xml/openapi/src/com/intellij/xml/breadcrumbs/BreadcrumbsComponent.java - platform/tools/idea - Git at Google

 /*
  * Copyright 2000-2014 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package com.intellij.xml.breadcrumbs;

 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.ui.ColorUtil;
 import com.intellij.ui.Gray;
 import com.intellij.ui.JBColor;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;

 import javax.swing.*;
 import java.awt.*;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseMotionListener;
 import java.util.*;
 import java.util.List;

 /**
  * @author spleaner
  */
 public class BreadcrumbsComponent<T extends BreadcrumbsItem> extends JComponent implements Disposable {
   private static final Logger LOG = Logger.getInstance("#com.intellij.xml.breadcrumbs.BreadcrumbsComponent");
   private static final Painter DEFAULT_PAINTER = new DefaultPainter(new ButtonSettings());

   private List<BreadcrumbsItemListener<T>> myListeners = ContainerUtil.createLockFreeCopyOnWriteList();
   private Crumb myHovered;
   private PagedImage myBuffer;
   private List<Crumb> myCrumbs = new ArrayList<Crumb>();
   private final CrumbLineMouseListener myMouseListener;
   private List<T> myItems;

   public BreadcrumbsComponent() {
     myMouseListener = new CrumbLineMouseListener(this);
     addMouseListener(myMouseListener);
     addMouseMotionListener(myMouseListener);

     setToolTipText("");
   }

   public void setItems(@Nullable final List<T> itemsList) {
     if (myItems != itemsList) {
       myItems = itemsList;
       myCrumbs = null;
     }

     repaint();
   }

   public void addBreadcrumbsItemListener(@NotNull final BreadcrumbsItemListener<T> listener) {
     myListeners.add(listener);
   }

   public void removeBreadcrumbsItemListener(@NotNull final BreadcrumbsItemListener<T> listener) {
     myListeners.remove(listener);
   }

   @Override
   public String getToolTipText(final MouseEvent event) {
     final Crumb c = getCrumb(event.getPoint());
     if (c != null) {
       final String text = c.getTooltipText();
       return text == null ? super.getToolTipText(event) : text;
     }

     return super.getToolTipText(event);
   }

   @Nullable
   public Crumb getCrumb(@NotNull final Point p) {
     if (myCrumbs != null) {
       final Rectangle r = getBounds();
       p.translate(r.x, r.y);

       if (!r.contains(p)) {
         return null;
       }

       if (myBuffer == null) {
         return null;
       }

       final int offset = myBuffer.getPageOffset();

       for (final Crumb each : myCrumbs) {
         if (((p.x + offset) >= each.getOffset()) && ((p.x + offset) < (each.getOffset() + each.getWidth()))) {
           return each;
         }
       }
     }

     return null;
   }

   public void setHoveredCrumb(@Nullable final Crumb crumb) {
     if (crumb != null) {
       crumb.setHovered(true);
     }

     if (myHovered != null) {
       myHovered.setHovered(false);
     }

     myHovered = crumb;
     repaint();
   }

   public void nextPage() {
     if (myBuffer != null) {
       final int page = myBuffer.getPage();
       if (page + 1 < myBuffer.getPageCount()) {
         myBuffer.setPage(page + 1);
       }
     }

     repaint();
   }

   public void previousPage() {
     if (myBuffer != null) {
       final int page = myBuffer.getPage();
       if (page - 1 >= 0) {
         myBuffer.setPage(page - 1);
       }
     }

     repaint();
   }

   @Override
   public void paint(final Graphics g) {
     final Graphics2D g2 = ((Graphics2D)g);
     final Dimension d = getSize();
     final FontMetrics fm = g2.getFontMetrics();

     if (myItems != null) {
       final boolean veryDirty = (myCrumbs == null) || (myBuffer != null && !myBuffer.isValid(d.width));

       final List<Crumb> crumbList = veryDirty ? createCrumbList(fm, myItems, d.width) : myCrumbs;
       if (crumbList != null) {
         if (veryDirty) {
           //final BufferedImage bufferedImage = createBuffer(crumbList, d.height);
           myBuffer = new PagedImage(getTotalWidth(crumbList), d.width);
           myBuffer.setPage(myBuffer.getPageCount() - 1); // point to the last page
         }

         assert myBuffer != null;

         super.paint(g2);

         //if (myDirty) {
         //  myBuffer.repaint(crumbList, getPainter());
         //myDirty = false;
         //}

         myBuffer.paintPage(g2, crumbList, DEFAULT_PAINTER, d.height);
         myCrumbs = crumbList;
       }
     }
     else {
       super.paint(g2);
     }
   }

   private void setSelectedCrumb(@NotNull final Crumb<T> c, final int modifiers) {
     final T selectedElement = c.getItem();

     final Set<BreadcrumbsItem> items = new HashSet<BreadcrumbsItem>();
     boolean light = false;
     for (final Crumb each : myCrumbs) {
       final BreadcrumbsItem item = each.getItem();
       if (item != null && items.contains(item)) {
         light = false;
       }

       each.setLight(light);

       if (item != null && !light) {
         items.add(item);
       }

       if (selectedElement == item) {
         each.setSelected(true);
         light = true;
       }
       else {
         each.setSelected(false);
       }
     }

     fireItemSelected(selectedElement, modifiers);

     repaint();
   }

   @SuppressWarnings({"ForLoopReplaceableByForEach"})
   private void fireItemSelected(@Nullable final T item, final int modifiers) {
     if (item != null) {
       for (BreadcrumbsItemListener listener : myListeners) {
         listener.itemSelected(item, modifiers);
       }
     }
   }

