MKMarkerAnnotationView cluster color - mapkit

I’ve been trying out the new iOS 11 MKMarkerAnnotationView, and finally clustering works like a charm. But the problem is that the clusters have the wrong color as you can see in the picture. How can I control this?

Nevermind I managed to figure it out.
I added the following to the mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) function of the delegate.
if let cluster = annotation as? MKClusterAnnotation {
let markerAnnotationView = MKMarkerAnnotationView()
markerAnnotationView.glyphText = String(cluster.memberAnnotations.count)
markerAnnotationView.markerTintColor = UIColor.appPrimary
markerAnnotationView.canShowCallout = false
return markerAnnotationView
}

if you are not using MKMapViewDelegate you can just set, in your MKMarkerAnnotationView subclass,
clusteringIdentifier = MKMapViewDefaultClusterAnnotationViewReuseIdentifier
and in your view controller
mapView.register(SubclassMarkerView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
mapView.register(SubclassMarkerView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultClusterAnnotationViewReuseIdentifier)

Related

Object detection from image using vision framework

I am trying to detect objects from a given image. From research I just found that we can detect and track an object for the videos using the following process:
private lazy var cameraLayer: AVCaptureVideoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
private func tapGestureAction(recognizer: UITapGestureRecognizer)
{
highlightView.frame.size = CGSize(width: 200, height: 200)
highlightView.center = recognizer.location(in: view)
let originalRect = highlightView.frame
var convertedRect = cameraLayer.metadataOutputRectConverted(fromLayerRect: originalRect)
convertedRect.origin.y = 1 - convertedRect.origin.y
previousObservation = VNDetectedObjectObservation(boundingBox: convertedRect)
}
Can we have similar method like metadataOutputRectConverted for imageView? I am trying to detect the object rect whenever the user taps on that object. How can this be accomplished?
this method to convert the camera output rect ( topleft(0,0) to bottomright(0,1)) to the UI rect. So, I think you do not need to convert it

UICollectionView Crash layoutAttributesForElementsInRect

I have a tableview and collectionview in view controller. The collection view gets populated based on selections made in the table view. I want the collectionview to be updated without animation. The collection view gets updated when a selection is made on the table. I'm also using a custom collectionview layout (UICollectionViewLayout). Here's the code that updates the collection view:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
guard var data = measurementData?[indexPath.item] else { return }
if data.name != unitData.selectedMeasurement {
unitData.selectedMeasurement = data.name
unitConversionTable?.collectionViewLayout.invalidateLayout()
//self.unitConversionTable?.reloadData()
UIView.performWithoutAnimation({ self.unitConversionTable?.reloadSections(NSIndexSet(index: 0)) })
}
}
The problem is that the application crashes if the entire collection view does not fit on the screen; unless I use reloadData() (which comes with the unwanted animations). Here's the actual message.
2016-04-13 22:42:23.367 aio Calculator[6288:273528] * Assertion
failure in -[UICollectionViewData
layoutAttributesForItemAtIndexPath:],
/BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3512.60.7/UICollectionViewData.m:666
2016-04-13 22:42:23.978 xxx [6288:273528] *Terminating app due to
uncaught exception 'NSInternalInconsistencyException', reason: 'no
UICollectionViewLayoutAttributes instance for
-layoutAttributesForItemAtIndexPath: {length = 2, path = 0 - 10}'
This particular case has 12 cells in the CV. But only 10 are displayed based on the result of layoutAttributesForElementsInRect (because only 10 fit).
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
var layoutAttributes = [UICollectionViewLayoutAttributes]()
cache.forEach({attributes in
if CGRectIntersectsRect(attributes.frame, rect) {
layoutAttributes.append(attributes)
}
})
print("layoutAttributesForElementsInRect \(rect) has \(layoutAttributes.count) attributes")
return layoutAttributes }
My print statements show that there are 12 items.
prepareLayout NumOfitems:12
But only 10 attributes.
layoutAttributesForElementsInRect (0.0, 0.0, 414.0, 736.0) has 10
attributes
So, everything appears to be correct; at least as far as I understand how it's suppose to work.
Why is the app crashing?
What am I missing?
Thanks!
==================
Update:
OK. I think I know what's going on. I re-read all the documentation. The definition for layoutAttributesForElementsInRect(rect: CGRect) clearly states:
Returns the layout attributes for all of the cells and views in the specified rectangle.
But then I started looking at the a sample projects and found
Collection View Transition which clearly returns all the cached attributes instead of just the ones that intersect with the given rect. I changed layoutAttributesForElementsInRect to return all cached attributes and now everything works fine.

