I’m working on an inventory display app (master/details) for Windows Phone 7 where the user has the ability to change the sorting. The source of the data is XML from the web, and depending on the sort chosen, the results are either a flat list (sorted by name, model number, etc.) or grouped by the selected attributes (color, size, etc.). I'll pre-determine whether the sort returns flat vs. group and it won't be user selectable.
I’m displaying the results in a WP7 pivot control and want/need the different sorts to appear in the same PivotItem (putting the sorts in different PivotItems isn’t really an option). The source for the list is an Observable Collection (actually at this point it’s a CollectionViewSource, but I’m not wedded to either). I’m using the MVVM Light framework.
I’ve played with LongListSelector from the Silverlight Toolkit and it looks like it does what I want. I've read a number of posts (starting with WP7 ListBox Grouping) and actually have it working for the flat list (no sort applied, just default as it is from the source). Now I’m trying to figure out the right way to use it.
My questions:
Is it possible to re-structure the way the data is displayed (flat/sorted vs. grouped) without having to build/maintain multiple observable collections of the same info (one for each sort variant)?
If not, is the best method to save a local copy of the data locally on the phone and work from there? I expect I'd take a hit on complexity but pick up savings on perf/responsiveness.
To display the various results in the same PivotItem, should I create user controls with the appropriate formatting and swap them in to the pivot based on the chosen sort, or can I do it via dynamic ItemSource & ItemTemplate changes?
Is Observable Collection/CollectionViewSource the way to go here?
It’s entirely possible (even likely) the answers are staring me in the face, but I’m new to this stuff and I’ve hit data overload. I could really use some guidance.
Thanks,
Rich
Is it possible to re-structure the way the data is displayed (flat/sorted vs. grouped) without having to build/maintain multiple observable collections of the same info (one for each sort variant)?
I think what you could try is using LINQ to query your given collection, and use that query as the source for your LLS. I'm not sure on how the performance would be, but you can give it a try. Alternatively, IIRC the various *ViewSource collections have ways of changing the view of your data, so you can check those out.
Related
I am trying to build a form with a phone input that includes country codes. Essentially, I am trying to make something a lot like this:
I already found and cleaned a list of flags, countries, and their codes, and built the method that creates a DropdownMenuItem for an arbitrary index. I then construct a list of them and pass it to the DropdownButton widget. It's all very simple, so I don't think the code is necessary. However, because I have so many countries, and therefore menu items, the menu lags significantly when opening. So, I was wondering if drop down menus are capable of loading large numbers of widgets in a smarter fashion than it seems they do.
Can a drop down menu could load the first 10 or so widgets around the selected index and display them, as that is all that will be in view initially, and then load the rest of the widgets asynchronously? I suspect that this will require a custom drop down menu, but I am not very well versed in the implementation of Flutter's drop down menu, so I am unsure of how to proceed with this.
Any help is appreciated.
I don't think that "loading" is the actual problem here, more likely it's the rendering/building of the widgets. You can improve the situation by using something like a ListView.builder that builds items on demand.
It seems like the default dropdown system is not based on a ListView.
You can create your own version of the dropdown (like a complete customized copy of the classes), which will require quite quite a lot of work and research.
Or alternatively, use something like a SimpleDialog with an embedded ListView to display the list. Like this one for Android.
This is sort of a best practice question, since I can think of a few ways that would work.
I want to implement an outline view. Let's suppose I want to implement the one in OmniFocus (my aim is very similar):
(I refer to the outline view in the main pane of that screenshot, not to the sidebar.)
So my data type is a task. Any task can have subtasks. Each task has one or zero parent tasks. Classic data model for displaying in an outline view, right?
BUT! I would like to offer the user the ability to group these tasks visually by a property of their choice. They could group them by milestone, or by assigned user, or by component… there'll be a bunch of these. And this grouping should appear in the outline view, at the top level of the hierarchy, just like the "Inbox", "Home" and "Work" items in this OmniFocus screenshot.
So it's fairly obvious that to display the grouping, I should use the built in NSOutlineView methods for drawing a group cell: the outlineView:isGroupItem: delegate method. The problem is, this setup is assuming that each item in the outline view is represented by an item in whatever data model I've connected it to: so both my tasks and my group headers have to be represented in the data model.
Therefore, just binding to the Core Data table that represents my tasks is a no-no. I could forego bindings all together and just go back to the old style data source methods, but then I lose a bunch of useful stuff. So is there a middle ground?
I could, for example, create another class TaskTemporaryGroup. I give that class an ivar NSSet that is subtasks, the same key path as could be used on a task to get its children. Then I can bind my set of TaskTemporaryGroup objects to a tree controller, and it'll arrange the whole tree regardless of the fact that the top level items are a different class to those lower down. I'd have to take care when implementing drag and drop, to make sure that the grouping rows can't be arbitrarily dragged about, but it might work.
