src/java.desktop/unix/classes/sun/java2d/x11/X11VolatileSurfaceManager.java

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package sun.java2d.x11;

import java.awt.GraphicsConfiguration;
import java.awt.ImageCapabilities;
import java.awt.Transparency;
import java.awt.image.ColorModel;

import sun.awt.X11GraphicsConfig;
import sun.awt.image.SunVolatileImage;
import sun.awt.image.VolatileSurfaceManager;
import sun.java2d.SurfaceData;

/**
 * X11 platform implementation of the VolatileSurfaceManager class.
 * The class attempts to create and use a pixmap-based SurfaceData
 * object (X11PixmapSurfaceData).
 * If this object cannot be created or re-created as necessary, the
 * class falls back to a system memory based SurfaceData object
 * (BufImgSurfaceData) that will be used until the accelerated
 * SurfaceData can be restored.
 */
public final class X11VolatileSurfaceManager extends VolatileSurfaceManager {

    private boolean accelerationEnabled;

    public X11VolatileSurfaceManager(SunVolatileImage vImg, Object context) {
        super(vImg, context);

        // We only accelerated opaque vImages currently
        accelerationEnabled = X11SurfaceData.isAccelerationEnabled() &&
            (vImg.getTransparency() == Transparency.OPAQUE);

        if ((context != null) && !accelerationEnabled) {
            // if we're wrapping a backbuffer drawable, we must ensure that
            // the accelerated surface is initialized up front, regardless
            // of whether acceleration is enabled. But we need to set
            // the  accelerationEnabled field to true to reflect that this
            // SM is actually accelerated.
            accelerationEnabled = true;
            sdAccel = initAcceleratedSurface();
            sdCurrent = sdAccel;

            if (sdBackup != null) {
                // release the system memory backup surface, as we won't be
                // needing it in this case
                sdBackup = null;
            }
        }
    }

    @Override
    protected boolean isAccelerationEnabled() {
        return accelerationEnabled;
    }

    /**
     * Create a pixmap-based SurfaceData object
     */
    @Override
    protected SurfaceData initAcceleratedSurface() {
        SurfaceData sData;

        try {
            X11GraphicsConfig gc = (X11GraphicsConfig)vImg.getGraphicsConfig();
            ColorModel cm = gc.getColorModel();
            long drawable = 0;
            if (context instanceof Long) {
                drawable = ((Long)context).longValue();
            }
            sData = X11SurfaceData.createData(gc,
                                              vImg.getWidth(),
                                              vImg.getHeight(),
                                              cm, vImg, drawable,
                                              Transparency.OPAQUE,
                                              false);
        } catch (NullPointerException | OutOfMemoryError e) {
            sData = null;
        }

        return sData;
    }

    @Override
    protected boolean isConfigValid(GraphicsConfiguration gc) {
        // REMIND: we might be too paranoid here, requiring that
        // the GC be exactly the same as the original one.  The
        // real answer is one that guarantees that pixmap copies
        // will be correct (which requires like bit depths and
        // formats).
        return ((gc == null) || (gc == vImg.getGraphicsConfig()));
    }

    /**
     * Need to override the default behavior because Pixmaps-based
     * images are accelerated but not volatile.
     */
    @Override
    public ImageCapabilities getCapabilities(GraphicsConfiguration gc) {
        if (isConfigValid(gc) && isAccelerationEnabled()) {
            // accelerated but not volatile
            return new ImageCapabilities(true);
        }
        // neither accelerated nor volatile
        return new ImageCapabilities(false);
    }
}