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.
Related
I am experiencing some delay in rendering part as my page contains lots of components like (inputs and labels etc). I have placed them in panelgridlayout.
I also used audit method in jdev there also found lots of time is taken by rendering.
So, I want to know which component will be the best or suitable for this. I also implemented panelGroupLayout (with horizontal and vertical) and panelfromlayout but has same slow rendering problem.
Please help me on this.
You need to check how many layout managers you have inside of others. Too many layout managers inside one another can affect render speed.
PanelGroup Layout is for taking a "small" island of content and making its contents horiz, vertical - like buttons or fields or even groups of other islands of content - or add scroll bars if needed, like for a table.
PanelGrid layout is designed to layout a "larger" area and give the layout a grid and allow you to place items almost exactly where you want it.
Some layout managers are designed to layout "the whole page" - like PanelStretch, PanelSlider and PanelGrid, while others are for specialized tasks or group of content, like PanelGroup, FormLayout, Tab, Accordion.
So, depending on the layout, using PanelGrid may mean you do not need the others, and can simply free position all the item which may speed up rendering.
That said, there are many variables that affect rendering speed, and the complexity of the items on the ADF Faces page is not the first thing we look at - The ADF Model layer, how that is implemented and how the data source is tuned (or not) can be a bigger source of impact on rendering.
You did not specify version, that would help as well.
Before PanelGrid we tended to use PanelStretch or PanelSlider as the main window layouts that laid out the main sections of the page - and put the other ones - panel group and formlayout inside it. With the advent of PanelGrid, some of this practice is no longer needed.
This, this and this may help as well.
I'm working on a view that's implementing a multi-column text layout using CoreText (using CTFramesetter).
CoreText usually fills each frame completely, so when I call CTFramesetterCreateFrame with three rects that make up my columns, I get a layout that's similar to the following image:
So the left column is filled completely, the middle column partially and the right column is empty. But instead, I'd like the text to distribute over the three columns so that they take up the least vertical space possible, like in this image:
How to achieve this with CoreText?
I don't mind going low-level here, even drawing each CTRun by hand is an option if necessary.
One idea I came up with would be to create a large frame with the width of a column and then figure out which CTLine to draw in which column. But this has a few limitations:
It would only work if all columns had the same width.
It does not work with clipping paths.
Unfortunately, I'll need to use clipping paths (as in kCTFrameClippingPathsAttributeName) so this idea is out. I could live the fixed column width limitation, though.
Another idea would be to reduce the height until the last frame overflows but that's a pretty brute-force way that surely wastes resources.
(BTW, due to compability requirements the use of TextKit classes like NSTextStorage isn't possible; the resulting view is intended to be used on Mac and iOS, but it needs to work on iOS < 7)
Since there doesn't seem to be a non-expensive way to solve this, here's how I've done it:
I did go with the "reduce the height until the last frame overflows" approach. To reduce the height, I simply have another clipping path (kCTFrameClippingPathsAttributeName) which is a rectangle that fills the bottom of the view to the required height.
The probably most expensive but simple way would have been to increase the rectangle height until finally the text doesn't fit inside the last frame any more.
Instead I've implemented a binary search for that. For my demo app, I usually find the correct height after 8-10 recursions which still is expensive but at least it's pixel-perfect and doesn't rely on any other information other than "did the last frame overflow".
I have a WPF application with many tabs..
in one tab.. i make a verycomplex vector drawing consisting of thousands of drawing visuals.. (this represents a machine and all elements need to be interactable..)
It takes 3/4 seconds for drawing this for the first time..After the first draw it should be done..
The problem is if i switch to another tab and comeback, it takes atlease 2,3 seconds to show the tabpage with drawing again.. Since there is no redraw, why should it take so much time..?
If the component is not going to change, you could call Freeze() on it to mark it as done. Without trying it out I don't know if that would help, but you could give it a shot.
Not all objects are Freezable. Check out the MSDN documentation for more info:
http://msdn.microsoft.com/en-us/library/ms750509.aspx
Another thing you could try would be rendering the vector art to a bitmap, and displaying that. Maybe it makes you feel icky to lose the vector precision, but if you know it's not going to change and it will look the same, what's the harm? (If you support printing or something that will require a hi-res version, you could always switch back for that operation.) For info on how to convert a UIElement to a bitmap, check out:
http://msdn.microsoft.com/en-us/library/system.windows.media.imaging.rendertargetbitmap.aspx
Another possible solution: You don't really explain what kind of interaction you are doing with the elements, but if all you want to do is zoom and pan, a RenderTransform may be good enough (which is more efficient than a LayoutTransform and/or moving all the elements individually). I haven't played around with combining Freeze() and a RenderTransform, but you may be able to get the desired zooming while reducing the amount of layout WPF has to do.
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.
I'm currently designing a web application which may be viewed by people in all kinds of resolutions 1024..1920 or even larger resolutions.
I've opted for a fixed-width design (as many other popular websites are, e.g. StackOverflow, CNN, Mint, WSJ, BofA etc.) with the lowest common denominator fitting in, meaning 1024.
Now a problem is that on some pages in my application I have to display grid-based data. I think I'm really going to anger people with large screens if I restrict them to 1024 width compacted grid data while keeping most of their screen empty.
I thought about making different style sheets and so forth for different resolutions but that will increase much of the maintenance work, graphics work etc. above of what I can manage.
Do you have any ideas how to solve this is a graceful manner (I'm just thinking maybe I have a 'creative block' here right now :) ) without having to go fully to a fluid design, which brings a bunch of problems in itself?
1) Multiple hard-coded views of the same data: Brief, Detailed, Verbose
Quick links, or tabs to allow the user to view different numbers of columns. If they need more details, they can choose the view that has more detail. They want to know, and will not be annoyed by having to scroll vertically.
2) User-Controlled columns
Allow the users to control what they see, and what columns are included in their view. You can even store and remember the views they select. The default should be the view you think most people would want to see.
3) Combination of the previous two
Allow them to choose a default, and then customize columns on a one-by-one basis. This is how MS Project works with its views, and it's very nice to work with.
Size the columns so that a reasonable number fit onto 1024, and use a horizontal scrollbar for the rest. Since your app doesn't use the extra real estate on other pages, you might decide to just stop there.
Otherwise, let the elements resize to fill the full width of the page if there is extra room (either use a table, or use min-width on the divs and 100% on the parent.