juce_ComponentMovementWatcher.cpp

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   By using JUCE, you agree to the terms of both the JUCE 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-privacy-policy
 
   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).
 
   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
{
 
ComponentMovementWatcher::ComponentMovementWatcher (Component* const comp)
    : component (comp),
      wasShowing (comp->isShowing())
{
    jassert (component != nullptr); // can't use this with a null pointer..
 
    component->addComponentListener (this);
    registerWithParentComps();
}
 
ComponentMovementWatcher::~ComponentMovementWatcher()
{
    if (component != nullptr)
        component->removeComponentListener (this);
 
    unregister();
}
 
//==============================================================================
void ComponentMovementWatcher::componentParentHierarchyChanged (Component&)
{
    if (component != nullptr && ! reentrant)
    {
        const ScopedValueSetter<bool> setter (reentrant, true);
 
        auto* peer = component->getPeer();
        auto peerID = peer != nullptr ? peer->getUniqueID() : 0;
 
        if (peerID != lastPeerID)
        {
            componentPeerChanged();
 
            if (component == nullptr)
                return;
 
            lastPeerID = peerID;
        }
 
        unregister();
        registerWithParentComps();
 
        componentMovedOrResized (*component, true, true);
 
        if (component != nullptr)
            componentVisibilityChanged (*component);
    }
}
 
void ComponentMovementWatcher::componentMovedOrResized (Component&, bool wasMoved, bool wasResized)
{
    if (component != nullptr)
    {
        if (wasMoved)
        {
            Point<int> newPos;
            auto* top = component->getTopLevelComponent();
 
            if (top != component)
                newPos = top->getLocalPoint (component, Point<int>());
            else
                newPos = top->getPosition();
 
            wasMoved = lastBounds.getPosition() != newPos;
            lastBounds.setPosition (newPos);
        }
 
        wasResized = (lastBounds.getWidth() != component->getWidth() || lastBounds.getHeight() != component->getHeight());
        lastBounds.setSize (component->getWidth(), component->getHeight());
 
        if (wasMoved || wasResized)
            componentMovedOrResized (wasMoved, wasResized);
    }
}
 
void ComponentMovementWatcher::componentBeingDeleted (Component& comp)
{
    registeredParentComps.removeFirstMatchingValue (&comp);
 
    if (component == &comp)
        unregister();
}
 
void ComponentMovementWatcher::componentVisibilityChanged (Component&)
{
    if (component != nullptr)
    {
        const bool isShowingNow = component->isShowing();
 
        if (wasShowing != isShowingNow)
        {
            wasShowing = isShowingNow;
            componentVisibilityChanged();
        }
    }
}
 
void ComponentMovementWatcher::registerWithParentComps()
{
    for (auto* p = component->getParentComponent(); p != nullptr; p = p->getParentComponent())
    {
        p->addComponentListener (this);
        registeredParentComps.add (p);
    }
}
 
void ComponentMovementWatcher::unregister()
{
    for (auto* c : registeredParentComps)
        c->removeComponentListener (this);
 
    registeredParentComps.clear();
}
 
} // namespace juce