   @Nullable
   private List<Crumb> createCrumbList(@NotNull final FontMetrics fm, @NotNull final List<T> elements, final int width) {
     if (elements.size() == 0) {
       return null;
     }

     final LinkedList<Crumb> result = new LinkedList<Crumb>();
     int screenWidth = 0;
     Crumb rightmostCrumb = null;

     // fill up crumb list first going from end to start
     for (int i = elements.size() - 1; i >= 0; i--) {
       final NavigationCrumb forward = new NavigationCrumb(this, fm, true, DEFAULT_PAINTER);
       final NavigationCrumb backward = new NavigationCrumb(this, fm, false, DEFAULT_PAINTER);

       final BreadcrumbsItem element = elements.get(i);
       final String s = element.getDisplayText();
       final Dimension d = DEFAULT_PAINTER.getSize(s, fm, width - forward.getWidth() - backward.getWidth());
       final Crumb crumb = new Crumb(this, s, d.width, element);
       if (screenWidth + d.width > width) {
         Crumb first = null;
         if (screenWidth + backward.getWidth() > width && !result.isEmpty()) {
           first = result.removeFirst();
           screenWidth -= first.getWidth();
         }

         // put backward crumb
         result.addFirst(backward);
         screenWidth += backward.getWidth();

         // put dummy crumb to fill up empty space (add it to the end!!!)
         int dummyWidth = width - screenWidth;
         if (dummyWidth > 0) {
           final DummyCrumb dummy = new DummyCrumb(dummyWidth);
           if (rightmostCrumb != null) {
             result.add(result.indexOf(rightmostCrumb) + 1, dummy);
           }
           else {
             result.addLast(dummy);
           }
         }

         // now add forward crumb
         screenWidth = forward.getWidth();
         result.addFirst(forward);

         if (first != null) {
           result.addFirst(first);
           screenWidth += first.getWidth();
         }

         rightmostCrumb = (first != null) ? first : crumb;
       }

       result.addFirst(crumb);

       screenWidth += d.width;
     }

     if (rightmostCrumb != null && screenWidth < width) {
       // fill up empty space with elements from the full screen
       int index = result.indexOf(rightmostCrumb);
       for (int i = index + 1; i < result.size(); i++) {
         final Crumb crumb = result.get(i);
         if (crumb instanceof NavigationCrumb || crumb instanceof DummyCrumb) {
           continue;
         }

         if (screenWidth + crumb.getWidth() < width) {
           result.add(++index, new Crumb(this, crumb.getString(), crumb.getWidth(), crumb.getItem()));
           screenWidth += crumb.getWidth();
           i++;
         }
         else {
           break;
         }
       }

       // add first dummy crumb
       if (screenWidth < width) {
         result.add(index + 1, new DummyCrumb(width - screenWidth));
       }
     }

     //assert screenWidth < width;

     // now fix up offsets going forward
     int offset = 0;
     for (final Crumb each : result) {
       each.setOffset(offset);
       offset += each.getWidth();
     }

     // set selected crumb
     if (result.size() > 0) {
       for (int i = result.size() - 1; i >= 0; i--) {
         final Crumb c = result.get(i);
         if (!(c instanceof DummyCrumb)) {
           c.setSelected(true);
           break;
         }
       }
     }

     return result;
   }

   private static int getTotalWidth(@NotNull final List<Crumb> crumbList) {
     int totalWidth = 0;
     for (final Crumb each : crumbList) {
       totalWidth += each.getWidth();
     }

     return totalWidth;
   }

   @Override
   public Dimension getMinimumSize() {
     return getPreferredSize();
   }

   @Override
   public Dimension getPreferredSize() {
     final Graphics2D g2 = (Graphics2D)getGraphics();
     return new Dimension(Integer.MAX_VALUE, g2 != null ? DEFAULT_PAINTER.getSize("DUMMY", g2.getFontMetrics(), Integer.MAX_VALUE).height + 1 : 1);
   }

   @Override
   public Dimension getMaximumSize() {
     return getPreferredSize();
   }

   @Override
   public void dispose() {
     removeMouseListener(myMouseListener);
     removeMouseMotionListener(myMouseListener);

     myListeners = null;
   }

   private static class PagedImage {
     private final int myPageWidth;
     private int myPage;
     private final int myTotalWidth;

     public PagedImage(int totalWidth, int pageWidth) {
       myPageWidth = pageWidth;
       myTotalWidth = totalWidth;
     }

     public int getPageCount() {
       if (myTotalWidth < myPageWidth) {
         return 1;
       }

       return myTotalWidth / myPageWidth;
     }

     public void setPage(final int page) {
       assert page >= 0;
       assert page < getPageCount();

       myPage = page;
     }

     public int getPage() {
       return myPage;
     }

     private void repaint(@NotNull final Graphics2D g2,
                          @NotNull final List<Crumb> crumbList,
                          @NotNull final Painter painter,
                          final int height) {
       //final int height = myImage.getHeight();
       final int pageOffset = getPageOffset();

       for (final Crumb each : crumbList) {
         if (each.getOffset() >= pageOffset && each.getOffset() < pageOffset + myPageWidth) {
           each.paint(g2, painter, height, pageOffset);
         }
       }
     }

     public int getPageOffset() {
       return myPage * myPageWidth;
     }

     public void paintPage(@NotNull final Graphics2D g2, @NotNull final List<Crumb> list, @NotNull final Painter p, final int height) {
       repaint(g2, list, p, height);
     }

     public boolean isValid(final int width) {
       return width == myPageWidth;
     }
   }

   private static class CrumbLineMouseListener extends MouseAdapter implements MouseMotionListener {
     private final BreadcrumbsComponent myBreadcrumbs;
     private Crumb myHoveredCrumb;

     public CrumbLineMouseListener(@NotNull final BreadcrumbsComponent line) {
       myBreadcrumbs = line;
     }

