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

TooltipWindow::TooltipWindow (Component* parentComp, int delayMs)
    : Component ("tooltip"),
      millisecondsBeforeTipAppears (delayMs)
{
    setAlwaysOnTop (true);
    setOpaque (true);

    if (parentComp != nullptr)
        parentComp->addChildComponent (this);

    if (Desktop::getInstance().getMainMouseSource().canHover())
        startTimer (123);
}

TooltipWindow::~TooltipWindow()
{
    hideTip();
}

void TooltipWindow::setMillisecondsBeforeTipAppears (const int newTimeMs) noexcept
{
    millisecondsBeforeTipAppears = newTimeMs;
}

void TooltipWindow::paint (Graphics& g)
{
    getLookAndFeel().drawTooltip (g, tipShowing, getWidth(), getHeight());
}

void TooltipWindow::mouseEnter (const MouseEvent&)
{
    hideTip();
}

void TooltipWindow::updatePosition (const String& tip, Point<int> pos, Rectangle<int> parentArea)
{
    setBounds (getLookAndFeel().getTooltipBounds (tip, pos, parentArea));
    setVisible (true);
}

#if JUCE_DEBUG
static Array<TooltipWindow*> activeTooltipWindows;
#endif

void TooltipWindow::displayTip (Point<int> screenPos, const String& tip)
{
    jassert (tip.isNotEmpty());

    if (! reentrant)
    {
        ScopedValueSetter<bool> setter (reentrant, true, false);

        if (tipShowing != tip)
        {
            tipShowing = tip;
            repaint();
        }

        if (auto* parent = getParentComponent())
        {
            updatePosition (tip, parent->getLocalPoint (nullptr, screenPos),
                            parent->getLocalBounds());
        }
        else
        {
            updatePosition (tip, screenPos, Desktop::getInstance().getDisplays().findDisplayForPoint (screenPos).userArea);

            addToDesktop (ComponentPeer::windowHasDropShadow
                            | ComponentPeer::windowIsTemporary
                            | ComponentPeer::windowIgnoresKeyPresses
                            | ComponentPeer::windowIgnoresMouseClicks);
        }

       #if JUCE_DEBUG
        activeTooltipWindows.addIfNotAlreadyThere (this);

        auto* parent = getParentComponent();

        for (auto* w : activeTooltipWindows)
        {
            if (w != this && w->tipShowing == tipShowing && w->getParentComponent() == parent)
            {
                // Looks like you have more than one TooltipWindow showing the same tip..
                // Be careful not to create more than one instance of this class with the
                // same parent component!
                jassertfalse;
            }
        }
       #endif

        toFront (false);
    }
}

String TooltipWindow::getTipFor (Component& c)
{
    if (Process::isForegroundProcess()
         && ! ModifierKeys::currentModifiers.isAnyMouseButtonDown())
    {
        if (auto* ttc = dynamic_cast<TooltipClient*> (&c))
            if (! c.isCurrentlyBlockedByAnotherModalComponent())
                return ttc->getTooltip();
    }

    return {};
}

void TooltipWindow::hideTip()
{
    if (! reentrant)
    {
        tipShowing.clear();
        removeFromDesktop();
        setVisible (false);

       #if JUCE_DEBUG
        activeTooltipWindows.removeAllInstancesOf (this);
       #endif
    }
}

void TooltipWindow::timerCallback()
{
    auto& desktop = Desktop::getInstance();
    auto mouseSource = desktop.getMainMouseSource();
    auto now = Time::getApproximateMillisecondCounter();

    auto* newComp = mouseSource.isTouch() ? nullptr : mouseSource.getComponentUnderMouse();

    if (newComp == nullptr || getParentComponent() == nullptr || newComp->getPeer() == getPeer())
    {
        auto newTip = newComp != nullptr ? getTipFor (*newComp) : String();
        bool tipChanged = (newTip != lastTipUnderMouse || newComp != lastComponentUnderMouse);
        lastComponentUnderMouse = newComp;
        lastTipUnderMouse = newTip;

        auto clickCount = desktop.getMouseButtonClickCounter();
        auto wheelCount = desktop.getMouseWheelMoveCounter();
        bool mouseWasClicked = (clickCount > mouseClicks || wheelCount > mouseWheelMoves);
        mouseClicks = clickCount;
        mouseWheelMoves = wheelCount;

        auto mousePos = mouseSource.getScreenPosition();
        bool mouseMovedQuickly = mousePos.getDistanceFrom (lastMousePos) > 12;
        lastMousePos = mousePos;

        if (tipChanged || mouseWasClicked || mouseMovedQuickly)
            lastCompChangeTime = now;

        if (isVisible() || now < lastHideTime + 500)
        {
            // if a tip is currently visible (or has just disappeared), update to a new one
            // immediately if needed..
            if (newComp == nullptr || mouseWasClicked || newTip.isEmpty())
            {
                if (isVisible())
                {
                    lastHideTime = now;
                    hideTip();
                }
            }
            else if (tipChanged)
            {
                displayTip (mousePos.roundToInt(), newTip);
            }
        }
        else
        {
            // if there isn't currently a tip, but one is needed, only let it
            // appear after a timeout..
            if (newTip.isNotEmpty()
                 && newTip != tipShowing
                 && now > lastCompChangeTime + (uint32) millisecondsBeforeTipAppears)
            {
                displayTip (mousePos.roundToInt(), newTip);
            }
        }
    }
}

} // namespace juce