- /*
- ==============================================================================
-
- 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
- {
-
- bool juce_performDragDropFiles (const StringArray&, const bool copyFiles, bool& shouldStop);
- bool juce_performDragDropText (const String&, bool& shouldStop);
-
-
- //==============================================================================
- class DragAndDropContainer::DragImageComponent : public Component,
- private Timer
- {
- public:
- DragImageComponent (const ScaledImage& im,
- const var& desc,
- Component* const sourceComponent,
- const MouseInputSource* draggingSource,
- DragAndDropContainer& ddc,
- Point<int> offset)
- : sourceDetails (desc, sourceComponent, Point<int>()),
- image (im),
- owner (ddc),
- mouseDragSource (draggingSource->getComponentUnderMouse()),
- imageOffset (transformOffsetCoordinates (sourceComponent, offset)),
- originalInputSourceIndex (draggingSource->getIndex()),
- originalInputSourceType (draggingSource->getType())
- {
- updateSize();
-
- if (mouseDragSource == nullptr)
- mouseDragSource = sourceComponent;
-
- mouseDragSource->addMouseListener (this, false);
-
- startTimer (200);
-
- setInterceptsMouseClicks (false, false);
- setWantsKeyboardFocus (true);
- setAlwaysOnTop (true);
- }
-
- ~DragImageComponent() override
- {
- owner.dragImageComponents.remove (owner.dragImageComponents.indexOf (this), false);
-
- if (mouseDragSource != nullptr)
- {
- mouseDragSource->removeMouseListener (this);
-
- if (auto* current = getCurrentlyOver())
- if (current->isInterestedInDragSource (sourceDetails))
- current->itemDragExit (sourceDetails);
- }
-
- owner.dragOperationEnded (sourceDetails);
- }
-
- void paint (Graphics& g) override
- {
- if (isOpaque())
- g.fillAll (Colours::white);
-
- g.setOpacity (1.0f);
- g.drawImage (image.getImage(), getLocalBounds().toFloat());
- }
-
- void mouseUp (const MouseEvent& e) override
- {
- if (e.originalComponent != this && isOriginalInputSource (e.source))
- {
- if (mouseDragSource != nullptr)
- mouseDragSource->removeMouseListener (this);
-
- // (note: use a local copy of this in case the callback runs
- // a modal loop and deletes this object before the method completes)
- auto details = sourceDetails;
- DragAndDropTarget* finalTarget = nullptr;
-
- auto wasVisible = isVisible();
- setVisible (false);
- Component* unused;
- finalTarget = findTarget (e.getScreenPosition(), details.localPosition, unused);
-
- if (wasVisible) // fade the component and remove it - it'll be deleted later by the timer callback
- dismissWithAnimation (finalTarget == nullptr);
-
- if (auto* parent = getParentComponent())
- parent->removeChildComponent (this);
-
- if (finalTarget != nullptr)
- {
- currentlyOverComp = nullptr;
- finalTarget->itemDropped (details);
- }
-
- // careful - this object could now be deleted..
