Control Layering With Dynamically Created Controls

[Jon_Ogden]

Hey all,

When creating controls in the IDE, you can set the “layer” position of controls with these buttons below:

If I create a control dynamically in code, how can I do this? I’ve not been able to find a property that determines the layering order of controls. I have an instance where I have a canvas control where sometimes I want to make the canvas completely transparent and bring up an HTML Viewer behind it. I want the HTML Viewer to be behind the canvas as there’s a number of custom mouse related commands that the canvas has that can’t be implemented on the HTML viewer.

Please tell me this is not something I can only do in the IDE…

Thanks,

Jon

[Jeremie_L]

I believe the last added control will be the top-most item.
But that might not be true on all platforms.

[Jon_Ogden]

That is correct and reflects what I am seeing. How then do I change that order in code. I can do it in the IDE, but I want to do it in code.

[Jeremie_L]

This might help:

Changing control z-order at runtime

I need to change the z-order of canvases created from a control set at runtime. I’ve found a few threads about this, and in one of them (https://forum.xojo.com/t/z-order-again/41380 @Sam_Rowlands mentioned it’s possible on the Mac with some declares involving NSViewSuperview. I’ve looked at the MBS collection and haven’t found the equivalent. My question is, can one change the control z-order with MBS? Mac-only is fine.

[Jon_Ogden]

Thanks. But I need it to be XPlat not just Mac. So looks like there’s no “built-in” way to do this?

[Jeremie_L]

Desktop doesn’t have a RemoveControl method unfortunately.

What if you move the control out of the Window by setting left and top to -1000.
Set the control.visible to false

Then add another identical control to your window. That last added control will then be the control with the highest z-order.

[Tim_Parnell]

@Jeremie_L

Desktop doesn’t have a RemoveControl method unfortunately.

Control.Close should do that.

[Jon_Ogden]

Actually, I can add/remove it at will utilizing control sets.

The issue I have is that when I want to show the HTML viewer, it’s showing an MJPEG stream. Just hiding that control will continue to consumer bandwidth as the MJPEG stream isn’t stopped. So I figured I would just create and close the control as needed. But I need it to remain BEHIND the canvas.

And obviously there is a property setting somewhere that sets the Z order. But it appears Xojo doesn’t allow that property to be set at run time - only in the IDE.

[Jeremie_L]

Forgot about that method.

[Wayne_Golding]

Can’t you use the parent property of the control? Assuming the canvas is the same size as the HTMLviewer, just use Canvas1.Parent = HTMLViewer1 which will change the z-order of the controls.

[Jon_Ogden]

Oh maybe I did it backwards. I made the HTMLViewer the Parent of the Canvas…

That did it, Wayne! Thank you for your sage advice!