JUCE/modules/juce_gui_basics/buttons/juce_ImageButton.cpp

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

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
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   Or:

   You may also use this code under the terms of the AGPLv3:
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  ==============================================================================
*/

namespace juce
{

ImageButton::ImageButton (const String& text_)
    : Button (text_),
      scaleImageToFit (true),
      preserveProportions (true),
      alphaThreshold (0)
{
}

ImageButton::~ImageButton()
{
}

void ImageButton::setImages (const bool resizeButtonNowToFitThisImage,
                             const bool rescaleImagesWhenButtonSizeChanges,
                             const bool preserveImageProportions,
                             const Image& normalImage_,
                             const float imageOpacityWhenNormal,
                             Colour overlayColourWhenNormal,
                             const Image& overImage_,
                             const float imageOpacityWhenOver,
                             Colour overlayColourWhenOver,
                             const Image& downImage_,
                             const float imageOpacityWhenDown,
                             Colour overlayColourWhenDown,
                             const float hitTestAlphaThreshold)
{
    normalImage = normalImage_;
    overImage = overImage_;
    downImage = downImage_;

    if (resizeButtonNowToFitThisImage && normalImage.isValid())
    {
        imageBounds.setSize (normalImage.getWidth(),
                             normalImage.getHeight());

        setSize (imageBounds.getWidth(), imageBounds.getHeight());
    }

    scaleImageToFit = rescaleImagesWhenButtonSizeChanges;
    preserveProportions = preserveImageProportions;

    normalOpacity = imageOpacityWhenNormal;
    normalOverlay = overlayColourWhenNormal;
    overOpacity   = imageOpacityWhenOver;
    overOverlay   = overlayColourWhenOver;
    downOpacity   = imageOpacityWhenDown;
    downOverlay   = overlayColourWhenDown;

    alphaThreshold = (uint8) jlimit (0, 0xff, roundToInt (255.0f * hitTestAlphaThreshold));

    repaint();
}

Image ImageButton::getCurrentImage() const
{
    if (isDown() || getToggleState())
        return getDownImage();

    if (isOver())
        return getOverImage();

    return getNormalImage();
}

Image ImageButton::getNormalImage() const
{
    return normalImage;
}

Image ImageButton::getOverImage() const
{
    return overImage.isValid() ? overImage
                               : normalImage;
}

Image ImageButton::getDownImage() const
{
    return downImage.isValid() ? downImage
                               : getOverImage();
}

void ImageButton::paintButton (Graphics& g,
                               bool shouldDrawButtonAsHighlighted,
                               bool shouldDrawButtonAsDown)
{
    if (! isEnabled())
    {
        shouldDrawButtonAsHighlighted = false;
        shouldDrawButtonAsDown = false;
    }

    Image im (getCurrentImage());

    if (im.isValid())
    {
        const int iw = im.getWidth();
        const int ih = im.getHeight();
        int w = getWidth();
        int h = getHeight();
        int x = (w - iw) / 2;
        int y = (h - ih) / 2;

        if (scaleImageToFit)
        {
            if (preserveProportions)
            {
                int newW, newH;
                const float imRatio = (float) ih / (float) iw;
                const float destRatio = (float) h / (float) w;

                if (imRatio > destRatio)
                {
                    newW = roundToInt ((float) h / imRatio);
                    newH = h;
                }
                else
                {
                    newW = w;
                    newH = roundToInt ((float) w * imRatio);
                }

                x = (w - newW) / 2;
                y = (h - newH) / 2;
                w = newW;
                h = newH;
            }
            else
            {
                x = 0;
                y = 0;
            }
        }

        if (! scaleImageToFit)
        {
            w = iw;
            h = ih;
        }

        imageBounds.setBounds (x, y, w, h);

        const bool useDownImage = shouldDrawButtonAsDown || getToggleState();

        getLookAndFeel().drawImageButton (g, &im, x, y, w, h,
                                          useDownImage ? downOverlay
                                                       : (shouldDrawButtonAsHighlighted ? overOverlay
                                                                            : normalOverlay),
                                          useDownImage ? downOpacity
                                                       : (shouldDrawButtonAsHighlighted ? overOpacity
                                                                            : normalOpacity),
                                          *this);
    }
}

bool ImageButton::hitTest (int x, int y)
{
    if (! Component::hitTest (x, y)) // handle setInterceptsMouseClicks
        return false;

    if (alphaThreshold == 0)
        return true;

    Image im (getCurrentImage());

    return im.isNull() || ((! imageBounds.isEmpty())
                            && alphaThreshold < im.getPixelAt (((x - imageBounds.getX()) * im.getWidth()) / imageBounds.getWidth(),
                                                               ((y - imageBounds.getY()) * im.getHeight()) / imageBounds.getHeight()).getAlpha());
}

} // namespace juce