Carla/source/modules/juce_gui_extra/native/juce_win32_HWNDComponent.cpp

/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

class HWNDComponent::Pimpl  : public ComponentMovementWatcher
{
public:
    Pimpl (HWND h, Component& comp)
        : ComponentMovementWatcher (&comp),
          hwnd (h),
          owner (comp)
    {
        if (owner.isShowing())
            componentPeerChanged();
    }

    ~Pimpl() override
    {
        removeFromParent();
        DestroyWindow (hwnd);
    }

    void componentMovedOrResized (bool wasMoved, bool wasResized) override
    {
        auto* topComponent = owner.getTopLevelComponent();

        if (auto* peer = owner.getPeer())
        {
            auto pos = topComponent->getLocalPoint (&owner, Point<int>());

            auto scaled = (Rectangle<int> (pos.x, pos.y, owner.getWidth(), owner.getHeight()).toDouble()
                            * peer->getPlatformScaleFactor()).getSmallestIntegerContainer();

            DWORD windowFlags = SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOOWNERZORDER;
            if (! wasMoved)    windowFlags |= SWP_NOMOVE;
            if (! wasResized)  windowFlags |= SWP_NOSIZE;

            SetWindowPos (hwnd, 0, scaled.getX(), scaled.getY(), scaled.getWidth(), scaled.getHeight(), windowFlags);
        }
    }

    void componentPeerChanged() override
    {
        auto* peer = owner.getPeer();

        if (currentPeer != peer)
        {
            removeFromParent();
            currentPeer = peer;

            addToParent();
        }

        auto isShowing = owner.isShowing();

        ShowWindow (hwnd, isShowing ? SW_SHOWNA : SW_HIDE);

        if (isShowing)
            InvalidateRect (hwnd, 0, 0);
     }

    void componentVisibilityChanged() override
    {
        componentPeerChanged();
    }

    void componentBroughtToFront (Component& comp) override
    {
        ComponentMovementWatcher::componentBroughtToFront (comp);
    }

    Rectangle<int> getHWNDBounds() const
    {
        if (auto* peer = owner.getPeer())
        {
            RECT r;
            GetWindowRect (hwnd, &r);

            return (Rectangle<int>::leftTopRightBottom (r.left, r.top, r.right, r.bottom).toDouble()
                     / peer->getPlatformScaleFactor()).getSmallestIntegerContainer();
        }

        return {};
    }

    HWND hwnd;

private:
    void addToParent()
    {
        if (currentPeer != nullptr)
        {
            auto windowFlags = GetWindowLongPtr (hwnd, -16);

            windowFlags &= ~(WS_POPUP | WS_CHILD);

            SetWindowLongPtr (hwnd, -16, windowFlags);
            SetParent (hwnd, (HWND) currentPeer->getNativeHandle());

            componentMovedOrResized (true, true);
        }
    }

    void removeFromParent()
    {
        SetParent (hwnd, NULL);
    }

    Component& owner;
    ComponentPeer* currentPeer = nullptr;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Pimpl)
};

//==============================================================================
HWNDComponent::HWNDComponent()
{
}

HWNDComponent::~HWNDComponent() {}

void HWNDComponent::setHWND (void* hwnd)
{
    if (hwnd != getHWND())
    {
        pimpl.reset();

        if (hwnd != nullptr)
            pimpl.reset (new Pimpl ((HWND) hwnd, *this));
    }
}

void* HWNDComponent::getHWND() const
{
    return pimpl == nullptr ? nullptr : (void*) pimpl->hwnd;
}

void HWNDComponent::resizeToFit()
{
    if (pimpl != nullptr)
        setBounds (pimpl->getHWNDBounds());
}

} // namespace juce