Fragment not getting deleted visually - android-fragments

I am trying to replace a Fragment with a new Fragment. For this I used following code.
transaction.replace(R.id.fragment_container,
newFragment);
But on viewing in AVD, its not actually getting replaced. newFragment(which is smaller in size) is displayed on top of old_fragment.
However on again accessing old_fragment it returns null.
I even tried
Fragment oldFragment =
getFragmentManager().findFragmentById(R.id.home_fragment);
transaction.remove(oldFragment);
Even this is not removing Fragment visually.
Could you please help me in actually removing any Fragment.
P.S.: I am using Android Compatibility Pack and building it for android 2.2.

This is some kind of behavior with Android Fragments.
If you have any Fragment added in XML Layout, then Fragments on that activity can't be removed. However it works correctly if all the Fragments are added dynamically.
Strange isn't it?
for reference please see.
http://groups.google.com/group/android-developers/browse_thread/thread/b56967e0f147168d

Related

Issues with wrapping PrismForms NavigationService

In PrismForms we got the problem, that the NavigationStack is empty after navigating to a new page. That means after using the hardware back-button on the SecondPage, the app is closed. Although the back-arrow in the header on Android isnt shown. If looking closely you can see the back-arrow for a short moment after the page is switched. I guess thats before the NavigationStack gets cleared.
To the first page we navigate with the following command in OnInitialized() in our App.xaml.cs which derives from PrismApplication.
NavigationService.NavigateAsync("NavigationPage/StartPage");
(If only Navigating to „StartPage“ here, the Stack doesnt get cleared.)
That has do to with PageNavigationService.ProcessNavigationForNavigationPage(...) calling
bool clearNavStack = GetClearNavigationPageNavigationStack(currentPage); and PageNavigationService.ProcessNavigationForContentPage(...) not.
From the StartPage to the next we navigate with NavigateAsync("SecondPage")“. Here the described behaviour appears.
For navigation we use a class which wraps the Prism NavigationService. We hold him as a property and get him via Unity in our constructor:
this.PrismNavigation = prismNavigation ?? throw new ArgumentNullException(nameof(prismNavigation));
The methods „NavigateAsync“ and „GoBackAsync“, etc. we just pass through.
This way we want to seperate our ViewModel-Project from references to XamarinForms to later be able to use the same ViewModels for for example a WPF-GUI.
Why is the stack beeing cleared by our own NavigationService? If we register the original Prism NavigationService in App.xaml.cs instead, navigating back works as expected again. We found the point in the framework and could avoid the clearing with a drity hack, but that’s against the navigation-logic implemented in PrismForms, but we don’t understand how to do it the correct way.
Every help appreciated!
We edited a few things to get it working after finding some interesting information by Brian Lagunas in the forlast-post here:
https://github.com/PrismLibrary/Prism/issues/591
Although the topic was about something else, it led to improvements for overwriting the Navigation Service.
Remember that in your viewModels the Navigation Service must be named "navigationService" by convention. Also we switched from just holding the Prism Navigation Service as a parameter to deriving from it as suggested in the link above.
public class MyNavigationService : UnityPageNavigationService

Blend not showing MVVM property values in design mode but shows object in binding dialougs, works fine when built

I am using MVVM light and blend. For awhile everything was good. Now though when I look at my views in blend no data from the views are being bound. I have some data that is static and some that is being provided from design time data providers.
1) Everything works fine at run time
2) My VM shows in blend in the binding dialougs for fields (i.e. dialoug for binding a text field to my model.
3) I get no errors in blend.
4) I have tried commenting out all the design time provider includes (ViewModelLocator SimpleIoC) does not change anything.
5) A simple property like a static field of "Page Name" or "Applicaiton Title" no longer shows in design time.
Bottom line is all I get in design time is a blank black screen. But in run time all is good.
Any thoughts? I am sure I have something it does not like but without errors it is hard to known.
.Net 4.5, VS 2013, Blend 4
After spending some time to comment out some code I found what was happening. There was a line of code that was erroring out when run by Blend. Blend was executing a line of code that was returnig null and erroring out. As soon as I changed that line of code (commented it out or fixed it so it does not throw an error on accessing it in design mode), all the properties bind and show in Blend.
If you are seeing this pull up your ViewModel code and look at whatcode is running in the constructor. Easiest thing to do is just comment out all the code, save and then build the project in blend (this will force Blend to reload the view). See if things start showing agian.

Emberjs CollectionView changes from 0.9.7.1 to 1.0.pre?

I had some code that connected an ArrayController with CollectionView that no longer works once I upgrade to 1.0.pre.
It seems that CollectionView no longer passes each element of the collection to its template view class?
I've distilled my issue to this jsFiddle: http://jsfiddle.net/chaodoze/CbwCN/
Notice it outputs to "1,2,3" on each line in 1.0.pre
In 0.9.7.1, it outputs correctly as a single digit on each line.
Am I doing something wrong here or is this a bug?
What is the best way to work-around this issue?
Thanks!
In 1.0.pre the view's context has changed. When you access {{content}} you are really accessing {{controller.content}}, which is [1,2,3]. You need to access the view's content, which in the individual number, that is done with {{view.content}}.
See http://jsfiddle.net/CbwCN/2/

