/**
* Starts this updater. This method initializes all the necessary resources and puts this {@link
* Runnable} on the asynch queue. If this updater is not active or is already running, this
* method just returns.
*/
public void start() {
if (!isActive() || isRunning()) return;
isRunning = true;
setDirty(false);
resetTileValues();
if (!targetSize.equals(thumbnailImageSize)) {
resetThumbnailImage();
}
if (targetSize.isEmpty()) return;
thumbnailGC =
new GC(thumbnailImage, sourceFigure.isMirrored() ? SWT.RIGHT_TO_LEFT : SWT.NONE);
thumbnailGraphics = new ScaledGraphics(new SWTGraphics(thumbnailGC));
thumbnailGraphics.scale(getScaleX());
thumbnailGraphics.translate(getSourceRectangle().getLocation().negate());
Color color = sourceFigure.getForegroundColor();
if (color != null) thumbnailGraphics.setForegroundColor(color);
color = sourceFigure.getBackgroundColor();
if (color != null) thumbnailGraphics.setBackgroundColor(color);
thumbnailGraphics.setFont(sourceFigure.getFont());
setScales(
targetSize.width / (float) getSourceRectangle().width,
targetSize.height / (float) getSourceRectangle().height);
Display.getCurrent().asyncExec(this);
}