- }
- }
-
- void mouseDrag (const MouseEvent& e) override
- {
- if (e.originalComponent != this && isOriginalInputSource (e.source))
- updateLocation (true, e.getScreenPosition());
- }
-
- void updateLocation (const bool canDoExternalDrag, Point<int> screenPos)
- {
- auto details = sourceDetails;
-
- setNewScreenPos (screenPos);
-
- Component* newTargetComp;
- auto* newTarget = findTarget (screenPos, details.localPosition, newTargetComp);
-
- setVisible (newTarget == nullptr || newTarget->shouldDrawDragImageWhenOver());
-
- if (newTargetComp != currentlyOverComp)
- {
- if (auto* lastTarget = getCurrentlyOver())
- if (details.sourceComponent != nullptr && lastTarget->isInterestedInDragSource (details))
- lastTarget->itemDragExit (details);
-
- currentlyOverComp = newTargetComp;
-
- if (newTarget != nullptr
- && newTarget->isInterestedInDragSource (details))
- newTarget->itemDragEnter (details);
- }
-
- sendDragMove (details);
-
- if (canDoExternalDrag)
- {
- auto now = Time::getCurrentTime();
-
- if (getCurrentlyOver() != nullptr)
- lastTimeOverTarget = now;
- else if (now > lastTimeOverTarget + RelativeTime::milliseconds (700))
- checkForExternalDrag (details, screenPos);
- }
-
- forceMouseCursorUpdate();
- }
-
- void updateImage (const ScaledImage& newImage)
- {
- image = newImage;
- updateSize();
- repaint();
- }
-
- void timerCallback() override
- {
- forceMouseCursorUpdate();
-
- if (sourceDetails.sourceComponent == nullptr)
- {
- deleteSelf();
- }
- else
- {
- for (auto& s : Desktop::getInstance().getMouseSources())
- {
- if (isOriginalInputSource (s) && ! s.isDragging())
- {
- if (mouseDragSource != nullptr)
- mouseDragSource->removeMouseListener (this);
-
- deleteSelf();
- break;
- }
- }
- }
- }
-
- bool keyPressed (const KeyPress& key) override
- {
- if (key == KeyPress::escapeKey)
- {
- const auto wasVisible = isVisible();
- setVisible (false);
-
- if (wasVisible)
- dismissWithAnimation (true);
-
- deleteSelf();
- return true;
- }
-
- return false;
- }
-
- bool canModalEventBeSentToComponent (const Component* targetComponent) override
- {
- return targetComponent == mouseDragSource;
- }
-
- // (overridden to avoid beeps when dragging)
- void inputAttemptWhenModal() override {}
-
- DragAndDropTarget::SourceDetails sourceDetails;
-
- private:
- ScaledImage image;
- DragAndDropContainer& owner;
- WeakReference<Component> mouseDragSource, currentlyOverComp;
- const Point<int> imageOffset;
- bool hasCheckedForExternalDrag = false;
- Time lastTimeOverTarget;
- int originalInputSourceIndex;
- MouseInputSource::InputSourceType originalInputSourceType;
-
- void updateSize()
- {
- const auto bounds = image.getScaledBounds().toNearestInt();
- setSize (bounds.getWidth(), bounds.getHeight());
- }
-
- void forceMouseCursorUpdate()
- {
- Desktop::getInstance().getMainMouseSource().forceMouseCursorUpdate();
- }
-
- DragAndDropTarget* getCurrentlyOver() const noexcept
- {
- return dynamic_cast<DragAndDropTarget*> (currentlyOverComp.get());
- }
-
- static Component* findDesktopComponentBelow (Point<int> screenPos)
- {
- auto& desktop = Desktop::getInstance();
-
- for (auto i = desktop.getNumComponents(); --i >= 0;)
- {
- auto* desktopComponent = desktop.getComponent (i);
- auto dPoint = desktopComponent->getLocalPoint (nullptr, screenPos);
-
- if (auto* c = desktopComponent->getComponentAt (dPoint))
- {
- auto cPoint = c->getLocalPoint (desktopComponent, dPoint);
-
- if (c->hitTest (cPoint.getX(), cPoint.getY()))
- return c;
- }
- }
-
- return nullptr;
- }
-
- Point<int> transformOffsetCoordinates (const Component* const sourceComponent, Point<int> offsetInSource) const
- {
- return getLocalPoint (sourceComponent, offsetInSource) - getLocalPoint (sourceComponent, Point<int>());
- }
-
