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WebLaf is a Java Swing Look and Feel and extended components library for cross-platform applications
/*
* This file is part of WebLookAndFeel library.
*
* WebLookAndFeel library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* WebLookAndFeel library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with WebLookAndFeel library. If not, see generators = new WeakHashMap ();
/**
* Generator references map operations lock.
*/
protected static final Object generatorsLock = new Object ();
/**
* File list this generator is working for.
*/
private final WebFileList list;
/**
* Element thumbnail is being generated for.
*/
private final FileElement element;
/**
* Whether should generate disabled state thumbnail or not.
*/
private final boolean disabled;
/**
* Whether generation was aborted or not.
*/
private boolean aborted;
/**
* Constructs thumbnail generator for the specified file element.
*
* @param list file list this generator is working for
* @param element element to queue thumbnail generation for
* @param disabled whether should generate disabled state thumbnail or not
*/
public ThumbnailGenerator ( final WebFileList list, final FileElement element, final boolean disabled )
{
super ();
this.list = list;
this.element = element;
this.disabled = disabled;
this.aborted = false;
}
/**
* Returns file list this generator is working for.
*
* @return file list this generator is working for
*/
public WebFileList getList ()
{
return list;
}
/**
* Returns file element for which thumbnail is being generated.
*
* @return file element for which thumbnail is being generated
*/
public FileElement getElement ()
{
return element;
}
/**
* Returns whether disabled thumbnail will also be generated or not.
*
* @return true if disabled thumbnail will also be generated, false otherwise
*/
public boolean isDisabled ()
{
return disabled;
}
/**
* Returns whether this generator was aborted or not.
*
* @return true if this generator was aborted, false otherwise
*/
public boolean isAborted ()
{
return aborted;
}
/**
* Abort thumbnail generation.
* Note that actual abort might occur after long-running operations, but it will surely cancel thumbnail update.
*/
public void abort ()
{
this.aborted = true;
}
/**
* Starts thumbnail generation.
*/
@Override
public void run ()
{
// Process abort check here
if ( aborted )
{
cleanup ();
return;
}
// Creating thumbnail
createThumbnail ( element.getFile (), list.isGenerateThumbnails () );
// Process abort check here
if ( aborted )
{
cleanup ();
return;
}
// Updating list view
// Repaint doesn't really require EDT but this is simply a dirty trick to invoke this call later
SwingUtilities.invokeLater ( new Runnable ()
{
@Override
public void run ()
{
list.repaint ( element );
}
} );
// Perform final cleanups
cleanup ();
}
/**
* Cleanup cached reference to this generator.
* This is required mostly in cases when generator was not aborted.
*/
private void cleanup ()
{
synchronized ( generatorsLock )
{
// Perform cleanup only if current generator is still an active one for this element
final ThumbnailGenerator generator = generators.get ( element );
if ( generator == this )
{
// Updating thumbnail load state
synchronized ( element.getLock () )
{
element.setThumbnailQueued ( false );
element.setDisabledThumbnailQueued ( false );
}
// Removing element generator reference
generators.remove ( element );
}
}
}
private void createThumbnail ( final File file, final boolean preview )
{
final FileThumbnailProvider thumbnailProvider = list.getThumbnailProvider ();
if ( thumbnailProvider != null && thumbnailProvider.accept ( file ) )
{
// Using thumbnail provider to generate thumbnail icon
final Dimension size = new Dimension ( WebFileListCellRenderer.thumbSize, WebFileListCellRenderer.thumbSize );
final ImageIcon thumb = element.getEnabledThumbnail () != null ? element.getEnabledThumbnail () :
thumbnailProvider.provide ( file, size, preview );
if ( thumb != null )
{
// Applying custom thumbnail
applyThumbnail ( thumb );
}
else
{
// Creating standard thumbnail
createStandardThumbnail ( file, preview );
}
}
else
{
// Creating standard thumbnail
createStandardThumbnail ( file, preview );
}
}
