juce_ImagePreviewComponent.cpp

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 /*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   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 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-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
{
 
ImagePreviewComponent::ImagePreviewComponent()
{
}
 
ImagePreviewComponent::~ImagePreviewComponent()
{
}
 
//==============================================================================
void ImagePreviewComponent::getThumbSize (int& w, int& h) const
{
    auto availableW = proportionOfWidth (0.97f);
    auto availableH = getHeight() - 13 * 4;
 
    auto scale = jmin (1.0,
                       availableW / (double) w,
                       availableH / (double) h);
 
    w = roundToInt (scale * w);
    h = roundToInt (scale * h);
}
 
void ImagePreviewComponent::selectedFileChanged (const File& file)
{
    if (fileToLoad != file)
    {
        fileToLoad = file;
        startTimer (100);
    }
}
 
void ImagePreviewComponent::timerCallback()
{
    stopTimer();
 
    currentThumbnail = Image();
    currentDetails.clear();
    repaint();
 
    FileInputStream in (fileToLoad);
 
    if (in.openedOk() && fileToLoad.existsAsFile())
    {
        if (auto format = ImageFileFormat::findImageFormatForStream (in))
        {
            currentThumbnail = format->decodeImage (in);
 
            if (currentThumbnail.isValid())
            {
                auto w = currentThumbnail.getWidth();
                auto h = currentThumbnail.getHeight();
 
                currentDetails
                    << fileToLoad.getFileName() << "\n"
                    << format->getFormatName() << "\n"
                    << w << " x " << h << " pixels\n"
                    << File::descriptionOfSizeInBytes (fileToLoad.getSize());
 
                getThumbSize (w, h);
 
                currentThumbnail = currentThumbnail.rescaled (w, h);
            }
        }
    }
}
 
void ImagePreviewComponent::paint (Graphics& g)
{
    if (currentThumbnail.isValid())
    {
        g.setFont (13.0f);
 
        auto w = currentThumbnail.getWidth();
        auto h = currentThumbnail.getHeight();
        getThumbSize (w, h);
 
        const int numLines = 4;
        auto totalH = 13 * numLines + h + 4;
        auto y = (getHeight() - totalH) / 2;
 
        g.drawImageWithin (currentThumbnail,
                           (getWidth() - w) / 2, y, w, h,
                           RectanglePlacement::centred | RectanglePlacement::onlyReduceInSize,
                           false);
 
        g.drawFittedText (currentDetails,
                          0, y + h + 4, getWidth(), 100,
                          Justification::centredTop, numLines);
    }
}
 
//==============================================================================
std::unique_ptr<AccessibilityHandler> ImagePreviewComponent::createAccessibilityHandler()
{
    return std::make_unique<AccessibilityHandler> (*this, AccessibilityRole::image);
}
 
} // namespace juce