platform/platform-api/src/com/intellij/util/ui/ButtonlessScrollBarUI.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.util.ui;

 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.registry.Registry;
 import com.intellij.ui.Gray;
 import com.intellij.ui.JBColor;
 import com.intellij.ui.LightColors;
 import com.intellij.ui.components.JBScrollPane;
 import com.intellij.util.ReflectionUtil;

 import javax.swing.*;
 import javax.swing.event.ChangeEvent;
 import javax.swing.plaf.basic.BasicScrollBarUI;
 import java.awt.*;
 import java.awt.event.*;
 import java.lang.reflect.Method;

 /**
  * @author max
  * @author Konstantin Bulenkov
  */
 public class ButtonlessScrollBarUI extends BasicScrollBarUI {
   private static final Logger LOG = Logger.getInstance("#" + ButtonlessScrollBarUI.class.getName());

   public static JBColor getGradientLightColor() {
     return new JBColor(Gray._251, Gray._95);
   }

   public static JBColor getGradientDarkColor() {
     return new JBColor(Gray._215, Gray._80);
   }

   private static JBColor getGradientThumbBorderColor() {
     return new JBColor(Gray._201, Gray._85);
   }

   public static JBColor getTrackBackground() {
     return new JBColor(LightColors.SLIGHTLY_GRAY, UIUtil.getListBackground());
   }

   public static JBColor getTrackBorderColor() {
     return new JBColor(Gray._230, UIUtil.getListBackground());
   }

   private static final BasicStroke BORDER_STROKE = new BasicStroke();

   private static int getAnimationColorShift() {
     return UIUtil.isUnderDarcula() ? 20 : 40;
   }

   private final AdjustmentListener myAdjustmentListener;
   private final MouseMotionAdapter myMouseMotionListener;
   private final MouseAdapter myMouseListener;
   private final HierarchyListener myHierarchyListener;
   private final AWTEventListener myAWTMouseListener;
   private final NSScrollerHelper.ScrollbarStyleListener myNSScrollerListener;
   private boolean myGlobalListenersAdded;

   public static final int DELAY_FRAMES = 4;
   public static final int FRAMES_COUNT = 10 + DELAY_FRAMES;

   private Animator myThumbFadeAnimator;
   private int myThumbFadeColorShift = 0;

   private boolean myMouseIsOverThumb = false;
   private boolean myMouseOverScrollbar;
   private double myMouseOverScrollbarExpandLevel = 0;

   private NSScrollerHelper.Style myMacScrollerStyle;
   private Animator myMouseOverScrollbarExpandAnimator;
   private Animator myMacScrollbarFadeAnimator;
   private double myMacScrollbarFadeLevel = 0;
   private boolean myMacScrollbarHidden;


   protected ButtonlessScrollBarUI() {
     myAdjustmentListener = new AdjustmentListener() {
       @Override
       public void adjustmentValueChanged(AdjustmentEvent e) {
         resetRegularThumbAnimator();
         resetMacScrollbarFadeout();
       }
     };

     myMouseMotionListener = new MouseMotionAdapter() {
       @Override
       public void mouseMoved(MouseEvent e) {
         boolean inside = isOverThumb(e.getPoint());
         if (inside != myMouseIsOverThumb) {
           myMouseIsOverThumb = inside;
           resetRegularThumbAnimator();
         }
       }
     };

     myMouseListener = new MouseAdapter() {
       @Override
       public void mouseEntered(MouseEvent e) {
         // only restart animations when fading hasn't started yet
         if (myMacScrollbarFadeLevel == 0) {
           myMouseOverScrollbar = true;
           resetMacScrollbarExpandAnimator();
           resetMacScrollbarFadeout();
         }
       }