     @Override
     public void mouseDragged(final MouseEvent e) {
       // nothing
     }

     @Override
     public void mouseMoved(final MouseEvent e) {
       final Crumb crumb = myBreadcrumbs.getCrumb(e.getPoint());
       if (crumb != myHoveredCrumb) {
         myBreadcrumbs.setHoveredCrumb(crumb);
         myHoveredCrumb = crumb;
       }
     }

     @Override
     public void mouseExited(final MouseEvent e) {
       mouseMoved(e);
     }

     @Override
     public void mouseEntered(final MouseEvent e) {
       mouseMoved(e);
     }

     @Override
     public void mouseClicked(final MouseEvent e) {
       final Crumb crumb = myBreadcrumbs.getCrumb(e.getPoint());
       if (crumb != null) {
         crumb.performAction(e.getModifiers());
       }
     }
   }

   private static class Crumb<T extends BreadcrumbsItem> {
     private final String myString;
     private int myOffset = -1;
     private final int myWidth;
     private T myItem;
     private BreadcrumbsComponent myLine;
     private boolean mySelected;
     private boolean myHovered;
     private boolean myLight;

     public Crumb(final BreadcrumbsComponent line, final String string, final int width, final T item) {
       this(string, width);

       myLine = line;
       myItem = item;
     }

     public Crumb(final String string, final int width) {
       myString = string;
       myWidth = width;
     }

     public String getString() {
       return myString;
     }

     public int getOffset() {
       LOG.assertTrue(myOffset != -1, "Negative offet for crumb: " + myString);
       return myOffset;
     }

     public int getWidth() {
       return myWidth;
     }

     public void setOffset(final int offset) {
       myOffset = offset;
     }

     public String toString() {
       return getString();
     }

     public void setSelected(final boolean selected) {
       mySelected = selected;
     }

     public void setLight(final boolean light) {
       myLight = light;
     }

     public boolean isHovered() {
       return myHovered;
     }

     public boolean isSelected() {
       return mySelected;
     }

     public boolean isLight() {
       return myLight;
     }

     public void paint(@NotNull final Graphics2D g2, @NotNull final Painter painter, final int height, final int pageOffset) {
       painter.paint(this, g2, height, pageOffset);
     }

     @Nullable
     public String getTooltipText() {
       final BreadcrumbsItem element = getItem();
       if (element != null) {
         return element.getTooltip();
       }

       return null;
     }

     public T getItem() {
       return myItem;
     }

     public void performAction(final int modifiers) {
       myLine.setSelectedCrumb(this, modifiers);
     }

     public void setHovered(final boolean b) {
       myHovered = b;
     }
   }

   private static class NavigationCrumb extends Crumb {
     @NonNls private static final String FORWARD = ">>";
     @NonNls private static final String BACKWARD = "<<";
     private final boolean myForward;
     private final BreadcrumbsComponent myLine;

     public NavigationCrumb(@NotNull final BreadcrumbsComponent line,
                            @NotNull final FontMetrics fm,
                            final boolean forward,
                            @NotNull final Painter p) {
       super(forward ? FORWARD : BACKWARD, p.getSize(forward ? FORWARD : BACKWARD, fm, Integer.MAX_VALUE).width);
       myForward = forward;
       myLine = line;
     }

     @Override
     public void performAction(final int modifiers) {
       if (myForward) {
         myLine.nextPage();
       }
       else {
         myLine.previousPage();
       }
     }
   }

   private static class DummyCrumb extends Crumb {
     public DummyCrumb(final int width) {
       super(null, width);
     }

     @Override
     public void paint(@NotNull final Graphics2D g2, @NotNull final Painter painter, final int height, final int pageOffset) {
       // does nothing
     }

     @Override
     public void performAction(final int modifiers) {
       // does nothing
     }

     @SuppressWarnings({"HardCodedStringLiteral"})
     public String toString() {
       return "DUMMY";
     }
   }

   abstract static class PainterSettings {
     private static final Color DEFAULT_FOREGROUND_COLOR = new JBColor(Gray._50, UIUtil.getListForeground());

     @Nullable
     Color getBackgroundColor(@NotNull final Crumb c) {
       return null;
     }

     @Nullable
     Color getForegroundColor(@NotNull final Crumb c) {
       return DEFAULT_FOREGROUND_COLOR;
     }

     @Nullable
     Color getBorderColor(@NotNull final Crumb c) {
       return null;
     }

