[TIMOB-18730] iOS8: DocumentViewer: Unbalanced calls to begin/end appearance transitions for QLRemotePreviewContentController

GitHub Issue	n/a
Type	Bug
Priority	High
Status	Closed
Resolution	Fixed
Resolution Date	2015-05-14T17:38:31.000+0000
Affected Version/s	n/a
Fix Version/s	Release 4.0.0, Release 4.1.0
Components	iOS
Labels	triage
Reporter	Eduardo Gomez
Assignee	Vishal Duggal
Created	2015-03-23T22:18:06.000+0000
Updated	2017-03-16T21:49:25.000+0000

Description

Issue Description

We get the following message when loading a pdf in the DocumentViewer component: "Unbalanced calls to begin/end appearance transitions for ". Getting this message is sometimes associated with the app freezing but generally app goes okay anyway.

Sample Code

var doc = "http://www.legis.state.ak.us/basis/iphonepages/IPV3get_documents.asp?session=29&docid=3324&minname=Agenda%5FLBA%5F17Mar15%5FLocation+Change%2Epdf";
var win = Ti.UI.createWindow();
win.open();
var file = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, 'document.pdf'),
    client = Ti.Network.createHTTPClient({
	onload : function() {
		// Open a doc viewer.
		var docViewer = Ti.UI.iOS.createDocumentViewer({
			url : file.nativePath
		});
		docViewer.show({
			animated : true
		});
	},
	onerror : function(e) {
		alert('Error: ' + e);
	}
});
client.open('GET', doc);
client.file = file;
client.send();

Console Output

-- Start simulator log -------------------------------------------------------
[INFO]  Application started
[DEBUG] Reading stylesheet from: /Users/egomez/Library/Developer/CoreSimulator/Devices/D2DD3F81-EDBF-4C3B-A975-A41501FF3702/data/Containers/Bundle/Application/AE4C1686-4155-44A9-A3F5-AF463281A0F4/TableViewRepro.app/stylesheet.plist
[DEBUG] 2015-03-23 16:01:38.614 TableViewRepro[10909:330239] You've implemented -[<UIApplicationDelegate> application:performFetchWithCompletionHandler:], but you still need to add "fetch" to the list of your supported UIBackgroundModes in your Info.plist.
[DEBUG] 2015-03-23 16:01:38.615 TableViewRepro[10909:330239] You've implemented -[<UIApplicationDelegate> application:didReceiveRemoteNotification:fetchCompletionHandler:], but you still need to add "remote-notification" to the list of your supported UIBackgroundModes in your Info.plist.
[INFO]  TableViewRepro/1.0 (4.0.0.944c821)
[DEBUG] Loading: /Users/egomez/Library/Developer/CoreSimulator/Devices/D2DD3F81-EDBF-4C3B-A975-A41501FF3702/data/Containers/Bundle/Application/AE4C1686-4155-44A9-A3F5-AF463281A0F4/TableViewRepro.app/app.js, Resource: app_js
[DEBUG] Application booted in 415.318012 ms
[DEBUG] 2015-03-23 16:01:40.414 TableViewRepro[10909:330239] Unbalanced calls to begin/end appearance transitions for <QLRemotePreviewContentController: 0x7fe105059000>.

Comments

Sebastian Klaus 2015-04-23

I'm geting this error too on iPhone 6 with 8.3 and SDK 3.5.1.GA Opening a PDF works random. And sometimes it crashes with this error. Hope, this will be fixed soon.

Vishal Duggal 2015-05-12

This might very much be an Apple bug. Essentially the View controller that is presenting the Document Viewer is in the process of disappearing while the preview is coming up. This is root cause of the warning about Unbalanced calls to begin/end appearance transitions. Not much we can do about it. Unrelated to this there are a couple of bugs in the Document Viewer. Test case here

   var doc = "http://www.legis.state.ak.us/basis/iphonepages/IPV3get_documents.asp?session=29&docid=3324&minname=Agenda%5FLBA%5F17Mar15%5FLocation+Change%2Epdf";
   var win = Ti.UI.createWindow({backgroundColor:'blue'});
   var win2 = Ti.UI.createWindow({backgroundColor:'yellow'});
   var file = Ti.Filesystem.getFile(Ti.Filesystem.applicationDataDirectory, 'document.pdf');
   
   var client = Ti.Network.createHTTPClient({
   	onload : function() {
   		// Open a doc viewer.
   		var docViewer = Ti.UI.iOS.createDocumentViewer({
   			url : file.nativePath
   		});
   		docViewer.show({
   			animated : true
   		});
   	},
   	onerror : function(e) {
   		alert('Error: ' + e);
   	}
   });
   
   var presentViewer = true;
   
   function presentDocument(){
   	if(presentViewer) {
   		presentViewer = false;
   		client.open('GET', doc);
   		client.file = file;
   		client.send(); 
   	} else {
   		win2.close();
   	}
   }
   
   win2.addEventListener('focus',function(){
   	presentDocument();
   })
   
   win.addEventListener('focus',function(){
   	if(presentViewer) {
   		win2.open({modal:true});
   	}
   });
   win.open();

Vishal Duggal 2015-05-12

Pulls pending master - https://github.com/appcelerator/titanium_mobile/pull/6839 4_0_X - https://github.com/appcelerator/titanium_mobile/pull/6840
Sebastian Klaus 2015-05-12

I solved it with a timeout of 300 ms
Lee Morris 2017-03-16

Closing ticket as the issue has been fixed.

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