- DragAndDropTarget* findTarget (Point<int> screenPos, Point<int>& relativePos,
- Component*& resultComponent) const
- {
- auto* hit = getParentComponent();
-
- if (hit == nullptr)
- hit = findDesktopComponentBelow (screenPos);
- else
- hit = hit->getComponentAt (hit->getLocalPoint (nullptr, screenPos));
-
- // (note: use a local copy of this in case the callback runs
- // a modal loop and deletes this object before the method completes)
- auto details = sourceDetails;
-
- while (hit != nullptr)
- {
- if (auto* ddt = dynamic_cast<DragAndDropTarget*> (hit))
- {
- if (ddt->isInterestedInDragSource (details))
- {
- relativePos = hit->getLocalPoint (nullptr, screenPos);
- resultComponent = hit;
- return ddt;
- }
- }
-
- hit = hit->getParentComponent();
- }
-
- resultComponent = nullptr;
- return nullptr;
- }
-
- void setNewScreenPos (Point<int> screenPos)
- {
- auto newPos = screenPos - imageOffset;
-
- if (auto* p = getParentComponent())
- newPos = p->getLocalPoint (nullptr, newPos);
-
- setTopLeftPosition (newPos);
- }
-
- void sendDragMove (DragAndDropTarget::SourceDetails& details) const
- {
- if (auto* target = getCurrentlyOver())
- if (target->isInterestedInDragSource (details))
- target->itemDragMove (details);
- }
-
- void checkForExternalDrag (DragAndDropTarget::SourceDetails& details, Point<int> screenPos)
- {
- if (! hasCheckedForExternalDrag)
- {
- if (Desktop::getInstance().findComponentAt (screenPos) == nullptr)
- {
- hasCheckedForExternalDrag = true;
-
- if (ComponentPeer::getCurrentModifiersRealtime().isAnyMouseButtonDown())
- {
- StringArray files;
- auto canMoveFiles = false;
-
- if (owner.shouldDropFilesWhenDraggedExternally (details, files, canMoveFiles) && ! files.isEmpty())
- {
- MessageManager::callAsync ([=] { DragAndDropContainer::performExternalDragDropOfFiles (files, canMoveFiles); });
- deleteSelf();
- return;
- }
-
- String text;
-
- if (owner.shouldDropTextWhenDraggedExternally (details, text) && text.isNotEmpty())
- {
- MessageManager::callAsync ([=] { DragAndDropContainer::performExternalDragDropOfText (text); });
- deleteSelf();
- return;
- }
- }
- }
- }
- }
-
- void deleteSelf()
- {
- delete this;
- }
-
- void dismissWithAnimation (const bool shouldSnapBack)
- {
- setVisible (true);
- auto& animator = Desktop::getInstance().getAnimator();
-
- if (shouldSnapBack && sourceDetails.sourceComponent != nullptr)
- {
- auto target = sourceDetails.sourceComponent->localPointToGlobal (sourceDetails.sourceComponent->getLocalBounds().getCentre());
- auto ourCentre = localPointToGlobal (getLocalBounds().getCentre());
-
- animator.animateComponent (this,
- getBounds() + (target - ourCentre),
- 0.0f, 120,
- true, 1.0, 1.0);
- }
- else
- {
- animator.fadeOut (this, 120);
- }
- }
-
- bool isOriginalInputSource (const MouseInputSource& sourceToCheck)
- {
- return (sourceToCheck.getType() == originalInputSourceType
- && sourceToCheck.getIndex() == originalInputSourceIndex);
- }
-
- JUCE_DECLARE_NON_COPYABLE (DragImageComponent)
- };
-
-
- //==============================================================================
- DragAndDropContainer::DragAndDropContainer() = default;
-
- DragAndDropContainer::~DragAndDropContainer() = default;
-
- void DragAndDropContainer::startDragging (const var& sourceDescription,
- Component* sourceComponent,
- const ScaledImage& dragImage,
- const bool allowDraggingToExternalWindows,
- const Point<int>* imageOffsetFromMouse,
- const MouseInputSource* inputSourceCausingDrag)
- {
- if (isAlreadyDragging (sourceComponent))
- return;
-
- auto* draggingSource = getMouseInputSourceForDrag (sourceComponent, inputSourceCausingDrag);
-
- if (draggingSource == nullptr || ! draggingSource->isDragging())
- {
- jassertfalse; // You must call startDragging() from within a mouseDown or mouseDrag callback!
