Access UMG Widgets Properties from C++

Development Programming & Scripting C++
1

Does anyone know how to read/write TextBlock, Button, Image position (X, Y) and size (X, Y) from C++?

Can you point me to the documentation?

The best I have found so far is:



        UTextBlock* someItem = NewObject<UTextBlock>(this, UTextBlock::StaticClass());
        someItem->SetText(FText::FromString(TEXT("ABC")));
        someItem->Font.Size = 24;
        someItem->SetColorAndOpacity(FSlateColor(FLinearColor(1.0f, 1.0f, 1.0f, 1.0f)));
        someItem->Justification = ETextJustify::Left;
        someItem->Margin = FMargin(0.0f);
        someItem->MinDesiredWidth = 200.0f;
        someItem->SetJustification(ETextJustify::Left);
        someItem->SetRenderTranslation(FVector2D(0.0, 0.0f));
2

Those are properties of a canvas panel slot, not the widget itself.

I haven’t tried it, but I’d guess this would work, assuming of course that the widget is placed on a canvas:


UCanvasPanelSlot* CanvasSlot = Cast< UCanvasPanelSlot >(MyWidget->Slot);
CanvasSlot->GetPosition()/GetSize()
2 Likes
3

Thank you Kamrann.

I suspected as much with the Slot member but without the Cast it doesn’t list the Get/Set functions for Size/Position. The UTextBlock Slot member is of type UPanelSlot*. When casted as you listed above I now get an Access Violation in the Canvas code. Most likely either it’s a bad cast or the object hasn’t been created yet. If memory serves me correctly there’s a function that can be called that forces the widget to fully create itself but I can’t seem to find it now.

Do you have any other suggestions you can share?

4

Not really without seeing more code showing the context in which you’re trying to do it.
Best bet would be to put a breakpoint in the debugger at the line of the cast, and check on the value of MyWidget->Slot that you are about to cast. The debugger should show you if it’s null, and if not, what kind of slot it is.

5

Well, thanks to you Kamrann I have it working :slight_smile:

It’s a matter of order of operations. Creating the widgets alone doesn’t give them the inheritance to any future class that it may be appended to :smiley: Basically, casting to Canvas anything without being added to the canvas won’t work, hence, the Access Violation. I ended up with the following:



        UTextBlock* someItem = NewObject<UTextBlock>(this, UTextBlock::StaticClass());
        panel->AddChild(someItem);
        Cast<UCanvasPanelSlot>(someItem->Slot)->SetPosition(FVector2D( x, y));
        Cast<UCanvasPanelSlot>(someItem->Slot)->SetSize(FVector2D( w, h));

And for completeness sake. . .I’ve been running with Visual Studio.