How to get the actual width and height of an uielement?

I have a window which resizes based on its content. To calculate the absolute size I need to first add up a few known values but then also add the size of the UnityEditor.UIElements.Toolbar at the top. I can imagine two ways of getting this information:

1) The the Toolbar class has a fixed/default styling which should know the height before even having an instance.

2) If the Toolbar instance already exists, I should be able to query its style, but the height property may not be set because it is dynamically stretching, so ideally, I would want to ask for the actually rendered size.

 

Thank you! The properties do work the way you described. Too bad for me, but waiting for the first render frame won't work since I need to calculate the window size before opening it as a popup. But still good info for the future!

 

I have a similar issue. Here is the work-around approach I took:

Code (CSharp):

1. public void OnPostVisualCreation()
2. {
3.     // Make invisble so you don't see the size re-adjustment
4.     // (Non-visible objects still go through transforms in the layout engine)
5.     Visual.visible = false;
6.     Visual.schedule.Execute(WaitOneFrame);
7. }
8.  
9. private void WaitOneFrame(TimerState obj)
10. {
11.     // Because waiting once wasn't working
12.     Visual.schedule.Execute(AutoSize);
13. }
14.  
15. private void AutoSize(TimerState obj)
16. {
17.     // Do any measurements, size adjustments you need (NaNs not an issue now)
18.     Visual.MarkDirtyRepaint();
19.     Visual.visible = true;
20. }

It would be really nice if you could just manually force a layout transformation on a particular VisualElement, but as it's been said, this is not currently possible.

 

Just wanted to +1 here, as I ran into the same issue as @Xarbrough. I wanted to size my EditorWindow (small utility popup) to the height of the content, but no way to get height of content until after first update.

 

You should be able to get the layout data after the layout pass but before the first frame by doing the following:

Code (CSharp):

1. root.RegisterCallback<GeometryChangedEvent>(GeometryChangedCallback);
2. //[...]
3. private void GeometryChangedCallback(GeometryChangedEvent evt)
4. {
5.     root.UnregisterCallback<GeometryChangedEvent>(GeometryChangedCallback);
6.     // Do what you need to do here, as geometry should be calculated.
7. }

I was originally doing similar with this:

Code (CSharp):

1. root.schedule.Execute(ExecuteDeferredTask).StartingIn(0);

But then was informed by @uMathieu that the GeometryChangedEvent example would do the trick (source: PropertyField children can only be queried after initial UI build)

 

This is the optimal solution if all the layout information is known at the time of the event. Obviously for dynamic cases, this is not true.

In my case, for example, I am simulating a generic modal popup dialog which is dynamically populated with title and content strings. But really any dynamic custom control that does it's own absolute layout could run into this issue.

 

I was having issues forcing a ScrollView to go the the last element after I added it because its new size wasn't calculated yet or something. I had to use a callback to GeometryChangedEvent and it worked fine.

Thanks!!

 

Hey hey, this is still a problem. I'm making a popupwindow and there is no real way of finding the height. When I use "Geometry changed event" it will blatantly return an incorrect result.


Relevant code


Clearly too short

 

I see, thank you so much!

I’m using UnityEditor.PopupWindow btw, I saw in a tutorial on the documentation that this was the way to do it but it still feels clumsy, hope a better API for editor popups comes along. Otherwise I’m really enjoying the UIElements API!

 

Unfortunately, this code gives me the same results:

Code (CSharp):

1.             public override Vector2 GetWindowSize()
2.             {
3.                 var resolvedStyle = editorWindow.rootVisualElement.resolvedStyle;
4.                 return new(280f, resolvedStyle.height + resolvedStyle.paddingTop + resolvedStyle.paddingBottom + resolvedStyle.marginTop + resolvedStyle.marginBottom + resolvedStyle.borderTopWidth + resolvedStyle.borderBottomWidth);
5.             }

So the padding is not coming from the root visual element, but from something higher up. For now I'll just do

+6

.

 

You can inspect this with the debugger, it should be on GameView: