JUCE/modules/juce_gui_basics/lookandfeel/juce_LookAndFeel.cpp

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

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

   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 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-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
{

static Typeface::Ptr getTypefaceForFontFromLookAndFeel (const Font& font)
{
    return LookAndFeel::getDefaultLookAndFeel().getTypefaceForFont (font);
}

typedef Typeface::Ptr (*GetTypefaceForFont) (const Font&);
extern GetTypefaceForFont juce_getTypefaceForFont;

//==============================================================================
LookAndFeel::LookAndFeel()
{
    /* if this fails it means you're trying to create a LookAndFeel object before
       the static Colours have been initialised. That ain't gonna work. It probably
       means that you're using a static LookAndFeel object and that your compiler has
       decided to intialise it before the Colours class.
    */
    jassert (Colours::white == Colour (0xffffffff));

    juce_getTypefaceForFont = getTypefaceForFontFromLookAndFeel;
}

LookAndFeel::~LookAndFeel()
{
    /* This assertion is triggered if you try to delete a LookAndFeel object while it's
         - still being used as the default LookAndFeel; or
         - is set as a Component's current lookandfeel; or
         - pointed to by a WeakReference somewhere else in the code

       Deleting a LookAndFeel is unlikely to cause a crash since most things will use a
       safe WeakReference to it, but it could cause some unexpected graphical behaviour,
       so it's advisable to clear up any references before destroying them!
    */
    jassert (masterReference.getNumActiveWeakReferences() == 0);
}

//==============================================================================
Colour LookAndFeel::findColour (int colourID) const noexcept
{
    const ColourSetting c = { colourID, Colour() };
    const int index = colours.indexOf (c);

    if (index >= 0)
        return colours.getReference (index).colour;

    jassertfalse;
    return Colours::black;
}

void LookAndFeel::setColour (int colourID, Colour newColour) noexcept
{
    const ColourSetting c = { colourID, newColour };
    const int index = colours.indexOf (c);

    if (index >= 0)
        colours.getReference (index).colour = newColour;
    else
        colours.add (c);
}

bool LookAndFeel::isColourSpecified (const int colourID) const noexcept
{
    const ColourSetting c = { colourID, Colour() };
    return colours.contains (c);
}

//==============================================================================
LookAndFeel& LookAndFeel::getDefaultLookAndFeel() noexcept
{
    return Desktop::getInstance().getDefaultLookAndFeel();
}

void LookAndFeel::setDefaultLookAndFeel (LookAndFeel* newDefaultLookAndFeel) noexcept
{
    Desktop::getInstance().setDefaultLookAndFeel (newDefaultLookAndFeel);
}

//==============================================================================
Typeface::Ptr LookAndFeel::getTypefaceForFont (const Font& font)
{
    if (defaultSans.isNotEmpty() && font.getTypefaceName() == Font::getDefaultSansSerifFontName())
    {
        Font f (font);
        f.setTypefaceName (defaultSans);
        return Typeface::createSystemTypefaceFor (f);
    }

    return Font::getDefaultTypefaceForFont (font);
}

void LookAndFeel::setDefaultSansSerifTypefaceName (const String& newName)
{
    if (defaultSans != newName)
    {
        Typeface::clearTypefaceCache();
        defaultSans = newName;
    }
}

//==============================================================================
MouseCursor LookAndFeel::getMouseCursorFor (Component& component)
{
    MouseCursor m (component.getMouseCursor());

    Component* parent = component.getParentComponent();
    while (parent != nullptr && m == MouseCursor::ParentCursor)
    {
        m = parent->getMouseCursor();
        parent = parent->getParentComponent();
    }

    return m;
}

LowLevelGraphicsContext* LookAndFeel::createGraphicsContext (const Image& imageToRenderOn, const Point<int>& origin,
                                                             const RectangleList<int>& initialClip)
{
    return new LowLevelGraphicsSoftwareRenderer (imageToRenderOn, origin, initialClip);
}

//==============================================================================
void LookAndFeel::setUsingNativeAlertWindows (bool shouldUseNativeAlerts)
{
    useNativeAlertWindows = shouldUseNativeAlerts;
}

bool LookAndFeel::isUsingNativeAlertWindows()
{
   #if JUCE_LINUX
    return false; // not available currently..
   #else
    return useNativeAlertWindows;
   #endif
}

} // namespace juce