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
Related
In iOS 11 the system apps all compress the navigation bar as you scroll down if you enable prefersLargeTitles:
I can't figure out how to implement this in my own apps though, the bar stays the same by default:
The only thing I can see is Hide Bars On Swipe, but that hides the whole bar rather than compressing it:
This is just an empty project created in Xcode 9 beta and with a new storyboard added.
What do I need to do to get the same behaviour as the system apps?
Don't set anything regarding Large Titles in Interface Builder / Storyboard, only in code. That worked for me.
So in the navigation bar in storyboards, Prefers Large Titles unchecked.
In your view controller:
self.navigationController?.navigationBar.prefersLargeTitles = true
It seems like this issue is happening to people for different reasons. None of the above answers helped me, but here's what DID work...
I deconstructed my app to find the cause, which was the view hierarchy in the storyboard. It appears that the UITableView view HAS to the the first view in your view controller. I had a UITableView with two UIImageViews behind it and that's what was causing the issue. Once I removed those UIImageViews everything worked correctly.
My fix: I ended up creating a UIView in code, adding my two image views to that, THEN adding that UIView to the UITableview.backgroundView.
Hope this helps someone.
If you have to target older iOS versions, you’ll also have to wrap the assignment in an availability check:
if #available(iOS 11, *) {
self.navigationController?.navigationBar.prefersLargeTitles = true
}
if #available(iOS 11.0, *) {
navigationController?.navigationBar.prefersLargeTitles = true
navigationController?.navigationBar.topItem?.title = "Hello"
navigationController?.navigationItem.largeTitleDisplayMode = .automatic
let attributes = [
NSAttributedStringKey.foregroundColor : UIColor.red,
]
navigationController?.navigationBar.largeTitleTextAttributes = attributes
} else {
// Fallback on earlier versions
}
http://iosrevisited.blogspot.in/2017/09/navigation-bar-with-large-titles-and.html
I can create Safari View Controller without problem:
let svc = SFSafariViewController(URL: NSURL(string: remote_url)!, entersReaderIfAvailable: true)
self.presentViewController(svc, animated: true, completion: nil)
Is there any way I can preload the URL before I present the view controller to the user?
For example, I can preload the URL (web content) in the background first, and after the user clicks on something, I can show the Safari View Controller with the content right away. The user will feel the page loading is faster or instant.
P.S. Workarounds/hacks are also acceptable. For example, using cache or starting the view controller in background, etc.
EDIT: please consider SFSafariViewController only.
Here is a solution.
Obviously, if you click on the button right away you'll see the loading.
But basically, I load the Browser and put the view behind another one and I put a button in this other view.
When you press the button, the browser is bring to the front, already loaded.
The only problem here is that I'm not using any transition but that's one solution at least.
import UIKit
import SafariServices
class ViewController: UIViewController {
var svc = SFSafariViewController(URL: NSURL(string: "https://microsoft.com/")!, entersReaderIfAvailable: true)
var safariView:UIView?
let containerView = UIView()
let btn = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
//let tmpView = svc.view
addChildViewController(svc)
svc.didMoveToParentViewController(self)
svc.view.frame = view.frame
containerView.frame = view.frame
containerView.backgroundColor = UIColor.redColor()
safariView = svc.view
view.addSubview(safariView!)
view.addSubview(containerView)
btn.setTitle("Webizer", forState: UIControlState.Normal)
btn.titleLabel!.textColor = UIColor.blackColor()
btn.addTarget(self, action: "buttonTouched:", forControlEvents: .TouchUpInside)
btn.frame = CGRectMake(20, 50, 100, 100)
containerView.addSubview(btn)
view.sendSubviewToBack(safariView!)
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func buttonTouched(sender: AnyObject) {
view.bringSubviewToFront(safariView!)
//self.presentViewController(svc, animated: true, completion: nil)
}
}
Sadly this behaviour is not supported with the current implementation of SFSafariViewController. I would encourage filing a radar with Apple to add support for this behaviour but like others have suggested your best bet is to use WKWebView and start loading before its added to the hierarchy.
I came across a lovely radar from Twitter that actually mentions exactly what you're asking for. I think you might find the following requests useful:
High Priority:
- Ability to warm the SFSafariViewController before actually presenting it with a URL, URL request, HTML data or file on disk
- Currently, are investing heavily into warming the shared URL cache for high priority Tweets so that if the user hits that Tweet we
will open UIWebView (sadly not WKWebView) with that pre-cached web
page. If we could just warm an SFSafariViewController with the
desired link, this would eliminate an enormous amount of effort on our
end.
You can see in their implementation they simply cache responses using UIWebView since WKWebView seems to obfuscate the caching semantics a bit. The only risk is that UIWebView is a likely candidate for deprecation as you see in their docs "In apps that run in iOS 8 and later, use the WKWebView class instead of using UIWebView."
So unfortunately it seems that their are many hoops you need to jump through to get this all going so your best bet for now is to just pester Apple and dupe Twitters radar.
You could try using a http cache, but I don't think it would work as the Safari View Controller is working as a separate process (probably the same as Safari), so that's why it e.g. circumvents ATS.
The only way I can think of this working is to somehow force the user's Safari to load it? openURL: or adding to Reading List maybe? This doesn't sound like a viable solution.
