Bug 33579 - Xamarin.Forms inconsistent fontsize behavior when Accessibilty settings are applied.
Summary: Xamarin.Forms inconsistent fontsize behavior when Accessibilty settings are a...
Alias: None
Product: Forms
Classification: Xamarin
Component: Android ()
Version: 2.0.0
Hardware: Macintosh Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2015-09-02 17:33 UTC by Shannon Haas
Modified: 2018-03-06 20:35 UTC (History)
7 users (show)

Tags: ac, accessibility, fontsize, android
Is this bug a regression?: ---
Last known good build:

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Description Shannon Haas 2015-09-02 17:33:54 UTC
In a Xamarin.Forms project, setting the Fontsize to a double or to NamedSize gets overridden by the accessibility setting in the Android. While in a standalone Xamarin.Android project, the behavior is what one would expect, the double does not get overridden, but the NamedSize does. 
Within the Xamarin.Forms iOS, neither the double or NamedSize is overridden, which is the complete opposite in Xamairn.Forms - Android. 
I believe we have two bugs. One, the Xamarin.Forms Android fontsize set to a double, should not be overridden. Two, the Xamarin.Forms iOS fontsize set to a NamedSize should be overridden by the accessibility setting.
Comment 2 adrianknight89 2016-10-20 19:11:42 UTC
I have a somewhat different opinion. Both double and NamedSize should function similarly. There should be a property to toggle accessibility on and off.

true => font size should change
false => font size should not change

In either case, the value assigned to FontSize should NOT change. 

Both Android and iOS should behave similarly.

I think NamedSize is another way to use hard-coded system values. I don't think it changes with respect to accessibility.
Comment 3 Adam Kemp 2016-10-20 23:12:19 UTC
IMO the entire point of a developer using named sizes is to get the system-supplied (dynamic) font size. I very strongly believe that named sizes should always honor the accessibility settings.

I also very strongly believe that no fixed font size should ever change automatically. A global setting would be too imprecise (what if you use a third-party control that handles accessibility differently than the rest of your code?), and a per-control setting would be too tedious.

A better approach if you want adjustable sizes without using named sizes would be to have a new unit so you could specify a relative font size (i.e., a base number that is adjusted according to the accessibility settings).
Comment 4 tim.rossiter99 2018-03-06 20:32:56 UTC
Any updates on this? It's still an issue 2 1/2 years after being reported....
Comment 5 tim.rossiter99 2018-03-06 20:35:00 UTC
It's not just font size too. Android has a setting below font size called "display size" that will resize everything on the app. would like to be able to disable this...