       @Override
       public void mouseExited(MouseEvent e) {
         if (myMouseIsOverThumb) {
           myMouseIsOverThumb = false;
           resetRegularThumbAnimator();
         }

         if (myMouseOverScrollbar) {
           myMouseOverScrollbar = false;
           resetMacScrollbarExpandAnimator();
           resetMacScrollbarFadeout();
         }
       }
     };

     myHierarchyListener = new HierarchyListener() {
       @Override
       public void hierarchyChanged(HierarchyEvent e) {
         if (e.getChanged() == scrollbar) {
           if ((HierarchyEvent.DISPLAYABILITY_CHANGED & e.getChangeFlags()) != 0) {
             updateGlobalListeners(false);
           }

           if ((HierarchyEvent.SHOWING_CHANGED & e.getChangeFlags()) != 0) {
             resetRegularThumbAnimator();
             resetMacScrollbarFadeout();
           }
         }
       }
     };
     myAWTMouseListener = new AWTEventListener() {
       public void eventDispatched(AWTEvent event) {
         if (event.getID() == MouseEvent.MOUSE_MOVED) {

             // user is moving inside the scrollpane of the scrollbar and fade-out hasn't started yet
           Container scrollpane = SwingUtilities.getAncestorOfClass(JScrollPane.class, scrollbar);
           if (scrollpane != null) {
             Point loc = ((MouseEvent)event).getLocationOnScreen();
             SwingUtilities.convertPointFromScreen(loc, scrollpane);
             if (scrollpane.contains(loc) && !myMacScrollbarHidden && myMacScrollbarFadeLevel == 0) {
               resetMacScrollbarFadeout();
             }
           }
         }
       }
     };
     myNSScrollerListener = new NSScrollerHelper.ScrollbarStyleListener() {
       @Override
       public void styleChanged() {
         updateMacScrollbarStyle();
       }
     };
   }

   protected boolean isMacOverlayScrollbar() {
     return myMacScrollerStyle == NSScrollerHelper.Style.Overlay && isMacOverlayScrollbarSupported();
   }

   public static boolean isMacOverlayScrollbarSupported() {
     return SystemInfo.isMac && !Registry.is("ide.mac.disableMacScrollbars");
   }

   private void updateMacScrollbarStyle() {
     NSScrollerHelper.Style style = NSScrollerHelper.getScrollerStyle();

     if (style != myMacScrollerStyle && scrollbar != null) {
       myMacScrollerStyle = style;
       JScrollBar scrollBar = scrollbar;
       uninstallUI(scrollBar);
       installUI(scrollBar);

       JScrollPane pane = JBScrollPane.findScrollPane(scrollBar);
       if (pane != null) pane.revalidate();
     }
   }

   public boolean alwaysShowTrack() {
     return !isMacOverlayScrollbar();
   }

   @Override
   public void layoutContainer(Container scrollbarContainer) {
     try {
       super.layoutContainer(scrollbarContainer);
     } catch (NullPointerException ignore) {
       //installUI is not performed yet or uninstallUI has set almost every field to null. Just ignore it //IDEA-89674
     }
   }

   @Override
   protected ModelListener createModelListener() {
     return new ModelListener() {
       @Override
       public void stateChanged(ChangeEvent e) {
         if (scrollbar != null) {
           super.stateChanged(e);
         }
       }
     };
   }

   public int getDecrementButtonHeight() {
     return Math.max(0, decrButton.getHeight());
   }
   public int getIncrementButtonHeight() {
     return Math.max(0, incrButton.getHeight());
   }

   private void resetRegularThumbAnimator() {
     if (isMacOverlayScrollbar()) return;

     myThumbFadeAnimator.reset();
     if (scrollbar != null && scrollbar.getValueIsAdjusting() || myMouseIsOverThumb || Registry.is("ui.no.bangs.and.whistles")) {
       myThumbFadeAnimator.suspend();
       myThumbFadeColorShift = getAnimationColorShift();
     }
     else {
       myThumbFadeAnimator.resume();
     }
   }

   private void resetMacScrollbarExpandAnimator() {
     if (!isMacOverlayScrollbar()) return;

     if (myMouseOverScrollbarExpandLevel == 0) {
       myMouseOverScrollbarExpandAnimator.reset();
       myMouseOverScrollbarExpandAnimator.suspend();
       if (myMouseOverScrollbar) {
         myMouseOverScrollbarExpandAnimator.resume();
       }
     }
   }

   private void resetMacScrollbarFadeout() {
     if (!isMacOverlayScrollbar()) return;

     myMacScrollbarFadeAnimator.suspend();
     myMacScrollbarFadeAnimator.reset();
     myMacScrollbarHidden = false;
     myMacScrollbarFadeLevel = 0;