The other point of contention is that I would like clicking on the table headers to sort the rows within each group, but not to sort the top level groups. I assume NSTreeController applies the sort descriptors to each level of the hierarchy? I could have my TaskTemporaryGroup class return the same thing (i.e. its desired sorting order, that I've calculated separately) for any of the key paths that I want to be able to sort the rest of the cells on, so that to the framework it would look like they stayed in the same order no matter what property they were sorted by. Is this a good way to go or is it a hack?
So, to summarize:
How do people suggest I implement this kind of hierarchy, where the top level is a special case and all subsequent levels are the same kind of object?
Is the way I described, with a class to represent the top level objects that happens to respond to the same key paths as the child objects, a good way to go?
Does anyone have any tips about how to make sorting work well in this scenario?
Or will trying to use bindings for this task cause me a world of hurt?
Thanks,
Amy
i have a pivot control with around 20 items that are data binded to an observable collection. One of these items has a long text inside, and I think it delays a bit to data bind. when i scroll too fast and pass this item, the headers start to behave strange, the highlighted header disappears from the screen and i see the other headers. the animation of headers stops.
How can i fix this? any ideas? You can reproduce this problem on a device.
thanx
I would have though that having 20 pivot items was more likely to be the cause of the problem, rather than a long pivot title. However, from a user experience point-of-view I would suggest that 20 pivot items is not going to provide a good user experience especially as all pivot items are loaded on when the pivot is started, so performance is likely to be poor, too.
I would suggest that you consider an alternative approach. Perhaps you could use the Panorama to provide a Hub-like experience with your data grouped into different Panorama items. You could then use a Pivot on secondary pages to show group contents where appropriate.
I can't say that I've experienced this, but then I haven't found a need to use a Pivot with 20 pages.
Could it be that if you're finding the need to flick that quikly through the pages that another UX would be more appropriate?
Perhaps a listbox to present a choice of items allowing ultra smooth and fast scrolling, from which the user can choose to select an item and drill down for details.
The databound project template provides some out of the box handling to demonstrate the concept, but don't be show to roll your own in a vanilla project template.
I've experienced the same issue with a pivot control with only 4 pivot items. The animation gets screwed up when the pivot item containing a long list is selected, so I'm guessing that because pivots don't load their data until the item is selected, that the pivot control is getting screwed up trying to load the long list while animating...so it gives up on the animation.
I haven't really figured out what to do about this yet. One solution is to not bind the data in the pivot item until that item is selected. This isn't really ideal, but it would likely solve the animation issue.
I'm trying to modify Brian Reindel's Accessible News Slider plugin (sorry, it won't let me link to it and also to my work location), to allow a visitor to fill in multiple copies of a form, sliding back and forth between them. I need for the visitor to be able to add and delete copies of the form from the list. I've modified one of his examples and created a little function to add an element to the list. However, no matter how many times I call the function, it only adds one element, and the plugin is not aware of it; I can see it in the DOM Inspector, but that's it. What am I missing?
this is Brian. Since you're already using jQuery and the plugin, you would gain a great deal by using the library to append elements to the DOM within your custom function. I wanted to give you some guidance, since this is probably more work than you were inititally expecting. Here are some hopefully helpful tips:
The plugin calculates some wrapper
element widths based upon the number
of list items. If you add/remove list
items, then you would need to modify
the calculations that were made or
else it won't scroll properly. You'll probably experience the same types of issues for the click events on the next/previous buttons.
If you have events registered on
elements that you add/remove from the
DOM, then you will need to
re-register those events, since when
the elements are gone, so are the
events that were "bound" to them. It
doesn't look like this is your
problem though at this point.
If you're adding form elements to the
DOM on the fly using the "Add" link,
then the user's cursor focus is no
longer on the form elements, and the
slider is no longer really
accessible. As much as I love
plugging my own plugin, it was meant
mostly to demonstrate usable, custom styled accessible
JavaScript, and I'm not sure it is
flexible enough to do what you want
without some rework.
If you have more specific questions about how to do certain things to get you started on the right track, let me know, and I would be happy to help. Depending on how much you plan to use jQuery on your projects (and I highly recommend that you use it), try out the book Learning jQuery.
I need a user interface that allows users to sort a table according to multiple columns (e.g. sort by color and then price within color, or alternatively price and then color within price). The only such interface I'm familiar with is the dialogue box found in Excel under data > sort, but this is rather clunky and does not yield itself to quick switching between views. I would much prefer an iTunes-style interface that allows quick sorting by clicking on column headers. However, such interfaces typically only allow sorting by one column (an exception is iTunes itself which has a very limited, apparently hard-coded ability to sort by "Album by Artist" and "Album by Year" by clicking on the Album header).
I can envision an interface where each column header has some numbers, such that clicking on 1 makes the column the primary sort key, clicking on 2 the secondary key, and so on. Alternatively, clicking (or right-clicking) on a column header could bring a drop-down menu with "primary sort", "secondary sort" etc. However, I've never seen such an interface implemented, and I don't have a good intuition of usability issues that may arise.
