juce_ComponentPeer.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
{
 
static uint32 lastUniquePeerID = 1;
 
//==============================================================================
ComponentPeer::ComponentPeer (Component& comp, int flags)
    : component (comp),
      styleFlags (flags),
      uniqueID (lastUniquePeerID += 2) // increment by 2 so that this can never hit 0
{
    auto& desktop = Desktop::getInstance();
    desktop.peers.add (this);
    desktop.addFocusChangeListener (this);
}
 
ComponentPeer::~ComponentPeer()
{
    auto& desktop = Desktop::getInstance();
    desktop.removeFocusChangeListener (this);
    desktop.peers.removeFirstMatchingValue (this);
    desktop.triggerFocusCallback();
}
 
//==============================================================================
int ComponentPeer::getNumPeers() noexcept
{
    return Desktop::getInstance().peers.size();
}
 
ComponentPeer* ComponentPeer::getPeer (const int index) noexcept
{
    return Desktop::getInstance().peers [index];
}
 
ComponentPeer* ComponentPeer::getPeerFor (const Component* const component) noexcept
{
    for (auto* peer : Desktop::getInstance().peers)
        if (&(peer->getComponent()) == component)
            return peer;
 
    return nullptr;
}
 
bool ComponentPeer::isValidPeer (const ComponentPeer* const peer) noexcept
{
    return Desktop::getInstance().peers.contains (const_cast<ComponentPeer*> (peer));
}
 
void ComponentPeer::updateBounds()
{
    setBounds (detail::ScalingHelpers::scaledScreenPosToUnscaled (component, component.getBoundsInParent()), false);
}
 
bool ComponentPeer::isKioskMode() const
{
    return Desktop::getInstance().getKioskModeComponent() == &component;
}
 
//==============================================================================
void ComponentPeer::handleMouseEvent (MouseInputSource::InputSourceType type, Point<float> pos, ModifierKeys newMods,
                                      float newPressure, float newOrientation, int64 time, PenDetails pen, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleEvent (*this, pos, time, newMods, newPressure, newOrientation, pen);
}
 
void ComponentPeer::handleMouseWheel (MouseInputSource::InputSourceType type, Point<float> pos, int64 time, const MouseWheelDetails& wheel, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleWheel (*this, pos, time, wheel);
}
 
void ComponentPeer::handleMagnifyGesture (MouseInputSource::InputSourceType type, Point<float> pos, int64 time, float scaleFactor, int touchIndex)
{
    if (auto* mouse = Desktop::getInstance().mouseSources->getOrCreateMouseInputSource (type, touchIndex))
        MouseInputSource (*mouse).handleMagnifyGesture (*this, pos, time, scaleFactor);
}
 
//==============================================================================
void ComponentPeer::handlePaint (LowLevelGraphicsContext& contextToPaintTo)
{
    Graphics g (contextToPaintTo);
 
    if (component.isTransformed())
        g.addTransform (component.getTransform());
 
    auto peerBounds = getBounds();
    auto componentBounds = component.getLocalBounds();
 
    if (component.isTransformed())
        componentBounds = componentBounds.transformedBy (component.getTransform());
 
    if (peerBounds.getWidth() != componentBounds.getWidth() || peerBounds.getHeight() != componentBounds.getHeight())
        // Tweak the scaling so that the component's integer size exactly aligns with the peer's scaled size
        g.addTransform (AffineTransform::scale ((float) peerBounds.getWidth()  / (float) componentBounds.getWidth(),
                                                (float) peerBounds.getHeight() / (float) componentBounds.getHeight()));
 
  #if JUCE_ENABLE_REPAINT_DEBUGGING
   #ifdef JUCE_IS_REPAINT_DEBUGGING_ACTIVE
    if (JUCE_IS_REPAINT_DEBUGGING_ACTIVE)
   #endif
    {
        g.saveState();
    }
  #endif
 
    JUCE_TRY
    {
        component.paintEntireComponent (g, true);
    }
    JUCE_CATCH_EXCEPTION
 