private void createStandardThumbnail ( final File file, final boolean preview )
{
// Using either image thumbnails or default file extension icons
final String ext = FileUtils.getFileExtPart ( file.getName (), false ).toLowerCase ( Locale.ROOT );
if ( preview && GlobalConstants.IMAGE_FORMATS.contains ( ext ) )
{
// If thumbnail was already specified we should re-use it
// It will save us a lot of time if we simply need to generate disabled state in addition to enabled one
final ImageIcon thumb = element.getEnabledThumbnail () != null ? element.getEnabledThumbnail () :
ImageUtils.createThumbnailIcon ( file.getAbsolutePath (), WebFileListCellRenderer.thumbSize );
if ( thumb != null )
{
// Applying standard image thumbnail
applyThumbnail ( thumb );
}
else
{
// Applying standard extension icon
applyStandardIcon ( file );
}
}
else
{
// Applying standard extension icon
applyStandardIcon ( file );
}
}
private void applyThumbnail ( final ImageIcon thumb )
{
// Process abort check here
if ( aborted )
{
return;
}
// Applying custom generated thumbnail icon
synchronized ( element.getLock () )
{
if ( element.isThumbnailQueued () )
{
// We had to check that queue wasn't cancelled from outside
element.setEnabledThumbnail ( thumb );
}
}
// Process abort check here
if ( aborted )
{
return;
}
if ( disabled )
{
// Re-using enabled state thumbnail to generate disabled state one
final ImageIcon disabledThumbnail = ImageUtils.createDisabledCopy ( thumb );
// Process abort check here
if ( aborted )
{
return;
}
if ( element.isDisabledThumbnailQueued () )
{
// We had to check that queue wasn't cancelled from outside
element.setDisabledThumbnail ( disabledThumbnail );
}
}
}
private void applyStandardIcon ( final File file )
{
// Process abort check here
if ( aborted )
{
return;
}
// Generating standard file extension icon
final ImageIcon enabledThumbnail = FileUtils.getStandardFileIcon ( file, true, true );
// Process abort check here
if ( aborted )
{
return;
}
if ( element.isThumbnailQueued () )
{
// We had to check that queue wasn't cancelled from outside
element.setEnabledThumbnail ( enabledThumbnail );
}
// Process abort check here
if ( aborted )
{
return;
}
if ( disabled )
{
// Standard icons are cached so we don't need to re-use enabled icon for disabled state one generation
final ImageIcon disabledThumbnail = FileUtils.getStandardFileIcon ( file, true, false );
// Process abort check here
if ( aborted )
{
return;
}
if ( element.isDisabledThumbnailQueued () )
{
// We had to check that queue wasn't cancelled from outside
element.setDisabledThumbnail ( disabledThumbnail );
}
}
}
/**
* Adds specified element into thumbnails generation queue.
*
* @param list file list this generator is working for
* @param element element to queue thumbnail generation for
* @param disabled whether should generate disabled state thumbnail or not
*/
public static void queueThumbnailLoad ( final WebFileList list, final FileElement element, final boolean disabled )
{
synchronized ( generatorsLock )
{
// Checking prerequisites and updating flags
synchronized ( element.getLock () )
{
// Skip generation if it was already done or in queue
if ( disabled ? ( element.isDisabledThumbnailQueued () || element.getDisabledThumbnail () != null ) :
( element.isThumbnailQueued () || element.getEnabledThumbnail () != null ) )
{
return;
}
// Updating thumbnail load state
element.setThumbnailQueued ( true );
element.setDisabledThumbnailQueued ( disabled );
}
// Queueing thumbnail generation
final ThumbnailGenerator generator = new ThumbnailGenerator ( list, element, disabled );
generators.put ( element, generator );
executorService.submit ( generator );
}
}
/**
* Forces thumbnail generation to be aborted for the specified element.
*
* @param element element to abort thumbnail generation for
*/
public static void abortThumbnailLoad ( final FileElement element )
{
synchronized ( generatorsLock )
{
// Aborting generator
final ThumbnailGenerator generator = generators.get ( element );
if ( generator != null )
{
generator.abort ();
}
// Cleaning up previous thumbnails
synchronized ( element.getLock () )
{
element.setEnabledThumbnail ( null );
element.setThumbnailQueued ( false );
element.setDisabledThumbnail ( null );
element.setDisabledThumbnailQueued ( false );
}
}
}
}