     JScrollBar sb = scrollbar; // concurrency in background editors initialization
     if (sb != null) {
       sb.repaint();

       if (!myMouseOverScrollbar && !sb.getValueIsAdjusting()) {
         myMacScrollbarFadeAnimator.resume();
       }
     }
   }

   public static BasicScrollBarUI createNormal() {
     return new ButtonlessScrollBarUI();
   }


   public static BasicScrollBarUI createTransparent() {
     return new ButtonlessScrollBarUI() {
       @Override
       public boolean alwaysShowTrack() {
         return false;
       }
     };
   }

   @Override
   public void installUI(JComponent c) {
     super.installUI(c);
     scrollbar.setFocusable(false);
     scrollbar.setOpaque(alwaysShowTrack());
   }

   @Override
   protected void installDefaults() {
     myMacScrollerStyle = NSScrollerHelper.getScrollerStyle();

     final int incGap = UIManager.getInt("ScrollBar.incrementButtonGap");
     final int decGap = UIManager.getInt("ScrollBar.decrementButtonGap");
     try {
       UIManager.put("ScrollBar.incrementButtonGap", 0);
       UIManager.put("ScrollBar.decrementButtonGap", 0);
       super.installDefaults();
     }
     finally {
       UIManager.put("ScrollBar.incrementButtonGap", incGap);
       UIManager.put("ScrollBar.decrementButtonGap", decGap);
     }
   }

   @Override
   protected void installListeners() {
     initRegularThumbAnimator();
     initMacScrollbarAnimators();

     super.installListeners();
     scrollbar.addAdjustmentListener(myAdjustmentListener);
     scrollbar.addMouseListener(myMouseListener);
     scrollbar.addMouseMotionListener(myMouseMotionListener);

     scrollbar.addHierarchyListener(myHierarchyListener);
     updateGlobalListeners(false);

     resetRegularThumbAnimator();
     resetMacScrollbarFadeout();
   }

   private static final Method setValueFrom = ReflectionUtil.getDeclaredMethod(TrackListener.class, "setValueFrom", MouseEvent.class);
   static {
     LOG.assertTrue(setValueFrom != null, "Cannot get TrackListener.setValueFrom method");
   }

   @Override
   protected TrackListener createTrackListener() {
     return new TrackListener() {
       @Override
       public void mousePressed(MouseEvent e) {
         if (scrollbar.isEnabled()
             && SwingUtilities.isLeftMouseButton(e)
             && !getThumbBounds().contains(e.getPoint())
             && NSScrollerHelper.getClickBehavior() == NSScrollerHelper.ClickBehavior.JumpToSpot
             && setValueFrom != null) {

           switch (scrollbar.getOrientation()) {
             case Adjustable.VERTICAL:
               offset = getThumbBounds().height / 2;
               break;
             case Adjustable.HORIZONTAL:
               offset = getThumbBounds().width / 2;
               break;
           }
           isDragging = true;
           try {
             setValueFrom.invoke(this, e);
           }
           catch (Exception ex) {
             LOG.error(ex);
           }

           return;
         }

         super.mousePressed(e);
       }
     };
   }

   private void updateGlobalListeners(boolean forceRemove) {
     boolean shouldAdd = scrollbar.isDisplayable();

     if (myGlobalListenersAdded && (!shouldAdd || forceRemove)) {
       Toolkit.getDefaultToolkit().removeAWTEventListener(myAWTMouseListener);
       NSScrollerHelper.removeScrollbarStyleListener(myNSScrollerListener);
       myGlobalListenersAdded = false;
     }

     if (!myGlobalListenersAdded && shouldAdd && !forceRemove) {
       Toolkit.getDefaultToolkit().addAWTEventListener(myAWTMouseListener, AWTEvent.MOUSE_MOTION_EVENT_MASK);
       NSScrollerHelper.addScrollbarStyleListener(myNSScrollerListener);
       myGlobalListenersAdded = true;
     }
   }