  #if JUCE_ENABLE_REPAINT_DEBUGGING
   #ifdef JUCE_IS_REPAINT_DEBUGGING_ACTIVE
    if (JUCE_IS_REPAINT_DEBUGGING_ACTIVE)
   #endif
    {
        // enabling this code will fill all areas that get repainted with a colour overlay, to show
        // clearly when things are being repainted.
        g.restoreState();
 
        static Random rng;
 
        g.fillAll (Colour ((uint8) rng.nextInt (255),
                           (uint8) rng.nextInt (255),
                           (uint8) rng.nextInt (255),
                           (uint8) 0x50));
    }
  #endif
 
    jassert (roundToInt (10.1f) == 10);
}
 
Component* ComponentPeer::getTargetForKeyPress()
{
    auto* c = Component::getCurrentlyFocusedComponent();
 
    if (c == nullptr)
        c = &component;
 
    if (c->isCurrentlyBlockedByAnotherModalComponent())
        if (auto* currentModalComp = Component::getCurrentlyModalComponent())
            c = currentModalComp;
 
    return c;
}
 
bool ComponentPeer::handleKeyPress (const int keyCode, const juce_wchar textCharacter)
{
    return handleKeyPress (KeyPress (keyCode,
                                     ModifierKeys::currentModifiers.withoutMouseButtons(),
                                     textCharacter));
}
 
bool ComponentPeer::handleKeyPress (const KeyPress& keyInfo)
{
    bool keyWasUsed = false;
 
    for (auto* target = getTargetForKeyPress(); target != nullptr; target = target->getParentComponent())
    {
        const WeakReference<Component> deletionChecker (target);
 
        if (auto* keyListeners = target->keyListeners.get())
        {
            for (int i = keyListeners->size(); --i >= 0;)
            {
                keyWasUsed = keyListeners->getUnchecked (i)->keyPressed (keyInfo, target);
 
                if (keyWasUsed || deletionChecker == nullptr)
                    return keyWasUsed;
 
                i = jmin (i, keyListeners->size());
            }
        }
 
        keyWasUsed = target->keyPressed (keyInfo);
 
        if (keyWasUsed || deletionChecker == nullptr)
            break;
    }
 
    if (! keyWasUsed && keyInfo.isKeyCode (KeyPress::tabKey))
    {
        if (auto* currentlyFocused = Component::getCurrentlyFocusedComponent())
        {
            currentlyFocused->moveKeyboardFocusToSibling (! keyInfo.getModifiers().isShiftDown());
            return true;
        }
    }
 
    return keyWasUsed;
}
 
bool ComponentPeer::handleKeyUpOrDown (const bool isKeyDown)
{
    bool keyWasUsed = false;
 
    for (auto* target = getTargetForKeyPress(); target != nullptr; target = target->getParentComponent())
    {
        const WeakReference<Component> deletionChecker (target);
 
        keyWasUsed = target->keyStateChanged (isKeyDown);
 
        if (keyWasUsed || deletionChecker == nullptr)
            break;
 
        if (auto* keyListeners = target->keyListeners.get())
        {
            for (int i = keyListeners->size(); --i >= 0;)
            {
                keyWasUsed = keyListeners->getUnchecked (i)->keyStateChanged (isKeyDown, target);
 
                if (keyWasUsed || deletionChecker == nullptr)
                    return keyWasUsed;
 
                i = jmin (i, keyListeners->size());
            }
        }
    }
 
    return keyWasUsed;
}
 
void ComponentPeer::handleModifierKeysChange()
{
    auto* target = Desktop::getInstance().getMainMouseSource().getComponentUnderMouse();
 
    if (target == nullptr)
        target = Component::getCurrentlyFocusedComponent();
 
    if (target == nullptr)
        target = &component;
 
    target->internalModifierKeysChanged();
}
 
void ComponentPeer::refreshTextInputTarget()
{
    const auto* lastTarget = std::exchange (textInputTarget, findCurrentTextInputTarget());
 
    if (lastTarget == textInputTarget)
        return;
 
    if (textInputTarget == nullptr)
        dismissPendingTextInput();
    else if (auto* c = Component::getCurrentlyFocusedComponent())
        textInputRequired (globalToLocal (c->getScreenPosition()), *textInputTarget);
}
 
