Is there a way to get a callback when a View appears/disappears on the screen?
I need this for analytics purposes - eg. I need to check how many times people saw a view versus how many times they clicked on it.
I can tell whether a view is on screen at a certain point in time but I'm wondering whether there is a callback for that.
Also note that I'm not interested when a View's state becomes VISIBLE and not even when a view gets rendered (because eg. in a ViewPager the Views of the second page are rendered before they actually appear on screen).
We did several workarounds for certain scenarios but I'd like to have something which is more generic. We need it in ListViews, GridViews, ScrollViews and ViewPagers and each one of them presents different challenges.
Does ViewTreeObserver.OnGlobalLayoutListener help? I have never used it myself though.
See: http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html
Related
I followed this link http://www.wintellect.com/devcenter/jprosise/handling-the-back-button-in-windows-10-uwp-apps and "successfully" make my button work. I mean I can make my backbutton work between pages. However, if I navigate to a control which is inside this page and will cover the whole screen, then it would not allow me to back to the page. I will stuck in that control.
I'm wondering how to solve this problem. Currently I can think two possible ways (0) Override OnBackRequested() inside the control's code behind or viewmodel? (1) Override OnHardwareButtonsBackPressed() inside the control's code behind or viewmodel?. I don't know if these are correct way to do it or there is some better way to do it. Another reason for me to override is that I need to make some changes to the page navigation behavior.
As you have guessed, you simply need to hide the control again when the back button is pressed or back is requested in some other way. I would listen for the BackRequested event (not the HardwareButtons.BackPressed event) in the page's code-behind, and in the handling method you can check to see if the control is currently shown. The reason I recommend the BackRequested event is because it is universal, while HardwareButtons.BackPressed only works on a phone. Anyway, if the control is visible, then hide it, and set the Handled property of the event arguments to true. If the control is already hidden, don't do anything special to handle the event (because in that case you will want the navigation system to handle it by navigating to the previous page, if there is one). There are many aspects to navigation in Windows 10 -- please see these pages on Navigation and the SystemNavigationManager.
I have a question regarding coded ui UIMap.
Every time I record an action on the same application, coded ui generates a new object for the same window in the application.
It looks like:
UIAdminWindow
UIAdminWindow1
UIAdminWindow2
and so on...
every window class holds different buttons, even though it's the same window.
Thus it's very hard to keep code maintenance.
What i would like is that every time i perform actions and records on a window, even if not at the same time, the already generated class for this window, will be updated with the new controls.
any suggestions to why it happens?
Thanks a lot!
You can clean up your UIMaps by doing two things:
Use the UIMap Toolbox (from codeplex) to move controls within the UIMap so they are all under one control tree.
When you have duplicate UI controls, go to the properties for the action that references the duplicate control and change the UI Control property to point to the original control in the UIMap.
The duplicate trees should now be unreferenced and you can delete it from your map, keeping things clean.
And yes, it's a pain to do, but it's worth it for maintainability.
In UIMap.uitest you can change the action name and the control name for better maintenance.
For example: you can set UIAdminWindow as FirstAcessWindow or other name that will express comfortably the control or the action.
What I can guess is that there is some randomly generated content or element identification data such as class or title that may be causing it. This may be caused by different username for example. Also you can update the element from UI map element tree.
this is not a technical question, but one for advice regarding the best practices in designing an Android tablet UI.
I've got my concept of an Android Phone app pinned down.
The first activity (master view) launched contains a tab bar with three fragments from which the user can launch detail view activities of different sorts.
Both the master-view activity and the detail-view activities have actions in their action bars. Different detail views have different action items.
My question is: How should I organize and display the action items on a tablet, where an activity combines both views side by side?
The problem is the unified action bar for both the master-view fragment and whatever kind of detail fragment is shown. I do not think it is a good idea to start messing with the contents of the action bar whenever a different kind of detail view is opened.
