Carla/source/modules/juce_gui_basics/windows/juce_CallOutBox.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
{

CallOutBox::CallOutBox (Component& c, Rectangle<int> area, Component* const parent)
    : content (c)
{
    addAndMakeVisible (content);

    if (parent != nullptr)
    {
        parent->addChildComponent (this);
        updatePosition (area, parent->getLocalBounds());
        setVisible (true);
    }
    else
    {
        setAlwaysOnTop (juce_areThereAnyAlwaysOnTopWindows());

        updatePosition (area, Desktop::getInstance().getDisplays().findDisplayForRect (area).userArea);

        addToDesktop (ComponentPeer::windowIsTemporary);

        startTimer (100);
    }

    creationTime = Time::getCurrentTime();
}

CallOutBox::~CallOutBox()
{
}

//==============================================================================
class CallOutBoxCallback  : public ModalComponentManager::Callback,
                            private Timer
{
public:
    CallOutBoxCallback (Component* c, const Rectangle<int>& area, Component* parent)
        : content (c), callout (*c, area, parent)
    {
        callout.setVisible (true);
        callout.enterModalState (true, this);
        startTimer (200);
    }

    void modalStateFinished (int) override {}

    void timerCallback() override
    {
        if (! Process::isForegroundProcess())
            callout.dismiss();
    }

    std::unique_ptr<Component> content;
    CallOutBox callout;

    JUCE_DECLARE_NON_COPYABLE (CallOutBoxCallback)
};

CallOutBox& CallOutBox::launchAsynchronously (Component* content, Rectangle<int> area, Component* parent)
{
    jassert (content != nullptr); // must be a valid content component!

    return (new CallOutBoxCallback (content, area, parent))->callout;
}

//==============================================================================
void CallOutBox::setArrowSize (const float newSize)
{
    arrowSize = newSize;
    refreshPath();
}

int CallOutBox::getBorderSize() const noexcept
{
    return jmax (getLookAndFeel().getCallOutBoxBorderSize (*this), (int) arrowSize);
}

void CallOutBox::paint (Graphics& g)
{
    getLookAndFeel().drawCallOutBoxBackground (*this, g, outline, background);
}

void CallOutBox::resized()
{
    auto borderSpace = getBorderSize();
    content.setTopLeftPosition (borderSpace, borderSpace);
    refreshPath();
}

void CallOutBox::moved()
{
    refreshPath();
}

void CallOutBox::childBoundsChanged (Component*)
{
    updatePosition (targetArea, availableArea);
}

bool CallOutBox::hitTest (int x, int y)
{
    return outline.contains ((float) x, (float) y);
}

void CallOutBox::inputAttemptWhenModal()
{
    if (dismissalMouseClicksAreAlwaysConsumed
         || targetArea.contains (getMouseXYRelative() + getBounds().getPosition()))
    {
        // if you click on the area that originally popped-up the callout, you expect it
        // to get rid of the box, but deleting the box here allows the click to pass through and
        // probably re-trigger it, so we need to dismiss the box asynchronously to consume the click..

        // For touchscreens, we make sure not to dismiss the CallOutBox immediately,
        // as Windows still sends touch events before the CallOutBox had a chance
        // to really open.

        auto elapsed = Time::getCurrentTime() - creationTime;

        if (elapsed.inMilliseconds() > 200)
            dismiss();
    }
    else
    {
        exitModalState (0);
        setVisible (false);
    }
}

void CallOutBox::setDismissalMouseClicksAreAlwaysConsumed (bool b) noexcept
{
    dismissalMouseClicksAreAlwaysConsumed = b;
}

enum { callOutBoxDismissCommandId = 0x4f83a04b };

void CallOutBox::handleCommandMessage (int commandId)
{
    Component::handleCommandMessage (commandId);

    if (commandId == callOutBoxDismissCommandId)
    {
        exitModalState (0);
        setVisible (false);
    }
}

void CallOutBox::dismiss()
{
    postCommandMessage (callOutBoxDismissCommandId);
}

bool CallOutBox::keyPressed (const KeyPress& key)
{
    if (key.isKeyCode (KeyPress::escapeKey))
    {
        inputAttemptWhenModal();
        return true;
    }

    return false;
}

void CallOutBox::updatePosition (const Rectangle<int>& newAreaToPointTo, const Rectangle<int>& newAreaToFitIn)
{
    targetArea = newAreaToPointTo;
    availableArea = newAreaToFitIn;

    auto borderSpace = getBorderSize();

    Rectangle<int> newBounds (content.getWidth()  + borderSpace * 2,
                              content.getHeight() + borderSpace * 2);

    auto hw = newBounds.getWidth() / 2;
    auto hh = newBounds.getHeight() / 2;
    auto hwReduced = (float) (hw - borderSpace * 2);
    auto hhReduced = (float) (hh - borderSpace * 2);
    auto arrowIndent = borderSpace - arrowSize;

    Point<float> targets[4] = { { (float) targetArea.getCentreX(), (float) targetArea.getBottom() },
                                { (float) targetArea.getRight(),   (float) targetArea.getCentreY() },
                                { (float) targetArea.getX(),       (float) targetArea.getCentreY() },
                                { (float) targetArea.getCentreX(), (float) targetArea.getY() } };

    Line<float> lines[4] = { { targets[0].translated (-hwReduced, hh - arrowIndent),    targets[0].translated (hwReduced, hh - arrowIndent) },
                             { targets[1].translated (hw - arrowIndent, -hhReduced),    targets[1].translated (hw - arrowIndent, hhReduced) },
                             { targets[2].translated (-(hw - arrowIndent), -hhReduced), targets[2].translated (-(hw - arrowIndent), hhReduced) },
                             { targets[3].translated (-hwReduced, -(hh - arrowIndent)), targets[3].translated (hwReduced, -(hh - arrowIndent)) } };

    auto centrePointArea = newAreaToFitIn.reduced (hw, hh).toFloat();
    auto targetCentre = targetArea.getCentre().toFloat();

    float nearest = 1.0e9f;

    for (int i = 0; i < 4; ++i)
    {
        Line<float> constrainedLine (centrePointArea.getConstrainedPoint (lines[i].getStart()),
                                     centrePointArea.getConstrainedPoint (lines[i].getEnd()));

        auto centre = constrainedLine.findNearestPointTo (targetCentre);
        auto distanceFromCentre = centre.getDistanceFrom (targets[i]);

        if (! centrePointArea.intersects (lines[i]))
            distanceFromCentre += 1000.0f;

        if (distanceFromCentre < nearest)
        {
            nearest = distanceFromCentre;
            targetPoint = targets[i];

            newBounds.setPosition ((int) (centre.x - hw),
                                   (int) (centre.y - hh));
        }
    }

    setBounds (newBounds);
}

void CallOutBox::refreshPath()
{
    repaint();
    background = {};
    outline.clear();

    const float gap = 4.5f;

    outline.addBubble (content.getBounds().toFloat().expanded (gap, gap),
                       getLocalBounds().toFloat(),
                       targetPoint - getPosition().toFloat(),
                       getLookAndFeel().getCallOutBoxCornerSize (*this), arrowSize * 0.7f);
}

void CallOutBox::timerCallback()
{
    toFront (true);
    stopTimer();
}

} // namespace juce