Are there applications that allow sorting by multiple columns using the column headers? Would you be able to point me to these? Are there any useful usability results regarding such interfaces -- which work better, which less so?
Also, while I am mostly interested in the specification of the interface, any hints to pass on to the people implementing it would be appreciated, e.g. publicly available libraries that provide parts of a solution (especially Java).
Edit: Two people have suggested using an Excel-style dialogue box. This is not going to work. For my application, users need to find the "best match" among existing table entries (which is often not a perfect match). The table is too big to keep in your head, so you need to keep scanning the relevant parts, and it's useful to repeatedly sort the table in order to get multiple views. Having to go through a dialogue box with multiple options for each change of view is just too slow; by the time you're done with the box, you've forgotten the results from the previous view.
I think Outlook supported sorting by multiple columns. After you clicked a columnheader, you would then shift-click additional column headers. I no longer use Outlook so I can't verify this. Hopefully it will be a starting point for you.
I've seen the shift-click interface that caparcode mentioned in a few applications, however I can't name any right now. Here's a nice web-based example though.
I would suggest using a Ctrl-Click (or Shift-click or whatever-click) approach to let the user select multiple columns. Clicking without Ctrl will just sort by the selected column, but holding the Ctrl-key adds the column to the sorter. Clicking again changes the direction. And give a feedback about the current sorter(s) similar as in these pictures. Most of the time the users will only use the single column sorter anyway, only advanced users will want to sort by multiple columns. But you should have the behavior documented somehow in the manual and in the "did you know" thingy.
But since users don't read, there is the risk that nobody will find the feature. But for this maybe you could have a feature like Windows when first started wanting you to click the start-button once to ensure you found the button. When you see the user not using the sorter at all, show him that clicking the column header will sort. Later, when you see he's not using the multi sort feature show him once that the feature exists.
Do it the way Excel does, or rather the way real people use Excel, which almost never involves that clunky dialogue box which you rightly wish to avoid. Basically, Excel preserves your current sort order as much as it can - so if you currently have it sorted in descending order by price, and now you sort by color (using the A-to-Z button on the toolbar*, NOT the dialogue box), the prices within a color will remain in descending order.
This approach does require a bit of reverse thinking from the user, because you sort first by the least important column, but it is very intuitive once you get it. (Yeah, I know, that sounds self-contradictory, but I don't know how else to describe it.)
To implement it, you'd have to store the user's sorting history somewhere; but as far as the interface is concerned, all you'd need is an up arrow and a down arrow in each column. Or, if you only want to allow A-to-Z sorting, just make the column headings themselves into links or buttons or whatever.
* Yes, I know the default Excel toolbars don't have A-Z and Z-A as separate buttons anymore, but one of the first things you do with a new installation of Excel is customize the toolbars to add these as well as Paste Values, right? Right?
How about the following? A single droplist labeled “Sort” in top margin of the table. The dropdown lists all fields to sort. Each field appears twice, once for ascending and once for descending sorts. Beside the dropdown is a button labeled “More” or perhaps simply “+”. The user chooses the field for the primary sort key from the dropdown. The sort is instantly applied (no “Sort” command button). If a secondary sort key is desired, the user clicks the More button and another dropdown list is inserted and opened for the user to select the second key. Additional lower order keys may be added with successive clicks of the More button. Dropdowns each include a “Clear” item to delete a key.
This makes a compact, simple, and uncluttered UI for the simplest and most common case of a single sort key (unlike Excel’s Sort Dialog or having numbers to the column headers), while also supporting the sorting an indefinite number of keys (again unlike Excel’s Sort Dialog). The user can see the sort order at a glance (unlike Excel and more easily than with numbers in the columns). It avoids the clunkinest of a dialog box.
Clickable column headers is a de facto standard that is also a good idea to include along with the above. It’s good practice to do what Outlook and Windows Explorer do and make lower order keys out of former sort orders. So, for example, if the table is sorted by date and the user sorts by category, then the table is sorted first by category and then by date. A user can thus do multi-ordered sorting by picking the lowest order sort field first and working up. However, this has poor discoverability and user may find that working “backwards” is counter-intuitive, so it should be supplemented with something like the dropdowns and More button. Relying on shift-clicking or ctrl-clicking likewise has discoverability issues.
Have you taken a look at Excel? That's a perfect example on how to sort on multiple columns.
Also, I use a detailed listview sometimes, and let the user hold the Ctrl key while selecting one or more columns to sort the info. (Clicking twice on a column does a descending sort.)
Seriously, what you want, Excel does. Why not use an interface people already know how to drive. I would suggest that. Or else you're going to either have to buy from a third party, or roll your own.
Development with Office is facilitated by VSTO (Visual Studio .NET tools for Office). It's up to you how much you want to automate Excel within an inch of its life :). It can be done.
In fact that is what I had to do. I had to read spreadsheets, extract data, convert to objects, then persist to Access (don't ask). Each sheet represents one record, and each directory represents a location, you get the idea. All done using the Office PIA Interop assemblies.
Just a thought.