The Android Design Guide does not tell you much on that front. There is a sample of a Contacts app in the "Multi-pane Layouts" section, but it does not actually deal with the problem. It evades it, by putting the single relevant action as an icon inside the detail view fragment.
Any advice with regards to best practices and references are appreciated.
I would suggest leaving your master details icons in the action bar, whilst putting your details view icons in another view/area within the details fragment.
My reasoning would be that icons in the action bar affect / are associated with the whole app / view on screen. Whilst your details icons only affect the details view and therefor should not be in the action menu when showing multiple fragments.
I guess you will have to see how the designs look..
I am not a fan of the action bar icons being changed from within the same activity (even if it contains multiple fragments), however when you load a new activity (like in your phone design) then I say yeah throw them in the action bar.
If I understand your question correctly, which I think is basically a question of how multiple Fragments (i.e. when on a multi-pane layout such as on a tablet) should contribute to the single ActionBar, it's quite straightforward and it is actually briefly discussed in the documentation here. Essentially, you can have the multiple Fragments all contributing their own menu items / action items to the single action bar, via some simple API calls.
Actually, I want to store some data in background page and the popup page just show that part of data say Data as a div element created in background page document.createElement("div"). Here, the background page will register some listeners to the tab update and change the Data elements accordingly. What the popup will do is to get that Data and appendit use the document.appendChild(Data).
(The purpose I intend is this will cause the popup changes immediately while the tab updage is triggered.)
However, the elements are shown as usual, what I am facing very headache is I have registered the onclick for the div object in backgroundpage as onclick="chrome.extension.getBackgroundPage().somefunc()". However, the first time, all the click will triger the right behavior but after the popup loses foucs and get focus again, all the click won't work.
I try to put something like change the onclick="somefunc()" and leave the func within the script of popup page. And there I want to log whether it is called by console.log("clicked"). Here, something unbelievable happens, the function is succefully trigerred BUT the console is null here, I cannot even call chrome.extension.getBackgroundPage() as well.
Here are a list of questions, maybe very hard to express for me...
1. Whether I can reuse the DOM element from the background page to the popup page directly by appendChild(chrome.extension.getBackgroundPage().getElementById()?
2.Will the onclick event registered in the background page still work in the popup pages?
3. What's the problem with the problem I am encountering? I have tried many ways to find out the reason but all in vain at last...
Best Regards,
If you need any more information, please let me know.
(PS: I am wonderning if it is called something like the event propogation, however, I am not an expert in this two pages communicating...)
I have a core data document based cocoa app that is working well except for one slightly odd problem.
For some reason, if I make a change to any of my fields the menu/window don't seem to recognize it - ie. the red close button doesn't get the black 'dirty' indicator and the File/Save menu item isn't enabled. However, if I attempt to close the application (via command-Q), I do get the popup asking me if I want to save my changes.
It seems that the document's dirty flag is being set, but the window/menu items aren't reacting to it. I am curious as to where I might look to see why this might be the case. I suspect that it may have something to do with my window not knowing about my ManagedObjectContext...
The only slightly atypical behaviour is that my document's makeWindowControllers method has been overridden and I am adding my window controllers using a call to my document's [self addWindowController:xxx] method. My window controllers subclass from NSWindowController so I had to add my own instance variable to each window controller to hold the ManagedObjectContext, but I suspect that this isn't getting passed to the window/menu. Not sure what the normal pattern is here...
Anyway, any thoughts would be much appreciated. Thanks
From the description it sounds like your UI elements are not actually bound to the document itself. If so, then the UI elements are not observing the document and are not reacting to changes in the document. Check the bindings.
Thanks in part to TechZen, and also re-reading my own question (in particular, where I said "I suspect that it may have something to do with my window not knowing about my ManagedObjectContext") I started to look at the bindings for my WindowController subclass.
As it turned out, I hadn't bound the window outlet for the File's Owner to my actual NSWindow. As soon as I did that, the black dirty dot and the window's menus started behaving correctly.