Adding fling-to-delete.
- Also fixing issue where the drop target icon changes color slower than the text.
Change-Id: I0bfa59da5d202016342f1c3de419ebcafd81ff6f
diff --git a/src/com/android/launcher2/DragController.java b/src/com/android/launcher2/DragController.java
index 019a749..2a88925 100644
--- a/src/com/android/launcher2/DragController.java
+++ b/src/com/android/launcher2/DragController.java
@@ -19,6 +19,7 @@
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Point;
+import android.graphics.PointF;
import android.graphics.Rect;
import android.os.Handler;
import android.os.IBinder;
@@ -26,6 +27,7 @@
import android.util.Log;
import android.view.KeyEvent;
import android.view.MotionEvent;
+import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.inputmethod.InputMethodManager;
@@ -60,6 +62,9 @@
static final int SCROLL_LEFT = 0;
static final int SCROLL_RIGHT = 1;
+ private static final float MAX_FLING_DEGREES = 35f;
+ private static final int FLING_TO_DELETE_THRESHOLD_Y_VELOCITY = -1400;
+
private Launcher mLauncher;
private Handler mHandler;
private final Vibrator mVibrator = new Vibrator();
@@ -86,8 +91,8 @@
/** Who can receive drop events */
private ArrayList<DropTarget> mDropTargets = new ArrayList<DropTarget>();
-
private ArrayList<DragListener> mListeners = new ArrayList<DragListener>();
+ private DropTarget mFlingToDeleteDropTarget;
/** The window token used as the parent for the DragView. */
private IBinder mWindowToken;
@@ -111,6 +116,9 @@
private int mTmpPoint[] = new int[2];
private Rect mDragLayerRect = new Rect();
+ protected int mFlingToDeleteThresholdVelocity;
+ private VelocityTracker mVelocityTracker;
+
/**
* Interface to receive notifications when a drag starts or stops
*/
@@ -141,6 +149,10 @@
mLauncher = launcher;
mHandler = new Handler();
mScrollZone = launcher.getResources().getDimensionPixelSize(R.dimen.scroll_zone);
+ mVelocityTracker = VelocityTracker.obtain();
+
+ float density = launcher.getResources().getDisplayMetrics().density;
+ mFlingToDeleteThresholdVelocity = (int) (FLING_TO_DELETE_THRESHOLD_Y_VELOCITY * density);
}
public boolean dragging() {
@@ -378,15 +390,35 @@
if (mDragging) {
mDragging = false;
clearScrollRunnable();
- for (DragListener listener : mListeners) {
- listener.onDragEnd();
- }
+ boolean isDeferred = false;
if (mDragObject.dragView != null) {
- if (!mDragObject.deferDragViewCleanupPostAnimation) {
+ isDeferred = mDragObject.deferDragViewCleanupPostAnimation;
+ if (!isDeferred) {
mDragObject.dragView.remove();
}
mDragObject.dragView = null;
}
+
+ // Only end the drag if we are not deferred
+ if (!isDeferred) {
+ for (DragListener listener : mListeners) {
+ listener.onDragEnd();
+ }
+ }
+ }
+
+ releaseVelocityTracker();
+ }
+
+ /**
+ * This only gets called as a result of drag view cleanup being deferred in endDrag();
+ */
+ void onDeferredEndDrag(DragView dragView) {
+ dragView.remove();
+
+ // If we skipped calling onDragEnd() before, do it now
+ for (DragListener listener : mListeners) {
+ listener.onDragEnd();
}
}
@@ -408,8 +440,11 @@
Log.d(Launcher.TAG, "DragController.onInterceptTouchEvent " + ev + " mDragging="
+ mDragging);
}
- final int action = ev.getAction();
+ // Update the velocity tracker
+ acquireVelocityTrackerAndAddMovement(ev);
+
+ final int action = ev.getAction();
final int[] dragLayerPos = getClampedDragLayerPos(ev.getX(), ev.getY());
final int dragLayerX = dragLayerPos[0];
final int dragLayerY = dragLayerPos[1];
@@ -425,7 +460,12 @@
break;
case MotionEvent.ACTION_UP:
if (mDragging) {
- drop(dragLayerX, dragLayerY);
+ PointF vec = isFlingingToDelete(mDragObject.dragSource);
+ if (vec != null) {
+ dropOnFlingToDeleteTarget(dragLayerX, dragLayerY, vec);
+ } else {
+ drop(dragLayerX, dragLayerY);
+ }
}
endDrag();
break;
@@ -529,6 +569,9 @@
return false;
}
+ // Update the velocity tracker
+ acquireVelocityTrackerAndAddMovement(ev);
+
final int action = ev.getAction();
final int[] dragLayerPos = getClampedDragLayerPos(ev.getX(), ev.getY());
final int dragLayerX = dragLayerPos[0];
@@ -553,10 +596,15 @@
case MotionEvent.ACTION_UP:
// Ensure that we've processed a move event at the current pointer location.
