Applying ChannelScrolling to remove calculateDragAngle
To avoid angle calculation changed the logic to use virtual areas.
When try to drag or pan, check where the current touch point locates
and determine how to drag a page.
Change-Id: Id9bd08a69c4ac93ff385c8088e6c16bed5dc5f88
Signed-off-by: kiwon <kiwon98.lee@samsung.com>
diff --git a/core/java/android/webkit/WebViewClassic.java b/core/java/android/webkit/WebViewClassic.java
index ae56e6b..7154f95 100644
--- a/core/java/android/webkit/WebViewClassic.java
+++ b/core/java/android/webkit/WebViewClassic.java
@@ -1258,6 +1258,40 @@
mAutoFillData = new WebViewCore.AutoFillData();
mEditTextScroller = new Scroller(context);
+
+ // Calculate channel distance
+ calculateChannelDistance(context);
+ }
+
+ /**
+ * Calculate sChannelDistance based on the screen information.
+ * @param context A Context object used to access application assets.
+ */
+ private void calculateChannelDistance(Context context) {
+ // The channel distance is adjusted for density and screen size
+ final DisplayMetrics metrics = context.getResources().getDisplayMetrics();
+ final double screenSize = Math.hypot((double)(metrics.widthPixels/metrics.densityDpi),
+ (double)(metrics.heightPixels/metrics.densityDpi));
+ if (screenSize < 3.0) {
+ sChannelDistance = 16;
+ } else if (screenSize < 5.0) {
+ sChannelDistance = 22;
+ } else if (screenSize < 7.0) {
+ sChannelDistance = 28;
+ } else {
+ sChannelDistance = 34;
+ }
+ sChannelDistance = (int)(sChannelDistance * metrics.density);
+ if (sChannelDistance < 16) sChannelDistance = 16;
+
+ if (DebugFlags.WEB_VIEW) {
+ Log.v(LOGTAG, "sChannelDistance : " + sChannelDistance
+ + ", density : " + metrics.density
+ + ", screenSize : " + screenSize
+ + ", metrics.heightPixels : " + metrics.heightPixels
+ + ", metrics.widthPixels : " + metrics.widthPixels
+ + ", metrics.densityDpi : " + metrics.densityDpi);
+ }
}
// WebViewProvider bindings
@@ -5715,32 +5749,13 @@
}
return mWebViewPrivate.super_dispatchKeyEvent(event);
}
-
- /*
- * Here is the snap align logic:
- * 1. If it starts nearly horizontally or vertically, snap align;
- * 2. If there is a dramitic direction change, let it go;
- *
- * Adjustable parameters. Angle is the radians on a unit circle, limited
- * to quadrant 1. Values range from 0f (horizontal) to PI/2 (vertical)
- */
- private static final float HSLOPE_TO_START_SNAP = .25f;
- private static final float HSLOPE_TO_BREAK_SNAP = .4f;
- private static final float VSLOPE_TO_START_SNAP = 1.25f;
- private static final float VSLOPE_TO_BREAK_SNAP = .95f;
- /*
- * These values are used to influence the average angle when entering
- * snap mode. If is is the first movement entering snap, we set the average
- * to the appropriate ideal. If the user is entering into snap after the
- * first movement, then we average the average angle with these values.
- */
- private static final float ANGLE_VERT = 2f;
- private static final float ANGLE_HORIZ = 0f;
- /*
- * The modified moving average weight.
- * Formula: MAV[t]=MAV[t-1] + (P[t]-MAV[t-1])/n
- */
- private static final float MMA_WEIGHT_N = 5;
+
+ private static final int SNAP_BOUND = 16;
+ private static int sChannelDistance = 16;
+ private int mFirstTouchX = -1; // the first touched point
+ private int mFirstTouchY = -1;
+ private int mDistanceX = 0;
+ private int mDistanceY = 0;
private boolean inFullScreenMode() {
return mFullScreenHolder != null;
@@ -5830,12 +5845,6 @@
}
}
- private float calculateDragAngle(int dx, int dy) {
- dx = Math.abs(dx);
- dy = Math.abs(dy);
- return (float) Math.atan2(dy, dx);
- }
-
/*
* Common code for single touch and multi-touch.
