Method SetDragDropPayload

examples/ThirdPartyLibs/imgui/imgui.cpp:13179–13220

Use 'cond' to choose to submit payload on drag start or every frame

// Use 'cond' to choose to submit payload on drag start or every frame
bool ImGui::SetDragDropPayload(const char* type, const void* data, size_t data_size, ImGuiCond cond)
{
	ImGuiContext& g = *GImGui;
	ImGuiPayload& payload = g.DragDropPayload;
	if (cond == 0)
		cond = ImGuiCond_Always;

	IM_ASSERT(type != NULL);
	IM_ASSERT(strlen(type) < IM_ARRAYSIZE(payload.DataType) && "Payload type can be at most 12 characters long");
	IM_ASSERT((data != NULL && data_size > 0) || (data == NULL && data_size == 0));
	IM_ASSERT(cond == ImGuiCond_Always || cond == ImGuiCond_Once);
	IM_ASSERT(payload.SourceId != 0);  // Not called between BeginDragDropSource() and EndDragDropSource()

	if (cond == ImGuiCond_Always || payload.DataFrameCount == -1)
	{
		// Copy payload
		ImStrncpy(payload.DataType, type, IM_ARRAYSIZE(payload.DataType));
		g.DragDropPayloadBufHeap.resize(0);
		if (data_size > sizeof(g.DragDropPayloadBufLocal))
		{
			// Store in heap
			g.DragDropPayloadBufHeap.resize((int)data_size);
			payload.Data = g.DragDropPayloadBufHeap.Data;
			memcpy((void*)payload.Data, data, data_size);
		}
		else if (data_size > 0)
		{
			// Store locally
			memset(&g.DragDropPayloadBufLocal, 0, sizeof(g.DragDropPayloadBufLocal));
			payload.Data = g.DragDropPayloadBufLocal;
			memcpy((void*)payload.Data, data, data_size);
		}
		else
		{
			payload.Data = NULL;
		}
		payload.DataSize = (int)data_size;
	}
	payload.DataFrameCount = g.FrameCount;

	return (g.DragDropAcceptFrameCount == g.FrameCount) || (g.DragDropAcceptFrameCount == g.FrameCount - 1);
}

bool ImGui::BeginDragDropTargetCustom(const ImRect& bb, ImGuiID id)
{