private static int GetSystemResourceDimenPx(AccessibilityService service, string resName)
{
var resourceId = service.Resources.GetIdentifier(resName, "dimen", "android");
if (resourceId > 0)
{
return(service.Resources.GetDimensionPixelSize(resourceId));
}
return(0);
}
public static Point GetOverlayAnchorPosition(AccessibilityService service, AccessibilityNodeInfo anchorView,
int overlayViewHeight, bool isOverlayAboveAnchor)
{
var anchorViewRect = new Rect();
anchorView.GetBoundsInScreen(anchorViewRect);
var anchorViewX = anchorViewRect.Left;
var anchorViewY = isOverlayAboveAnchor ? anchorViewRect.Top : anchorViewRect.Bottom;
anchorViewRect.Dispose();
if (isOverlayAboveAnchor)
{
anchorViewY -= overlayViewHeight;
}
anchorViewY -= GetStatusBarHeight(service);
return(new Point(anchorViewX, anchorViewY));
}
private static int GetNavigationBarHeight(AccessibilityService service)
{
return(GetSystemResourceDimenPx(service, "navigation_bar_height"));
}
private static int GetStatusBarHeight(AccessibilityService service)
{
return(GetSystemResourceDimenPx(service, "status_bar_height"));
}
public static Point GetOverlayAnchorPosition(AccessibilityService service, AccessibilityNodeInfo anchorNode,
AccessibilityNodeInfo root, IEnumerable <AccessibilityWindowInfo> windows, int overlayViewHeight,
bool isOverlayAboveAnchor)
{
Point point = null;
if (anchorNode != null)
{
// Update node's info since this is still a reference from an older event
anchorNode.Refresh();
if (!anchorNode.VisibleToUser)
{
return(new Point(-1, -1));
}
if (!anchorNode.Focused)
{
return(null);
}
// node.VisibleToUser doesn't always give us exactly what we want, so attempt to tighten up the range
// of visibility
var inputMethodHeight = 0;
if (windows != null)
{
if (IsStatusBarExpanded(windows))
{
return(new Point(-1, -1));
}
inputMethodHeight = GetInputMethodHeight(windows);
}
var minY = 0;
var rootNodeHeight = GetNodeHeight(root);
if (rootNodeHeight == -1)
{
return(null);
}
var maxY = rootNodeHeight - GetNavigationBarHeight(service) - GetStatusBarHeight(service) -
inputMethodHeight;
point = GetOverlayAnchorPosition(service, anchorNode, overlayViewHeight, isOverlayAboveAnchor);
if (point.Y < minY)
{
if (isOverlayAboveAnchor)
{
// view nearing bounds, anchor to bottom
point.X = -1;
point.Y = 0;
}
else
{
// view out of bounds, hide overlay
point.X = -1;
point.Y = -1;
}
}
else if (point.Y > (maxY - overlayViewHeight))
{
if (isOverlayAboveAnchor)
{
// view out of bounds, hide overlay
point.X = -1;
point.Y = -1;
}
else
{
// view nearing bounds, anchor to top
point.X = 0;
point.Y = -1;
}
}
else if (isOverlayAboveAnchor && point.Y < (maxY - (overlayViewHeight * 2) - GetNodeHeight(anchorNode)))
{
// This else block forces the overlay to return to bottom alignment as soon as space is available
// below the anchor view. Removing this will change the behavior to wait until there isn't enough
// space above the anchor view before returning to bottom alignment.
point.X = -1;
point.Y = 0;
}
}
return(point);
}
