Bug? mx:HTML sets DragManager.isDragging to true

Forum|Forum|15 years ago
February 24, 2011
2 replies
1214 views

I have encountered an issue when using the mx:HTML Air component alongside Flex panels that have images that I want to allow for drag and drop. These panels and images are not rendered inside of the mx:HTML component. I have written a small sample program that demonstrates my issue and am hoping someone can help me in determining a way around this issue (other than the 2 silly ones I have come up with).

When I initially run the program I can drag the image that exists outside of the mx:HTML component just fine. However, when I click on a link inside the mx:HTML component the image that exists outside is no longer draggable. When I debug into this and put a breakpoint inside my mouseMove handler, the DragManager.isDragging flag is set to true. This even happens when I have started the app and never hovered over the image or attempted to drag anything. It just seems that any interaction with the mx:HTML component sets this isDragging state to true and there is a check inside of the NativeDragManager that exits if isDragging is already set to true so no dragging occurs.

After additional experimentation I found 2 really bad workarounds:

1) After clicking on a link inside the mx:HTML, during the HTML load, I can repeatedly click on something outside of the mx:HTML component (stealing focus away from the mx:HTML component, maybe a key??) and the Image object on the other panel stays draggable.

2) If for some reason the Image object on the other panel is no longer draggable I can find something within the mx:HTML component (an image, for example), drag it a little bit and let go of it and this seems to clear the drag state and my Image in the other panel becomes draggable again.

Am I just overlooking something here? It looks to me like a bug in the Air/Flex/Flash framework. I have posted a bug report to Adobe but have heard nothing back yet. I have tried this on both Mac and Windows 7 and the same issue occurs. I am using Flex 4 and have replicated this on AIR 1.5.3, 2.0 and 2.5.1.

Thanks in advance,

Kevin

Here's the code:

<?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"
                            width="1024"
                            height="768">
     <fx:Script>
          <![CDATA[
               import flash.desktop.NativeDragOptions;
               import mx.core.DragSource;
               import mx.events.DragEvent;
               import mx.events.InterDragManagerEvent;
               import mx.events.InterManagerRequest;
               import mx.managers.DragManager;
               import mx.managers.ISystemManager;
               import mx.managers.SystemManagerGlobals;
               
               protected function image1_mouseMoveHandler(event:MouseEvent):void
               {
                    var dragInitiator:Image = event.currentTarget as Image;
                    var ds:DragSource = new DragSource();
                    ds.addData(dragInitiator, "img");               
                    DragManager.doDrag(dragInitiator, ds, event, img);          
               }
          ]]>
     </fx:Script>
     <fx:Declarations>
          <!-- Place non-visual elements (e.g., services, value objects) here -->
     </fx:Declarations>
     
     <mx:HDividedBox width="100%" height="100%">
          <mx:HTML
               id="myHtml"
               location="http://www.adobe.com/"
               width="70%"
               height="100%" />
          <s:VGroup width="30%" id="myPanel">
               <s:TextInput id="textInput" />
               <s:Label
                    width="100%"
                    text="On startup you can drag the image below.  Click on a hyperlink within the HTML widget and you can no longer drag the image anymore." />               
               <mx:Image 
                    id="img"
                    source="http://www.adobe.com/homepage/include/style/default/SiteHeader/logo.png" 
                    mouseMove="image1_mouseMoveHandler(event)"/>
          </s:VGroup>
     </mx:HDividedBox>
</s:WindowedApplication>

Performance issues

This topic has been closed for replies.

Mihai Balan

Adobe Employee

Hi Kevin,

I might just have a better work-around for you. This workaround consists in using native drag events instead of "classic" drag events (see http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/desktop/NativeDragManager.html and related classes). You can see below the modified sample that doesn't have this bug anymore.

Hope this proves useful,

Mihai

<?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"
                            width="1024"
                            height="768">
     <fx:Script>
          <![CDATA[
               import flash.desktop.NativeDragOptions;
               
               import mx.core.DragSource;
               import mx.events.DragEvent;
               import mx.events.InterDragManagerEvent;
               import mx.events.InterManagerRequest;
               import mx.managers.DragManager;
               import mx.managers.ISystemManager;
               import mx.managers.SystemManagerGlobals;
               
               protected function image1_mouseMoveHandler(event:MouseEvent):void
               {
                    var dragInitiator:Image = event.currentTarget as Image;
                    //var ds:DragSource = new DragSource();
                    //ds.addData(dragInitiator, "image/png");               
                    //DragManager.doDrag(dragInitiator, ds, event, img);
                    
                    // Create new clipboard object
                    var cb:Clipboard = new Clipboard();
                    // Add the image URL to the clipboard (you could also add the actual bitmap data, etc.)
                    cb.setData(ClipboardFormats.URL_FORMAT, img.source, true);
                    // Extract the actual bitmap from the image component
                    var bmp:Bitmap = img.content as Bitmap;
                    // Start dragging
                    NativeDragManager.doDrag(dragInitiator, cb, bmp.bitmapData);
               }
          ]]>
     </fx:Script>
     
     <fx:Declarations>
          <!-- Place non-visual elements (e.g., services, value objects) here -->
     </fx:Declarations>
     
     <mx:HDividedBox width="100%" height="100%">
          <mx:HTML
               id="myHtml"
               location="http://www.adobe.com/"
               width="70%"
               height="100%" />
          
          <s:VGroup width="30%" id="myPanel">
               <s:TextInput id="textInput" />
               <s:Label
                    width="100%"
                    text="On startup you can drag the image below.  Click on a hyperlink within the HTML widget and you can no longer drag the image anymore." />               
               
               <mx:Image 
                    id="img"
                    source="http://www.adobe.com/homepage/include/style/default/SiteHeader/logo.png" 
                    mouseMove="image1_mouseMoveHandler(event)"/>
          </s:VGroup>
     </mx:HDividedBox>
</s:WindowedApplication>

Anonymous

Mihai and Chris,

Thanks so much for your assistance on this one. That workaround does indeed work for our app!

Kevin

chris.campbell

Legend

Hi Kevin,

Thanks for the great example and description. I've confirmed this on both Mac and Win and have opened a new internal bug (#2816510). I don't have a better workaround for you yet but I'll ask around and see if I can come up with something. Please feel free to contact me on this thread or email me at ccampbel@adobe.com for updates.

Thanks,

Chris

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