- return;
- }
-
- const auto lastMouseDown = draggingSource->getLastMouseDownPosition().roundToInt();
-
- struct ImageAndOffset
- {
- ScaledImage image;
- Point<double> offset;
- };
-
- const auto imageToUse = [&]() -> ImageAndOffset
- {
- if (! dragImage.getImage().isNull())
- return { dragImage, imageOffsetFromMouse != nullptr ? dragImage.getScaledBounds().getConstrainedPoint (-imageOffsetFromMouse->toDouble())
- : dragImage.getScaledBounds().getCentre() };
-
- const auto scaleFactor = 2.0;
- auto image = sourceComponent->createComponentSnapshot (sourceComponent->getLocalBounds(), true, (float) scaleFactor)
- .convertedToFormat (Image::ARGB);
- image.multiplyAllAlphas (0.6f);
-
- const auto relPos = sourceComponent->getLocalPoint (nullptr, lastMouseDown).toDouble();
- const auto clipped = (image.getBounds().toDouble() / scaleFactor).getConstrainedPoint (relPos);
-
- Image fade (Image::SingleChannel, image.getWidth(), image.getHeight(), true);
- Graphics fadeContext (fade);
-
- ColourGradient gradient;
- gradient.isRadial = true;
- gradient.point1 = clipped.toFloat() * scaleFactor;
- gradient.point2 = gradient.point1 + Point<float> (0.0f, scaleFactor * 400.0f);
- gradient.addColour (0.0, Colours::white);
- gradient.addColour (0.375, Colours::white);
- gradient.addColour (1.0, Colours::transparentWhite);
-
- fadeContext.setGradientFill (gradient);
- fadeContext.fillAll();
-
- Image composite (Image::ARGB, image.getWidth(), image.getHeight(), true);
- Graphics compositeContext (composite);
-
- compositeContext.reduceClipRegion (fade, {});
- compositeContext.drawImageAt (image, 0, 0);
-
- return { ScaledImage (composite, scaleFactor), clipped };
- }();
-
- auto* dragImageComponent = dragImageComponents.add (new DragImageComponent (imageToUse.image, sourceDescription, sourceComponent,
- draggingSource, *this, imageToUse.offset.roundToInt()));
-
- if (allowDraggingToExternalWindows)
- {
- if (! Desktop::canUseSemiTransparentWindows())
- dragImageComponent->setOpaque (true);
-
- dragImageComponent->addToDesktop (ComponentPeer::windowIgnoresMouseClicks
- | ComponentPeer::windowIsTemporary);
- }
- else
- {
- if (auto* thisComp = dynamic_cast<Component*> (this))
- {
- thisComp->addChildComponent (dragImageComponent);
- }
- else
- {
- jassertfalse; // Your DragAndDropContainer needs to be a Component!
- return;
- }
- }
-
- dragImageComponent->sourceDetails.localPosition = sourceComponent->getLocalPoint (nullptr, lastMouseDown);
- dragImageComponent->updateLocation (false, lastMouseDown);
- dragImageComponent->grabKeyboardFocus();
-
- #if JUCE_WINDOWS
- // Under heavy load, the layered window's paint callback can often be lost by the OS,
- // so forcing a repaint at least once makes sure that the window becomes visible..
- if (auto* peer = dragImageComponent->getPeer())
- peer->performAnyPendingRepaintsNow();
- #endif
-
- dragOperationStarted (dragImageComponent->sourceDetails);
- }
-
- bool DragAndDropContainer::isDragAndDropActive() const
- {
- return dragImageComponents.size() > 0;
- }
-
- int DragAndDropContainer::getNumCurrentDrags() const
- {
- return dragImageComponents.size();
- }
-
- var DragAndDropContainer::getCurrentDragDescription() const
- {
- // If you are performing drag and drop in a multi-touch environment then
- // you should use the getDragDescriptionForIndex() method instead!
- jassert (dragImageComponents.size() < 2);
-
- return dragImageComponents.size() != 0 ? dragImageComponents[0]->sourceDetails.description
- : var();
- }
-
- var DragAndDropContainer::getDragDescriptionForIndex (int index) const
- {
- if (! isPositiveAndBelow (index, dragImageComponents.size()))
- return {};
-
- return dragImageComponents.getUnchecked (index)->sourceDetails.description;
- }
-
- void DragAndDropContainer::setCurrentDragImage (const ScaledImage& newImage)
- {
- // If you are performing drag and drop in a multi-touch environment then
- // you should use the setDragImageForIndex() method instead!
