Carla/source/modules/juce_gui_basics/layout/juce_ResizableEdgeComponent.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   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
{

ResizableEdgeComponent::ResizableEdgeComponent (Component* componentToResize,
                                                ComponentBoundsConstrainer* boundsConstrainer,
                                                Edge e)
   : component (componentToResize),
     constrainer (boundsConstrainer),
     edge (e)
{
    setRepaintsOnMouseActivity (true);
    setMouseCursor (isVertical() ? MouseCursor::LeftRightResizeCursor
                                 : MouseCursor::UpDownResizeCursor);
}

ResizableEdgeComponent::~ResizableEdgeComponent() = default;

//==============================================================================
bool ResizableEdgeComponent::isVertical() const noexcept
{
    return edge == leftEdge || edge == rightEdge;
}

void ResizableEdgeComponent::paint (Graphics& g)
{
    getLookAndFeel().drawStretchableLayoutResizerBar (g, getWidth(), getHeight(), isVertical(),
                                                      isMouseOver(), isMouseButtonDown());
}

void ResizableEdgeComponent::mouseDown (const MouseEvent&)
{
    if (component == nullptr)
    {
        jassertfalse; // You've deleted the component that this resizer was supposed to be using!
        return;
    }

    originalBounds = component->getBounds();

    if (constrainer != nullptr)
        constrainer->resizeStart();
}

void ResizableEdgeComponent::mouseDrag (const MouseEvent& e)
{
    if (component == nullptr)
    {
        jassertfalse; // You've deleted the component that this resizer was supposed to be using!
        return;
    }

    auto newBounds = originalBounds;

    switch (edge)
    {
        case leftEdge:      newBounds.setLeft (jmin (newBounds.getRight(), newBounds.getX() + e.getDistanceFromDragStartX())); break;
        case rightEdge:     newBounds.setWidth (jmax (0, newBounds.getWidth() + e.getDistanceFromDragStartX())); break;
        case topEdge:       newBounds.setTop (jmin (newBounds.getBottom(), newBounds.getY() + e.getDistanceFromDragStartY())); break;
        case bottomEdge:    newBounds.setHeight (jmax (0, newBounds.getHeight() + e.getDistanceFromDragStartY())); break;
        default:            jassertfalse; break;
    }

    if (constrainer != nullptr)
    {
        constrainer->setBoundsForComponent (component, newBounds,
                                            edge == topEdge,
                                            edge == leftEdge,
                                            edge == bottomEdge,
                                            edge == rightEdge);
    }
    else
    {
        if (auto* p = component->getPositioner())
            p->applyNewBounds (newBounds);
        else
            component->setBounds (newBounds);
    }
}

void ResizableEdgeComponent::mouseUp (const MouseEvent&)
{
    if (constrainer != nullptr)
        constrainer->resizeEnd();
}

} // namespace juce