TextInputTarget* ComponentPeer::findCurrentTextInputTarget()
{
    auto* c = Component::getCurrentlyFocusedComponent();
 
    if (c == &component || component.isParentOf (c))
        if (auto* ti = dynamic_cast<TextInputTarget*> (c))
            if (ti->isTextInputActive())
                return ti;
 
    return nullptr;
}
 
void ComponentPeer::closeInputMethodContext() {}
 
void ComponentPeer::dismissPendingTextInput()
{
    closeInputMethodContext();
}
 
//==============================================================================
void ComponentPeer::handleBroughtToFront()
{
    component.internalBroughtToFront();
}
 
void ComponentPeer::setConstrainer (ComponentBoundsConstrainer* const newConstrainer) noexcept
{
    constrainer = newConstrainer;
}
 
void ComponentPeer::handleMovedOrResized()
{
    const bool nowMinimised = isMinimised();
 
    if (component.flags.hasHeavyweightPeerFlag && ! nowMinimised)
    {
        const WeakReference<Component> deletionChecker (&component);
 
        auto newBounds = detail::ComponentHelpers::rawPeerPositionToLocal (component, getBounds());
        auto oldBounds = component.getBounds();
 
        const bool wasMoved   = (oldBounds.getPosition() != newBounds.getPosition());
        const bool wasResized = (oldBounds.getWidth() != newBounds.getWidth() || oldBounds.getHeight() != newBounds.getHeight());
 
        if (wasMoved || wasResized)
        {
            component.boundsRelativeToParent = newBounds;
 
            if (wasResized)
                component.repaint();
 
            component.sendMovedResizedMessages (wasMoved, wasResized);
 
            if (deletionChecker == nullptr)
                return;
        }
    }
 
    if (isWindowMinimised != nowMinimised)
    {
        isWindowMinimised = nowMinimised;
        component.minimisationStateChanged (nowMinimised);
        component.sendVisibilityChangeMessage();
    }
 
    const auto windowInSpecialState = isFullScreen() || isKioskMode() || nowMinimised;
 
    if (! windowInSpecialState)
        lastNonFullscreenBounds = component.getBounds();
}
 
void ComponentPeer::handleFocusGain()
{
    if (component.isParentOf (lastFocusedComponent)
          && lastFocusedComponent->isShowing()
          && lastFocusedComponent->getWantsKeyboardFocus())
    {
        Component::currentlyFocusedComponent = lastFocusedComponent;
        Desktop::getInstance().triggerFocusCallback();
        lastFocusedComponent->internalKeyboardFocusGain (Component::focusChangedDirectly);
    }
    else
    {
        if (! component.isCurrentlyBlockedByAnotherModalComponent())
            component.grabKeyboardFocus();
        else
            ModalComponentManager::getInstance()->bringModalComponentsToFront();
    }
}
 
void ComponentPeer::handleFocusLoss()
{
    if (component.hasKeyboardFocus (true))
    {
        lastFocusedComponent = Component::currentlyFocusedComponent;
 
        if (lastFocusedComponent != nullptr)
        {
            Component::currentlyFocusedComponent = nullptr;
            Desktop::getInstance().triggerFocusCallback();
            lastFocusedComponent->internalKeyboardFocusLoss (Component::focusChangedByMouseClick);
        }
    }
}
 