     @Nullable
     Font getFont(@NotNull final Graphics g2, @NotNull final Crumb c) {
       return null;
     }
   }

   static class ButtonSettings extends PainterSettings {
     protected static final Color DEFAULT_BG_COLOR = new JBColor(Gray._245, new Color(101, 104, 106));
     private static final Color LIGHT_BG_COLOR = new JBColor(Gray._253, Gray._130);
     private static final Color CURRENT_BG_COLOR = new JBColor(new Color(250, 250, 220), new Color(97, 97, 75));
     protected static final Color HOVERED_BG_COLOR = new JBColor(Gray._220, ColorUtil.shift(DEFAULT_BG_COLOR, 1.2));

     private static final Color LIGHT_TEXT_COLOR = new JBColor(Gray._170, UIUtil.getListForeground());

     protected static final Color DEFAULT_BORDER_COLOR = new JBColor(Gray._90, Gray._50);
     private static final Color LIGHT_BORDER_COLOR = new JBColor(Gray._170, Gray._70);

     static Color getBackgroundColor(boolean selected, boolean hovered, boolean light, boolean navigationCrumb) {
       if (hovered) {
         return HOVERED_BG_COLOR;
       }

       if (selected) {
         return CURRENT_BG_COLOR;
       }

       if (light && !navigationCrumb) {
         return LIGHT_BG_COLOR;
       }

       return DEFAULT_BG_COLOR;
     }

     @Override
     @Nullable
     Color getBackgroundColor(@NotNull final Crumb c) {
       final BreadcrumbsItem item = c.getItem();
       if (item != null) {
         final CrumbPresentation presentation = item.getPresentation();
         if (presentation != null) {
           return presentation.getBackgroundColor(c.isSelected(), c.isHovered(), c.isLight());
         }
       }
       return getBackgroundColor(c.isSelected(), c.isHovered(), c.isLight(), c instanceof NavigationCrumb);
     }

     @Override
     @Nullable
     Color getForegroundColor(@NotNull final Crumb c) {
       if (c.isLight() && !c.isHovered() && !(c instanceof NavigationCrumb)) {
         return LIGHT_TEXT_COLOR;
       }

       return super.getForegroundColor(c);
     }

     @Override
     @Nullable
     Color getBorderColor(@NotNull final Crumb c) {
       return (c.isLight() && !c.isHovered() && !(c instanceof NavigationCrumb)) ? LIGHT_BORDER_COLOR : DEFAULT_BORDER_COLOR;
     }
   }

   abstract static class Painter {
     public static final int ROUND_VALUE = SystemInfo.isMac ? 3 : 2;

     private final PainterSettings mySettings;

     public Painter(@NotNull final PainterSettings s) {
       mySettings = s;
     }

     protected PainterSettings getSettings() {
       return mySettings;
     }

     abstract void paint(@NotNull final Crumb c, @NotNull final Graphics2D g2, final int height, final int pageOffset);

     @NotNull
     Dimension getSize(@NotNull @NonNls final String s, @NotNull final FontMetrics fm, final int maxWidth) {
       final int w = fm.stringWidth(s);
       return new Dimension(w > maxWidth ? maxWidth : w, fm.getHeight());
     }

   }

   private static class DefaultPainter extends Painter {
     public DefaultPainter(@NotNull final PainterSettings s) {
       super(s);
     }

     @Override
     public void paint(@NotNull final Crumb c, @NotNull final Graphics2D g2, final int height, final int pageOffset) {
       final PainterSettings s = getSettings();
       final Font oldFont = g2.getFont();
       final int offset = c.getOffset() - pageOffset;

       final Color bg = s.getBackgroundColor(c);
       final int width = c.getWidth();
       if (bg != null) {
         g2.setColor(bg);
         g2.fillRoundRect(offset + 2, 0, width - 4, height - 3, ROUND_VALUE, ROUND_VALUE);
       }

       final Color borderColor = s.getBorderColor(c);
       if (borderColor != null) {
         g2.setColor(borderColor);
         g2.drawRoundRect(offset + 1, 0, width - 2, height - 3, ROUND_VALUE, ROUND_VALUE);
       }

       final Color textColor = s.getForegroundColor(c);
       if (textColor != null) {
         g2.setColor(textColor);
       }

       final Font font = s.getFont(g2, c);
       if (font != null) {
         g2.setFont(font);
       }

       final FontMetrics fm = g2.getFontMetrics();

       String string = c.getString();
       if (fm.stringWidth(string) > width) {
         final int dotsWidth = fm.stringWidth("...");
         final StringBuilder sb = new StringBuilder();
         int length = 0;
         for (int i = 0; i < string.length(); i++) {
           final int charWidth = fm.charWidth(string.charAt(i));
           if (length + charWidth + dotsWidth > width) {
             break;
           }

           length += charWidth;
           sb.append(string.charAt(i));
         }

         string = sb.append("...").toString();
       }

       UIUtil.applyRenderingHints(g2);
       g2.drawString(string, offset + ROUND_VALUE, height - fm.getDescent() - 2);

       g2.setFont(oldFont);
     }

     @Override
     @NotNull
     Dimension getSize(@NotNull @NonNls final String s, @NotNull final FontMetrics fm, final int maxWidth) {
       final int width = fm.stringWidth(s) + (ROUND_VALUE * 2);
       return new Dimension(width > maxWidth ? maxWidth : width, fm.getHeight() + 4);
     }
   }
 }
	/*
	* Copyright 2000-2014 JetBrains s.r.o.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.intellij.xml.breadcrumbs;

	import com.intellij.openapi.Disposable;
	import com.intellij.openapi.diagnostic.Logger;
	import com.intellij.openapi.util.SystemInfo;
	import com.intellij.ui.ColorUtil;
	import com.intellij.ui.Gray;
	import com.intellij.ui.JBColor;
	import com.intellij.util.containers.ContainerUtil;
	import com.intellij.util.ui.UIUtil;
	import org.jetbrains.annotations.NonNls;
	import org.jetbrains.annotations.NotNull;
	import org.jetbrains.annotations.Nullable;

	import javax.swing.*;
	import java.awt.*;
	import java.awt.event.MouseAdapter;
	import java.awt.event.MouseEvent;
	import java.awt.event.MouseMotionListener;
	import java.util.*;
	import java.util.List;

