Positioning ListViews in WinJS Metro apps using scrollIntoView - microsoft-metro

I am building a jscript-based Windows 8 Metro app. The main screen of this application is a scrolling "panorama" view with several list views showing various aspects of the app's state. In some cases the user will select something on the page which results in a navigation to another page (using the WinJS.Navigation.navigate method.
When the user hits the back arrow on the other page, it returns to the main screen, and I use "scrollIntoView" on to position the screen to the section that the user was working on before the navigation occurred.
Unfortunately this hardly ever results in correctly positioning the view. It seems random. I suspect that the page isn't finished being built yet and that the scroll values are set based on the state at some snapshot in time.
Now the question:
Is there some what to be notified by WinJS ListView objects that they are completely rendered and layed out? Or is this the job of the page's ready function?
Thanks for any insight!

Putting multiple list views side by side is Not A Good Idea(TM). I would recommend putting one list view, and placing your content in a grouped data source to get the groups. If the items have different templates, then you can use a custom item Template selector to dynamically select a template.
Additionally, to ensure that the list view is scrolled to the right position, you need to use the indexOfFirstVisible to set the items the name suggests.

Related

Nested self-referencing navigation/routing in a flutter app

I'm exploring creating a flutter app. The app is supposed to have a navigation bar with items that can have individual/nested routing depending on which of the items is active. This from what I've read on the flutter documentation is feasible and a common use case.
However, I might have a slight different use case where I can't know for certain what particular routes are to be used.
In the above image, the green navigation starts with posts. From Posts, the user can navigate to either an author or comments. From author and comments the user can navigate to either posts, author or comments.
It's therefore not exactly trivial to know which routes a specific page can be routed to, as they can self reference, to infinity.
Adding a cherry on top, each bottom navigation should be independent of each other, so switching the bottom bar navigation back and forth should only replace what's seen in the body of the page. If the user is ten pages deep, they should retain that layout if they decide to go back.
How can this routing architecture be constructed?

Wicket AjaxTabbedPanel with tab content panels that defer rendering until tab is activated

I have a page with an AjaxTabbedPanel with lots of tabs with content like charts, reports, etc., whose content is quite expensive to produce. Most users spend most of their time on the first panel and don't need to venture to the tabs with charts, reports etc.,
To avoid unnecessary work on the back end and provide a faster initial page render I thought it would be advantageous to avoid doing the work to populate a tab's contents until (and only if) the user clicks on a tab to activate and thus render that tab's content.
Of course the first tab will always load during initial page load as that is the one that is active by default but the other tabs' contents will lay dormant until the user clicks on the corresponding tab, avoiding doing any work for those dormant panels until necessary.
Is that possible?
I thought that I could possibly employ the AjaxLazyLoadedPanel but it seems to be designed for a different purpose and the lazy loaded panel is regularly polled until it is 'ready' but that's not what I need in my case: there's no need for polling, we will know when to render a panel's content i.e. when activation of the panel occurs.
TabbedPanel does not need a tab's content as long at is isn't shown.
Make sure that you implement ITab#getPanel() 'lazy', i.e. the panel is created only when that method is called the first time. See PanelCachingTab for inspiration.

Build some sort of workflow in JavaFX

I'm trying to build some sort of visual workflow in JavaFX. I want my application to have one main screen with the next and previous buttons, something like an installer. When a user clicks next, all the elements of the next screen appear in the same element. All previous choices of the user have to be saved. So when a user clicks on the previous button that all of his choices are still there.
How would I go on to do this?
I found these links on Google, but they don't seem to help me. Something like this is a bit the direction that I want to go, but the code in this tutorial isnt't really that good for scene's with a lot of elements.
The DataFX Framework provides a Flow API that can be used to define workflows. By doing so you can simply navigate between MVC Groups by only using annotations or configurations. You can find some examples of the API here:
http://www.guigarage.com/2014/06/datafx-tutorial-5/
http://www.guigarage.com/2015/02/quick-overview-datafx-mvc-flow-api/
http://www.guigarage.com/2015/01/datafx-tutorial-6/
I haven't worked with JavaFX in a while, but I'll start by saying I really hope you are using the JavaFX scene builder.
The way I would do it off the top of my head without going back and relearning JavaFX is to create a main window in the scene builder, and have a sort of central content display area, which holds another custom JavaFX container that contains the content you want to display, of which you can then create several of and swap out which one is being displayed programmatically.
Basically, create several smaller components representing each step or screen and display them programmatically in an owning container.

