Does anyone have an example of how to zoom an MKMapView to the area of all visible annotations using the annotationVisibleRect property on MKMapView? I have seen this post which offers a decent solution, but it seems that this annotationVisibleRect property would be the simplest solution.
Short answer: There is not a solution to this problem using annotationVisibleRect.
There is no example because this property cannot be used in this way. The limited documentation provided for it is certainly misleading for someone who is looking for something convenient from MapKit to do a somewhat common task.
annotationVisibleRect is the rect with regard to the MKAnnotationContainerView coordinate system. MKAnnotationContainerView is the superview for your annotations. If you look in MKMapView.h, you'll find this:
// annotationVisibleRect is the visible rect where the annotations views are currently displayed.
// The delegate can use annotationVisibleRect when animating the adding of the annotations views in mapView:didAddAnnotationViews:
#property (nonatomic, readonly) CGRect annotationVisibleRect;
Its specific purpose is for manipulation (animation) of the annotation views by providing a rectangle in their superview's coordinate system that matches the map view's viewport.
You might think (as I did) that this or similar will do the trick:
CGRect visibleRect = self.mapView.annotationVisibleRect;
MKCoordinateRegion visibleRegion = [self.mapView convertRect:visibleRect toRegionFromView:self.mapView];
[self.mapView setRegion:visibleRegion animated:YES];
It won't. Calling setRegion:animated: may cause the application to crash because the "fromView" is the incorrect coordinate system and may cause the latitude or longitude to go over their min/max values. You'd actually have to do something like this:
- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
if(views.count > 0) {
MKAnnotationView *view = [views objectAtIndex:0];
CGRect visibleRect = self.mapView.annotationVisibleRect;
MKCoordinateRegion visibleRegion = [self.mapView convertRect:visibleRect toRegionFromView:view.superview];
[self.mapView setRegion:visibleRegion animated:YES];
}
}
This won't crash the application, but it won't change the region either. If you compare visibleRegion to self.mapView.region, you will find that they are identical. That is because the annotationVisibleRect represents the same area that is visible in the map view -- just in a different coordinate system to make it convenient for you to do things like make the map pins come flying in from the edge of the view. See this answer for details on how it is used.
Also, for reference, here's where the MKAnnotationView sits in relation to MKMapView:
MKMapView
+-UIView
+-MKScrollContainerView
+-MKAnnotationContainerView <-- coordinate system of annotationVisibleRect
+-MKAnnotationView
Hope that helps clear some things up -- if not, ask away.
SWIFT 4
I think what your looking for is
mapView.showAnnotations(annotations:[MKAnnotation], animated: Bool)
You simply pass in an array of all the annotations you're trying to show which is the MKMapView.annotations
mapView.showAnnotations(mapView.annotations, animated: true)
Related
This seems to be possible because the MKUserLocation annotation is placed at the user's current altitude. However, the protocol for MKAnnotation only includes a coordinate. Is there a way to adjust its altitude as well? Thanks!
Here is method :-
[mapView showAnnotations:yourAnnotationArray animated:YES];
You can pull from an array stored in the map view:
yourAnnotationArray = mapView.annotations;
and quickly adjust the altitude :-
mapView.camera.altitude *= 1.4;
try multipling the cameras altitude by a fraction of one, like mapView.camera.altitude *= .85; for a closer viewport
I have a newb question, which I have tried unsuccessfully to find answers for on the web. The task is simple: I want to create a core data document-based app but alter the values in some label objects. Using interface builder, I can build the core data model and populate it, using an array controller, table, etc. all without writing any code. So far so good. My test example is to build a core data model with Box entities that have length and width attributes. I would like a label to display the area, i.e. length*width for any geometrically challenged :).
So after browsing around, I've decided I need to create an NSWindowController subclass and use that to update the label when a box in the table is selected. Have attempted this, but have failed. Before I even hook up the label to the window controller, I have a problem. Following the template comments, I added this to Document.m:
- (void)makeWindowControllers
{
NSLog(#"Adding custom Window Controller");
MyWindowController* myWindowController = [[MyWindowController alloc] init];
[self addWindowController:myWindowController];
}
Also added this to the template MyWindowController.m:
- (id)init
{
self = [super initWithWindowNibName:#"MyWindowController"];
return self;
}
The window controller has its own NIB file from Interface builder where I put the table and label etc. The file owner is set to MyWindowController. Probably forgetting other things, but that's what I remember for now.
The log message appears at startup, but then I get an exception "this class is not key value coding-compliant for the key managedObjectContext" before the window appears. I'm guessing that I don't have the window controller hooked up to the document class properly? My other thought is that the array controller is in the window controller nib, not the document nib, so maybe it's looking in the wrong place for the managedObjectContext?
I would try a different approach: Add area to your Box entity as a read-only attribute. Auto-create a Box class with Xcode ("Create NSManagedObject Subclass" menu item in the "Editor" menu when viewing the data model), then add this to Box.h
#property (weak, readonly) NSString * area;
and this to Box.m
- (NSNumber *)area
{
return [NSNumber numberWithDouble:([[self length] doubleValue] - [[self width] doubleValue])];
}
+ (NSSet *)keyPathsForValuesAffectingArea
{
return [NSSet setWithObjects:#"length", #"width", nil];
}
If you do this you can just bind area to a label value like you do for the other Box properties. No need to subclass NSWindowController or watch for changes.
while using map view in my application some times MKMapKit delegate method 'mapView: regionDidChange' do not call.
Its happens only when I drag the map. but when i zoom in or Zoom out Its working perfectly. So its create issue related to place new annotations on map while dragging the map.