	/**
	* @author spleaner
	*/
	public class BreadcrumbsComponent<T extends BreadcrumbsItem> extends JComponent implements Disposable {
	private static final Logger LOG = Logger.getInstance("#com.intellij.xml.breadcrumbs.BreadcrumbsComponent");
	private static final Painter DEFAULT_PAINTER = new DefaultPainter(new ButtonSettings());

	private List<BreadcrumbsItemListener<T>> myListeners = ContainerUtil.createLockFreeCopyOnWriteList();
	private Crumb myHovered;
	private PagedImage myBuffer;
	private List<Crumb> myCrumbs = new ArrayList<Crumb>();
	private final CrumbLineMouseListener myMouseListener;
	private List<T> myItems;

	public BreadcrumbsComponent() {
	myMouseListener = new CrumbLineMouseListener(this);
	addMouseListener(myMouseListener);
	addMouseMotionListener(myMouseListener);

	setToolTipText("");
	}

	public void setItems(@Nullable final List<T> itemsList) {
	if (myItems != itemsList) {
	myItems = itemsList;
	myCrumbs = null;
	}

	repaint();
	}

	public void addBreadcrumbsItemListener(@NotNull final BreadcrumbsItemListener<T> listener) {
	myListeners.add(listener);
	}

	public void removeBreadcrumbsItemListener(@NotNull final BreadcrumbsItemListener<T> listener) {
	myListeners.remove(listener);
	}

	@Override
	public String getToolTipText(final MouseEvent event) {
	final Crumb c = getCrumb(event.getPoint());
	if (c != null) {
	final String text = c.getTooltipText();
	return text == null ? super.getToolTipText(event) : text;
	}

	return super.getToolTipText(event);
	}

	@Nullable
	public Crumb getCrumb(@NotNull final Point p) {
	if (myCrumbs != null) {
	final Rectangle r = getBounds();
	p.translate(r.x, r.y);

	if (!r.contains(p)) {
	return null;
	}

	if (myBuffer == null) {
	return null;
	}

	final int offset = myBuffer.getPageOffset();

	for (final Crumb each : myCrumbs) {
	if (((p.x + offset) >= each.getOffset()) && ((p.x + offset) < (each.getOffset() + each.getWidth()))) {
	return each;
	}
	}
	}

	return null;
	}

	public void setHoveredCrumb(@Nullable final Crumb crumb) {
	if (crumb != null) {
	crumb.setHovered(true);
	}

	if (myHovered != null) {
	myHovered.setHovered(false);
	}

	myHovered = crumb;
	repaint();
	}

	public void nextPage() {
	if (myBuffer != null) {
	final int page = myBuffer.getPage();
	if (page + 1 < myBuffer.getPageCount()) {
	myBuffer.setPage(page + 1);
	}
	}

	repaint();
	}

	public void previousPage() {
	if (myBuffer != null) {
	final int page = myBuffer.getPage();
	if (page - 1 >= 0) {
	myBuffer.setPage(page - 1);
	}
	}

	repaint();
	}

	@Override
	public void paint(final Graphics g) {
	final Graphics2D g2 = ((Graphics2D)g);
	final Dimension d = getSize();
	final FontMetrics fm = g2.getFontMetrics();

	if (myItems != null) {
	final boolean veryDirty = (myCrumbs == null) \|\| (myBuffer != null && !myBuffer.isValid(d.width));

	final List<Crumb> crumbList = veryDirty ? createCrumbList(fm, myItems, d.width) : myCrumbs;
	if (crumbList != null) {
	if (veryDirty) {
	//final BufferedImage bufferedImage = createBuffer(crumbList, d.height);
	myBuffer = new PagedImage(getTotalWidth(crumbList), d.width);
	myBuffer.setPage(myBuffer.getPageCount() - 1); // point to the last page
	}

	assert myBuffer != null;

	super.paint(g2);

	//if (myDirty) {
	// myBuffer.repaint(crumbList, getPainter());
	//myDirty = false;
	//}

	myBuffer.paintPage(g2, crumbList, DEFAULT_PAINTER, d.height);
	myCrumbs = crumbList;
	}
	}
	else {
	super.paint(g2);
	}
	}

	private void setSelectedCrumb(@NotNull final Crumb<T> c, final int modifiers) {
	final T selectedElement = c.getItem();

	final Set<BreadcrumbsItem> items = new HashSet<BreadcrumbsItem>();
	boolean light = false;
	for (final Crumb each : myCrumbs) {
	final BreadcrumbsItem item = each.getItem();
	if (item != null && items.contains(item)) {
	light = false;
	}

	each.setLight(light);

	if (item != null && !light) {
	items.add(item);
	}

	if (selectedElement == item) {
	each.setSelected(true);
	light = true;
	}
	else {
	each.setSelected(false);
	}
	}

	fireItemSelected(selectedElement, modifiers);

	repaint();
	}

	@SuppressWarnings({"ForLoopReplaceableByForEach"})
	private void fireItemSelected(@Nullable final T item, final int modifiers) {
	if (item != null) {
	for (BreadcrumbsItemListener listener : myListeners) {
	listener.itemSelected(item, modifiers);
	}
	}
	}

