of this method after all currently available touch data + * has been provided to one of these two methods.

+ * + * @param directions Combination of direction flags, see {@link #DIRECTION_HORIZONTAL}, + * {@link #DIRECTION_VERTICAL}, {@link #DIRECTION_ALL} + * @return true if the slop threshold has been crossed, false otherwise + */ + 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; + } + + /** + * Check if the specified pointer tracked in the current gesture has crossed + * the required slop threshold. + *

+ *

This depends on internal state populated by + * {@link #shouldInterceptTouchEvent(android.view.MotionEvent)} or + * {@link #processTouchEvent(android.view.MotionEvent)}. You should only rely on + * the results of this method after all currently available touch data + * has been provided to one of these two methods.

+ * + * @param directions Combination of direction flags, see {@link #DIRECTION_HORIZONTAL}, + * {@link #DIRECTION_VERTICAL}, {@link #DIRECTION_ALL} + * @param pointerId ID of the pointer to slop check as specified by MotionEvent + * @return true if the slop threshold has been crossed, false otherwise + */ + 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; + } + + /** + * Check if any of the edges specified were initially touched in the currently active gesture. + * If there is no currently active gesture this method will return false. + * + * @param edges Edges to check for an initial edge touch. See {@link #EDGE_LEFT}, + * {@link #EDGE_TOP}, {@link #EDGE_RIGHT}, {@link #EDGE_BOTTOM} and + * {@link #EDGE_ALL} + * @return true if any of the edges specified were initially touched in the current gesture + */ + 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; + } + + /** + * Check if any of the edges specified were initially touched by the pointer with + * the specified ID. If there is no currently active gesture or if there is no pointer with + * the given ID currently down this method will return false. + * + * @param edges Edges to check for an initial edge touch. See {@link #EDGE_LEFT}, + * {@link #EDGE_TOP}, {@link #EDGE_RIGHT}, {@link #EDGE_BOTTOM} and + * {@link #EDGE_ALL} + * @return true if any of the edges specified were initially touched in the current gesture + */ + 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( + mVelocityTracker.getXVelocity(mActivePointerId), + mMinVelocity, mMaxVelocity); + final float yvel = clampMag( + mVelocityTracker.getYVelocity(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); + ViewCompat.offsetLeftAndRight(mCapturedView, clampedX - oldLeft); + } + if (dy != 0) { + clampedY = mCallback.clampViewPositionVertical(mCapturedView, top, dy); + ViewCompat.offsetTopAndBottom(mCapturedView, clampedY - oldTop); + } + + if (dx != 0 || dy != 0) { + final int clampedDx = clampedX - oldLeft; + final int clampedDy = clampedY - oldTop; + mCallback.onViewPositionChanged(mCapturedView, clampedX, clampedY, + clampedDx, clampedDy); + } + } + + /** + * Determine if the currently captured view is under the given point in the + * parent view's coordinate system. If there is no captured view this method + * will return false. + * + * @param x X position to test in the parent's coordinate system + * @param y Y position to test in the parent's coordinate system + * @return true if the captured view is under the given point, false otherwise + */ + public boolean isCapturedViewUnder(int x, int y) { + return isViewUnder(mCapturedView, x, y); + } + + /** + * Determine if the supplied view is under the given point in the + * parent view's coordinate system. + * + * @param view Child view of the parent to hit test + * @param x X position to test in the parent's coordinate system + * @param y Y position to test in the parent's coordinate system + * @return true if the supplied view is under the given point, false otherwise + */ + 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(); + } + + /** + * Find the topmost child under the given point within the parent view's coordinate system. + * The child order is determined using {@link ViewDragHelper.Callback#getOrderedChildIndex(int)}. + * + * @param x X position to test in the parent's coordinate system + * @param y Y position to test in the parent's coordinate system + * @return The topmost child view under (x, y) or null if none found. + */ + 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; + } + + private boolean isValidPointerForActionMove(int pointerId) { + if (!isPointerDown(pointerId)) { + Log.e(TAG, "Ignoring pointerId=" + pointerId + " because ACTION_DOWN was not received " + + "for this pointer before ACTION_MOVE. It likely happened because " + + " ViewDragHelper did not receive all the events in the event stream."); + return false; + } + return true; + } +} diff --git a/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelperExtras.java b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelperExtras.java new file mode 100644 index 0000000..638f2fa --- /dev/null +++ b/core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelperExtras.java @@ -0,0 +1,24 @@ +package ca.allanwang.kau.swipe; + +/** + * Created by Allan Wang on 2017-07-05. + *

+ * Collection of addition methods added into ViewDragHelper that weren't in the original + */ + +public interface ViewDragHelperExtras { + + + /** + * Sets the new size of a given edge + * Any touch within this range will be defined to have started from an edge + * + * @param size the new size in px + */ + void setEdgeSize(int size); + + void setMaxVelocity(float maxVel); + + float getMaxVelocity(); + +} diff --git a/core/src/main/res/values/styles.xml b/core/src/main/res/values/styles.xml index 2067c6d..71d88a2 100644 --- a/core/src/main/res/values/styles.xml +++ b/core/src/main/res/values/styles.xml @@ -13,6 +13,10 @@ true + +