private void drawPlaces(Canvas canvas, double pixelsPerDegree, double offset)
{
try
{
if (OrientationManager.HasLocation && NearbyPlaces != null)
{
lock (NearbyPlaces)
{
var userLocation = OrientationManager.Location;
var latitude1 = userLocation.Latitude;
var longitude1 = userLocation.Longitude;
_allBounds.Clear();
// Loop over the list of nearby places (those within 10 km of the user's current
// location), and compute the relative bearing from the user's location to the
// place's location. This determines the position on the compass view where the
// pin will be drawn.
foreach (var place in NearbyPlaces)
{
var latitude2 = place.Latitiude;
var longitude2 = place.Longitude;
var bearing = MathUtils.getBearing(latitude1, longitude1, latitude2, longitude2);
var name = place.Name;
var distanceKm = MathUtils.getDistance(latitude1, longitude1, latitude2, longitude2);
var text = this.Context.Resources.GetString(
Resource.String.place_text_format, name, _distanceFormat.Format(distanceKm));
// Measure the text and offset the text bounds to the location where the text
// will finally be drawn.
var textBounds = new Rect();
_placePaint.GetTextBounds(text, 0, text.Length, textBounds);
textBounds.OffsetTo((int)(offset + bearing * pixelsPerDegree
+ PLACE_PIN_WIDTH / 2 + PLACE_TEXT_MARGIN), canvas.Height / 2
- (int)PLACE_TEXT_HEIGHT);
// Extend the bounds rectangle to include the pin icon and a small margin
// to the right of the text, for the overlap calculations below.
textBounds.Left -= (int)(PLACE_PIN_WIDTH + PLACE_TEXT_MARGIN);
textBounds.Right += (int)PLACE_TEXT_MARGIN;
// This loop attempts to find the best vertical position for the string by
// starting at the bottom of the display and checking to see if it overlaps
// with any other labels that were already drawn. If there is an overlap, we
// move up and check again, repeating this process until we find a vertical
// position where there is no overlap, or when we reach the limit on
// overlapping place names.
bool intersects;
var numberOfTries = 0;
do
{
intersects = false;
numberOfTries++;
textBounds.Offset(0, (int)-(PLACE_TEXT_HEIGHT + PLACE_TEXT_LEADING));
foreach (var existing in _allBounds)
{
if (Rect.Intersects(existing, textBounds))
{
intersects = true;
break;
}
}
} while (intersects && numberOfTries <= MAX_OVERLAPPING_PLACE_NAMES);
// Only draw the string if it would not go high enough to overlap the compass
// directions. This means some places may not be drawn, even if they're nearby.
if (numberOfTries <= MAX_OVERLAPPING_PLACE_NAMES)
{
_allBounds.Add(textBounds);
canvas.DrawBitmap(_placeBitmap, (float)(offset + bearing * pixelsPerDegree - PLACE_PIN_WIDTH / 2), textBounds.Top + 2, _paint);
canvas.DrawText(
text,
(float)(offset + bearing * pixelsPerDegree + PLACE_PIN_WIDTH / 2 + PLACE_TEXT_MARGIN),
(float)(textBounds.Top + PLACE_TEXT_HEIGHT),
_placePaint);
}
}
}
}
}
catch (Exception e)
{
Log.Debug("Exception", e.Message);
}
}