handleMoveEvent(dragLayerX, dragLayerY);
-
mHandler.removeCallbacks(mScrollRunnable);
+
if (mDragging) {
- drop(dragLayerX, dragLayerY);
+ PointF vec = isFlingingToDelete(mDragObject.dragSource);
+ if (vec != null) {
+ dropOnFlingToDeleteTarget(dragLayerX, dragLayerY, vec);
+ } else {
+ drop(dragLayerX, dragLayerY);
+ }
}
endDrag();
break;
@@ -569,6 +617,58 @@
return true;
}
+ /**
+ * Determines whether the user flung the current item to delete it.
+ *
+ * @return the vector at which the item was flung, or null if no fling was detected.
+ */
+ private PointF isFlingingToDelete(DragSource source) {
+ if (mFlingToDeleteDropTarget == null) return null;
+ if (!source.supportsFlingToDelete()) return null;
+
+ ViewConfiguration config = ViewConfiguration.get(mLauncher);
+ mVelocityTracker.computeCurrentVelocity(1000, config.getScaledMaximumFlingVelocity());
+
+ if (mVelocityTracker.getYVelocity() < mFlingToDeleteThresholdVelocity) {
+ // Do a quick dot product test to ensure that we are flinging upwards
+ PointF vel = new PointF(mVelocityTracker.getXVelocity(),
+ mVelocityTracker.getYVelocity());
+ PointF upVec = new PointF(0f, -1f);
+ float theta = (float) Math.acos(((vel.x * upVec.x) + (vel.y * upVec.y)) /
+ (vel.length() * upVec.length()));
+ if (theta <= Math.toRadians(MAX_FLING_DEGREES)) {
+ return vel;
+ }
+ }
+ return null;
+ }
+
+ private void dropOnFlingToDeleteTarget(float x, float y, PointF vel) {
+ final int[] coordinates = mCoordinatesTemp;
+
+ mDragObject.x = coordinates[0];
+ mDragObject.y = coordinates[1];
+ mDragObject.dragComplete = true;
+
+ // Clean up dragging on the target if it's not the current fling delete target otherwise,
+ // start dragging to it.
+ if (mLastDropTarget != null && mFlingToDeleteDropTarget != mLastDropTarget) {
+ mLastDropTarget.onDragExit(mDragObject);
+ }
+
+ // Drop onto the fling-to-delete target
+ boolean accepted = false;
+ mFlingToDeleteDropTarget.onDragEnter(mDragObject);
+ mFlingToDeleteDropTarget.onDragExit(mDragObject);
+ if (mFlingToDeleteDropTarget.acceptDrop(mDragObject)) {
+ mFlingToDeleteDropTarget.onFlingToDelete(mDragObject, mDragObject.x, mDragObject.y,
+ vel);
+ accepted = true;
+ }
+ mDragObject.dragSource.onDropCompleted((View) mFlingToDeleteDropTarget, mDragObject,
+ accepted);
+ }
+
private void drop(float x, float y) {
final int[] coordinates = mCoordinatesTemp;
final DropTarget dropTarget = findDropTarget((int) x, (int) y, coordinates);
@@ -659,6 +759,27 @@
}
/**
+ * Sets the current fling-to-delete drop target.
+ */
+ public void setFlingToDeleteDropTarget(DropTarget target) {
+ mFlingToDeleteDropTarget = target;
+ }
+
+ private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
+ if (mVelocityTracker == null) {
+ mVelocityTracker = VelocityTracker.obtain();
+ }
+ mVelocityTracker.addMovement(ev);
+ }
+
+ private void releaseVelocityTracker() {
+ if (mVelocityTracker != null) {
+ mVelocityTracker.recycle();
+ mVelocityTracker = null;
+ }
+ }
+
+ /**
* Set which view scrolls for touch events near the edge of the screen.
*/
public void setScrollView(View v) {