   private void initRegularThumbAnimator() {
     myThumbFadeAnimator = new Animator("Regular scrollbar thumb animator", FRAMES_COUNT, FRAMES_COUNT * 50, false) {
       @Override
       public void paintNow(int frame, int totalFrames, int cycle) {
         myThumbFadeColorShift = getAnimationColorShift();
         if (frame > DELAY_FRAMES) {
           myThumbFadeColorShift *= 1 - ((double)(frame - DELAY_FRAMES)) / ((double)(totalFrames - DELAY_FRAMES));
         }

         if (scrollbar != null) {
           scrollbar.repaint(((ButtonlessScrollBarUI)scrollbar.getUI()).getThumbBounds());
         }
       }
     };
   }

   private void initMacScrollbarAnimators() {
     myMouseOverScrollbarExpandAnimator = new Animator("Mac scrollbar mouse over animator", 10, 200, false) {
       @Override
       protected void paintCycleEnd() {
         myMouseOverScrollbarExpandLevel = 1;
         if (scrollbar != null) scrollbar.repaint();
       }

       @Override
       public void paintNow(int frame, int totalFrames, int cycle) {
         int delay = totalFrames / 2;
         int frameAfterDelay = frame - delay;

         if (frameAfterDelay > 0) {
           myMouseOverScrollbarExpandLevel = frameAfterDelay / (float)(totalFrames - delay);
           if (scrollbar != null) scrollbar.repaint();
         }
       }
     };

     myMacScrollbarFadeAnimator = new Animator("Mac scrollbar fade animator", 30, 1000, false) {
       @Override
       protected void paintCycleEnd() {
         myMacScrollbarHidden = true;
         myMouseOverScrollbar = false;
         myMouseOverScrollbarExpandLevel = 0;

         if (scrollbar != null) scrollbar.repaint();
       }

       @Override
       public void paintNow(int frame, int totalFrames, int cycle) {
         int delay = (int)(totalFrames / 1.5);
         int frameAfterDelay = frame - delay;

         if (frameAfterDelay > 0) {
           myMacScrollbarFadeLevel = frameAfterDelay / (float)(totalFrames - delay);
         }
         if (scrollbar != null) scrollbar.repaint();
       }
     };
   }

   private boolean isOverThumb(Point p) {
     final Rectangle bounds = getThumbBounds();
     return bounds != null && bounds.contains(p);
   }

   @Override
   public Rectangle getThumbBounds() {
     return super.getThumbBounds();
   }

   @Override
   protected void uninstallListeners() {
     if (scrollTimer != null) {
       // it is already called otherwise
       super.uninstallListeners();
     }

     scrollbar.removeAdjustmentListener(myAdjustmentListener);
     scrollbar.removeMouseListener(myMouseListener);
     scrollbar.removeMouseMotionListener(myMouseMotionListener);

     scrollbar.removeHierarchyListener(myHierarchyListener);
     updateGlobalListeners(true);

     Disposer.dispose(myThumbFadeAnimator);
     Disposer.dispose(myMouseOverScrollbarExpandAnimator);
     Disposer.dispose(myMacScrollbarFadeAnimator);
   }

   @Override
   protected Dimension getMinimumThumbSize() {
     final int thickness = getThickness();
     return isVertical() ? new Dimension(thickness, thickness * 2) : new Dimension(thickness * 2, thickness);
   }

   protected int getThickness() {
     return isMacOverlayScrollbar() ? 15 : 13;
   }

   @Override
   public Dimension getMaximumSize(JComponent c) {
     int thickness = getThickness();
     return new Dimension(thickness, thickness);
   }

   @Override
   public Dimension getMinimumSize(JComponent c) {
     return getMaximumSize(c);
   }

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

   @Override
   public boolean contains(JComponent c, int x, int y) {
     if (isMacOverlayScrollbar() && !alwaysShowTrack() && myMacScrollbarHidden) return false;
     return super.contains(c, x, y);
   }


