I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...
You can use a UILongPressGestureRecognizer for this. Wherever you create or initialize the mapview, first attach the recognizer to it:
ReplyDeleteUILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc]
initWithTarget:self action:@selector(handleLongPress:)];
lpgr.minimumPressDuration = 2.0; //user needs to press for 2 seconds
[self.mapView addGestureRecognizer:lpgr];
[lpgr release];
Then in the gesture handler:
- (void)handleLongPress:(UIGestureRecognizer *)gestureRecognizer
{
if (gestureRecognizer.state != UIGestureRecognizerStateBegan)
return;
CGPoint touchPoint = [gestureRecognizer locationInView:self.mapView];
CLLocationCoordinate2D touchMapCoordinate =
[self.mapView convertPoint:touchPoint toCoordinateFromView:self.mapView];
YourMKAnnotationClass *annot = [[YourMKAnnotationClass alloc] init];
annot.coordinate = touchMapCoordinate;
[self.mapView addAnnotation:annot];
[annot release];
}
YourMKAnnotationClass is a class you define that conforms to the MKAnnotation protocol. If your app will only be running on iOS 4.0 or later, you can use the pre-defined MKPointAnnotation class instead.
For examples on creating your own MKAnnotation class, see the sample apps WeatherMap and MapCallouts.
I have a UIImageView with a UILongPressGestureRecognizer attached that never seems to detect a long press gesture no matter how I configure the gesture recognizer.
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