I have do this code in mapView:regionDidChange:
int j=0;
-(void) mapView:(MKMapView *)mapsView regionDidChangeAnimated:(BOOL)animated{
zoomLevel = self.mapView.region.span.latitudeDelta;
if (![appDelegate internetConnected]){
return;
}
if (appDelegate.isMapViewRegionChanged) {
if (j==0) {
j++;
return;
}else{
j=0;
appDelegate.isMapViewRegionChanged = FALSE;
return;
}
}
[self callGetMapViewWithObject:nil];
}
/*
first boolean is to check Internet connection.
[appDelegate internetConnected]
Second condition is to return when we navigate from any view controller too map View controller.
appDelegate.isMapViewRegionChanged
Third is a method to place new annotations.
[self callGetMapViewWithObject:nil];
*/
I checked all conditions and booleans but my coding is not reason for this bug.
so may be its related to region did change method.
So while using my app with map, 20% of time its behave like Ideal(method do not call).
can some one help me out with this.
Thank you in advance.
EDIT It broke randomly, so I now call the function again (undoing what I said below), no changes extra... and um, it works. I feel like I'm flipping a coin.
I just had this happen because I have a subclassed MKMapView. I don't know if you're subclassing this or not, but for some reason Apple's super functions, eg: -(void) scrollViewDidScroll; called super but was not intercepted properly and skipped that call.
When I removed the "overridden" call, that was just a call to [super scrollView], it started working properly.
I don't know why apple's code is broken that way (calling super doesn't have the same effect not overriding it), but make sure you're not subclassing these:
ScrollView functions
MKMapView functions...
or perhaps using the WildCard Gesture Recognizer provided very kindly by the answer to why Map Views don't respond to touchesBegan/Moved etc here: How to intercept touches events on a MKMapView or UIWebView objects? .
If this doesn't help, ensure you don't have a view on top of the other views, improper delegates, xibs are arranged and hooked up, the usual stuff.
I am developing a control for an IPAD application (My first time doing Apple development). Its a simple control that mimics a grid - consists of a collection of UIViews (each of which represents a cell) all added to a parent UIView (in a grid like fashion).
One of the requirements is to implement a swipe gesture - the users swipe across the grid to activate/inactivate the cell - this corresponds to a 1/0 in the database.
I create a UISwipeGesture and added it to each of my UIView which represents a cell. That appears to be an incorrect approach as it fires the event for the UIView in which the swipe originated but not across all the UIViews.
My understanding would be that i need to implement the SwipeGesture across the parent UIView which contains all these children UIView. However if i do that how will i know which child UIView has been swiped over? Or any other approach which would make sense?
I know this thread is fairly old, but I created a Swipe extension method that might have helped.
View.Swipe(UISwipeGestureRecognizerDirection.Right).Event += Swipe_Event;
void Swipe_Event(ViewExtensions.SwipeClass sender, UISwipeGestureRecognizer recognizer)
{
View view = sender.View; // do something with view that was swiped.
}
This may not answer your question, but I can speak to the approach I've taken here with a similar use case:
1) I would abandon UIScrollView and use UITableView. You'll notice that UITableView inherits from UIScrollView and has all the performance benefits of virtualization and cell / view re-use. Which you'll find terribly useful as you work towards optimizing your app for performance on device.
2) Utilize the UITableViewCell's ContentView to create custom "Grid" cells. Or better yet, utilize MonoTouch.Dialog if you're not required to create Grid rows ad-hoc.
3) Use this awesome class (props to #praeclarum) to setup gestures in MonoTouch. You essentially provide a UIGestureRecognizer as a generic argument. You can then utilize the LocationInView method to grab the point in the UITableView where the gesture occurred
public void HandleSwipe(UISwipeGestureRecognizer recognizer)
{
if(recognizer.State == UIGestureRecognizerState.Ended) {
var point = recognizer.LocationInView(myTableView);
var indexPath = myTableView.IndexPathForRowAtPoint(point);
// do associated calculations here
}
}
I think you're correct that the gesture recognizer has to be attached to the parent view. In the action method associated with the gesture recognizer I think you can use the Monotouch equivalent of CGRectContainsPoint() to determine whether the swipe occurred in a particular subview. I imagine you would have to iterate through the subviews until you found the one in which the swipe occurred. I'm not aware of a method that would immediately identify the swiped subview.
Does any one have an idea how to access the UIScroller class , which is the default subview of UIWebView ?
I want to handle the touches, zooming , panning and scrolling features inside the webview .
Thanks..
I know this thread is old but if anyone comes across it there's a new way.
As of iOS 5 UIWebView now has a property called scrollView which you can't replace but you can set the properties of it. Most people just want to disable zooming/bouncing/scrolling all together which can be done by setting the properties of the scrollView for example if webview is a UIWebView:
webview.scrollView.bounces = NO; //Disables webview from bouncing
webview.scrollView.minimumZoomScale = webview.scrollView.maximumZoomScale = 1.0; //Forces zoom to be at 1 (can be whatever you fancy) and disables zooming
webview.scrollView.bouncesZoom = NO; //Disables bouncing when zooming exceeds minimum or maximum zoom
I suppose you could set the delegate for the scrollView if you want more control, though to be on the safe side you might want to store the original delegate and call its methods appropriately in your custom delegate.
Handling the touches would be more difficult since you can't replace the scrollView to provide your own handlers. Best you could do is add some gesture recognizers as part of the UIView and try to handle them there, but I think UIWebView will still receive the events. Alternatively in iOS 5 they let you access the gesture recognizers directly on UIScrollView.
You can find this by going like this:
[webview objectAtIndex:0]
That should be where it is. If not, put this in your code somewhere and run the program to search for the index of the UIScroller, and replace the 0 above with that index:-
for (UIView *subview in [webView subviews]){
NSLog(#"subviews of webView : %#", [[subview class] description]);
}