I have an app with a medium-sized storyboard, which is complicated enough for me not to want to mess around with it too much.
I want to copy this storyboard and change the color scheme and let the user select which color scheme to use.
My question is: can I programmatically select which storyboard will be used by default on startup? If yes - how do I do that?
I looked at a somewhat related question: Storyboards Orientation Support in Xcode 4.5 and iOS 6.x ?
Based on that code I made an extension method:
static bool IsStoryboardLoading {get;set;}
public static T ConsiderSwitchingStoryboard<T> (this UIViewController from) where T: UIViewController
{
if (!IsStoryboardLoading && LocalStorage.Instance.IsWhiteScheme && false) {
try {
IsStoryboardLoading = true;
UIStoryboard storyboard = UIStoryboard.FromName ("MainStoryboard_WHITE", NSBundle.MainBundle);
T whiteView = storyboard.InstantiateViewController (typeof(T).Name) as T;
from.PresentViewController (whiteView, false, null);
return whiteView;
} finally {
IsStoryboardLoading = false;
}
}
return null;
}
}
and then I use it in ViewDidAppear override:
public override void ViewDidAppear (bool animated)
{
this.ConsiderSwitchingStoryboard<MyViewController> ();
}
This code works in some cases but in others it causes an error when performing a push segue:
NSGenericException Reason: Could not find a navigation controller for segue 'segSearchResults'. Push segues can only be used when the source controller is managed by an instance of UINavigationController.
at (wrapper managed-to-native) MonoTouch.ObjCRuntime.Messaging:void_objc_msgSendSuper_IntPtr_IntPtr (intptr,intptr,intptr,intptr)
It might be simpler to just use 1 Storyboard and have 2 sets of controllers in the same storyboard. Just use different storyboard ids for the controllers. You can use the same class on those if needed.
For example:
var whiteController = Storyboard.InstantiateViewController("MyWhiteController") as MyController;
var blueController = Storyboard.InstantiateViewController("MyBlueController") as MyController;
Both could create an instance of MyController, but pull out different layouts from the same storyboard file.
Another option is to use UIAppearance to dynamically set a "style" on all controls of a certain type in your app.
For example, to set the default UIBarButtonItem image throughout your app:
UIBarButtonItem.Appearance.SetBackgroundImage(UIImage.FromFile("yourpng.png"), UIControlState.Normal, UIBarMetrics.Detault);
(You might check my parameters there)
Related
I am using MvvmCross and using ShowViewModel to navigate between view. It takes the default navigation behavior i.e., slides from Right->Left . I want few view controllers to slide from bottom to top . Can someone let me know how we can do this in MvvmCross. These are not overlays but regular view controllers.
You can achieve this by setting a custom delegate for your Navigation Controller. This can be done by override following method in your custom ViewPresenter
protected override void OnMasterNavigationControllerCreated()
{
this.MasterNavigationController.WeakDelegate = new NavigationControllerDelegate();
}
Within this delegate you can set your transitions, e.g.:
public class NavigationControllerDelegate : UINavigationControllerDelegate
{
public override IUIViewControllerAnimatedTransitioning GetAnimationControllerForOperation(UINavigationController navigationController, UINavigationControllerOperation operation, UIViewController fromViewController, UIViewController toViewController)
{
if (operation == UINavigationControllerOperation.Push)
{
if (fromViewController is MenuViewController)
{
return new BottomToTopTransition();
}
...
}
}
}
BottomToTopTransition is also a custom class and inherits from UIViewControllerAnimatedTransitioning. Last step is to override AnimateTransition() in this transition class and you are done.
In a cross platform Xamarin app built with the MvvmCross framework I'm using a ToggleButton Widget in an Android .axml layout. I've bound the Checked property to a View Model property using a converter using the following binding syntax:
Checked MarketBuySellViewModel.Direction, Converter=DirectionBool, ConverterParameter='Sell'
Everything works well. On the iOS side, it appears you can use UIButton as a ToggleButton by using the Selected property. This implies that the following binding should achieve what I want on iOS:
set.Bind (SellButton).For(b => b.Selected).To (vm => vm.MarketBuySellViewModel.Direction).WithConversion("DirectionBool", "Sell");
I don't get any binding errors in the application output but the binding itself doesn't seem to work. Clicking the button doesn't set the Direction property and setting the direction to a different value does not set the Selected property on the UIButton.