You can always experiment with custom presentation of the view controller, attach it the view hierarchy, trigger appearance events, but set its frame to CGRectMake(0,0,1,1) or attach it somewhere off-screen, then wait a while and represent it with a correct frame.
you can download the web page using the following code . and represent it with the help of svc
let data:NSData?
do {
let weatherData = try NSData(contentsOfURL: NSURL(string: remote_url)!, options: NSDataReadingOptions())
data = weatherData
print(weatherData)
} catch {
print(error)
}
and load it when you needed in the svc
While it's technically possible to use the solution above to achieve what you're asking, this may not pass App Store review. Per the SFSafariViewController docs:
In accordance with App Store Review Guidelines, this view controller must be used to visibly present information to users; the controller may not be hidden or obscured by other views or layers. Additionally, an app may not use SFSafariViewController to track users without their knowledge and consent.
I have been trying to focus the first button but focus engine takes the third button right below the tab bar as the first item to be focussed. I tried with preferred focus view but found that when i place the buttons in vertical order then preferred takes the preferred view to be focussed but when i placed all the buttons in horizontal plane it always takes the third button.The other approach i can think of if Focus Guide but i wonder how that will work in this scenario?
override weak var preferredFocusedView: UIView? {
get {
return thrirdButton
}
}
It happens because focus engine takes the nearest possible focus element as 1st element as you can see from the picture attached.I have attached the context screenshot for the view controller. Any help or clue to solve this will be appreciated.
Solution :
We need to add focus guide just above button 3 and redirect it to button one when the focus guide is focussed.
private var focusGuide = UIFocusGuide()
self.view.addLayoutGuide(focusGuide)
self.focusGuide.bottomAnchor.constraintEqualToAnchor(self.button3.topAnchor).active = true
self.focusGuide.leftAnchor.constraintEqualToAnchor(self.button3.leftAnchor).active = true
// Width and height
self.focusGuide.widthAnchor.constraintEqualToAnchor(self.button3.widthAnchor).active = true
self.focusGuide.heightAnchor.constraintEqualToAnchor(self.button3.heightAnchor).active = true
focusGuide.centerXAnchor.constraintEqualToAnchor(self.button3.centerXAnchor).active = true
override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
self.focusGuide.preferredFocusedView = button1
}
Try adding a UIFocusGuide just above the button rows. In that case, before reaching the button, it will hit your focus guide in which you can redirect the preferredFocusedView to that particular button. The code to redirect is to be done by overriding didUpdateFocusInContext method.
Assuming you have setup the focus guide in viewDidload, the following is a sample,
override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
super.didUpdateFocusInContext(context, withAnimationCoordinator: coordinator)
self.focusGuide.preferredFocusedView = self.mypreferredbutton
}
TO initialise a focus guide ( Do the addition of guide to view in viewDidLoad)
var focusGuide = UIFocusGuide()
self.view.addLayoutGuide(self.sidefocusGuide)
self.focusGuide.leftAnchor.constraintEqualToAnchor(self.placerLabel.leftAnchor).active = true
self.focusGuide.rightAnchor.constraintEqualToAnchor(self.placerLabel.rightAnchor).active = true
self.focusGuide.topAnchor.constraintEqualToAnchor(self.audioTable.topAnchor).active = true
I too faced a similar issue but somehow able to do it through this. The preferredFocusedView approach will also work, but you have to do lot of circus by updating some reference variable and then calling setneedsfocusupdate for that view. Try the focus guide way. Hope it helps.
EDITED:
I have added code how to setup the guide. In this case I have put the guide on the right side of my view. So, whenever your focus hits the guide, it redirects to the preferredfocusguide view that you want the focus to go to in the didUpdateFocusInContext. "There is only one view in focus at anytime.", remember thes ? So, the moment it hits the guide, the overriden method gets hit which in turn moves your focus to the guide's preferred view. For examples, you can refer to Apple's UIKitCatlog app for tvOS and here is one link explaining the same.
The best way to give the initial focus to your preferred view is by using preferredFocusEnivronments.
override var preferredFocusEnvironments: [UIFocusEnvironment] {
return [firstButton]
}
preferredFocusEnvironments will be called before didUpdateFocus, that way you can inform the system, where you want the focus to be redirected.
i want to show the thumbnail of the previous image taken by camera instead of the cancel button while camera is running ...
Is that possible ?? Need help ..
Yep. Just capture the last image, keep it in memory (or save it to disk), then use it as one of the controls. We can do this using the overlay property of the Titanium.Media.showCamera function. Here is a quick example:
First we need an overlay view to show the image.
var overlayView = Ti.UI.createView();
var imageView = Ti.UI.createImageView({
width:44,
height:44,
left : 5
});
overlayView.add(imageView);
Now this is the function we use to open the camera with the overlay view. Note that we don't have controls so you need to add those (for closing etc). All we do right now is set the overlays image.
Titanium.Media.showCamera({
success:function(event) {
// called when media returned from the camera
imageView.image = event.media;
},
cancel:function() {},
error:function(error) {},
saveToPhotoGallery:true,
allowEditing:true,
mediaTypes:[Ti.Media.MEDIA_TYPE_PHOTO],
overlay : overlayView,
showControls: false // This is important!
});
To really make this work, you may need to save the event.media in a global variable, or use a similiar technique make sure overlayView will not be nulled out / garbage collected.
Also this is a barebones solution, not very robust, but this is the basic method I would use!
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)