- jassert (dragImageComponents.size() < 2);
-
- dragImageComponents[0]->updateImage (newImage);
- }
-
- void DragAndDropContainer::setDragImageForIndex (int index, const ScaledImage& newImage)
- {
- if (isPositiveAndBelow (index, dragImageComponents.size()))
- dragImageComponents.getUnchecked (index)->updateImage (newImage);
- }
-
- DragAndDropContainer* DragAndDropContainer::findParentDragContainerFor (Component* c)
- {
- return c != nullptr ? c->findParentComponentOfClass<DragAndDropContainer>() : nullptr;
- }
-
- bool DragAndDropContainer::shouldDropFilesWhenDraggedExternally (const DragAndDropTarget::SourceDetails&, StringArray&, bool&)
- {
- return false;
- }
-
- bool DragAndDropContainer::shouldDropTextWhenDraggedExternally (const DragAndDropTarget::SourceDetails&, String&)
- {
- return false;
- }
-
- void DragAndDropContainer::dragOperationStarted (const DragAndDropTarget::SourceDetails&) {}
- void DragAndDropContainer::dragOperationEnded (const DragAndDropTarget::SourceDetails&) {}
-
- const MouseInputSource* DragAndDropContainer::getMouseInputSourceForDrag (Component* sourceComponent,
- const MouseInputSource* inputSourceCausingDrag)
- {
- if (inputSourceCausingDrag == nullptr)
- {
- auto minDistance = std::numeric_limits<float>::max();
- auto& desktop = Desktop::getInstance();
-
- auto centrePoint = sourceComponent ? sourceComponent->getScreenBounds().getCentre().toFloat() : Point<float>();
- auto numDragging = desktop.getNumDraggingMouseSources();
-
- for (auto i = 0; i < numDragging; ++i)
- {
- if (auto* ms = desktop.getDraggingMouseSource (i))
- {
- auto distance = ms->getScreenPosition().getDistanceSquaredFrom (centrePoint);
-
- if (distance < minDistance)
- {
- minDistance = distance;
- inputSourceCausingDrag = ms;
- }
- }
- }
- }
-
- // You must call startDragging() from within a mouseDown or mouseDrag callback!
- jassert (inputSourceCausingDrag != nullptr && inputSourceCausingDrag->isDragging());
-
- return inputSourceCausingDrag;
- }
-
- bool DragAndDropContainer::isAlreadyDragging (Component* component) const noexcept
- {
- for (auto* dragImageComp : dragImageComponents)
- {
- if (dragImageComp->sourceDetails.sourceComponent == component)
- return true;
- }
-
- return false;
- }
-
- //==============================================================================
- DragAndDropTarget::SourceDetails::SourceDetails (const var& desc, Component* comp, Point<int> pos) noexcept
- : description (desc),
- sourceComponent (comp),
- localPosition (pos)
- {
- }
-
- void DragAndDropTarget::itemDragEnter (const SourceDetails&) {}
- void DragAndDropTarget::itemDragMove (const SourceDetails&) {}
- void DragAndDropTarget::itemDragExit (const SourceDetails&) {}
- bool DragAndDropTarget::shouldDrawDragImageWhenOver() { return true; }
-
- //==============================================================================
- void FileDragAndDropTarget::fileDragEnter (const StringArray&, int, int) {}
- void FileDragAndDropTarget::fileDragMove (const StringArray&, int, int) {}
- void FileDragAndDropTarget::fileDragExit (const StringArray&) {}
-
- void TextDragAndDropTarget::textDragEnter (const String&, int, int) {}
- void TextDragAndDropTarget::textDragMove (const String&, int, int) {}
- void TextDragAndDropTarget::textDragExit (const String&) {}
-
- } // namespace juce
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