How can I give WKWebView a colored background

I'm working on an app in which I load different html files with mostly dark backgrounds. Right now there's a small white flash when navigating from one page to another, presumably since the next page has not loaded yet. I'd like to get rid of that flash and thought the most straightforward way would be to give the WebView a background color.
I tried setting the color for the WebView as well as the scrollView inside of it, but that doesn't seem to work:
self.webView?.backgroundColor = UIColor.blackColor()
self.webView?.scrollView.backgroundColor = UIColor.blackColor()
I see a flash of the color when the view is loaded the first time, but not on subsequent navigation.
To stop 'white flash' on your dark background, do this
webView.opaque = false
This doesn't really solve background colour issue, but at least it stops 'white flash' you are experiencing.
Apparently there seem to be no way to change background colour of WKWebView before loading HTML on it.
Swift 4
webView.isOpaque = false
self.webView = WKWebView()
self.webView.backgroundColor = UIColor(red:0.11, green:0.13, blue:0.19, alpha:1)
self.webView.scrollView.backgroundColor = UIColor(red:0.11, green:0.13, blue:0.19, alpha:1)
Don't forget that your WKWebView is an optional so maybe you don't init it.
I used to hide the WKWebView when I did the load request in one project.
webView.isHidden = true
webView.load(req)
When the load was completed I set the webView visible again.
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
videoView.isHidden = false
}
func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
activityIndicator.stopAnimating()
videoView.isHidden = false
}
Click on the WKWebView in soryboard, and choose preferred Background color from attributes inspector panel.
Then put content.isOpaque = false where your WKWebView is loaded from, for example in viewDidLoad()
#IBOutlet weak var content: WKWebView!
...
content.isOpaque = false

How to hide the iOS 8 Today Widget when there is nothing to display?

I'm using the today widget for iOS8 to display information relevant to the current day. The problem is I don't want to display the widget/section at all if there are no relevant messages to show.
I know it must be possible as the BA app does it (it only shows the widget when there is a flight, the rest of the time its not visible at all). I just cant figure out a way to achieve this behaviour.
Does anyone know how this can be done?
I found the way to do this is using the NCWidgetController. This allows you to easily specify when the today widget should be displayed based on whatever criteria you see fit.
Simply add the following into your viewDidLoad method (or anywhere that will be called when the widget reloads) in the today widget view controller and it will work:
BOOL hasDataToDisplay = NO;
NCWidgetController *widgetController = [NCWidgetController widgetController];
[widgetController setHasContent:hasDataToDisplay forWidgetWithBundleIdentifier:#"com.my-company.my-app.my-widget"];
Apple Docs: https://developer.apple.com/library/ios/documentation/NotificationCenter/Reference/NCWidgetController_Class/index.html#//apple_ref/occ/cl/NCWidgetController
WARNING: The NCWidgetController cannot be reset from the widget itself once you have set there is no content to display. In other words once you set it to NO then there is no going back unless you trigger it from the parent/containing app.
In the widget's ViewController's viewDidLoad method add the following:
BOOL DisplayWidget = NO;
[[NCWidgetController widgetController] setHasContent:DisplayWidget
forWidgetWithBundleIdentifier:#"<widget's bunder identifier>"];
This will disable the widget from showing.
To enable it again, you must do that from the containing app using the same line passing YES to setHasContent parameter. Make sure to add the necessary imports to the containing app in the ViewController which will re-enable the widget:
#import <NotificationCenter/NotificationCenter.h>
#interface ViewController () <NCWidgetProviding> {...}
[Check out page 41 of the documentations for widgets
https://developer.apple.com/library/ios/documentation/General/Conceptual/ExtensibilityPG/ExtensibilityPG.pdf ]
The approach which I used, though not perfect and has a small remnant in Notification Center, but worked for me:
In viewDidLoad() set preferred content size height to 1:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view from its nib.
preferredContentSize = CGSizeMake(0, 1)
view.setNeedsLayout()
}
then when widget updates, gets real height and set it:
var data: NSData?
func updateData() {
// fetch data
if let data = data {
let viewHeight: CGFloat
// UI preperation and initialize viewHeight var
preferredContentSize = CGSizeMake(0, viewHeight);
} else {
preferredContentSize = CGSizeMake(0, 1);
}
}
func widgetPerformUpdateWithCompletionHandler(completionHandler: ((NCUpdateResult) -> Void)) {
// Perform any setup necessary in order to update the view.
// If an error is encountered, use NCUpdateResult.Failed
// If there's no update required, use NCUpdateResult.NoData
// If there's an update, use NCUpdateResult.NewData
updateData()
completionHandler(data != nil ? NCUpdateResult.NewData : NCUpdateResult.NoData)
}
It is better use
+ (instancetype)widgetController
then call
- (void)setHasContent:(BOOL)flag forWidgetWithBundleIdentifier:(NSString *)bundleID

