paulxstretch/deps/juce/modules/juce_gui_basics/misc/juce_DropShadower.cpp

390 lines
11 KiB
C++

/*
==============================================================================
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
{
class DropShadower::ShadowWindow : public Component
{
public:
ShadowWindow (Component* comp, const DropShadow& ds)
: target (comp), shadow (ds)
{
setVisible (true);
setAccessible (false);
setInterceptsMouseClicks (false, false);
if (comp->isOnDesktop())
{
#if JUCE_WINDOWS
const auto scope = [&]() -> std::unique_ptr<ScopedThreadDPIAwarenessSetter>
{
if (comp != nullptr)
if (auto* handle = comp->getWindowHandle())
return std::make_unique<ScopedThreadDPIAwarenessSetter> (handle);
return nullptr;
}();
#endif
setSize (1, 1); // to keep the OS happy by not having zero-size windows
addToDesktop (ComponentPeer::windowIgnoresMouseClicks
| ComponentPeer::windowIsTemporary
| ComponentPeer::windowIgnoresKeyPresses);
}
else if (Component* const parent = comp->getParentComponent())
{
parent->addChildComponent (this);
}
}
void paint (Graphics& g) override
{
if (Component* c = target)
shadow.drawForRectangle (g, getLocalArea (c, c->getLocalBounds()));
}
void resized() override
{
repaint(); // (needed for correct repainting)
}
float getDesktopScaleFactor() const override
{
if (target != nullptr)
return target->getDesktopScaleFactor();
return Component::getDesktopScaleFactor();
}
private:
WeakReference<Component> target;
DropShadow shadow;
JUCE_DECLARE_NON_COPYABLE (ShadowWindow)
};
class DropShadower::VirtualDesktopWatcher final : public ComponentListener,
private Timer
{
public:
//==============================================================================
VirtualDesktopWatcher (Component& c) : component (&c)
{
component->addComponentListener (this);
update();
}
~VirtualDesktopWatcher() override
{
stopTimer();
if (auto* c = component.get())
c->removeComponentListener (this);
}
bool shouldHideDropShadow() const
{
return hasReasonToHide;
}
void addListener (void* listener, std::function<void()> cb)
{
listeners[listener] = std::move (cb);
}
void removeListener (void* listener)
{
listeners.erase (listener);
}
//==============================================================================
void componentParentHierarchyChanged (Component& c) override
{
if (component.get() == &c)
update();
}
private:
//==============================================================================
void update()
{
const auto newHasReasonToHide = [this]()
{
if (! component.wasObjectDeleted() && isWindows && component->isOnDesktop())
{
startTimerHz (5);
return ! isWindowOnCurrentVirtualDesktop (component->getWindowHandle());
}
stopTimer();
return false;
}();
if (std::exchange (hasReasonToHide, newHasReasonToHide) != newHasReasonToHide)
for (auto& l : listeners)
l.second();
}
void timerCallback() override
{
update();
}
//==============================================================================
WeakReference<Component> component;
const bool isWindows = (SystemStats::getOperatingSystemType() & SystemStats::Windows) != 0;
bool hasReasonToHide = false;
std::map<void*, std::function<void()>> listeners;
};
class DropShadower::ParentVisibilityChangedListener : public ComponentListener
{
public:
ParentVisibilityChangedListener (Component& r, ComponentListener& l)
: root (&r), listener (&l)
{
updateParentHierarchy();
}
~ParentVisibilityChangedListener() override
{
for (auto& compEntry : observedComponents)
if (auto* comp = compEntry.get())
comp->removeComponentListener (this);
}
void componentVisibilityChanged (Component& component) override
{
if (root != &component)
listener->componentVisibilityChanged (*root);
}
void componentParentHierarchyChanged (Component& component) override
{
if (root == &component)
updateParentHierarchy();
}
private:
class ComponentWithWeakReference
{
public:
explicit ComponentWithWeakReference (Component& c)
: ptr (&c), ref (&c) {}
Component* get() const { return ref.get(); }
bool operator< (const ComponentWithWeakReference& other) const { return ptr < other.ptr; }
private:
Component* ptr;
WeakReference<Component> ref;
};
void updateParentHierarchy()
{
const auto lastSeenComponents = std::exchange (observedComponents, [&]
{
std::set<ComponentWithWeakReference> result;
for (auto node = root; node != nullptr; node = node->getParentComponent())
result.emplace (*node);
