C++ WeakReference::get方法代码示例

    void checkForExternalDrag (DragAndDropTarget::SourceDetails& details, const Point<int>& screenPos)
    {
        if (! hasCheckedForExternalDrag)
        {
            if (Desktop::getInstance().findComponentAt (screenPos) == nullptr)
            {
                hasCheckedForExternalDrag = true;
                StringArray files;
                bool canMoveFiles = false;

                if (owner.shouldDropFilesWhenDraggedExternally (details, files, canMoveFiles)
                     && files.size() > 0)
                {
                    WeakReference<Component> thisWeakRef (this);
                    setVisible (false);
                    isDoingExternalDrag = true;

                    if (ModifierKeys::getCurrentModifiersRealtime().isAnyMouseButtonDown())
                        DragAndDropContainer::performExternalDragDropOfFiles (files, canMoveFiles);

                    delete thisWeakRef.get();
                    return;
                }
            }
        }
    }

/**
 * Retrieve a requires file that might be loaded for this
 * instance.
 *
 * @param name   The name used for the requires file.
 *
 * @return The loaded requires file, or OREF_NULL if this instance
 *         has not used the file yet.
 */
PackageClass *InterpreterInstance::getRequiresFile(RexxActivity *activity, RexxString *name)
{
    WeakReference *ref = (WeakReference *)requiresFiles->get(name);
    if (ref != OREF_NULL)
    {
        PackageClass *resolved = (PackageClass *)ref->get();
        if (resolved != OREF_NULL)
        {
            // get the guard lock on this...this will ensure that
            // the initializer is run before we grab this from the cache
            GuardLock lock(activity, resolved, ThePackageClass);
            return resolved;
        }
        // this was garbage collected, remove it from the table
        requiresFiles->remove(name);
    }
    return OREF_NULL;
}

/**
 * Check for a package already in the requires cache.
 *
 * @param name   The name of the target.
 *
 * @return The PackageClass instance, if any.
 */
RoutineClass *PackageManager::checkRequiresCache(RexxString *name, ProtectedObject &result)
{
    // first check this using the specified name.  Since we need to perform checks in the
    // macro space, it's possible this will be loaded under the simple name.  We'll need to check
    // table again using the fully resolved name afterward.
    WeakReference *requiresRef = (WeakReference *)loadedRequires->get(name);
    if (requiresRef != OREF_NULL)
    {
        RoutineClass *resolved = (RoutineClass *)requiresRef->get();
        if (resolved != OREF_NULL)
        {
            result = resolved;
            return resolved;
        }
        // this was garbage collected, remove it from the table
        loadedRequires->remove(name);
    }
    return OREF_NULL;
}

 DragAndDropTarget* getCurrentlyOver()
 {
     return dynamic_cast <DragAndDropTarget*> (currentlyOverComp.get());
 }

    void updateLocation (const bool canDoExternalDrag, const Point<int>& screenPos)
    {
        // (note: use a local copy of this in case a callback runs a modal loop and deletes
        // this object before it returns)
        DragAndDropTarget::SourceDetails details (sourceDetails);

        Point<int> newPos (screenPos + imageOffset);

        if (getParentComponent() != nullptr)
            newPos = getParentComponent()->getLocalPoint (nullptr, newPos);

        //if (newX != getX() || newY != getY())
        {
            setTopLeftPosition (newPos.getX(), newPos.getY());

            Point<int> relPos;
            DragAndDropTarget* const newTarget = findTarget (screenPos, relPos);
            Component* newTargetComp = dynamic_cast <Component*> (newTarget);

            drawImage = (newTarget == nullptr) || newTarget->shouldDrawDragImageWhenOver();

            if (newTargetComp != currentlyOverComp)
            {
                DragAndDropTarget* const lastTarget = getCurrentlyOver();

                if (lastTarget != nullptr && details.sourceComponent != nullptr
                      && lastTarget->isInterestedInDragSource (details))
                    lastTarget->itemDragExit (details);

                currentlyOverComp = newTargetComp;

                if (newTarget != nullptr)
                {
                    details.localPosition = relPos;

                    if (newTarget->isInterestedInDragSource (details))
                        newTarget->itemDragEnter (details);
                }
            }

            {
                DragAndDropTarget* const target = getCurrentlyOver();
                if (target != nullptr)
                {
                    details.localPosition = relPos;

                    if (target->isInterestedInDragSource (details))
                        target->itemDragMove (details);
                }
            }

            if (getCurrentlyOver() == nullptr && canDoExternalDrag && ! hasCheckedForExternalDrag)
            {
                if (Desktop::getInstance().findComponentAt (screenPos) == nullptr)
                {
                    hasCheckedForExternalDrag = true;
                    StringArray files;
                    bool canMoveFiles = false;

                    if (owner->shouldDropFilesWhenDraggedExternally (details, files, canMoveFiles)
                         && files.size() > 0)
                    {
                        WeakReference<Component> thisWeakRef (this);
                        setVisible (false);

                        if (ModifierKeys::getCurrentModifiersRealtime().isAnyMouseButtonDown())
                            DragAndDropContainer::performExternalDragDropOfFiles (files, canMoveFiles);

                        delete thisWeakRef.get();
                        return;
                    }
                }
            }
        }
    }