[FLEX-34653] Setting applicationDPI (autoscaling) on desktop works incorrectly.

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Apache Flex 4.13.0
• Component/s: Layout - General, Skinning
• Labels: DPI Scaling automatic
• Environment: Windows ( Possible Mac - Not checked ).
• Assignee: Unassigned
• Reporter: Jim Moore
• Created: 02/Dec/14 16:57
• Updated: 20/May/16 08:37

Description

The issue occurs when using automatic scaling and setting the application DPI and overriding the runtimeDPIProvider to set the runtimeDPI where it is incorrectly returned from the OS ( On desktop devices for instance ).

If the two values match ie 1:1 scaling, there is no issue. But if they differ then the application content is scalled correctly , but the stage size is also scaled, incorrect. This leads to the application being clipped when scaling up and excess space when scaling down.. See code excepts to recreate...

ScaleIssue.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
					   xmlns:s="library://ns.adobe.com/flex/spark" 
					   xmlns:mx="library://ns.adobe.com/flex/mx"
					   applicationDPI="160"
					   runtimeDPIProvider="myRuntimeDPIProvider">
	
		<s:Label id="LeftMarker" left="0" verticalCenter="0" text="&lt;--- LEFT" fontSize="24"/>

		<s:Label id="MiddleMarker" horizontalCenter="0" verticalCenter="0" text="&gt; &gt; &gt; MIDDLE &lt; &lt; &lt;" fontSize="24"/>

		<s:Label id="RightMarker" right="0" verticalCenter="0" text="RIGHT ---&gt;" fontSize="24"/>
							 
</s:WindowedApplication>

myRuntimeDPIProvider.as

package 
{
	
	import mx.core.DPIClassification;
	import mx.core.RuntimeDPIProvider;
	
	public class myRuntimeDPIProvider extends RuntimeDPIProvider
	{
				
		/**
		 * Overrride getter function so we can set the dpi manually when running on desktop device
		 * This would normally be a bit more sophisticated... 
		 * 
		 * @return 
		 * 
		 */		
		override public function get runtimeDPI():Number
		{			
			return DPIClassification.DPI_240;
		}
		
	}
}

You should see the text labels pointing to the left and right screen edges.. but instead the right hand label is off screen.

Hope that makes sense.

J