return result;
}());
const auto withDifference = [] (const auto& rangeA, const auto& rangeB, auto&& callback)
{
std::vector<ComponentWithWeakReference> result;
std::set_difference (rangeA.begin(), rangeA.end(), rangeB.begin(), rangeB.end(), std::back_inserter (result));
for (const auto& item : result)
if (auto* c = item.get())
callback (*c);
};
withDifference (lastSeenComponents, observedComponents, [this] (auto& comp) { comp.removeComponentListener (this); });
withDifference (observedComponents, lastSeenComponents, [this] (auto& comp) { comp.addComponentListener (this); });
}
Component* root = nullptr;
ComponentListener* listener = nullptr;
std::set<ComponentWithWeakReference> observedComponents;
JUCE_DECLARE_NON_COPYABLE (ParentVisibilityChangedListener)
JUCE_DECLARE_NON_MOVEABLE (ParentVisibilityChangedListener)
};
//==============================================================================
DropShadower::DropShadower (const DropShadow& ds) : shadow (ds) {}
DropShadower::~DropShadower()
{
if (virtualDesktopWatcher != nullptr)
virtualDesktopWatcher->removeListener (this);
if (owner != nullptr)
{
owner->removeComponentListener (this);
owner = nullptr;
}
updateParent();
const ScopedValueSetter<bool> setter (reentrant, true);
shadowWindows.clear();
}
void DropShadower::setOwner (Component* componentToFollow)
{
if (componentToFollow != owner)
{
if (owner != nullptr)
owner->removeComponentListener (this);
// (the component can't be null)
jassert (componentToFollow != nullptr);
owner = componentToFollow;
jassert (owner != nullptr);
updateParent();
owner->addComponentListener (this);
// The visibility of `owner` is transitively affected by the visibility of its parents. Thus we need to trigger the
// componentVisibilityChanged() event in case it changes for any of the parents.
visibilityChangedListener = std::make_unique<ParentVisibilityChangedListener> (*owner,
static_cast<ComponentListener&> (*this));
virtualDesktopWatcher = std::make_unique<VirtualDesktopWatcher> (*owner);
virtualDesktopWatcher->addListener (this, [this]() { updateShadows(); });
updateShadows();
}
}
void DropShadower::updateParent()
{
if (Component* p = lastParentComp)
p->removeComponentListener (this);
lastParentComp = owner != nullptr ? owner->getParentComponent() : nullptr;
if (Component* p = lastParentComp)
p->addComponentListener (this);
}
void DropShadower::componentMovedOrResized (Component& c, bool /*wasMoved*/, bool /*wasResized*/)
{
if (owner == &c)
updateShadows();
}
void DropShadower::componentBroughtToFront (Component& c)
{
if (owner == &c)
updateShadows();
}
void DropShadower::componentChildrenChanged (Component&)
{
updateShadows();
}
void DropShadower::componentParentHierarchyChanged (Component& c)
{
if (owner == &c)
{
updateParent();
updateShadows();
}
}
void DropShadower::componentVisibilityChanged (Component& c)
{
if (owner == &c)
updateShadows();
}
void DropShadower::updateShadows()
{
if (reentrant)
return;
const ScopedValueSetter<bool> setter (reentrant, true);
if (owner != nullptr
&& owner->isShowing()
&& owner->getWidth() > 0 && owner->getHeight() > 0
&& (Desktop::canUseSemiTransparentWindows() || owner->getParentComponent() != nullptr)
&& (virtualDesktopWatcher == nullptr || ! virtualDesktopWatcher->shouldHideDropShadow()))
{
while (shadowWindows.size() < 4)
shadowWindows.add (new ShadowWindow (owner, shadow));
const int shadowEdge = jmax (shadow.offset.x, shadow.offset.y) + shadow.radius;
const int x = owner->getX();
const int y = owner->getY() - shadowEdge;
const int w = owner->getWidth();
const int h = owner->getHeight() + shadowEdge + shadowEdge;
for (int i = 4; --i >= 0;)
{
// there seem to be rare situations where the dropshadower may be deleted by
// callbacks during this loop, so use a weak ref to watch out for this..
WeakReference<Component> sw (shadowWindows[i]);
if (sw != nullptr)
{
sw->setAlwaysOnTop (owner->isAlwaysOnTop());
if (sw == nullptr)
return;
switch (i)
{
case 0: sw->setBounds (x - shadowEdge, y, shadowEdge, h); break;
case 1: sw->setBounds (x + w, y, shadowEdge, h); break;
case 2: sw->setBounds (x, y, w, shadowEdge); break;
case 3: sw->setBounds (x, owner->getBottom(), w, shadowEdge); break;
default: break;
}
if (sw == nullptr)
return;
sw->toBehind (i == 3 ? owner.get() : shadowWindows.getUnchecked (i + 1));
}
}
}
else
{
shadowWindows.clear();
}
}
} // namespace juce