JUCE/modules/juce_gui_basics/windows/juce_ComponentPeer.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   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
{

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
{
    Desktop::getInstance().peers.add (this);
}

ComponentPeer::~ComponentPeer()
{
    auto& desktop = Desktop::getInstance();
    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 (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 (peerBounds.getWidth()  / (float) componentBounds.getWidth(),
                                                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

    /** If this fails, it's probably be because your CPU floating-point precision mode has
        been set to low.. This setting is sometimes changed by things like Direct3D, and can
        mess up a lot of the calculations that the library needs to do.
    */
    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 (auto* currentlyFocused = Component::getCurrentlyFocusedComponent())
        {
            const bool isTab      = (keyInfo == KeyPress::tabKey);
            const bool isShiftTab = (keyInfo == KeyPress (KeyPress::tabKey, ModifierKeys::shiftModifier, 0));

            if (isTab || isShiftTab)
            {
                currentlyFocused->moveKeyboardFocusToSibling (isTab);
                keyWasUsed = (currentlyFocused != Component::getCurrentlyFocusedComponent());

                if (keyWasUsed || deletionChecker == nullptr)
                    break;
            }
        }
    }

    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();
}

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::dismissPendingTextInput() {}

//==============================================================================
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 = Component::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();
    }

    if (! isFullScreen())
        lastNonFullscreenBounds = component.getBounds();
}

void ComponentPeer::handleFocusGain()
{
    if (component.isParentOf (lastFocusedComponent)
          && lastFocusedComponent->isShowing()
          && lastFocusedComponent->getWantsKeyboardFocus())
    {
        Component::currentlyFocusedComponent = lastFocusedComponent;
        Desktop::getInstance().triggerFocusCallback();
        lastFocusedComponent->internalFocusGain (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->internalFocusLoss (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<int> ComponentPeer::getAreaCoveredBy (Component& subComponent) const
{
    return 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 (int index)       { jassert (index == 0); ignoreUnused (index); }

//==============================================================================
std::function<ModifierKeys()> ComponentPeer::getNativeRealtimeModifiers = nullptr;

ModifierKeys ComponentPeer::getCurrentModifiersRealtime() noexcept
{
    if (getNativeRealtimeModifiers != nullptr)
        return getNativeRealtimeModifiers();

    return ModifierKeys::currentModifiers;
}


} // namespace juce