Always use focus selection color for code completion proposals

Fixes eclipse-platform#1688

bundles/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/TableOwnerDrawSupport.java

@@ -73,7 +73,7 @@ private static StyleRange[] getStyledRanges(TableItem item, int column) {
 		return (StyleRange[])item.getData(STYLED_RANGES_KEY + column);
 	}
 
-	private TableOwnerDrawSupport(Table table) {
+	protected TableOwnerDrawSupport(Table table) {
 		int orientation= table.getStyle() & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
 		fSharedLayout= new TextLayout(table.getDisplay());
 		fSharedLayout.setOrientation(orientation);

bundles/org.eclipse.jface.text/src/org/eclipse/jface/internal/text/link/contentassist/CompletionProposalPopup2.java

@@ -57,6 +57,7 @@
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension;
 import org.eclipse.jface.text.TextUtilities;
+import org.eclipse.jface.text.contentassist.CompletionTableDrawSupport;
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension2;
@@ -269,7 +270,7 @@ private void createProposalSelector() {
 
 		fIsColoredLabelsSupportEnabled= fContentAssistant.isColoredLabelsSupportEnabled();
 		if (fIsColoredLabelsSupportEnabled)
-			TableOwnerDrawSupport.install(fProposalTable);
+			CompletionTableDrawSupport.install(fProposalTable);
 
 		fProposalTable.setLocation(0, 0);
 		if (fAdditionalInfoController != null)

bundles/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionProposalPopup.java

@@ -613,7 +613,7 @@ void createProposalSelector() {
 
 		fIsColoredLabelsSupportEnabled= fContentAssistant.isColoredLabelsSupportEnabled();
 		if (fIsColoredLabelsSupportEnabled)
-			TableOwnerDrawSupport.install(fProposalTable);
+			CompletionTableDrawSupport.install(fProposalTable);
 
 		fProposalTable.setLocation(0, 0);
 		if (fAdditionalInfoController != null)

bundles/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/CompletionTableDrawSupport.java

@@ -0,0 +1,40 @@
+package org.eclipse.jface.text.contentassist;
+
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.widgets.Table;
+
+import org.eclipse.jface.internal.text.TableOwnerDrawSupport;
+
+/**
+ * When a completion table (for example for code completion) is requested by the user, the user
+ * needs to be able to continue typing in the linked text control. In such cases, the focus is not
+ * on the completion table. To ensure the selected code completion proposal always displays in the
+ * correct color, even if the completion table is not focused, the non-focused colors are overridden
+ * with the focus colors.
+ */
+public class CompletionTableDrawSupport extends TableOwnerDrawSupport {
+
+	public static void install(Table table) {
+		TableOwnerDrawSupport listener= new CompletionTableDrawSupport(table);
+		table.addListener(SWT.Dispose, listener);
+		table.addListener(SWT.MeasureItem, listener);
+		table.addListener(SWT.EraseItem, listener);
+		table.addListener(SWT.PaintItem, listener);
+	}
+
+	private CompletionTableDrawSupport(Table table) {
+		super(table);
+	}
+
+	@Override
+	protected Color getSelectedRowBackgroundColorNoFocus() {
+		return super.getSelectedRowBackgroundColor();
+	}
+
+	@Override
+	protected Color getSelectedRowForegroundColorNoFocus() {
+		return super.getSelectedRowForegroundColor();
+	}
+
+}