Component* ComponentPeer::getLastFocusedSubcomponent() const noexcept
{
    return (component.isParentOf (lastFocusedComponent) && lastFocusedComponent->isShowing())
                ? static_cast<Component*> (lastFocusedComponent)
                : &component;
}
 
void ComponentPeer::handleScreenSizeChange()
{
    component.parentSizeChanged();
    handleMovedOrResized();
}
 
void ComponentPeer::setNonFullScreenBounds (const Rectangle<int>& newBounds) noexcept
{
    lastNonFullscreenBounds = newBounds;
}
 
const Rectangle<int>& ComponentPeer::getNonFullScreenBounds() const noexcept
{
    return lastNonFullscreenBounds;
}
 
Point<int> ComponentPeer::localToGlobal (Point<int> p)   { return localToGlobal (p.toFloat()).roundToInt(); }
Point<int> ComponentPeer::globalToLocal (Point<int> p)   { return globalToLocal (p.toFloat()).roundToInt(); }
 
Rectangle<int> ComponentPeer::localToGlobal (const Rectangle<int>& relativePosition)
{
    return relativePosition.withPosition (localToGlobal (relativePosition.getPosition()));
}
 
Rectangle<int> ComponentPeer::globalToLocal (const Rectangle<int>& screenPosition)
{
    return screenPosition.withPosition (globalToLocal (screenPosition.getPosition()));
}
 
Rectangle<float> ComponentPeer::localToGlobal (const Rectangle<float>& relativePosition)
{
    return relativePosition.withPosition (localToGlobal (relativePosition.getPosition()));
}
 
Rectangle<float> ComponentPeer::globalToLocal (const Rectangle<float>& screenPosition)
{
    return screenPosition.withPosition (globalToLocal (screenPosition.getPosition()));
}
 
Rectangle<int> ComponentPeer::getAreaCoveredBy (const Component& subComponent) const
{
    return detail::ScalingHelpers::scaledScreenPosToUnscaled
            (component, component.getLocalArea (&subComponent, subComponent.getLocalBounds()));
}
 
//==============================================================================
namespace DragHelpers
{
    static bool isFileDrag (const ComponentPeer::DragInfo& info)
    {
        return ! info.files.isEmpty();
    }
 
    static bool isSuitableTarget (const ComponentPeer::DragInfo& info, Component* target)
    {
        return isFileDrag (info) ? dynamic_cast<FileDragAndDropTarget*> (target) != nullptr
                                 : dynamic_cast<TextDragAndDropTarget*> (target) != nullptr;
    }
 
    static bool isInterested (const ComponentPeer::DragInfo& info, Component* target)
    {
        return isFileDrag (info) ? dynamic_cast<FileDragAndDropTarget*> (target)->isInterestedInFileDrag (info.files)
                                 : dynamic_cast<TextDragAndDropTarget*> (target)->isInterestedInTextDrag (info.text);
    }
 
    static Component* findDragAndDropTarget (Component* c, const ComponentPeer::DragInfo& info, Component* lastOne)
    {
        for (; c != nullptr; c = c->getParentComponent())
            if (isSuitableTarget (info, c) && (c == lastOne || isInterested (info, c)))
                return c;
 
        return nullptr;
    }
}
 
bool ComponentPeer::handleDragMove (const ComponentPeer::DragInfo& info)
{
    auto* compUnderMouse = component.getComponentAt (info.position);
    auto* lastTarget = dragAndDropTargetComponent.get();
    Component* newTarget = nullptr;
 
    if (compUnderMouse != lastDragAndDropCompUnderMouse)
    {
        lastDragAndDropCompUnderMouse = compUnderMouse;
        newTarget = DragHelpers::findDragAndDropTarget (compUnderMouse, info, lastTarget);
 
        if (newTarget != lastTarget)
        {
            if (lastTarget != nullptr)
            {
                if (DragHelpers::isFileDrag (info))
                    dynamic_cast<FileDragAndDropTarget*> (lastTarget)->fileDragExit (info.files);
                else
                    dynamic_cast<TextDragAndDropTarget*> (lastTarget)->textDragExit (info.text);
            }
 
            dragAndDropTargetComponent = nullptr;
 
            if (DragHelpers::isSuitableTarget (info, newTarget))
            {
                dragAndDropTargetComponent = newTarget;
                auto pos = newTarget->getLocalPoint (&component, info.position);
 