	@Nullable
	private List<Crumb> createCrumbList(@NotNull final FontMetrics fm, @NotNull final List<T> elements, final int width) {
	if (elements.size() == 0) {
	return null;
	}

	final LinkedList<Crumb> result = new LinkedList<Crumb>();
	int screenWidth = 0;
	Crumb rightmostCrumb = null;

	// fill up crumb list first going from end to start
	for (int i = elements.size() - 1; i >= 0; i--) {
	final NavigationCrumb forward = new NavigationCrumb(this, fm, true, DEFAULT_PAINTER);
	final NavigationCrumb backward = new NavigationCrumb(this, fm, false, DEFAULT_PAINTER);

	final BreadcrumbsItem element = elements.get(i);
	final String s = element.getDisplayText();
	final Dimension d = DEFAULT_PAINTER.getSize(s, fm, width - forward.getWidth() - backward.getWidth());
	final Crumb crumb = new Crumb(this, s, d.width, element);
	if (screenWidth + d.width > width) {
	Crumb first = null;
	if (screenWidth + backward.getWidth() > width && !result.isEmpty()) {
	first = result.removeFirst();
	screenWidth -= first.getWidth();
	}

	// put backward crumb
	result.addFirst(backward);
	screenWidth += backward.getWidth();

	// put dummy crumb to fill up empty space (add it to the end!!!)
	int dummyWidth = width - screenWidth;
	if (dummyWidth > 0) {
	final DummyCrumb dummy = new DummyCrumb(dummyWidth);
	if (rightmostCrumb != null) {
	result.add(result.indexOf(rightmostCrumb) + 1, dummy);
	}
	else {
	result.addLast(dummy);
	}
	}

	// now add forward crumb
	screenWidth = forward.getWidth();
	result.addFirst(forward);

	if (first != null) {
	result.addFirst(first);
	screenWidth += first.getWidth();
	}

	rightmostCrumb = (first != null) ? first : crumb;
	}

	result.addFirst(crumb);

	screenWidth += d.width;
	}

	if (rightmostCrumb != null && screenWidth < width) {
	// fill up empty space with elements from the full screen
	int index = result.indexOf(rightmostCrumb);
	for (int i = index + 1; i < result.size(); i++) {
	final Crumb crumb = result.get(i);
	if (crumb instanceof NavigationCrumb \|\| crumb instanceof DummyCrumb) {
	continue;
	}

	if (screenWidth + crumb.getWidth() < width) {
	result.add(++index, new Crumb(this, crumb.getString(), crumb.getWidth(), crumb.getItem()));
	screenWidth += crumb.getWidth();
	i++;
	}
	else {
	break;
	}
	}

	// add first dummy crumb
	if (screenWidth < width) {
	result.add(index + 1, new DummyCrumb(width - screenWidth));
	}
	}

	//assert screenWidth < width;

	// now fix up offsets going forward
	int offset = 0;
	for (final Crumb each : result) {
	each.setOffset(offset);
	offset += each.getWidth();
	}

	// set selected crumb
	if (result.size() > 0) {
	for (int i = result.size() - 1; i >= 0; i--) {
	final Crumb c = result.get(i);
	if (!(c instanceof DummyCrumb)) {
	c.setSelected(true);
	break;
	}
	}
	}

	return result;
	}

	private static int getTotalWidth(@NotNull final List<Crumb> crumbList) {
	int totalWidth = 0;
	for (final Crumb each : crumbList) {
	totalWidth += each.getWidth();
	}

	return totalWidth;
	}

	@Override
	public Dimension getMinimumSize() {
	return getPreferredSize();
	}

	@Override
	public Dimension getPreferredSize() {
	final Graphics2D g2 = (Graphics2D)getGraphics();
	return new Dimension(Integer.MAX_VALUE, g2 != null ? DEFAULT_PAINTER.getSize("DUMMY", g2.getFontMetrics(), Integer.MAX_VALUE).height + 1 : 1);
	}

	@Override
	public Dimension getMaximumSize() {
	return getPreferredSize();
	}

	@Override
	public void dispose() {
	removeMouseListener(myMouseListener);
	removeMouseMotionListener(myMouseListener);

	myListeners = null;
	}

	private static class PagedImage {
	private final int myPageWidth;
	private int myPage;
	private final int myTotalWidth;

	public PagedImage(int totalWidth, int pageWidth) {
	myPageWidth = pageWidth;
	myTotalWidth = totalWidth;
	}

	public int getPageCount() {
	if (myTotalWidth < myPageWidth) {
	return 1;
	}

	return myTotalWidth / myPageWidth;
	}

	public void setPage(final int page) {
	assert page >= 0;
	assert page < getPageCount();

	myPage = page;
	}

	public int getPage() {
	return myPage;
	}

	private void repaint(@NotNull final Graphics2D g2,
	@NotNull final List<Crumb> crumbList,
	@NotNull final Painter painter,
	final int height) {
	//final int height = myImage.getHeight();
	final int pageOffset = getPageOffset();

