I have an app that creates a variable number of ScatterviewItems based on which tagged object is placed on the surface table.
The ScatterViewItems are added programatically to the ScatterView based on info looked up in a DB
The Scatterview does a good job of displaying this info
However, I would like them to be
evenly distributed across the table and
not have any items overlapping
Any ideas how to do that?
Sounds like you need collision detection.
There's two parts to this problem: detection and resolution. Detection is seeing if any item's bounding intersects with any other item's bounding. If the items are retangular or circular this is pretty straightforeward. It can get complex if you're dealing with other geometries.
Resoltion is what to do once you've detected a collision. Google will help you find the myriad algorithms for this. Here's a couple links to stackoverflow discussions: WPF: Collision Detection with Rotated Squares, Applying Coefficient of Restitution in a collision resolution method, Best way to detect collision between sprites?.
You can implement collision to work so that items bound off of each other as they scatter. Depending on the number of items, this might cause so much collision that the items don't scatter well. If this happens, just run the collision detection one items have stopped moving.
UniformGrid ?
You can also create your own panel by iheriting from Panel.
You will find some uber-valuable info in the Dr. WPF ItemsControl How-To series : http://drwpf.com/blog/itemscontrol-a-to-z/
That's a must-read, period.
ScatterViewItem has properties Center and Orientation which you can use to programmatically position items. If you know the size of each item you should be able to use these properties to position them in whichever way is ideal for your situation. By hooking into the Loaded event of each and checking ActualWidth/ActualHeight, you can get the dimensions. If you can use a fixed initial size for all of your SVIs, that's even easier.
You could lay them out by calculating a simple grid (plus some randomness to make it look more natural), or you may be looking for what's called a "force directed layout", which gives each object a repellent force relative to its size. After a while the elements will naturally be evenly spaced from one another, though they may still overlap if they run out of room. I haven't seen a WPF example of this, but see flare.prefused.org/demo (layout > force) for what I mean in Flash.
Related
I'm working on a form that shows many our company's products in a FlowLayout, but on some categories that hold many products, performance in scrolling is noticeably affected. I switched to a List so I could leverage the performance benefits of using a renderer, but now I'm not happy with the layout since there's a lot of wasted space, especially if the device is in landscape mode.
My next thought was to use a Table, which I believe also uses renderers to optimize the display of its data; but to mimic a FlowLayout, I'd need to get the preferred width of some placeholder component, then divide the container's width by that to get the number of columns, and then fill the model with that number of columns in mind. I'd also need to change all that if the device changes orientation.
Before I go down that rabbit hole, I'm wondering if I'm making things unnecessarily complicated for myself and if there's already something that I can use to achieve that goal. So to summarize, what would be the most efficient way to display data (that would be shown as buttons) sequentially from left to right, and top to bottom?
I wouldn't use FlowLayout for anything serious although I doubt its the reason for your performance issues, those probably relate to something else. There is a performance how do I video which is a bit old but mostly still relevant: http://www.codenameone.com/how-do-i---improve-application-performance-or-track-down-performance-issues.html
In design terms flow layout is hugely problematic since the elements are not aligned properly thus producing a UI that doesn't look good when spanning multiple rows. I suggest using a grid layout which has a mode called auto fit. By using setAutoFit(true) on a grid of even 1x1 all the elements will take up all available space uniformly based on screen size and adapt with orientation changes.
I need to display many markers on a WPF image. The markers can be lines, circles, squares, etc. and there can be several hundreds of them.
Both the image source and the markers data are updated every few seconds. The markers are associated with specific pixels on the image and their size should be absolute in relation to the screen (i.e. when I move the image the markers should move along with it, but if i zoom in, they should take the same space of the screen as before).
Currently, I've implemented this using the AdornerLayer. This solution has several problems but the most significant one is that the UI doesn't fare well under the load even for 120 such markers.
I wanted to ask what would be the best way to go about implementing this? I thought of two solutions:
Inherit from Canvas and make sure it is invalidated not for every
added marker but for a range of markers at once
Create a control that holds an image and change its OnDraw to draw all the markers
I would appreciate some pointers from someone with experience with a similar problem.
Your use case looks quite specialized, so a specialized solution seems in order. I'd try a variant of your second option — extend Image, overriding its OnRender method.
I'm looking at some new options for displaying a percentage value as a fill in a custom shape. Consider the effect to be similar to a "progress thermometer" in a traditional dashboard UI sense.
Considerations
Goal - a graphic element showing a percentage value for a custom report.
Format - Either a full graphic (or infographic) itself, or part of a PDF via Photoshop/InDesign or even iBooks (as an excuse to use it).
