Responsive Grid Implementation in Xamarin.Forms - layout

What would be the right way to create a responsive fluid grid in Xamarin.Forms? In the CSS world, this can be accomplished by using inline-block divs or flexboxes. What is the equivalent in Xamarin.Forms? (I don't consider checking screen sizes programatically and changing the column number as a responsive solution but rather an adaptive one as in media queries.)

Unfortunately, there is no equivalent in Xamarin.Forms.
You have to query the device type and/or the screen-resolution maybe also the device orientation an then implement different layouts for phones and tablets and/or device orientation, if you want to optimize your app.

Related

Scaling a kha-app for retina on iPad

I have a kha app that runs perfecly on an iPad2 (1024/768px).
When I run the same project on a later iPad Mini with 2048/1516. My coordinates are all half the size, which kinda makes sense.
So when I double all the sizes of my objects and GFX it will work on the iPad mini, but will be too big for iPad2.
I looked into a backbuffer and a renderTarget as explained here:
https://www.youtube.com/watch?v=OV1PTo5XSCA
There is also the windowSize option in khafile, which seems to do nothing.
Surface x and y coodinates always seem to come in in real screen coodrdinates of the device.
What is the best way to write a resolution independent app?
Perfect would be a way that is either retina or non-retina, depending on the device, where the code stays the same.
According to https://github.com/Kode/Kha/wiki/Screen-Size-and-Scaling there's automated scaling for some targets. If you need other targets you have to manually scale everything to fit the screen.
The page mentions using this class for the task: https://github.com/Kode/Kha/blob/master/Sources/kha/Scaler.hx
Also you could take a look at how Wyngine does it:
https://github.com/laxa88/wyngine/search?utf8=%E2%9C%93&q=scale & https://github.com/laxa88/wyngine/blob/master/Wyngine.hx
You replied (to my comment) that scaling wasn't enough. So far it was enough for all of my games with the right display settings, but if you really need retina sized graphics you always have the option of using multiple graphics sets. Eg:
a set for retina resultion (eg iPad 3)
a default resolution (eg iPad 2) set at half retina size
a low res set for cheap android devices?
At startup of your app you check the screen size. You use that to choose the internal game size and the graphics set that fits the actual screen resolution the best. The internal game size as well as all X/Y positions for the selected graphics set can be calculated by applying the graphics sets scale factor to the raw base values.
Finally you use Scale.scale() to scale your game from the internal game size to fit devices like the iPad pro 12" and the wide variety of Android devices.
That approach is common with a lot of game engines, google should find you links like https://v-play.net/doc/vplay-different-screen-sizes/ that also explain screen ratios and how those can be handled.

How to apply layout constraints to in windows phone 8.1?

How can I apply layout constraints to layout so that it auto adjusts it self for every device like we apply in iOS?
The app I developed leaves blank spaces when I run it on higher size devices.
There are several techniques you can use. Which is best depends on your app's specific design:
Use a fluid control such as GridView or ListView which will expand to fill the available space.
Use a relative size layout control such as a Grid to lay things out by percentages.
Use Visual States to choose different controls or layouts for different size or aspect ratio screens
Use a ViewBox to stretch a layout to fit
Windows 10 adds a few new controls that can help:
RelativePanel to specify control locations relative to other controls (on top off, to the left of, etc.)
Adaptive triggers to automatically switch Visual States based on window size changes
See Defining layouts and views on MSDN for details and quickstarts.
There were several sessions at Build 2015 which touched on this subject, although more aimed at Windows 10 capabilities than at Windows Phone 8.1

Supporting multiple screen sizes/resolutions/aspect ratios using MonoGame

What is the recommended way of supporting multiple screen resolutions/aspect ratios across devices like iPad, iPhone, Windows Phones, and Android phones/tablets? Should I simply #if/#else specific code for each device? I don't know how well this would work. Especially for Android phones/tablets which come in all different sizes. Any pointers would be greatly appreciated.
Here is what we are doing for our game:
All menu or ui elements are positioned based on the screen size (we implement Horizontal and Vertical alignment)
All levels scroll, so on some devices you just see less of level of the level at a time
Our levels also zoom in on smaller devices where needed
Design fixed levels (ones that don't scroll) so that a bit of unused space is on the edges of the screen. This way it can get cropped on some devices no problem.
Make 3 sizes of images: small (3GS), medium (iPhone 4, Android, WP7, iPad), large iPad3
Position sprites/ui elements based on an images size
Take advantage of the #2x naming scheme for images
We made an iPhone-only and iPad-only version of the app, this helps in only having to put 2 sets of images in each app
Using the screen size for positioning is your best bet. Being able to center or dock to the bottom or right of the screen is also very helpful in general.
I could tell more, but I can't reveal specifics about our game yet.

grid vs layout based widget toolkits

grid only widget toolkits (like Cocoa Touch) vs layout based toolkits (like Swing or gtk+)
iOS Cocoa Touch, being only grid based, had to port all applications when the screen resolution was upgraded (iPhone4) or enlarged (iPad)
If you could choose what would you use?
If I were designing for a platform where screen sizes could vary, I'd use a layout manager based toolkit. However if I could garuntee the same screen resolution and screen size, I'd choose to use a grid based toolkit, as it would mean I wouldn't need to think about all the logic that goes into making a layout manager based UI.

How to create Liquid Layout in android

I am into a project in university, I would like to know that how can I use liquid layout in android so that different screen sizes must see the application according to its resolution?
In simple words, I would like to create an application whose layout is perfect in all the type of screens :)
I know how to create it in simple html/css in websites for PCs, but how to do it in android?
Can anyone please give suggestions/help/tutorial link?
Thanks,
Usman
Android provides "liquid" layouts out of the box - the layout dimensions and contained elements adapt to screen resolution automatically. It is gracefully handled by the Android framework. There are various kind of layouts available (LinearLayout, FrameLayout etc.) so you need to check carefully which type of layout is the best for you.
You should avoid AbsoluteLayout. While it is true it lets you specify exact locations (x/y coordinates) of its children it is less flexible and harder to maintain than other types of layouts without absolute positioning. It is now deprecated anyway.
Useful links:
To read more about different layouts see: http://developer.android.com/guide/topics/ui/layout-objects.html
Good tutorials are also available here: http://developer.android.com/resources/tutorials/views/index.html in the "Layouts" section.
AbsoluteLayout doc: http://developer.android.com/reference/android/widget/AbsoluteLayout.html
Update:
Layout itself will adapt to different kind of resolutions automatically but you need to keep it mind that elements contained in a layout can look differently. The same image will be smaller on high-res screen than on low-res screen. Luckily, Android provides a way to deal with this problem in a simple manner. You can supply different images depending on the resolution that a device has (this is a bit of a simplification because there are other factors eg. pixel density in addition to resolution that matters). By the same token, it is also possible to supply a different layout but it is not that common.
Links:
Full story on multiple screen support: http://developer.android.com/guide/practices/screens_support.html
Sample code: http://developer.android.com/resources/samples/MultiResolution/index.html

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