How to toggle visibility of NSSplitView subView + hide Pane Splitter divider?

We have a parent Split view (NSSplitView), and two subviews, Content and SideBar (the sidebar is on the right).
What would be the optimal Cocoa-friendly way to toggle the SideBar view?
I would really love it, if the suggested solution includes animation
I really don't need any suggestions related to external plugins, etc (e.g. BWToolkit)
HINT : I've been trying to do that, but still I had issues hiding the divider of the NSSplitView as well. How could I do it, while hiding it at the same time?
Here's a pretty decent tutorial that shows how to do this: Unraveling the Mysteries of NSSplitView.
Hiding the divider is done in NSSplitView's delegate method splitView:shouldHideDividerAtIndex:.
You will have to animate the frame size change yourself if you don't like the way NSSplitView does it.
Easiest way to do it is as follows - and it's animated: [SWIFT 5]
splitViewItems[1].animator().isCollapsed = true // Show side pane
splitViewItems[1].animator().isCollapsed = false // hide side pane
I wrote a Swift version of the content in the link from #Nathan's answer that works for me. In the context of my example splitView is set elsewhere, probably as an instance property on an encompassing class:
func toggleSidebar () {
if splitView.isSubviewCollapsed(splitView.subviews[1] as NSView) {
openSidebar()
} else {
closeSidebar()
}
}
func closeSidebar () {
let mainView = splitView.subviews[0] as NSView
let sidepanel = splitView.subviews[1] as NSView
sidepanel.hidden = true
let viewFrame = splitView.frame
mainView.frame.size = NSMakeSize(viewFrame.size.width, viewFrame.size.height)
splitView.display()
}
func openSidebar () {
let sidepanel = splitView.subviews[1] as NSView
sidepanel.hidden = false
let viewFrame = splitView.frame
sidepanel.frame.size = NSMakeSize(viewFrame.size.width, 200)
splitView.display()
}
These functions will probably methods in a class, they are for me. If your splitView can be nil you obviously have to check for that. This also assumes you have two subviews and the one at index 1, here as sidePanel is the one you want to collapse.
In Xcode 9.0 with Storyboards open Application Scene select View->Menu->Show sidebar. CTRL-click Show Sidebar, in sent actions delete the provided one, click on x. From the circle CTRL drag to First Responder in application scene and select toggleSideBar to connect to. Open storyboard and select the first split view item and in attributes inspector change behaviour from default to sidebar. Run and try with view menu item show/hide. All done in interface builder no code. toggleSideBar handles the first split view item. https://github.com/Dis3buted/SplitViewController
I got some artifacts with the code above, likely because it was out of context. I am sure it works where it was meant to. Anyway, here is a very streamlined implementation:
// this is the declaration of a left vertical subview of
// 'splitViewController', which is the name of the split view's outlet
var leftView: NSView {
return self.splitViewController.subviews[0] as NSView
}
// here is the action of a button that toggles the left vertical subview
// the left subview is always restored to 100 pixels here
#IBAction func someButton(sender: AnyObject) {
if splitViewController.isSubviewCollapsed(leftView) {
splitViewController.setPosition(100, ofDividerAtIndex: 0)
leftView.hidden = false
} else {
splitViewController.setPosition(0, ofDividerAtIndex: 0)
leftView.hidden = true
}
}
To see a good example using animations, control-click to download this file.
If your NSSplitView control is part of a NSSplitViewController object, then you can simply use this:
splitViewController.toggleSidebar(nil)