Usage - I'd like the process to be programmatic, for re-use. It needs to be accurate, and I'd like the solution to be somewhat object oriented to apply to other datasets and graphical containers. This rules out hand-drawn charting.
Source data - currently a pivot table in Excel, but I can work with any other host as required.
Shape - is a custom vector shape that will originate from Illustrator/Inkscape. final format as best fits resolution and rendering of the report. I would also be interested in any other generative shape ideas (such as java/javascript).
Fill - I'd like to be able to represent the fill as both an actual percentage of total area (true up), and as a percentage of the vertical scale. I'd imagine this flexibility would also help reuse of the method as a fill value against selected object variables (height, area, whatever).
I know I'm being slightly vague in the programming languages or hosts side of things, but this gives me an opportunity to break out of the usual analytic toolchain and scope out some innovative or new solutions. I'm specifically interested in open source solutions, but I'm very keen to review other current methods you might suggest.
This might be a little open ended for you, but d3.js is very powerful. There might be some useful templates on the site, or you can build your own from the library.
If you limit yourself to shapes where the percentage can be easily converted into a new shape by varying one of the dimensions, then the display part can be covered by creating a second shape based on the first one, and filling in 100% of the second shape.
This obviously works best with simple shapes like squares, rectangles, circles, etc, where it is simple to convert "50% of the area" or "75% of the height" into manipulation of vector nodes.
However, things gets significantly more difficult if you want to support genuinely arbitrary custom shapes. One way to handle that would be to break up a complex "progress bar" into "progress pieces" (e.g. a thermometer bulb that represents 10% of total progress, then a simple bar for the remaining 90%).
As has been mentioned, D3 seems like it would meet your needs - here are some simple examples of what I think you are asking:
Changing the fill color of a distinct shape: http://jsfiddle.net/jsl6906/YCMb8/
Changing the 'fill amount' of a simple shape: http://jsfiddle.net/jsl6906/YCMb8/1/
How can I wrap shapes around the world, so that a shape is shown more than once at low zoom?
Example:
I draw a polygon over USA.
I zoom out so that I can see two USA's.
I only see one polygon: ( I want to see two!
The map data effectively has 2 USAs. That implies you should actually want 2 polygons, one of which will be hidden most of the time.
Might as well cater for the worst case and treat a single USA as the exception rather than the rule.
You can't.
As others have already pointed out, the fact that, at far zoom levels certain features get repeated on either side of the map is an unwanted but inevitable side-effect of a projected surface that enables continuous scrolling. This has only been an issue in recent versions of the Bing Maps control - the earlier v6.x control prevented the map from panning across the 180th meridian.
I cannot think of any possible reason why you'd ever want to show two USAs, let alone target data to be positioned on each one. So the solution is to modify either the zoom level at which the map is displayed, or the size of the application window in which it is being displayed so that this situation doesn't occur.
I'm working on a WP7 app that uses bing maps to display ~600 pushpins. When i add them to the map using map.Children.Add(pushpin) the UI freezes for ~200 ms. I've seen that in silverlight you can use Microsoft.Maps.EntityCollection to add pins to a map but unfortunately I couldn't find how to use the assembly on WP7. Does anyone know a solution to this?
Maybe you're looking at the problem the wrong way round. WP7 is a compact (though powerful) that excels at showing the user what they want to know quickly (when the apps are written properly).
The user can't possibly see 600 pushpins in one go on a device that small, so why not just show them pushpins that are in the viewable area (or close to it) and add pushpins as the user pans around the map?
Alternatively you could "trickle" feed the pushpins by adding them one (or more) at a time using the DispatcherTimer so that the user sees pushpins being gradually added without drastically affecting performance.
Another possibility (which is what I usually do) is to add a MapItemsControl with the DataTemplate set to a Pushpin and to bind the collection to your collection of pushpin locations. If the binding is to an ObservableCollection you can "trickle" feed it as mentioned above if perf is an issue.
In a viewpoint similar to Derek's, I find it highly unlikely that you seriously want to put 600 pins on the screen at the same time. I'm guessing that they span a large geographic area and the user is unlikely to see more than a handful at a time.
If this is the case, you can trivially apply a cliprect to cull your points, then add the resultant modest list to a layer, and Presto! High performance.
In addition, there is the issue of what to do when the user zooms a long way out, bringing so many pins into view that they merge into one big useless but brightly coloured blob. This is a more complex problem traditionally solved with a quadtree, and I have a suspicion that you just said "a what?" but luckily Google is your friend.
Oh, and to address your stated problem - don't add the pins directly to a map. Add them to a MapLayer and then add that.