Bug 493047 - [HighDPI] Clipboard Example: Image looses it's qualityI20160506-0830

during ImageTransfer

Change-Id: I6613d843b41675f48adf7c595a77e9784418ce50
Signed-off-by: Niraj Modi <niraj.modi@in.ibm.com>

1 files changed, 49 insertions, 3 deletions

diff --git a/examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/clipboard/ClipboardExample.java b/examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/clipboard/ClipboardExample.java
index 412080c318..350293ec8c 100644
--- a/examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/clipboard/ClipboardExample.java
+++ b/examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/clipboard/ClipboardExample.java
@@ -25,6 +25,7 @@ import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
+import org.eclipse.swt.graphics.ImageDataProvider;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.FillLayout;
@@ -55,7 +56,50 @@ public class ClipboardExample {
 	StyledText styledText;
 	Label status;
 	static final int HSIZE = 100, VSIZE = 60;
-	
+
+static final class AutoScaleImageDataProvider implements ImageDataProvider {
+	ImageData imageData;
+	int currentZoom;
+	public AutoScaleImageDataProvider (ImageData data) {
+		this.imageData = data;
+		this.currentZoom = getDeviceZoom ();
+	}
+
+	@Override
+	public ImageData getImageData (int zoom) {
+		return autoScaleImageData(imageData, zoom, currentZoom);
+	}
+
+	static ImageData autoScaleImageData (ImageData imageData, int targetZoom, int currentZoom) {
+		if (!isAutoScaleEnable () || imageData == null || targetZoom == currentZoom) return imageData;
+		float scaleFactor = ((float) targetZoom)/((float) currentZoom);
+		return imageData.scaledTo (Math.round (imageData.width * scaleFactor), Math.round (imageData.height * scaleFactor));
+	}
+
+	static boolean isAutoScaleEnable () {
+		String value = System.getProperty ("swt.enable.autoScale");
+		if (value != null && "false".equalsIgnoreCase (value))
+			return false;
+		else
+			return true;
+	}
+
+	static int getDeviceZoom () {
+		int zoom = 100;
+		if (isAutoScaleEnable ()) {
+			String value = System.getProperty ("org.eclipse.swt.internal.deviceZoom");
+			if (value != null) {
+				try {
+					zoom = Integer.parseInt(value);
+				} catch (NumberFormatException e) {
+					e.printStackTrace();
+				}
+			}
+		}
+		return zoom;
+	}
+}
+
 public static void main( String[] args) {
 	Display display = new Display();
 	new ClipboardExample().open(display);
@@ -473,7 +517,8 @@ void createImageTransfer(Composite copyParent, Composite pasteParent){
 		public void widgetSelected(SelectionEvent e) {
 			if (copyImage[0] != null) {
 				status.setText("");
-				clipboard.setContents(new Object[] {copyImage[0].getImageData()}, new Transfer[] {ImageTransfer.getInstance()});
+				// Fetch ImageData at current zoom and save in the clip-board.
+				clipboard.setContents(new Object[] {copyImage[0].getImageDataAtCurrentZoom()}, new Transfer[] {ImageTransfer.getInstance()});
 			} else {
 				status.setText("No image to copy");
 			}
@@ -539,7 +584,8 @@ void createImageTransfer(Composite copyParent, Composite pasteParent){
 					pasteImage[0].dispose();
 				}
 				status.setText("");
-				pasteImage[0] = new Image(e.display, data);
+				// Consume the ImageData at current zoom as-is.
+				pasteImage[0] = new Image(e.display, new AutoScaleImageDataProvider(data));
 				pasteVBar.setEnabled(true);
 				pasteHBar.setEnabled(true);
 				pasteOrigin.x = 0; pasteOrigin.y = 0;