/// <summary>Find the nearest touchable view to the specified view.</summary>
/// <remarks>Find the nearest touchable view to the specified view.</remarks>
/// <param name="root">The root of the tree in which to search</param>
/// <param name="x">X coordinate from which to start the search</param>
/// <param name="y">Y coordinate from which to start the search</param>
/// <param name="direction">Direction to look</param>
/// <param name="deltas">
/// Offset from the <x, y> to the edge of the nearest view. Note that this array
/// may already be populated with values.
/// </param>
/// <returns>The nearest touchable view, or null if none exists.</returns>
public virtual android.view.View findNearestTouchable(android.view.ViewGroup root
, int x, int y, int direction, int[] deltas)
{
java.util.ArrayList <android.view.View> touchables = root.getTouchables();
int minDistance = int.MaxValue;
android.view.View closest = null;
int numTouchables = touchables.size();
int edgeSlop = android.view.ViewConfiguration.get(root.mContext).getScaledEdgeSlop
();
android.graphics.Rect closestBounds = new android.graphics.Rect();
android.graphics.Rect touchableBounds = mOtherRect;
{
for (int i = 0; i < numTouchables; i++)
{
android.view.View touchable = touchables.get(i);
// get visible bounds of other view in same coordinate system
touchable.getDrawingRect(touchableBounds);
root.offsetRectBetweenParentAndChild(touchable, touchableBounds, true, true);
if (!isTouchCandidate(x, y, touchableBounds, direction))
{
continue;
}
int distance = int.MaxValue;
switch (direction)
{
case android.view.View.FOCUS_LEFT:
{
distance = x - touchableBounds.right + 1;
break;
}
case android.view.View.FOCUS_RIGHT:
{
distance = touchableBounds.left;
break;
}
case android.view.View.FOCUS_UP:
{
distance = y - touchableBounds.bottom + 1;
break;
}
case android.view.View.FOCUS_DOWN:
{
distance = touchableBounds.top;
break;
}
}
if (distance < edgeSlop)
{
// Give preference to innermost views
if (closest == null || closestBounds.contains(touchableBounds) || (!touchableBounds
.contains(closestBounds) && distance < minDistance))
{
minDistance = distance;
closest = touchable;
closestBounds.set(touchableBounds);
switch (direction)
{
case android.view.View.FOCUS_LEFT:
{
deltas[0] = -distance;
break;
}
case android.view.View.FOCUS_RIGHT:
{
deltas[0] = distance;
break;
}
case android.view.View.FOCUS_UP:
{
deltas[1] = -distance;
break;
}
case android.view.View.FOCUS_DOWN:
{
deltas[1] = distance;
break;
}
}
}
}
}
}
return(closest);
}
private android.view.View findNextFocus(android.view.ViewGroup root, android.view.View
focused, android.graphics.Rect focusedRect, int direction)
{
java.util.ArrayList <android.view.View> focusables = root.getFocusables(direction);
if (focusables.isEmpty())
{
// The focus cannot change.
return(null);
}
if (direction == android.view.View.FOCUS_FORWARD || direction == android.view.View
.FOCUS_BACKWARD)
{
if (focused != null && !focusables.contains(focused))
{
// Add the currently focused view to the list to have it sorted
// along with the other views.
focusables.add(focused);
}
try
{
// Note: This sort is stable.
mSequentialFocusComparator.setRoot(root);
java.util.Collections.sort(focusables, mSequentialFocusComparator);
}
finally
{
mSequentialFocusComparator.recycle();
}
int count = focusables.size();
switch (direction)
{
case android.view.View.FOCUS_FORWARD:
{
if (focused != null)
{
int position = focusables.lastIndexOf(focused);
if (position >= 0 && position + 1 < count)
{
return(focusables.get(position + 1));
}
}
return(focusables.get(0));
}
case android.view.View.FOCUS_BACKWARD:
{
if (focused != null)
{
int position = focusables.indexOf(focused);
if (position > 0)
{
return(focusables.get(position - 1));
}
}
return(focusables.get(count - 1));
}
}
return(null);
}
// initialize the best candidate to something impossible
// (so the first plausible view will become the best choice)
mBestCandidateRect.set(focusedRect);
switch (direction)
{
case android.view.View.FOCUS_LEFT:
{
mBestCandidateRect.offset(focusedRect.width() + 1, 0);
break;
}
case android.view.View.FOCUS_RIGHT:
{
mBestCandidateRect.offset(-(focusedRect.width() + 1), 0);
break;
}
case android.view.View.FOCUS_UP:
{
mBestCandidateRect.offset(0, focusedRect.height() + 1);
break;
}
case android.view.View.FOCUS_DOWN:
{
mBestCandidateRect.offset(0, -(focusedRect.height() + 1));
break;
}
}
android.view.View closest = null;
int numFocusables = focusables.size();
{
for (int i = 0; i < numFocusables; i++)
{
android.view.View focusable = focusables.get(i);
// only interested in other non-root views
if (focusable == focused || focusable == root)
{
continue;
}
// get visible bounds of other view in same coordinate system
focusable.getDrawingRect(mOtherRect);
root.offsetDescendantRectToMyCoords(focusable, mOtherRect);
if (isBetterCandidate(direction, focusedRect, mOtherRect, mBestCandidateRect))
{
mBestCandidateRect.set(mOtherRect);
closest = focusable;
}
}
}
return(closest);
}