How to implement drag and drop in Flex Grid control?
- by Bogdan
I have a simple Grid control with some buttons that I want to be able to move around. The code below does work, but it takes a lot of effort to actually do the drag&drop and it is not clear where the drop will happen. I have to move the mouse around a lot to get to a state where the drop is not rejected. I would appreciate any suggestions on how to make this more "user friendly".
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" verticalAlign="middle" horizontalAlign="center" height="200" width="200">
<mx:Script>
<![CDATA[
import mx.containers.GridItem;
import mx.controls.Button;
import mx.core.DragSource;
import mx.events.*;
import mx.managers.DragManager;
private function dragInit(event:MouseEvent):void
{
if(event.buttonDown)
{
var button:Button = event.currentTarget as Button;
var dragSource:DragSource = new DragSource();
dragSource.addData(button, 'button');
DragManager.doDrag(button, dragSource, event);
}
}
private function dragEnter(event:DragEvent): void
{
var target:GridItem = event.currentTarget as GridItem;
if (event.dragSource.hasFormat('button') && target.getChildren().length == 0)
{
DragManager.acceptDragDrop(target);
DragManager.showFeedback(DragManager.MOVE);
}
}
private function dragDrop(event:DragEvent): void
{
var target:GridItem = event.currentTarget as GridItem;
var button:Button = event.dragSource.dataForFormat('button') as Button;
target.addChild(button);
}
]]>
</mx:Script>
<mx:Grid>
<mx:GridRow width="100%" height="100%">
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
<mx:Button label="A" width="40" height="40" mouseMove="dragInit(event)"/>
</mx:GridItem>
</mx:GridRow>
<mx:GridRow width="100%" height="100%">
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
<mx:Button label="B" width="40" height="40" mouseMove="dragInit(event)"/>
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
</mx:GridRow>
<mx:GridRow width="100%" height="100%">
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
<mx:Button label="C" width="40" height="40" mouseMove="dragInit(event)"/>
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
<mx:GridItem width="44" height="44" dragEnter="dragEnter(event)" dragDrop="dragDrop(event)">
</mx:GridItem>
</mx:GridRow>
</mx:Grid>
<mx:Style>
GridItem
{
borderColor: #A09999;
borderStyle: solid;
borderThickness: 2;
horizontal-align: center;
vertical-align: center;
}
Grid
{
borderColor: #A09999;
borderStyle: solid;
borderThickness: 2;
horizontalGap: 0;
verticalGap: 0;
horizontal-align: center;
vertical-align: center;
}
</mx:Style>
</mx:Application>