	for (final Crumb each : crumbList) {
	if (each.getOffset() >= pageOffset && each.getOffset() < pageOffset + myPageWidth) {
	each.paint(g2, painter, height, pageOffset);
	}
	}
	}

	public int getPageOffset() {
	return myPage * myPageWidth;
	}

	public void paintPage(@NotNull final Graphics2D g2, @NotNull final List<Crumb> list, @NotNull final Painter p, final int height) {
	repaint(g2, list, p, height);
	}

	public boolean isValid(final int width) {
	return width == myPageWidth;
	}
	}

	private static class CrumbLineMouseListener extends MouseAdapter implements MouseMotionListener {
	private final BreadcrumbsComponent myBreadcrumbs;
	private Crumb myHoveredCrumb;

	public CrumbLineMouseListener(@NotNull final BreadcrumbsComponent line) {
	myBreadcrumbs = line;
	}

	@Override
	public void mouseDragged(final MouseEvent e) {
	// nothing
	}

	@Override
	public void mouseMoved(final MouseEvent e) {
	final Crumb crumb = myBreadcrumbs.getCrumb(e.getPoint());
	if (crumb != myHoveredCrumb) {
	myBreadcrumbs.setHoveredCrumb(crumb);
	myHoveredCrumb = crumb;
	}
	}

	@Override
	public void mouseExited(final MouseEvent e) {
	mouseMoved(e);
	}

	@Override
	public void mouseEntered(final MouseEvent e) {
	mouseMoved(e);
	}

	@Override
	public void mouseClicked(final MouseEvent e) {
	final Crumb crumb = myBreadcrumbs.getCrumb(e.getPoint());
	if (crumb != null) {
	crumb.performAction(e.getModifiers());
	}
	}
	}

	private static class Crumb<T extends BreadcrumbsItem> {
	private final String myString;
	private int myOffset = -1;
	private final int myWidth;
	private T myItem;
	private BreadcrumbsComponent myLine;
	private boolean mySelected;
	private boolean myHovered;
	private boolean myLight;

	public Crumb(final BreadcrumbsComponent line, final String string, final int width, final T item) {
	this(string, width);

	myLine = line;
	myItem = item;
	}

	public Crumb(final String string, final int width) {
	myString = string;
	myWidth = width;
	}

	public String getString() {
	return myString;
	}

	public int getOffset() {
	LOG.assertTrue(myOffset != -1, "Negative offet for crumb: " + myString);
	return myOffset;
	}

	public int getWidth() {
	return myWidth;
	}

	public void setOffset(final int offset) {
	myOffset = offset;
	}

	public String toString() {
	return getString();
	}

	public void setSelected(final boolean selected) {
	mySelected = selected;
	}

	public void setLight(final boolean light) {
	myLight = light;
	}

	public boolean isHovered() {
	return myHovered;
	}

	public boolean isSelected() {
	return mySelected;
	}

	public boolean isLight() {
	return myLight;
	}

	public void paint(@NotNull final Graphics2D g2, @NotNull final Painter painter, final int height, final int pageOffset) {
	painter.paint(this, g2, height, pageOffset);
	}

	@Nullable
	public String getTooltipText() {
	final BreadcrumbsItem element = getItem();
	if (element != null) {
	return element.getTooltip();
	}

	return null;
	}

	public T getItem() {
	return myItem;
	}

	public void performAction(final int modifiers) {
	myLine.setSelectedCrumb(this, modifiers);
	}

	public void setHovered(final boolean b) {
	myHovered = b;
	}
	}

	private static class NavigationCrumb extends Crumb {
	@NonNls private static final String FORWARD = ">>";
	@NonNls private static final String BACKWARD = "<<";
	private final boolean myForward;
	private final BreadcrumbsComponent myLine;

	public NavigationCrumb(@NotNull final BreadcrumbsComponent line,
	@NotNull final FontMetrics fm,
	final boolean forward,
	@NotNull final Painter p) {
	super(forward ? FORWARD : BACKWARD, p.getSize(forward ? FORWARD : BACKWARD, fm, Integer.MAX_VALUE).width);
	myForward = forward;
	myLine = line;
	}

	@Override
	public void performAction(final int modifiers) {
	if (myForward) {
	myLine.nextPage();
	}
	else {
	myLine.previousPage();
	}
	}
	}

	private static class DummyCrumb extends Crumb {
	public DummyCrumb(final int width) {
	super(null, width);
	}

	@Override
	public void paint(@NotNull final Graphics2D g2, @NotNull final Painter painter, final int height, final int pageOffset) {
	// does nothing
	}

	@Override
	public void performAction(final int modifiers) {
	// does nothing
	}

	@SuppressWarnings({"HardCodedStringLiteral"})
	public String toString() {
	return "DUMMY";
	}
	}

	abstract static class PainterSettings {
	private static final Color DEFAULT_FOREGROUND_COLOR = new JBColor(Gray._50, UIUtil.getListForeground());

	@Nullable
	Color getBackgroundColor(@NotNull final Crumb c) {
	return null;
	}

	@Nullable
	Color getForegroundColor(@NotNull final Crumb c) {
	return DEFAULT_FOREGROUND_COLOR;
	}