* (x, y) denotes current focus point, which is the touch point for single touch
@@ -5861,6 +5870,12 @@
switch (action) {
case MotionEvent.ACTION_DOWN: {
mConfirmMove = false;
+
+ // Channel Scrolling
+ mFirstTouchX = x;
+ mFirstTouchY = y;
+ mDistanceX = mDistanceY = 0;
+
if (!mEditTextScroller.isFinished()) {
mEditTextScroller.abortAnimation();
}
@@ -5998,20 +6013,16 @@
break;
}
- // Only lock dragging to one axis if we don't have a scale in progress.
- // Scaling implies free-roaming movement. Note this is only ever a question
- // if mZoomManager.supportsPanDuringZoom() is true.
- mAverageAngle = calculateDragAngle(deltaX, deltaY);
- if (detector == null || !detector.isInProgress()) {
- // if it starts nearly horizontal or vertical, enforce it
- if (mAverageAngle < HSLOPE_TO_START_SNAP) {
- mSnapScrollMode = SNAP_X;
- mSnapPositive = deltaX > 0;
- mAverageAngle = ANGLE_HORIZ;
- } else if (mAverageAngle > VSLOPE_TO_START_SNAP) {
+ if ((detector == null || !detector.isInProgress())
+ && SNAP_NONE == mSnapScrollMode) {
+ int ax = Math.abs(x - mFirstTouchX);
+ int ay = Math.abs(y - mFirstTouchY);
+ if (ax < SNAP_BOUND && ay < SNAP_BOUND) {
+ break;
+ } else if (ax < SNAP_BOUND) {
mSnapScrollMode = SNAP_Y;
- mSnapPositive = deltaY > 0;
- mAverageAngle = ANGLE_VERT;
+ } else if (ay < SNAP_BOUND) {
+ mSnapScrollMode = SNAP_X;
}
}
@@ -6030,31 +6041,21 @@
if (deltaX == 0 && deltaY == 0) {
keepScrollBarsVisible = true;
} else {
- mAverageAngle +=
- (calculateDragAngle(deltaX, deltaY) - mAverageAngle)
- / MMA_WEIGHT_N;
- if (mSnapScrollMode != SNAP_NONE) {
- if (mSnapScrollMode == SNAP_Y) {
- // radical change means getting out of snap mode
- if (mAverageAngle < VSLOPE_TO_BREAK_SNAP) {
- mSnapScrollMode = SNAP_NONE;
- }
- }
+ if (mSnapScrollMode == SNAP_X || mSnapScrollMode == SNAP_Y) {
+ mDistanceX += Math.abs(deltaX);
+ mDistanceY += Math.abs(deltaY);
if (mSnapScrollMode == SNAP_X) {
- // radical change means getting out of snap mode
- if (mAverageAngle > HSLOPE_TO_BREAK_SNAP) {
+ if (mDistanceY > sChannelDistance) {
mSnapScrollMode = SNAP_NONE;
- }
+ } else if (mDistanceX > sChannelDistance) {
+ mDistanceX = mDistanceY = 0;
}
} else {
- if (mAverageAngle < HSLOPE_TO_START_SNAP) {
- mSnapScrollMode = SNAP_X;
- mSnapPositive = deltaX > 0;
- mAverageAngle = (mAverageAngle + ANGLE_HORIZ) / 2;
- } else if (mAverageAngle > VSLOPE_TO_START_SNAP) {
- mSnapScrollMode = SNAP_Y;
- mSnapPositive = deltaY > 0;
- mAverageAngle = (mAverageAngle + ANGLE_VERT) / 2;
+ if (mDistanceX > sChannelDistance) {
+ mSnapScrollMode = SNAP_NONE;
+ } else if (mDistanceY > sChannelDistance) {
+ mDistanceX = mDistanceY = 0;
+ }
}
}
if (mSnapScrollMode != SNAP_NONE) {
@@ -6089,6 +6090,7 @@
break;
}
case MotionEvent.ACTION_UP: {
+ mFirstTouchX = mFirstTouchY = -1;
if (mIsEditingText && mSelectionStarted) {
endScrollEdit();
mPrivateHandler.sendEmptyMessageDelayed(SCROLL_HANDLE_INTO_VIEW,