I’m working on making an inventory for my game, I want to make a SWindow that can be moved around. That SWindow would contain an SOverlay that contains a background image and a SUniformGrid.
I tried my best but I cant get the window to drag or move 
I think I’m going about this the right way but I am open to suggestions. I’m not crazy about UMG and I would rather stick with slate. Bellow is the full cpp code to my Inventory and my custom window class. I use my custom window class (EtherWindow) in my Inventory.
Inventory.cpp
#include "TheEther.h"
#include "Items/BaseItem.h"
#include "UI/EtherOverlay.h"
#include "UI/EtherWindow.h"
#include "UI/InventorySlot.h"
#include "UI/Inventory.h"
TSharedRef<SEtherWindow> myInventoryWindow = SNew(SEtherWindow);
TSharedRef<SEtherOverlay> myInventoryOverlay = SNew(SEtherOverlay);
TSharedRef<SUniformGridPanel> myInventoryGridPanel = SNew(SUniformGridPanel);
SInventory::SInventory()
{
//Default values for inventory.
myIsVisible = false;
myIsConstructed = false;
myNumRows = 3;
myNumColumns = 3;
myWidth = 700;
myHeight = 700;
}
SInventory::~SInventory()
{
}
void SInventory::AddItem(ABaseItem* itemToAdd)
{
bool itemWasAdded = false;
//Find the next free slot in the inventory to add the item.
for (int32 i = 0; i < mySlots.Num() && itemWasAdded == false; i++)
{
//Check to see if the slot is free.
if (mySlots*->GetInventoryItem() == NULL)
{
mySlots*->SetInventoryItem(itemToAdd);
itemWasAdded = true;
}
}
//Check to see if the item was added successfully.
if (itemWasAdded == true)
{
//Remove the item from the world since it was successfully picked up.
itemToAdd->Destroy();
}
}
void SInventory::InitializeSlots(UWorld* playersWorld)
{
TSharedPtr<SInventorySlot> inventorySlotWidget;
//Create the visual representation of the inventory.
for (int32 currRowIndex = 0; currRowIndex < myNumRows; currRowIndex++)
{
for (int32 currColIndex = 0; currColIndex < myNumColumns; currColIndex++)
{
myInventoryGridPanel->AddSlot(currColIndex, currRowIndex)
//Dynamically create the inventory slots and add them to the list.
SAssignNew(inventorySlotWidget, SInventorySlot)
];
mySlots.Add(inventorySlotWidget.Get());
}
}
}
void SInventory::Construct(const FArguments& InArgs)
{
FSlateBrush* imageSlateBrush = new FSlateBrush();
this->OwnerHUD = InArgs._OwnerHUD;
this->InventoryBackgroundTexture = InArgs._InventoryBackgroundTexture;
//Convert our UTexture2D to an FSlateBrush.
imageSlateBrush->SetResourceObject(InventoryBackgroundTexture.Get());
//Prevent construction more than once.
if (myIsConstructed == false)
{
FSlateApplication::Get().AddWindow(myInventoryWindow, false);
myInventoryWindow->SetContent(SNew(SBox)
.WidthOverride(myWidth)
.HeightOverride(myHeight)
SNew(SImage)
.Image(imageSlateBrush)
]);
ChildSlot
.VAlign(VAlign_Center)
.HAlign(HAlign_Center)
myInventoryWindow
];
myIsConstructed = true;
}
}
void SInventory::ToggleVisibility()
{
if (myIsVisible == true)
{
this->SetVisibility(EVisibility::Collapsed);
myIsVisible = false;
}
else
{
this->SetVisibility(EVisibility::Visible);
myIsVisible = true;
}
this->ToggleSlotsVisibility();
myInventoryOverlay->ToggleVisibility();
}
void SInventory::ToggleSlotsVisibility()
{
//Only show the slots if the inventory is visible.
for (int i = 0; i < mySlots.Num(); i++)
{
if (myIsVisible == true)
{
mySlots*->SetVisibility(EVisibility::Visible);
}
else
{
mySlots*->SetVisibility(EVisibility::Collapsed);
}
}
}
///Getters
int SInventory::GetNumRows()
{
return myNumRows;
}
int SInventory::GetNumColumns()
{
return myNumColumns;
}
bool SInventory::GetIsVisible()
{
return myIsVisible;
}
EtherWindow.cpp
#include "TheEther.h"
#include "UI/EtherWindow.h"
SEtherWindow::SEtherWindow()
{
myIsVisible = false;
this->bIsCursorDecoratorWindow = true;
this->bDragAnywhere = true;
this->bHasOSWindowBorder = true;
this->bHasSizingFrame = true;
}
void SEtherWindow::Construct(const FArguments& InArgs)
{
}
FReply SEtherWindow::OnMouseMove(const FGeometry& geometry, const FPointerEvent& mouseEvent)
{
this->MoveWindowTo(mouseEvent.GetScreenSpacePosition() + FSlateApplication::Get().GetCursorSize());
return FReply::Handled();
}
void SEtherWindow::ToggleVisibility()
{
myIsVisible = !myIsVisible;
this->EnableWindow(myIsVisible);
if (myIsVisible == true)
{
this->ShowWindow();
}
else
{
this->HideWindow();
}
}
///Getters
bool SEtherWindow::GetIsVisible()
{
return myIsVisible;
}