Flex: PopUpManager giving "...null object reference" error

I have a main application calling several ViewStack states, each with popup windows. If I don't open any popup windows, I can move between states fine. If I open a popup window then try to change the state using currentState=... I get the error:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at spark.components::Scroller/focusInHandler()[E:\dev\4.y\frameworks\projects\spark\src\spark\components\Scroller.as:2139]
at flash.display::Stage/set focus()
at mx.core::UIComponent/setFocus() [E:\dev\4.y\frameworks\projects\framework\src\mx\core\UIComponent.as:9905]
...
I see others having the same problem, for example here:
http://forums.adobe.com/thread/1031531
http://forums.adobe.com/message/2767130
http://forums.adobe.com/message/3448443
http://forums.adobe.com/thread/655749?tstart=-1
http://forums.adobe.com/thread/801149
http://flex4examples.wordpress.com/2011/05/05/skinnabletextbase-focusmanager-runtime-error-popup/
http://bugs.adobe.com/jira/browse/SDK-32036?page=com.atlassian.jira.plugin.system.issuetabpanels%3Aall-tabpanel
But I haven't figured out how to implement the recommended solution. It sounds like I should just include:
import mx.managers.PopUpManager; PopUpManager;
inside my main application and it should work, but it doesn't work for me.
My application has each view state in a different file, each defined using <views:View>. Also, all of the popups are separate files defined as <s:TitleWindow>. Each file includes this line:
import mx.managers.PopUpManager;
I wonder if this means each file is using a different popup manager(?), when it's a singleton and only one should be used for the whole app (how to set that up?).
The code I use to call a popup is:
var _popupName:MyTitleWindowFileName = MyTitleWindowFileName(
PopUpManager.createPopUp(this, MyTitleWindowFileName, true));
_popupName.addEventListener(MyAppController.CLOSE_POPUP,onClosePopUp);
PopUpManager.centerPopUp(_popupName); // call popup
Note that when the main application (the one defined as <s:Application>) runs, the ViewStack states have not been loaded yet (since they get loaded when they are used the first time). Not sure if that has any cause/effect here.
I've tried to follow Adobe's example code in the "Passing data to and from a Spark pop-up window" section here:
http://help.adobe.com/en_US/flex/using/WS6c678f7b363d5da52e8f1ca1124a0430dcf-8000.html#WS6c678f7b363d5da52e8f1ca1124a0430dcf-7ffe
Any ideas much appreciated.
Based on your comments, it seems like the error occurs because the focus remains in the popup. I would expect the PopUpManager and FocusManager classes to handle this better.
One thing I can think of is that the FocusManager may be trying to handle this. But since the state changes, the item that originally had focus (in the view stack child, before the pop up was opened) may no longer be there when the view state changes. Just a hunch, w/out seeing your code.
Here's some things you can do to either work around the problem (or better) further debug it to understand what is happening:
Use FocusManager.setFocus() to move the focus back to an object in the view stack child before closing the pop up
Use FocusManager.getFocus() to debug and see where it thinks the focus is at various stages (before opening popup, before/after changing state, and before/after closing pop up).
It appears this is the situation I'm experiencing:
Adobe Air: scroller throws error when changes focus between different applications
It's an Adobe bug. Solution from Adobe is:
This bug is easily fixed by changing Scroller to do a null pointer check on focusManager before using it.
which is what the first link above attempts to do.
Another link: http://forums.adobe.com/message/3812805

Sometimes willHideViewController from UISplitViewControllerDelegate is not called

I have a problem.
My app is a tab bar controller and its first view controller is a split view controller.
This seems to be not ok for Apple because documents say a split voew controller must be the root, so perhaps that is the reason of my problems.
The problem is that sometimes, willHideViewController from UISplitViewControllerDelegate is not called, so, for this reason, the upper/left button sometimes is not created, which is anoying.
I realised, to reproduce this error, try several times this:
-Landscape mode.
-Select a tab different to split view controller tap.
-Move the iPad to portrait in that tab.
-Go to the split view controller tab, and sometimes, willHideViewController is not called so you will not see the upper button. However if I rotate my iPad to landscape and after that to portrait, it's fixed.
I tried to force manually several rotations to work around this problem, but no luck.
I still have to try any split view controller clone class from github or similar.
Do you have idea what's going on or any work around?
Here I show you two examples working properly.
Thanks a lot for your help.
Where do you set the splitViewControllers delegate? Perhaps you can set the delegate when you load the tab. It sounds like you set it only when you have rotated once?
Otherwise, see this example
Here they have the TableViewController be the delegate of the splitviewcontroller. Perhaps you could do the same with the TabBarController?
I've concluded that this can't be done in any way that I consider 'sufficiently' legitimate. It's possible to get frustratingly close, but the issue of having the willShow..., willHide disseminated to the split view controllers under each tab remains.
The solution that seems most likely to work is,
https://github.com/grgcombs/IntelligentSplitViewController/blob/master/IntelligentSplitViewController.m
Though this code is undoubtedly clever, it's a bit too 'side door' for me. I suspect (but don't know) that just invoking the delegate methods is not sufficient. Surely the UISplitViewController itself needs to change it's internal state as well as calling the delegate methods? This method 'just' invokes the delegate methods when there's an orientation change.
So... I've decided on a more legitimate solution, which is to use the new method introduced in iOS 5.
- (BOOL) splitViewController:(UISplitViewController *)svc
shouldHideViewController:(UIViewController *)vc
inOrientation:(UIInterfaceOrientation)orientation
{
return NO;
}
So, the master menu is never hidden, and therefore the problem of managing the popover doesn't arise.
Of course, this is still not totally 'legit' as it still includes UISplitViewControllers that are not at the top level (the UITabViewController is at the top level, and the split views are on each tab)
Good luck with whichever solution you choose.
I'll update this reply when I've confirmed Apple will approve an app using this solution.

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