                if (DragHelpers::isFileDrag (info))
                    dynamic_cast<FileDragAndDropTarget*> (newTarget)->fileDragEnter (info.files, pos.x, pos.y);
                else
                    dynamic_cast<TextDragAndDropTarget*> (newTarget)->textDragEnter (info.text, pos.x, pos.y);
            }
        }
    }
    else
    {
        newTarget = lastTarget;
    }
 
    if (! DragHelpers::isSuitableTarget (info, newTarget))
        return false;
 
    auto pos = newTarget->getLocalPoint (&component, info.position);
 
    if (DragHelpers::isFileDrag (info))
        dynamic_cast<FileDragAndDropTarget*> (newTarget)->fileDragMove (info.files, pos.x, pos.y);
    else
        dynamic_cast<TextDragAndDropTarget*> (newTarget)->textDragMove (info.text, pos.x, pos.y);
 
    return true;
}
 
bool ComponentPeer::handleDragExit (const ComponentPeer::DragInfo& info)
{
    DragInfo info2 (info);
    info2.position.setXY (-1, -1);
    const bool used = handleDragMove (info2);
 
    jassert (dragAndDropTargetComponent == nullptr);
    lastDragAndDropCompUnderMouse = nullptr;
    return used;
}
 
bool ComponentPeer::handleDragDrop (const ComponentPeer::DragInfo& info)
{
    handleDragMove (info);
 
    if (WeakReference<Component> targetComp = dragAndDropTargetComponent)
    {
        dragAndDropTargetComponent = nullptr;
        lastDragAndDropCompUnderMouse = nullptr;
 
        if (DragHelpers::isSuitableTarget (info, targetComp))
        {
            if (targetComp->isCurrentlyBlockedByAnotherModalComponent())
            {
                targetComp->internalModalInputAttempt();
 
                if (targetComp->isCurrentlyBlockedByAnotherModalComponent())
                    return true;
            }
 
            ComponentPeer::DragInfo infoCopy (info);
            infoCopy.position = targetComp->getLocalPoint (&component, info.position);
 
            // We'll use an async message to deliver the drop, because if the target decides
            // to run a modal loop, it can gum-up the operating system..
            MessageManager::callAsync ([=]
            {
                if (auto* c = targetComp.get())
                {
                    if (DragHelpers::isFileDrag (info))
                        dynamic_cast<FileDragAndDropTarget*> (c)->filesDropped (infoCopy.files, infoCopy.position.x, infoCopy.position.y);
                    else
                        dynamic_cast<TextDragAndDropTarget*> (c)->textDropped (infoCopy.text, infoCopy.position.x, infoCopy.position.y);
                }
            });
 
            return true;
        }
    }
 
    return false;
}
 
//==============================================================================
void ComponentPeer::handleUserClosingWindow()
{
    component.userTriedToCloseWindow();
}
 
bool ComponentPeer::setDocumentEditedStatus (bool)
{
    return false;
}
 
void ComponentPeer::setRepresentedFile (const File&)
{
}
 
//==============================================================================
int ComponentPeer::getCurrentRenderingEngine() const                             { return 0; }
void ComponentPeer::setCurrentRenderingEngine ([[maybe_unused]] int index)       { jassert (index == 0); }
 
//==============================================================================
std::function<ModifierKeys()> ComponentPeer::getNativeRealtimeModifiers = nullptr;
 
ModifierKeys ComponentPeer::getCurrentModifiersRealtime() noexcept
{
    if (getNativeRealtimeModifiers != nullptr)
        return getNativeRealtimeModifiers();
 
    return ModifierKeys::currentModifiers;
}
 
//==============================================================================
void ComponentPeer::forceDisplayUpdate()
{
    Desktop::getInstance().displays->refresh();
}
 
void ComponentPeer::globalFocusChanged ([[maybe_unused]] Component* comp)
{
    refreshTextInputTarget();
}
 
} // namespace juce