Show pin icon in pinned Find Usages tabs

platform/core-api/src/com/intellij/util/IconUtil.java

@@ -93,6 +93,30 @@ public class IconUtil {
     return new ImageIcon(img);
   }
 
+  public static Icon cropIcon(@NotNull Icon icon, Rectangle area) {
+    if (!new Rectangle(icon.getIconWidth(), icon.getIconHeight()).contains(area)) {
+      return icon;
+    }
+
+    final BufferedImage image = GraphicsEnvironment
+      .getLocalGraphicsEnvironment()
+      .getDefaultScreenDevice()
+      .getDefaultConfiguration()
+      .createCompatibleImage(icon.getIconWidth(), icon.getIconHeight(), Transparency.TRANSLUCENT);
+    final Graphics2D g = image.createGraphics();
+    icon.paintIcon(new JPanel(), g, 0, 0);
+    g.dispose();
+
+    final BufferedImage img = UIUtil.createImage(area.width, area.height, Transparency.TRANSLUCENT);
+    for (int col = 0; col < area.width; col++) {
+      for (int row = 0; row < area.height; row++) {
+        img.setRGB(col, row, image.getRGB(col + area.x, row + area.y));
+      }
+    }
+
+    return new ImageIcon(img);
+  }
+
   @NotNull
   public static Icon flip(@NotNull Icon icon, boolean horizontal) {
     int w = icon.getIconWidth();

platform/lang-impl/src/com/intellij/usageView/impl/UsageViewManagerImpl.java

@@ -83,6 +83,7 @@ public class UsageViewManagerImpl extends UsageViewManager {
     content.setTabName(tabName);
     content.setToolwindowTitle(toolwindowTitle);
     content.putUserData(contentKey, Boolean.TRUE);
+    content.putUserData(ToolWindow.SHOW_CONTENT_ICON, Boolean.TRUE);
 
     myFindContentManager.addContent(content);
     myFindContentManager.setSelectedContent(content);

platform/platform-impl/src/com/intellij/ui/content/impl/ContentImpl.java

@@ -27,7 +27,9 @@ import com.intellij.ui.LayeredIcon;
 import com.intellij.ui.content.AlertIcon;
 import com.intellij.ui.content.Content;
 import com.intellij.ui.content.ContentManager;
+import com.intellij.util.IconUtil;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
@@ -36,6 +38,8 @@ import java.beans.PropertyChangeListener;
 import java.beans.PropertyChangeSupport;
 
 public class ContentImpl extends UserDataHolderBase implements Content {
+  private static Icon ourEmptyPinIcon = null;
+
   private String myDisplayName;
   private String myDescription;
   private JComponent myComponent;
@@ -113,13 +117,23 @@ public class ContentImpl extends UserDataHolderBase implements Content {
   @Override
   public Icon getIcon() {
     if (myIsLocked) {
-      return myIcon == null ? AllIcons.Nodes.PinToolWindow : myLayeredIcon;
+      return myIcon == null ? getEmptyPinIcon() : myLayeredIcon;
     }
     else {
       return myIcon;
     }
   }
 
+  @NotNull
+  private static Icon getEmptyPinIcon() {
+    if (ourEmptyPinIcon == null) {
+      Icon icon = AllIcons.Nodes.PinToolWindow;
+      int width = icon.getIconWidth();
+      ourEmptyPinIcon = IconUtil.cropIcon(icon, new Rectangle(width / 2, 0, width - width / 2, icon.getIconHeight()));
+    }
+    return ourEmptyPinIcon;
+  }
+
   @Override
   public void setDisplayName(String displayName) {
     String oldValue = myDisplayName;