	@Nullable
	Color getBorderColor(@NotNull final Crumb c) {
	return null;
	}

	@Nullable
	Font getFont(@NotNull final Graphics g2, @NotNull final Crumb c) {
	return null;
	}
	}

	static class ButtonSettings extends PainterSettings {
	protected static final Color DEFAULT_BG_COLOR = new JBColor(Gray._245, new Color(101, 104, 106));
	private static final Color LIGHT_BG_COLOR = new JBColor(Gray._253, Gray._130);
	private static final Color CURRENT_BG_COLOR = new JBColor(new Color(250, 250, 220), new Color(97, 97, 75));
	protected static final Color HOVERED_BG_COLOR = new JBColor(Gray._220, ColorUtil.shift(DEFAULT_BG_COLOR, 1.2));

	private static final Color LIGHT_TEXT_COLOR = new JBColor(Gray._170, UIUtil.getListForeground());

	protected static final Color DEFAULT_BORDER_COLOR = new JBColor(Gray._90, Gray._50);
	private static final Color LIGHT_BORDER_COLOR = new JBColor(Gray._170, Gray._70);

	static Color getBackgroundColor(boolean selected, boolean hovered, boolean light, boolean navigationCrumb) {
	if (hovered) {
	return HOVERED_BG_COLOR;
	}

	if (selected) {
	return CURRENT_BG_COLOR;
	}

	if (light && !navigationCrumb) {
	return LIGHT_BG_COLOR;
	}

	return DEFAULT_BG_COLOR;
	}

	@Override
	@Nullable
	Color getBackgroundColor(@NotNull final Crumb c) {
	final BreadcrumbsItem item = c.getItem();
	if (item != null) {
	final CrumbPresentation presentation = item.getPresentation();
	if (presentation != null) {
	return presentation.getBackgroundColor(c.isSelected(), c.isHovered(), c.isLight());
	}
	}
	return getBackgroundColor(c.isSelected(), c.isHovered(), c.isLight(), c instanceof NavigationCrumb);
	}

	@Override
	@Nullable
	Color getForegroundColor(@NotNull final Crumb c) {
	if (c.isLight() && !c.isHovered() && !(c instanceof NavigationCrumb)) {
	return LIGHT_TEXT_COLOR;
	}

	return super.getForegroundColor(c);
	}

	@Override
	@Nullable
	Color getBorderColor(@NotNull final Crumb c) {
	return (c.isLight() && !c.isHovered() && !(c instanceof NavigationCrumb)) ? LIGHT_BORDER_COLOR : DEFAULT_BORDER_COLOR;
	}
	}

	abstract static class Painter {
	public static final int ROUND_VALUE = SystemInfo.isMac ? 3 : 2;

	private final PainterSettings mySettings;

	public Painter(@NotNull final PainterSettings s) {
	mySettings = s;
	}

	protected PainterSettings getSettings() {
	return mySettings;
	}

	abstract void paint(@NotNull final Crumb c, @NotNull final Graphics2D g2, final int height, final int pageOffset);

	@NotNull
	Dimension getSize(@NotNull @NonNls final String s, @NotNull final FontMetrics fm, final int maxWidth) {
	final int w = fm.stringWidth(s);
	return new Dimension(w > maxWidth ? maxWidth : w, fm.getHeight());
	}

	}

	private static class DefaultPainter extends Painter {
	public DefaultPainter(@NotNull final PainterSettings s) {
	super(s);
	}

	@Override
	public void paint(@NotNull final Crumb c, @NotNull final Graphics2D g2, final int height, final int pageOffset) {
	final PainterSettings s = getSettings();
	final Font oldFont = g2.getFont();
	final int offset = c.getOffset() - pageOffset;

	final Color bg = s.getBackgroundColor(c);
	final int width = c.getWidth();
	if (bg != null) {
	g2.setColor(bg);
	g2.fillRoundRect(offset + 2, 0, width - 4, height - 3, ROUND_VALUE, ROUND_VALUE);
	}

	final Color borderColor = s.getBorderColor(c);
	if (borderColor != null) {
	g2.setColor(borderColor);
	g2.drawRoundRect(offset + 1, 0, width - 2, height - 3, ROUND_VALUE, ROUND_VALUE);
	}

	final Color textColor = s.getForegroundColor(c);
	if (textColor != null) {
	g2.setColor(textColor);
	}

	final Font font = s.getFont(g2, c);
	if (font != null) {
	g2.setFont(font);
	}

	final FontMetrics fm = g2.getFontMetrics();

	String string = c.getString();
	if (fm.stringWidth(string) > width) {
	final int dotsWidth = fm.stringWidth("...");
	final StringBuilder sb = new StringBuilder();
	int length = 0;
	for (int i = 0; i < string.length(); i++) {
	final int charWidth = fm.charWidth(string.charAt(i));
	if (length + charWidth + dotsWidth > width) {
	break;
	}

	length += charWidth;
	sb.append(string.charAt(i));
	}

	string = sb.append("...").toString();
	}

	UIUtil.applyRenderingHints(g2);
	g2.drawString(string, offset + ROUND_VALUE, height - fm.getDescent() - 2);

	g2.setFont(oldFont);
	}

	@Override
	@NotNull
	Dimension getSize(@NotNull @NonNls final String s, @NotNull final FontMetrics fm, final int maxWidth) {
	final int width = fm.stringWidth(s) + (ROUND_VALUE * 2);
	return new Dimension(width > maxWidth ? maxWidth : width, fm.getHeight() + 4);
	}
	}
	}