Bug 32512 - Inconsistant usage of DynamicType on iOS
Summary: Inconsistant usage of DynamicType on iOS
Alias: None
Product: Forms
Classification: Xamarin
Component: iOS ()
Version: 1.4.4
Hardware: PC Mac OS
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2015-07-27 22:01 UTC by Cody Beyer (MSFT)
Modified: 2015-08-11 19:59 UTC (History)
3 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Cody Beyer (MSFT) 2015-07-27 22:01:49 UTC
### Description

The following app is the ListView sample located here: http://developer.xamarin.com/samples/xamarin-forms/WorkingWithListview/

When using DynamicText in iOS, some text elements respect the change, while others do not. 

### Sample


### Steps to Reproduce

1. Download sample
2. on iPhone or iPhone Simulator, select General > Accessibility > Larger Text 
3. Enable larger text and slide the size slider to max
4. Run sample app
5. Swap through the different tabs

### Expected Results

Either all text elements should respect DynamicText, or none should

### Actual Results

Elements are inconsistent in their DynamicText support

### Version

=== Xamarin Studio ===

Version 5.9.5 (build 6)
Installation UUID: 14e9db9d-4a59-440f-8c5b-890f54ec8c58
	Mono 4.0.3 ((detached/e4f44c1)
	GTK+ 2.24.23 (Raleigh theme)

	Package version: 400030019

=== Apple Developer Tools ===

Xcode 6.4 (7720)
Build 6E35b

=== Xamarin.iOS ===

Version: (Business Edition)
Hash: 7cf6633
Branch: master
Build date: 2015-07-21 16:27:35-0400

=== Xamarin.Android ===

Version: (Business Edition)
Android SDK: /Users/codybeyer/Library/Developer/Xamarin/android-sdk-macosx
	Supported Android versions:
		2.3   (API level 10)
		4.0.3 (API level 15)
		4.2   (API level 17)
		4.3   (API level 18)
		4.4   (API level 19)
		5.0   (API level 21)
Java SDK: /usr
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)

=== Xamarin Android Player ===

Version: Unknown version
Location: /Applications/Xamarin Android Player.app

=== Xamarin.Mac ===

Version: (Business Edition)

=== Build Information ===

Release ID: 509050006
Git revision: c50b1022a6b36f9b2a55beb7814b87811d1dba52
Build date: 2015-07-16 18:13:13-04
Xamarin addins: 6571e3228ff9e432a98b468630ec5ffd35f2f6b3

=== Operating System ===

Mac OS X 10.10.4
Darwin Codys-Macintosh.local 14.4.0 Darwin Kernel Version 14.4.0
    Thu May 28 11:35:04 PDT 2015
    root:xnu-2782.30.5~1/RELEASE_X86_64 x86_64
Comment 2 CraigD 2015-08-11 19:59:37 UTC
The built-in cell types (eg. TextCell) will adhere to iOS 8 DynamicText - this is demonstrated in the first tab of the example.

Custom cell types (or other text-display controls) should use the Style property with one of the Device.Style options set using DyanmicResource as explained here:
if they are intended to support iOS 8 DyamicText.

This has *not* been done throughout the sample mentioned - rather font sizes have been hardcoded with FontSize="Small" (for example) which explicitly overrides iOS 8 DynamicText. This is why the sample behaves with fixed font sizes on some screens.

To support iOS 8 DynamicText in the sample (or other Xamarin.Forms apps), first _remove_ any FontSize settings on the elements, and then _add_ a Style using DynamicResource syntax, referring to one of the built-in Device.Styles.

When dealing with a ListView control, it most likely requires HasUnevenRows=true to be set as well, so that the row height can grow automatically if the font size is enlarged.