Need architecture direction

I'm creating an app and I need some help with design.
Launch Screen - I want to show 6-8 "category" buttons with labels loaded from an array ("normal" buttons from interface builder - not tab bar buttons or menu bar buttons).
Table Screen - When one of the category buttons is pushed on the launch screen, I want to show a table view with all of the items in that category.
Detail Screen - When one of the items on the table screen is selected, go to a new screen with details for the item. There will be an action button on this screen which will remove the item from the list if pressed.
My questions are as follows:
1) I don't want to show navigation buttons on the first screen. Can I still use a Navigation-Based application and hide the navigation controls on the first screen, or would it be better (easier) to create a view-based application and put a navigation controller "inside" one of the views? I'm totally open to any basic design approach suggestions you may have.
2) I've figured out how to create a sqlite3 file, add it to the project, query it, and generate the table view from the results, but I'm not sure about how to store the sqlite file in a way that will persist on the device when the user upgrades the app later. Any pointers on that?
Thanks for any help/links/documentation you can point me to. I've watched a million tutorials but none of the ones I've seen really address basic app design.
Now for Q1, both ways work fine but if you have buttons from the first screen, having a uinavigationcontroller might make it slightly easier if you plan to have back buttons on the screens after the first screen.
For Q2, to make the database persist when the user updates their app at some stage, simply keep the original database and include a new database (with a different name) with additional content, then modify your original database and import any additional content to it.
You can also do variations of that also, ie import content from old database to new database and etc. But the key is to keep the database file names different, ie add database_v1.sqlite, database_v2.sqlite and etc.
BTW don't forget to clean up any databases you won't use in future.

Wizard style of interface in iPhone

How would one implement a wizard style interface for the iPhone?
For instance I have a form that I would like to break down into 5
different pages or views instead of putting all the information to fill out
into one page or view.
This interface must have the ability to go prev or next in case they want
to change something on page 2 when they are on page 4.
This interface must have the ability to go to page 3 directly and still be
able to go prev and next. Seems like using UINavigationController wouldn't
work here since views 1 and 2 are not on the stack so prev would not work.
Update: Check out the "gas cubby" application. It has what I'm looking for. UITableView presents the items you can fill out. Selecting a row takes you to the detail view to enter data and prev and next to fill in other information.
UINavigationController seems like the obvious solution. It gives you nice, familiar page transitions for free, and if you need to jump to a specific page you can just set up your navigation stack without using the transition animations.
I would say use a Navigation Controller. On the 1st view, show the 5 options in a Table View. The user selects a row, and then the corresponding section is pushed onto the stack as a new UIViewController. So, if they are in view #3 and want to go back to view #1 (to be honest, I would recommend rethinking whether or not somebody in the real world will actually want to do this), they hit "back" and then select view #1 from the table.
I can't think of a better way to do this because you won't have room to do something like breadcrumbing, which Apple would recommend against anyway. You could use a tab bar but that is more like options then some sort of wizard workflow.
If you really want them to be able to skip around the process, the combination of a UINavigation controller with a UISegmentedControl to jump to sections would do what you want. You can either embed the segmented control in the nav bar or place it just below the nav bar (which seems more like what you want since you have five sections).
If the Segmented control is not quite to your taste just put up any set of five buttons to change sections and make them visually appealing.
A "wizard" UI is typically used when you have a relatively small number of steps where one step depends on the previous, at least at some steps, the results or presentation depends on previous steps. This is like a navigation tree that usually results in the use of the navigation controller, but with only one potential branch at each each step. My feeling is that the navigation UI would be perfect, but with one exception; A button on the right hand side of the navigation bar that is the left to right mirror image of the "back" button that is usually found in the left part of the navigation button. That button would navigate to the the next step, and at each step the page presented would allow the user to fill in the information for that step. The only problem then is navigating to a step not the next or previous, and this could be corrected with a custom button that includes a drop-down list of the steps in the process. And this would fit nicely with the rest of the iPhone UI, which Gas Cubby's wizard UI (as good as it is) does not.