[Android] make NavigationBar support Transluscent status

[bentmar]

If the app has flag Transluscentstatus then we should support that when creating the navbar. Now that we dont draw a statusbarunderlay anymore this opens up to many interesting UI possibilities

Description of Change

Adds a padding and adjusts the height of the Navigationbar if Transluscentstatus flag is set to true.

Bugs Fixed

• none

API Changes

none

Changed:
The way we calculate the height for the navigationbar.
Adds padding to the navigationbar
Changes are only made if TransluscentStatus = true

Behavioral Changes

Now this is possible
https://forums.xamarin.com/discussion/comment/293844/#Comment_293844
by adding this is MainActivity

 Window.AddFlags(WindowManagerFlags.TranslucentStatus);

PR Checklist

• Has tests (if omitted, state reason in description)
• [X ] Rebased on top of master at time of PR
• [ X] Changes adhere to coding standard
• [ X] Consolidate commits as makes sense

[adrianknight89]

I think that if you are adding a padding, you need to account for how some pages (like MDP) are positioned during layout. Also, what happens if the user removes this Window flag through a DependencyService call? Will it get rid of the padding?

[bentmar]

Thx for your input adrian!

you need to account for how some pages (like MDP) are positioned during layout.

https://forums.xamarin.com/discussion/comment/293695/#Comment_293695
this uses MDP, MDP has nothing to do with how a navigationpages navbar is layed out "?"

If you remove the Transluscent, it wouldn be transluscent anymore (thats all I can see) and the next time a navbar is layed out, it doesnt add padding.

This is what ive seen from testing on 5 different devices.

Note that if you use transluscent today your navbar and its content gets hidden under the statusbar = you cant even use it (well you can but...)

[adrianknight89]

If you remove the Transluscent, it wouldn be transluscent anymore (thats all I can see) and the next time a navbar is layed out, it doesnt add padding.

I guess this is what I was getting at. To remove the padding, do you need to wait until the navbar is laid out next time or can you force it to layout once the translucent status is removed? I haven't tested these changes, so I'm only speculating. Maybe it's better to detect translucent changes and force navbar layout?

[bentmar]

I see the transluscent status as a "either you have it, or you dont" I have never seen apps that toggles in and out of transluscent during runtime. And if a user were to toggle it on and off, then wouldnt it be possible to handle that forceLayout in a customrenderer?

Update: To remove the padding when removing transluscent would make it look wrong. The height doesnt change when your remove it. it changes the next layout, and in that same layout it doesnt add the padding = looks like it should

[jimmgarrido]

This will need to be fixed in ContentPage and TabbedPage as well. MasterDetailPage should be fine once the other ones are fixed, but it'll have to be tested with the different combination of Detail/Master pages just to be sure.

I opened up a bug report with a repro project to track this.

[bentmar]

one thing I haven't tested with this is TabbedPage with no navigation bar. If the tabbed page has no navbar then the tabbar needs to get the same adjustments as I give the navbar

UPDATE (Tested, and solved) : This is easily handled in a custom TabbedPageRenderer

  var tablayout = FindViewById<TabLayout>(Resource.Id.sliding_tabs);
  tablayout.SetPadding(0, GetStatusBarHeight(), 0, 0); //GetStatusBarHeight() is found in the changes

Id prefer this solution to anyone who has this specific layout instead of adding numerous checks in XF code to slow down android even more

[bentmar]

@jimmgarrido

About your bug. TransluscentStatus behaviour is expected to layout content behind status bar if I'm not wrong here.

this is exactly what I'm trying to achieve :)
But we have to adjust the navbars layout to still make it look good.

Contentpages with no navbars are supposed to go under the statusbar, check the link https://us.v-cdn.net/5019960/uploads/editor/sc/o4mdus3r0wsv.gif (the gif is huge, so it might take a few seconds to load) too see what I mean

[kentcb]

@davidortinau is this going to be merged anytime soon? It's blocking us from upgrading XF. See here.

[rmarinho]

@bentmar can you rebase to run some tests please ?

Also can you please post some screenshots so we can better understand the changes? thanks

[bentmar]

@rmarinho yes, if not today il do it this weekend!

[bentmar]

#1287 made a new PR that also covers TransluscentNavigation flag, and has some images. (im not a github pro hence a new pr)

[rmarinho]

Closing since #1287 replaces this