Custom UI Video Rendering

InitSDK (with ENABLE_CUSTOMIZED_UI_FLAG)
  -> AuthSDK (JWT)
    -> JoinMeeting
      -> OnConnecting: Create window + CustomUIMgr + VideoContainer
        -> OnInMeeting: Create video elements + subscribe to participants
          -> Message loop (window events + SDK callbacks)
            -> OnEnded: Destroy everything

InitParam initParam;
initParam.strWebDomain = L"https://zoom.us";
initParam.emLanguageID = LANGUAGE_English;
initParam.enableLogByDefault = true;

// CRITICAL: This is what makes it Custom UI mode
initParam.obConfigOpts.optionalFeatures = ENABLE_CUSTOMIZED_UI_FLAG;

SDKError err = InitSDK(initParam);

#include <customized_ui/zoom_customized_ui.h>
#include <customized_ui/customized_ui_mgr.h>
#include <customized_ui/customized_video_container.h>
#include <customized_ui/customized_share_render.h>

ICustomizedUIMgr* pCustomUIMgr = nullptr;
ICustomizedVideoContainer* pVideoContainer = nullptr;

// Create the manager (global SDK function)
SDKError err = CreateCustomizedUIMgr(&pCustomUIMgr);

// Optional: check license (log warning, don't abort)
err = pCustomUIMgr->HasLicense();
if (err != SDKERR_SUCCESS) {
    std::cout << "WARNING: HasLicense returned " << err << std::endl;
}

// Register for destroy notifications
pCustomUIMgr->SetEvent(&myUIMgrEventListener);

// Create video container inside your Win32 window
RECT rc;
::GetClientRect(hMyWindow, &rc);
err = pCustomUIMgr->CreateVideoContainer(&pVideoContainer, hMyWindow, rc);

pVideoContainer->SetEvent(&myVideoContainerEventListener);
pVideoContainer->Show();
pVideoContainer->SetBkColor(RGB(30, 30, 30)); // Dark background

IVideoRenderElement* pElement = nullptr;
err = pVideoContainer->CreateVideoElement(&pElement, VideoRenderElement_ACTIVE);

IActiveVideoRenderElement* pActive = dynamic_cast<IActiveVideoRenderElement*>(pElement);
RECT activeRect = { 0, 0, windowWidth, (int)(windowHeight * 0.7) };
pActive->SetPos(activeRect);
pActive->Show();
pActive->Start();  // Begin auto-tracking active speaker

IMeetingParticipantsController* pParticipants =
    pMeetingService->GetMeetingParticipantsController();
IList<unsigned int>* pUserList = pParticipants->GetParticipantsList();

for (int i = 0; i < pUserList->GetCount() && i < MAX_GALLERY; i++) {
    unsigned int userId = pUserList->GetItem(i);

    IVideoRenderElement* pNormElement = nullptr;
    err = pVideoContainer->CreateVideoElement(&pNormElement, VideoRenderElement_NORMAL);

    INormalVideoRenderElement* pNormal =
        dynamic_cast<INormalVideoRenderElement*>(pNormElement);

    pNormal->Subscribe(userId);
    pNormal->SetResolution(VideoRenderResolution_360p);
    pNormal->Show();

    // Position in gallery strip
    int elemWidth = windowWidth / galleryCount;
    RECT r = { i * elemWidth, galleryTop, (i+1) * elemWidth, windowHeight };
    pNormal->SetPos(r);
}

void LayoutVideoElements() {
    RECT clientRect;
    ::GetClientRect(hMyWindow, &clientRect);
    int totalWidth = clientRect.right - clientRect.left;
    int totalHeight = clientRect.bottom - clientRect.top;

    // Resize container to fill window
    pVideoContainer->Resize(clientRect);

    if (galleryElements.empty()) {
        // Active speaker only — full window
        RECT activeRect = { 0, 0, totalWidth, totalHeight };
        pActiveElement->SetPos(activeRect);
    } else {
        // Active speaker: top 70%, gallery: bottom 30%
        int activeHeight = (int)(totalHeight * 0.7);
        RECT activeRect = { 0, 0, totalWidth, activeHeight };
        pActiveElement->SetPos(activeRect);

        int elemWidth = totalWidth / (int)galleryElements.size();
        for (int i = 0; i < galleryElements.size(); i++) {
            RECT r = { i * elemWidth, activeHeight, (i+1) * elemWidth, totalHeight };
            galleryElements[i]->SetPos(r);
        }
    }
}

// Create share render (hidden until someone shares)
ICustomizedShareRender* pShareRender = nullptr;
RECT rc;
::GetClientRect(hMyWindow, &rc);
pCustomUIMgr->CreateShareRender(&pShareRender, hMyWindow, rc);
pShareRender->SetEvent(&myShareEventListener);
pShareRender->Hide();

// In ShareRenderEventListener:
void onSharingSourceNotification(unsigned int nShareSourceID) {
    if (nShareSourceID > 0) {
        pShareRender->SetShareSourceID(nShareSourceID);
        pShareRender->SetViewMode(CSM_FULLFILL);
        pShareRender->Show();
    } else {
        pShareRender->Hide();
    }
}

void Cleanup() {
    if (pVideoContainer) {
        pVideoContainer->DestroyAllVideoElement();
        pCustomUIMgr->DestroyVideoContainer(pVideoContainer);
        pVideoContainer = nullptr;
    }
    if (pShareRender) {
        pCustomUIMgr->DestroyShareRender(pShareRender);
        pShareRender = nullptr;
    }
    if (pCustomUIMgr) {
        DestroyCustomizedUIMgr(pCustomUIMgr);
        pCustomUIMgr = nullptr;
    }
    if (hMyWindow) {
        DestroyWindow(hMyWindow);
        hMyWindow = nullptr;
    }
}

#include <windows.h>
#include <cstdint>
#include <zoom_sdk.h>
#include <customized_ui/zoom_customized_ui.h>          // CreateCustomizedUIMgr()
#include <customized_ui/customized_ui_mgr.h>           // ICustomizedUIMgr, ICustomizedUIMgrEvent
#include <customized_ui/customized_video_container.h>   // ICustomizedVideoContainer, elements
#include <customized_ui/customized_share_render.h>      // ICustomizedShareRender
#include <meeting_service_interface.h>
#include <meeting_service_components/meeting_audio_interface.h>          // Before participants!
#include <meeting_service_components/meeting_participants_ctrl_interface.h>