Bug 231465 - CTabFolder should share selectionHighlightGradientColorsCache across instances

1 files changed, 44 insertions, 11 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolderRenderer.java b/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolderRenderer.java
index 1a05182d94..b081a3f780 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolderRenderer.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolderRenderer.java
@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.swt.custom;
 
+import java.util.Hashtable;
 import org.eclipse.swt.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.widgets.*;
@@ -52,6 +53,7 @@ public class CTabFolderRenderer {
 	 * We have to recompute the colors if the border color changes
 	 */
 	Color lastBorderColor = null;
+	static Hashtable ColorCache = new Hashtable ();
 	
 	//TOP_LEFT_CORNER_HILITE is laid out in reverse (ie. top to bottom)
 	//so can fade in same direction as right swoop curve
@@ -124,6 +126,35 @@ public class CTabFolderRenderer {
 		this.parent = parent;
 	}
 	
+	static Color getColor(Display display, RGB rgb) {
+		Color color;
+		Object [] colorData = (Object []) ColorCache.get(rgb);
+		if (colorData != null) {
+			color = (Color) colorData[0];
+			int refcount = ((Integer) colorData[1]).intValue();
+			colorData[1] = new Integer(refcount + 1);
+		} else {
+			color = new Color(display, rgb);
+			ColorCache.put(rgb, new Object[] {color, new Integer(1)});
+		}
+		return color;
+	}
+	
+	static void releaseColor(Color color) {
+		RGB rgb = color.getRGB();
+		Object [] colorData = (Object []) ColorCache.get(rgb);
+		if (colorData != null) {
+			int refcount = ((Integer) colorData[1]).intValue();
+			refcount--;
+			if (refcount == 0) {
+				ColorCache.remove(rgb);
+				color.dispose();
+			} else {
+				colorData[1] = new Integer(refcount);
+			}
+		}
+	}
+	
 	void antialias (int[] shape, Color innerColor, Color outerColor, GC gc){
 		// Don't perform anti-aliasing on Mac and WPF because the platform
 		// already does it.  The simple style also does not require anti-aliasing.
@@ -374,7 +405,8 @@ public class CTabFolderRenderer {
 	
 	void createAntialiasColors() {
 	    disposeAntialiasColors();
-	    lastBorderColor = parent.getDisplay().getSystemColor(BORDER1_COLOR);
+	    Display display = parent.getDisplay();
+	    lastBorderColor = display.getSystemColor(BORDER1_COLOR);
 	    RGB lineRGB = lastBorderColor.getRGB();
 	    /* compute the selected color */
 	    RGB innerRGB = parent.selectionBackground.getRGB();
@@ -392,7 +424,7 @@ public class CTabFolderRenderer {
 			int red = from.red + 2*(to.red - from.red)/3;
 			int green = from.green + 2*(to.green - from.green)/3;
 			int blue = from.blue + 2*(to.blue - from.blue)/3;
-			selectedOuterColor = new Color(parent.getDisplay(), red, green, blue);
+			selectedOuterColor = getColor(display, new RGB(red, green, blue));
 	    }
 	    if (innerRGB != null) {
 			RGB from = lineRGB;
@@ -400,7 +432,7 @@ public class CTabFolderRenderer {
 			int red = from.red + 2*(to.red - from.red)/3;
 			int green = from.green + 2*(to.green - from.green)/3;
 			int blue = from.blue + 2*(to.blue - from.blue)/3;
-			selectedInnerColor = new Color(parent.getDisplay(), red, green, blue);
+			selectedInnerColor = getColor(display, new RGB(red, green, blue));
 	    }
 	    /* compute the tabArea color */
 	    outerRGB = parent.getParent().getBackground().getRGB();
@@ -410,7 +442,7 @@ public class CTabFolderRenderer {
 			int red = from.red + 2*(to.red - from.red)/3;
 			int green = from.green + 2*(to.green - from.green)/3;
 			int blue = from.blue + 2*(to.blue - from.blue)/3;
-			tabAreaColor = new Color(parent.getDisplay(), red, green, blue);
+			tabAreaColor = getColor(display, new RGB(red, green, blue));
 	    }
 	}
 
@@ -436,13 +468,14 @@ public class CTabFolderRenderer {
 		selectionHighlightGradientColorsCache = new Color[fadeGradientSize];
 		int denom = fadeGradientSize - 1;
 
+		Display display = parent.getDisplay();
 		for (int i = 0; i < fadeGradientSize; i++) {
 			int propFrom = denom - i;
 			int propTo = i;
 			int red = (to.red * propTo + from.red * propFrom) / denom;
 			int green = (to.green * propTo  + from.green * propFrom) / denom;
 			int blue = (to.blue * propTo  + from.blue * propFrom) / denom;
-			selectionHighlightGradientColorsCache[i] = new Color(parent.getDisplay(), red, green, blue);
+			selectionHighlightGradientColorsCache[i] = getColor(display, new RGB(red, green, blue));
 		}
 	}
 	
@@ -457,15 +490,15 @@ public class CTabFolderRenderer {
 		disposeAntialiasColors();
 		disposeSelectionHighlightGradientColors();
 		if (fillColor != null) {
-		    fillColor.dispose();
+			releaseColor(fillColor);
 		    fillColor = null;
 		}
 	}
 	
 	void disposeAntialiasColors() {
-	    if (tabAreaColor != null) tabAreaColor.dispose();
-	    if (selectedInnerColor != null) selectedInnerColor.dispose();
-	    if (selectedOuterColor != null) selectedOuterColor.dispose();
+	    if (tabAreaColor != null) releaseColor(tabAreaColor);
+	    if (selectedInnerColor != null) releaseColor(selectedInnerColor);
+	    if (selectedOuterColor != null) releaseColor(selectedOuterColor);
 	    tabAreaColor = selectedInnerColor = selectedOuterColor = null;
 	}
 
@@ -473,7 +506,7 @@ public class CTabFolderRenderer {
 		if(selectionHighlightGradientColorsCache == null)
 			return;
 		for (int i = 0; i < selectionHighlightGradientColorsCache.length; i++) {
-			selectionHighlightGradientColorsCache[i].dispose();
+			releaseColor(selectionHighlightGradientColorsCache[i]);
 		}
 		selectionHighlightGradientColorsCache = null;
 	}
@@ -1624,7 +1657,7 @@ public class CTabFolderRenderer {
 		
 	Color getFillColor() {
 		if (fillColor == null) {
-			fillColor = new Color(parent.getDisplay(), CLOSE_FILL);
+			fillColor = getColor(parent.getDisplay(), CLOSE_FILL);
 		}
 		return fillColor;
 	}