Do I need to create a Custom Binding or am I simply setting up the binding incorrectly?
I also tried using a UISegmentedControl to achieve the same effect. Is binding to this control supported at all in MvvmCross? I don't see any reference to it in the source code. Does this mean I need to create custom bindings for it too?
For the UIButton, I don't believe there's any included Selected binding built into MvvmCross. Because of this - and because Selected doesn't have a simple paired event SelectedChanged, then I believe Selected binding should work one-way (from ViewModel to View) but not two-way.
There is a binding for the On of a UISwitch control and that's the control I've seen used most in these situations.
If you wanted to add a custom 2-way binding for Selected then I guess you'd have to do this using the ValueChanged event (but would need to check that is correct).
To do so, you'd just build a target binding something like:
public class MvxUIButtonSelectedTargetBinding : MvxPropertyInfoTargetBinding<UIButton>
{
public MvxUIButtonSelectedTargetBinding(object target, PropertyInfo targetPropertyInfo)
: base(target, targetPropertyInfo)
{
var view = View;
view.ValueChanged += HandleValueChanged;
}
private void HandleValueChanged(object sender, System.EventArgs e)
{
var view = View;
if (view == null)
return;
FireValueChanged(view.Selected);
}
public override MvxBindingMode DefaultMode
{
get { return MvxBindingMode.TwoWay; }
}
protected override void Dispose(bool isDisposing)
{
base.Dispose(isDisposing);
if (isDisposing)
{
var view = View;
if (view != null)
{
view.ValueChanged -= HandleValueChanged;
}
}
}
}
and this could be registered in Setup in protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry) using something like:
registry.RegisterPropertyInfoBindingFactory(typeof(MvxUIButtonSelectedTargetBinding), typeof(UIButton),
"Selected");
Similarly, I don't believe anyone has added a two way UISegmentedControl binding yet - but would happily see one added.
Building a two way UISegmentedControl binding would be quite straight-forward - you'd just have to bind to the pair SelectedSegment and ValueChanged - with code similar to above.
Alternatively, you could switch to using a custom MySegmentedControl which had a nicer Value`ValueChanged` pair which would automatically work without a custom binding - e.g.:
public class MySegmentedControl : UISegmentedControl
{
// add more constructors if required
public int Value
{
get { return base.SelectedSegment; }
set { base.SelectedSegment = value; }
}
}
If any or all of these custom bindings are needed, then the Mvx project is happy to get these bindings added as issues or pull requests along with test/demo UIs in the https://github.com/slodge/MvvmCross-Tutorials/blob/master/ApiExamples/ApiExamples.Touch/Views/FirstView.cs project
Could be helpful to someone else, so i'm sharing my experience. I needed a two way binding for UISegmentedControl.SelectedSegment property to a ViewModel. The one way biding (ViewModel => View) works by default. I couldn't able to properly utilize the solution proposed by Stuart - to subclass the UISegmentedControl. I tried to ensure that the linker does not rip off the new custom control code, but this didn't help me a bit. So a perfectly viable solution is the one with MvxPropertyInfoTargetBinding. Here is the code working ok for me:
public class MvxUISegmentedControlSelectedSegmentTargetBinding : MvxPropertyInfoTargetBinding<UISegmentedControl>
{
public MvxUISegmentedControlSelectedSegmentTargetBinding(object target, PropertyInfo targetPropertyInfo)
: base(target, targetPropertyInfo)
{
this.View.ValueChanged += HandleValueChanged;
}
private void HandleValueChanged(object sender, System.EventArgs e)
{
var view = this.View;
if (view == null)
{
return;
}
FireValueChanged(view.SelectedSegment);
}
public override MvxBindingMode DefaultMode
{
get { return MvxBindingMode.TwoWay; }
}
protected override void Dispose(bool isDisposing)
{
base.Dispose(isDisposing);
if (isDisposing)
{
var view = this.View;
if (view != null)
{
view.ValueChanged -= HandleValueChanged;
}
}
}
}
public class Setup : MvxTouchSetup
{
...
protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
{
registry.RegisterPropertyInfoBindingFactory(typeof(MvxUISegmentedControlSelectedSegmentTargetBinding), typeof(UISegmentedControl), "SelectedSegment");
}
}
I want to use a third party view controller that already inherits from UIViewController (https://bitbucket.org/thedillonb/monotouch.slideoutnavigation/src/f4e51488598b/MonoTouch.SlideoutNavigation?at=master), how would I integrate that with MVVMCross?
I could just take the source and change it to inherit from MvxViewController, but guessing I will run into this with other libraries.
Do I need to implement all the interfaces MvxViewController does? IMvxTouchView? IMvxEventSourceViewController?
For this particular case, where you don't actually want to do any data-binding so you can just use a custom presenter - e.g. see #Blounty's answer, or see this project demo - https://github.com/fcaico/MvxSlidingPanels.Touch
If you ever do need to convert third party ViewController base classes so that they support data-binding, then the easiest way is exactly what you guessed:
inherit from them to provide an EventSource-ViewController
inherit from the EventSource-ViewController to add the Mvx BindingContext
This technique is exactly how MvvmCross itself extends each of UIViewController, UITableViewController, UITabBarController, etc in order to provide data-binding.
For example, see:
extending UIViewController to provide an eventsource - MvxEventSourceViewController.cs
extending the event source ViewController to provide a binding context - MvxViewController.cs
Note that because C# doesn't have any Multiple-Inhertiance or any true Mixin support, this adaption of ViewControllers does involve a little cut-and-paste, but we have tried to minimise this through the use of event hooks and extension methods.
If it helps, this iOS technique for a previous MvvmCross version was discussed in Integrating Google Mobile Analytics with MVVMCross (obviously this is out of date now - but the general principles kind of remain the same - we adapt an existing viewcontroller via inheritance)
In Android, a similar process is also followed for Activity base classes - see ActionBarSherlock with latest MVVMCross
You can use a custom view presenter like below, This is pretty much straight out of my app using the SlideOutNavigation.
public class Presenter
: IMvxTouchViewPresenter
{
private readonly MvxApplicationDelegate applicationDelegate;
private readonly UIWindow window;
private SlideoutNavigationController slideNavigationController;
private IMvxTouchViewCreator viewCreator;
public Presenter(MvxApplicationDelegate applicationDelegate, UIWindow window)
{
this.applicationDelegate = applicationDelegate;
this.window = window;
this.slideNavigationController = new SlideoutNavigationController();
this.slideNavigationController.SlideWidth = 200f;
this.window.RootViewController = this.slideNavigationController;
}
public async void Show(MvxViewModelRequest request)
{
var creator = Mvx.Resolve<IMvxTouchViewCreator>();
if (this.slideNavigationController.MenuView == null)
{
// TODO: MAke this not be sucky
this.slideNavigationController.MenuView = (MenuView)creator.CreateView(new MenuViewModel());
((MenuView) this.slideNavigationController.MenuView).MenuItemSelectedAction = this.MenuItemSelected;
}
var view = creator.CreateView(request);
this.slideNavigationController.TopView = (UIViewController)view;
}
public void ChangePresentation(MvxPresentationHint hint)
{
Console.WriteLine("Change Presentation Requested");
}
public bool PresentModalViewController(UIViewController controller, bool animated)
{
Console.WriteLine("Present View Controller Requested");
return true;
}
public void NativeModalViewControllerDisappearedOnItsOwn()
{
Console.WriteLine("NativeModalViewControllerDisappearedOnItsOwn");
}
private void MenuItemSelected(string targetType, string objectId)
{
var type = Type.GetType(string.Format("App.Core.ViewModels.{0}ViewModel, AppCore", targetType));
var parameters = new Dictionary<string, string>();
parameters.Add("objectId", objectId);
this.Show(new MvxViewModelRequest { ViewModelType = type, ParameterValues = parameters });
}
}
I have an iPhone app that supports all orientations but in one UIViewController I only want to support portrait (or upside down).
