Draggable formpanels don't destroy properly - extjs

Question

I have a grid with records from a store using the modern material theme on ExtJS 7.2. I want to create multiple floating, draggable formpanels from this view, but when I drag the formpanel around, closing it leaves a blank white space where the formpanel was, obscuring the background. Here is the source for the formpanel.
onItemClick: function (grid,rowIndex,e) {
var record = grid.getStore().getAt(rowIndex);
var form = Ext.create({
xtype: 'formpanel',
id: `${record.id}_form_${record.get('blah')}`,
title: `Invoice ${record.get('blah')}`,
floating: true,
closable: true,
centered: true,
draggable: true,
shadow: true,
width:300,
height:window.innerHeight*0.8,
scrollable: true,
modal: null,
items: [
{
xtype: 'textfield',
name: 'Blah',
label: 'Blah',
value: record.get('blah'),
},
{
xtype: 'toolbar',
docked: 'bottom',
items: [{
xtype: 'button',
text: 'Save',
ui: 'raised round',
iconCls: 'x-fa fa-save',
handler: function() {
var theform = this.up('formpanel').getFields();
record.set(
{
'blah': theform['Blah'].getValue(),
}
);
this.up('formpanel').destroy();
}
},'->', {
xtype: 'button',
text: 'Cancel',
ui: 'raised round',
iconCls: 'x-fa fa-close',
handler: function() {
this.up('formpanel').destroy();
},
}]
}
]
});
Ext.Viewport.add(form);
}
Does anyone have experience with this problem? I have tried messing around with a custom Ext.drag.Source object, but with no success so far. When I try to close a formpanel that has been dragged, I get an error:
TypeError: Argument 1 of Node.replaceChild is not an object.
Any help would be appreciated.

Answer 1

there is not property called "floating" in the modern toolkit. Did you mean "floated"?
Instead of adding to Viewport better use show() method.
Something like this:
onItemClick: function (grid,rowIndex,e) {
var record = grid.getStore().getAt(rowIndex);
var form = Ext.create({
xtype: 'formpanel',
id: `${record.id}_form_${record.get('blah')}`,
title: `Invoice ${record.get('blah')}`,
floated: true, // It is not called "floating"
closable: true,
centered: true,
draggable: true,
shadow: true,
width:300,
height:window.innerHeight*0.8,
scrollable: true,
modal: null,
items: [
{
xtype: 'textfield',
name: 'Blah',
label: 'Blah',
value: record.get('blah'),
},
{
xtype: 'toolbar',
docked: 'bottom',
items: [{
xtype: 'button',
text: 'Save',
ui: 'raised round',
iconCls: 'x-fa fa-save',
handler: function() {
var theform = this.up('formpanel').getFields();
record.set(
{
'blah': theform['Blah'].getValue(),
}
);
this.up('formpanel').destroy();
}
},'->', {
xtype: 'button',
text: 'Cancel',
ui: 'raised round',
iconCls: 'x-fa fa-close',
handler: function() {
this.up('formpanel').destroy();
},
}]
}
]
});
form.show(); // Show instead of add to Viewport.
//Ext.Viewport.add(form);
}