JUCE/modules/juce_gui_basics/windows/juce_TopLevelWindow.cpp

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

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   Copyright (c) Raw Material Software Limited

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   Or:

   You may also use this code under the terms of the AGPLv3:
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   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

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

namespace juce
{

//==============================================================================
TopLevelWindow::TopLevelWindow (const String& name, const bool shouldAddToDesktop)
    : Component (name)
{
    setTitle (name);

    setOpaque (true);

    if (shouldAddToDesktop)
        Component::addToDesktop (TopLevelWindow::getDesktopWindowStyleFlags());
    else
        setDropShadowEnabled (true);

    setWantsKeyboardFocus (true);
    setBroughtToFrontOnMouseClick (true);
    isCurrentlyActive = detail::TopLevelWindowManager::getInstance()->addWindow (this);
}

TopLevelWindow::~TopLevelWindow()
{
    shadower = nullptr;
    detail::TopLevelWindowManager::getInstance()->removeWindow (this);
}

//==============================================================================
void TopLevelWindow::focusOfChildComponentChanged (FocusChangeType)
{
    auto* wm = detail::TopLevelWindowManager::getInstance();

    if (hasKeyboardFocus (true))
        wm->checkFocus();
    else
        wm->checkFocusAsync();
}

void TopLevelWindow::setWindowActive (const bool isNowActive)
{
    if (isCurrentlyActive != isNowActive)
    {
        isCurrentlyActive = isNowActive;
        activeWindowStatusChanged();
    }
}

void TopLevelWindow::activeWindowStatusChanged()
{
}

bool TopLevelWindow::isUsingNativeTitleBar() const noexcept
{
    return useNativeTitleBar && (isOnDesktop() || ! isShowing());
}

void TopLevelWindow::visibilityChanged()
{
    if (isShowing())
        if (auto* p = getPeer())
            if ((p->getStyleFlags() & (ComponentPeer::windowIsTemporary
                                        | ComponentPeer::windowIgnoresKeyPresses)) == 0)
                toFront (true);
}

void TopLevelWindow::parentHierarchyChanged()
{
    setDropShadowEnabled (useDropShadow);
}

int TopLevelWindow::getDesktopWindowStyleFlags() const
{
    int styleFlags = ComponentPeer::windowAppearsOnTaskbar;

    if (useDropShadow)       styleFlags |= ComponentPeer::windowHasDropShadow;
    if (useNativeTitleBar)   styleFlags |= ComponentPeer::windowHasTitleBar;

    return styleFlags;
}

void TopLevelWindow::setDropShadowEnabled (const bool useShadow)
{
    useDropShadow = useShadow;

    if (isOnDesktop())
    {
        shadower = nullptr;
        Component::addToDesktop (getDesktopWindowStyleFlags());
    }
    else
    {
        if (useShadow && isOpaque())
        {
            if (shadower == nullptr)
            {
                shadower = getLookAndFeel().createDropShadowerForComponent (*this);

                if (shadower != nullptr)
                    shadower->setOwner (this);
            }
        }
        else
        {
            shadower = nullptr;
        }
    }
}

void TopLevelWindow::setUsingNativeTitleBar (const bool shouldUseNativeTitleBar)
{
    if (useNativeTitleBar != shouldUseNativeTitleBar)
    {
        detail::FocusRestorer focusRestorer;
        useNativeTitleBar = shouldUseNativeTitleBar;
        recreateDesktopWindow();
        sendLookAndFeelChange();
    }
}

void TopLevelWindow::recreateDesktopWindow()
{
    if (isOnDesktop())
    {
        Component::addToDesktop (getDesktopWindowStyleFlags());
        toFront (true);
    }
}

void TopLevelWindow::addToDesktop()
{
    shadower = nullptr;
    Component::addToDesktop (getDesktopWindowStyleFlags());
    setDropShadowEnabled (isDropShadowEnabled()); // force an update to clear away any fake shadows if necessary
}

void TopLevelWindow::addToDesktop (int windowStyleFlags, void* nativeWindowToAttachTo)
{
    /* It's not recommended to change the desktop window flags directly for a TopLevelWindow,
       because this class needs to make sure its layout corresponds with settings like whether
       it's got a native title bar or not.

       If you need custom flags for your window, you can override the getDesktopWindowStyleFlags()
       method. If you do this, it's best to call the base class's getDesktopWindowStyleFlags()
       method, then add or remove whatever flags are necessary from this value before returning it.
    */
    jassert ((windowStyleFlags & ~ComponentPeer::windowIsSemiTransparent)
               == (getDesktopWindowStyleFlags() & ~ComponentPeer::windowIsSemiTransparent));

    Component::addToDesktop (windowStyleFlags, nativeWindowToAttachTo);

    if (windowStyleFlags != getDesktopWindowStyleFlags())
        sendLookAndFeelChange();
}

std::unique_ptr<AccessibilityHandler> TopLevelWindow::createAccessibilityHandler()
{
    return std::make_unique<AccessibilityHandler> (*this, AccessibilityRole::window);
}

//==============================================================================
void TopLevelWindow::centreAroundComponent (Component* c, const int width, const int height)
{
    if (c == nullptr)
        c = TopLevelWindow::getActiveTopLevelWindow();

    if (c == nullptr || c->getBounds().isEmpty())
    {
        centreWithSize (width, height);
    }
    else
    {
        const auto scale = getDesktopScaleFactor() / Desktop::getInstance().getGlobalScaleFactor();

        const auto [targetCentre, parentArea] = [&]
        {
            const auto globalTargetCentre = c->localPointToGlobal (c->getLocalBounds().getCentre()) / scale;

            if (auto* parent = getParentComponent())
                return std::make_pair (parent->getLocalPoint (nullptr, globalTargetCentre), parent->getLocalBounds());

            return std::make_pair (globalTargetCentre, c->getParentMonitorArea() / scale);
        }();

        setBounds (Rectangle { width, height }
                     .withCentre (targetCentre)
                     .constrainedWithin (parentArea.reduced (12, 12)));
    }
}

//==============================================================================
int TopLevelWindow::getNumTopLevelWindows() noexcept
{
    return detail::TopLevelWindowManager::getInstance()->windows.size();
}

TopLevelWindow* TopLevelWindow::getTopLevelWindow (const int index) noexcept
{
    return detail::TopLevelWindowManager::getInstance()->windows [index];
}

TopLevelWindow* TopLevelWindow::getActiveTopLevelWindow() noexcept
{
    TopLevelWindow* best = nullptr;
    int bestNumTWLParents = -1;

    for (int i = TopLevelWindow::getNumTopLevelWindows(); --i >= 0;)
    {
        auto* tlw = TopLevelWindow::getTopLevelWindow (i);

        if (tlw->isActiveWindow())
        {
            int numTWLParents = 0;

            for (auto* c = tlw->getParentComponent(); c != nullptr; c = c->getParentComponent())
                if (dynamic_cast<const TopLevelWindow*> (c) != nullptr)
                    ++numTWLParents;

            if (bestNumTWLParents < numTWLParents)
            {
                best = tlw;
                bestNumTWLParents = numTWLParents;
            }
        }
    }

    return best;
}

} // namespace juce