I have added the following code to my UIViewController but it still rotates.
public override bool ShouldAutorotateToInterfaceOrientation (UIInterfaceOrientation toInterfaceOrientation)
{
// Return true for supported orientations
return ((toInterfaceOrientation != UIInterfaceOrientation.LandscapeLeft) && (toInterfaceOrientation != UIInterfaceOrientation.LandscapeRight));
}
No matter where I add the ShouldAutorotateToInterfaceOrientation code it still rotates!
Is there a way to allow the app to support all orientations for all UIViewControllers except one?
Also i am using a NavigationController - does that affect things?
if you use iOS 6 you must override GetSupportedInterfaceOrientations method instead ShouldAutorotateToInterfaceOrientation
public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations()
{ ... }
Probably this happens because your root navigation controller brings it own rotation. Lets assume that your root navigation controller is a normal UINavigationViewController. Create a derived own version:
public class UINavigationControllerWithoutRotation : UINavigationController
{
public UINavigationControllerWithoutRotation()
{
}
public UINavigationControllerWithoutRotation(UIViewController viewController) : base(viewController)
{
}
public override bool ShouldAutorotate()
{
return false;
}
}
Now use this as the root controller. Find the code saying something like:
var myRootController = new UINavigationController();
and replace it with
var myRootController = new UINavigationControllerWithoutRotation();
That should do the job. Keep in mind, that you have to do it a little bit different if for instance your root view controller is a UITabBarController!
I've created a new class that inherits from TTDefaultStyleSheet.
public class BlackStyleSheet : TTDefaultStyleSheet
{
public BlackStyleSheet() : base()
{
Console.WriteLine("BlackStyleSheet created.");
}
public override UIColor TabBarTintColor
{
get
{
Console.WriteLine("BlackStyleSheet.TabBarTintColor returned.");
return UIColor.Black;
}
}
[Export ("tabTintColor")]
public override UIColor TabTintColor
{
get
{
Console.WriteLine("BlackStyleSheet.TabTintColor returned.");
return UIColor.Black;
}
}
}
And I set this custom style sheet as the default in my FinishedLaunching method.
public override void FinishedLaunching (UIApplication application)
{
Three20.TTStyleSheet.GlobalStyleSheet = new BlackStyleSheet();
Three20.TTDefaultStyleSheet.GlobalStyleSheet = new BlackStyleSheet();
Console.WriteLine("Three20 style sheet set.");
}
Then, I create the actual TTTabStrip and TTTabItem elements within my own custom UIViewController's ViewDidLoad() method. The TTTabItem objects are declared at the class level instead of the method level.
tab1 = new TTTabItem("1");
tab2 = new TTTabItem("2");
tab3 = new TTTabItem("3");
TabStrip = new TTTabStrip();
TabStrip.Frame = new RectangleF(0,0,View.Frame.Width, 44);
TabStrip.TabItems = NSArray.FromNSObjects(tab1,tab2,tab3);
TabStrip.SelectedTabIndex = 0;
View.AddSubview(TabStrip);
When the TTDefaultStyleSheet.GlobalStyleSheet property is set to the new custom stylesheet, the app crashes. When this property setting is removed, the app runs perfectly, but the tab strip remains grey.
In all forums I've read (none seem to be MonoTouch-specific), they all indicate that creating your own stylesheet, then setting it to the global stylesheet is the way to go. But this doesn't seem to work for me with MonoTouch.
Does anyone have any ideas?
Thank you,
John K.
I tried your example in XCode with Objective-C and I can confirm that this this approach does work. I also tried for myself with MonoTouch and saw the same results you report.
I have found several problems in the Three20 binding code in the past that seem to cause aborts like this. You can try and fix up the existing binding code or create only the bindings you need from Three20 manually.
http://docs.xamarin.com/ios/advanced_topics/binding_objective-c_types