In Android app, I am using a menubar with tabs attached to it. And each tab has a fragment.
I am trying to set visibility of components (like button) in a fragment to invisible at runtime. But it is not taking effect.
What am I missing?
Main activity class calls a method in Fragment class to set visibility of the button.
But it is not taking effect.
In fragment class,
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState){
View view = inflater.inflate(R.layout.fm_hd_fragment, container, false);
multicastUp = (Button) view.findViewById(R.id.FmHdMulticastUp);
multicastDown = (Button) view.findViewById(R.id.FmHdMulticastDown);
multicastDisplay = (TextView)view.findViewById(R.id.FmHdCurrentMulticast);
.
.
.
}
public static void showcontrol(){
multicastDisplay.setVisibility(View.VISIBLE);
multicastDown.setVisibility(View.VISIBLE);
multicastUp.setVisibility(View.VISIBLE);
}
In class that wants to update this fragment
FragmentWrapper.showcontrol();
Figured out the issue...
I was trying to update activity from Service directly.
When I use intents from service to update Activity, the UI update works fine.
Related
I am trying to implement a login scenario with Xamarin Forms and Prism.
My application root page is a MasterDetail page (HomeMasterDetailPage); this being used to provide the side menu.
What I am trying to do is to have the HomeMasterDetailPage page shown with Content set to an instance of LoginPage. When the user logs in, the Content should change to an instance of HomeDetailContentPage. It should not be possible to return to the LoginPage using the back button.
I am using the NavigationService from Prism Forms.
My start up is like this...
public partial class App : PrismApplication {
public App(IPlatformInitializer initializer = null)
: base(initializer) {
}
protected override void OnInitialized() {
InitializeComponent();
Uri uri = new Uri($"/{nameof(NavigationPage)}/{nameof(HomeMasterDetailPage)}/{nameof(HomeDetailContentPage)}", UriKind.Absolute);
var settings = Container.Resolve<SettingsService>();
if (!settings.DeviceUserID.HasValue)
uri = new Uri($"/{nameof(NavigationPage)}/{nameof(HomeMasterDetailPage)}/{nameof(LoginPage)}", UriKind.Absolute);
NavigationService.NavigateAsync(uri);
}
protected override void RegisterTypes() {
Container.RegisterTypeForNavigation<NavigationPage>();
Container.RegisterTypeForNavigation<LoginPage, LoginPageViewModel>();
Container.RegisterTypeForNavigation<HomeMasterDetailPage, HomePageViewModel>();
Container.RegisterTypeForNavigation<HomeMasterContentPage>();
Container.RegisterTypeForNavigation<HomeDetailContentPage>();
}
}
This correctly displays the LoginPage within the HomeMasterDetailPage if the user is not already logged on, and the HomeDetailContentPage within the same HomeMasterDetailPage if the user is logged on.
The problem comes when actually logging on; the following is the code within the view model for the LoginPage...
protected async Task ExecuteLoginCommand() {
Uri uri = new Uri($"/{nameof(NavigationPage)}/{nameof(HomeMasterDetailPage)}/{nameof(HomeDetailContentPage)}", UriKind.Absolute);
await this.navigationService.NavigateAsync(uri);
}
It is my understanding that by using an absolute Uri this should reset the navigation so that the new page arrangement (/NavigationPage/HomeMasterDetailPage/HomeDetailContentPage) is at the top and bottom of the stack, allowing me to then move forward from there. Instead, I am getting an unhandled exception (on Android 7.0).
What am I doing wrong?
Note: All of the examples that I see have the MasterDetailPage at the root with Content being set to NavigationPage/ContentPage; when I try this I do not get exceptions, however the side menu operates differently within the MasterDetailPage - when you tap on the "hamburger" the side menu slides in over everything (including the action/title bar) and the only way to clear it is to tap outside of the side menu that slides in whereas when I show the MasterDetailPage within a NavigationPage the side menu slides in below the action/title bar and the hamburger changes to an arrow that you can click to hide the side menu again.
I can't say I've tested this exact scenario. However, if your LoginPage is the Detail of a MasterDetailPage, you may not want to perform the navigation from the LoginPage. You could, instead create a SuccessfulLoginEvent, which you would then publish from the LoginPage using the IEventAggregator, and you would subscribe to on your MasterDetailPage's ViewModel. You could then perform the navigation as _navigationService.NavigateAsync("NavigationPage/ViewA") and it should reset the Detail such that the back button doesn't bring you to the LoginPage.
Alternatively, you can simply perform an absolute Navigation which has the effect of:
Application.Current.MainPage = new MyPage().
To do to this, you could do the navigation from anywhere as:
_navigationService.NavigateAsync("/MyMasterDetailPage/NavigationPage/ViewA")
I'm working with Android TV for the first time and I'm learning to use Leanback by modifying the example tv app that is provided.
The issue I'm having is that when I press left on the first item in the lists the navigation drawer opens and focus goes to the headers in the navigation drawer. When this happens, the info_field view in the ImageCardViews collapse behind the image.
What happens: The info field on the ImageCardView hides when I open the navigation drawer.
What I want to Happen: The info field remains visible when I open the navigation drawer.
I'm sure there's a way to do this because I've seen it in some Android TV apps, like Twitch. What's the best way to have the info_field visible when the navigation drawer is open?
I've worked out how to do it. In the CardPresenter, in onCreateViewHolder, when creating the ImageCardView I've overridden the BaseCardView method, setActivated(boolean activated) to always pass 'true' into it's super. And then call setActivated so that it's activated from the beginning. Like this:
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent) {
ImageCardView cardView = new ImageCardView(parent.getContext()) {
#Override
public void setActivated(boolean activated) {
super.setActivated(true);
}
#Override
public void setSelected(boolean selected) {
updateCardBackgroundColor(this, selected);
super.setSelected(selected);
}
};
cardView.setActivated(true);
cardView.setFocusable(true);
cardView.setFocusableInTouchMode(true);
return new ViewHolder(cardView)
}
So that did the trick for me. The ImageCardView never collapses.
I think if you look at this SO post you'll get most of the way there. The info view hides due to what leanback calls "expanding".
Try just calling enableMainFragmentScaling(false); in your BrowseFragment and see if that does what you want. If it doesn't feel like exactly what you want, refer to the post I linked to.
Additionally, if you've tried what I recommend in the linked SO post, you could also call the API on the BaseCardView setInfoVisibility() and pass it CARD_REGION_VISIBLE_ALWAYS. This just requires calling on a reference to your card which shouldn't need an override of the Presenter or Card.
I want to show or hide a subview in a fragment when it is shown or hidden, but no way to check the fragment is visible to user.
In android native, it seems to have a method, but Xamarin no.
Do you have any special way to get it?
I can see only a property for fragment.
public override bool UserVisibleHint {
get {
return base.UserVisibleHint;
}
set {
base.UserVisibleHint = value;
}
}
But I need a method to check this.
thanks.
You can use the IsVisible property on the Fragment (see: https://developer.xamarin.com/api/property/Android.App.Fragment.IsVisible/)
Additionally, you can override the OnHiddenChanged method on your fragment class to get notified when the Fragment's visibility changes
it seems to have a method, but Xamarin no.
What method are you referring to?
We are using a rehosted designer (currently WF 4.0) with a lot of custom activities, all of them have custom designers. For a bunch of them, I would like to add entries to the context menu of the designer when in design mode. I'm talking about this menu:
E.g. for a XAML coded activity I would like to have an "Open source..." entry which will load the XAML source of that specific activity into a new designer. To do that I must add the entry to the menu, and when clicked figure out on which activity it was clicked. Both parts are unclear to me. How can I achieve that?
In WF 3 there was the ActivityDesignerVerb class to do that. In WF 4 there seems to be workflowDesigner.Context.Services.Publish<ICommandService>(...), but I can't figure out how to use that to add a custom action to the context menu. How can I do that?
This SO entry shows something for internal debugger commands, but I want to add a completely new command.
Solving it in the host
If you want to solve this on the workflow designer host, and not in the individual activities, it's quite simple and straightforward to do this.
When you host the workflow designer and create the workflow designer, you can simply access its ContextMenu property and modify its Items collection.
var wfd = new WorkflowDesigner();
wfd.ContextMenu.Items.Add(new MenuItem() { Header = "Hello", Command = yourCommand, });
If you want different menu items for each activity, you can subscribe to the SelectionChanged event:
wfd.Context.Items.Subscribe<Selection>(SelectionChanged);
And then implement your own logic:
private void SelectionChanged(Selection selection)
{
// Remove old menu item
if (oldMenuItem != null)
{
wfd.ContextMenu.Items.Remove(oldMenuItem);
oldMenuItem = null;
}
var modelItem = selection.PrimarySelection;
if (selection.SelectionCount == 1 && modelItem != null)
{
// Get activity type
var activityType = modelItem.ItemType;
var menuItem = new MenuItem() { /* ... */ };
wfd.ContextMenu.Items.Add(menuItem);
oldMenuItem = menuItem;
}
}
Solving it in the activity designer
If you want to always show a specific context menu item regardless of where your workflow designer UI is hosted, you can create a custom item in your activity designer XAML:
<sap:ActivityDesigner.ContextMenu>
<ContextMenu>
<MenuItem Header="Show" Command="{Binding YourCommand}"/>
</ContextMenu>
</sap:ActivityDesigner.ContextMenu>
OK so all you need to do is implement the ICommand interface on your custom activity.
So, for example - expose a custom command property from the customer activity class, then in the constructor apply a delegate event to the command handler -
/// <summary>
/// Custom activity
/// </summary>
public partial class CustomActivityDesigner
{
/// <summary>
/// Command used to display a dialog at design time
/// </summary>
public ICommand ShowCustomDialog{ get; set; }
public CustomSchedulerDesigner()
{
InitializeComponent();
ShowCustomDialog= new DelegateCommand(x =>
//Do some stuff here that will display your dialog
//you may want to consider passing the `this.ModelItem`
//to your dialog so it can then interact with the ModelTrees etc
//for example
var dialog = new MyDialog(this.ModelItem);
dialog.ShowDialog();
);
}
}
Finally,
hook the new command up to the UI via the activity designer xaml.
<sap:ActivityDesigner.ContextMenu>
<ContextMenu>
<MenuItem Header="Show" Command="{Binding ShowCustomDialog}"/>
</ContextMenu>
</sap:ActivityDesigner.ContextMenu>
I have a scenario where I need to set focus dynamically on search icon in browse fragment .For that I need to get reference of the search icon.Any idea how it can be done.
Thanks
BrowseFragment class accesses search icon using title view's getSearchAffordanceView()
private final BrowseFrameLayout.OnFocusSearchListener mOnFocusSearchListener =
new BrowseFrameLayout.OnFocusSearchListener() {
#Override
public View onFocusSearch(View focused, int direction) {
// If headers fragment is disabled, just return null.
if (!mCanShowHeaders) return null;
final View searchOrbView = mTitleView.getSearchAffordanceView();
.
.
.
Since mTitleView is BrowseFragment's private member, you cannot get search icon reference directly. The only properties you can control for search affordance in the fragment title are: visibility and color. Visibility is controlled by the presence of a search listener.