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authorAllan Wang <me@allanwang.ca>2017-07-05 14:47:58 -0700
committerAllan Wang <me@allanwang.ca>2017-07-05 14:47:58 -0700
commit36471abc904ff4aa3109bd06efbc3ed493f082b2 (patch)
tree7b7f8a9b7828d0171ad2b5854a67b0108e772de7 /core/src
parent10e2ee9d4f105d9737b98b1caacf5e6ccb1c3c7d (diff)
downloadkau-36471abc904ff4aa3109bd06efbc3ed493f082b2.tar.gz
kau-36471abc904ff4aa3109bd06efbc3ed493f082b2.tar.bz2
kau-36471abc904ff4aa3109bd06efbc3ed493f082b2.zip
Setup swipe for all directions
Diffstat (limited to 'core/src')
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/RelativeSlider.kt27
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackHelper.kt3
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackLayout.kt161
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeBackPage.kt11
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/SwipeListener.kt4
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelper.java1515
-rw-r--r--core/src/main/kotlin/ca/allanwang/kau/swipe/ViewDragHelperExtras.java24
-rw-r--r--core/src/main/res/values/styles.xml4
8 files changed, 1699 insertions, 50 deletions
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<View>(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<Int, Int> {
+ 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.
+ * <p>
+ * 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. <code>on*</code>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 <code>STATE_*</code> 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.
+ * <p>
+ * <p>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 <code>onViewReleased</code> returns,
+ * the view will stop in place and the ViewDragHelper will return to
+ * {@link #STATE_IDLE}.</p>
+ *
+ * @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 <code>index</code>
+ */
+ 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.
+ * <p>
+ * <p>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.</p>
+ * <p>
+ * <p>If this method returns true, a call to {@link #onViewCaptured(android.view.View, int)}
+ * will follow if the capture is successful.</p>
+ *
+ * @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 <code>child</code> 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.
+ * <p>
+ * <p>This operation does not count as a capture event, though {@link #getCapturedView()}
+ * will still report the sliding view while the slide is in progress.</p>
+ *
+ * @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 <code>value</code>
+ */
+ 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 <code>value</code>
+ */
+ 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 <code>continueSettling</code> 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).
+ * <p>
+ * <p>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.</p>
+ *
+ * @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.
+ * <p>
+ * <p>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.</p>
+ *
+ * @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.
+ * <p>
+ * <p>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.</p>
+ *
+ * @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.
+ * <p>
+ * 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 @@
<item name="android:windowDrawsSystemBarBackgrounds">true</item>
</style>
+ <style name="Kau.Translucent.NoAnimation">
+ <item name="android:windowAnimationStyle">@null</item>
+ </style>
+
<style name="Kau.Translucent.About">
<item name="android:windowEnterTransition">@transition/kau_enter_slide_top</item>
<item name="android:windowReturnTransition">@transition/kau_about_return_upwards</item>