   @Override
   protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds) {
     if (alwaysShowTrack() || myMouseOverScrollbarExpandLevel > 0) {
       doPaintTrack(g, c, trackBounds);
     }
   }

   protected void doPaintTrack(Graphics g, JComponent c, Rectangle bounds) {
     if (isMacOverlayScrollbar() && !alwaysShowTrack()) {
       bounds = getMacScrollBarBounds(bounds, false);
       boolean vertical = isVertical();

       final Paint paint;
       final Color start = adjustColor(UIUtil.getSlightlyDarkerColor(getTrackBackground()));
       final Color end = adjustColor(getTrackBackground().brighter());

       if (vertical) {
         paint = UIUtil.getGradientPaint(bounds.x + 1, bounds.y, start, bounds.width + 1, bounds.y, end);
       }
       else {
         paint = UIUtil.getGradientPaint(bounds.x, bounds.y + 1, start, bounds.x, bounds.height + 1, end);
       }

       Graphics2D g2d = (Graphics2D)g;
       g2d.setPaint(paint);
       g2d.fillRect(bounds.x, bounds.y, bounds.width, bounds.height);

       g.setColor(adjustColor(start.darker()));
     }
     else {
       g.setColor(getTrackBackground());
       g.fillRect(bounds.x, bounds.y, bounds.width, bounds.height);

       g.setColor(getTrackBorderColor());
     }

     if (isVertical()) {
       g.drawLine(bounds.x, bounds.y, bounds.x, bounds.y + bounds.height);
     }
     else {
       g.drawLine(bounds.x, bounds.y, bounds.x + bounds.width, bounds.y);
     }
   }

   @Override
   protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
     doPaintThumb(g, thumbBounds);
   }

   private void doPaintThumb(Graphics g, Rectangle thumbBounds) {
     if (thumbBounds.isEmpty() || !scrollbar.isEnabled()) {
       return;
     }

     if (isMacOverlayScrollbar()) {
       paintMacThumb(g, thumbBounds);
     }
     else {
       g.translate(thumbBounds.x, thumbBounds.y);
       paintMaxiThumb((Graphics2D)g, thumbBounds);
       g.translate(-thumbBounds.x, -thumbBounds.y);
     }
   }

   private void paintMacThumb(Graphics g, Rectangle thumbBounds) {
     if (myMacScrollbarHidden) return;

     thumbBounds = getMacScrollBarBounds(thumbBounds, true);
     Graphics2D g2d = (Graphics2D)g;
     RenderingHints oldHints = g2d.getRenderingHints();
     g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

     g2d.setColor(adjustColor(new JBColor(Gray._0, Gray._128)));

     int arc = Math.min(thumbBounds.width, thumbBounds.height);
     g2d.fillRoundRect(thumbBounds.x, thumbBounds.y, thumbBounds.width, thumbBounds.height, arc, arc);

     g2d.setRenderingHints(oldHints);
   }

   private Rectangle getMacScrollBarBounds(Rectangle baseBounds, boolean thumb) {
     boolean vertical = isVertical();

     int borderSize = 2;
     int baseSize = vertical ? baseBounds.width : baseBounds.height;

     int maxSize = baseSize - (thumb ? borderSize * 2 : 0);
     int minSize = Math.min(baseSize / 2, 7) + (thumb ? 0 : borderSize * 2);

     int currentSize = minSize + (int)(myMouseOverScrollbarExpandLevel * (maxSize - minSize));

     int currentBolderSize = thumb ? borderSize : 0;

     int x = baseBounds.x;
     int y = baseBounds.y;
     int width;
     int height;

     if (vertical) {
       x += baseBounds.width - currentSize - currentBolderSize;
       y += currentBolderSize;
       width = currentSize;
       height = baseBounds.height - currentBolderSize * 2;
     }
     else {
       x += currentBolderSize;
       y += baseBounds.height - currentSize - currentBolderSize;
       width = baseBounds.width - currentBolderSize * 2;
       height = currentSize;
     }

     width = Math.max(width, currentSize);
     height = Math.max(height, currentSize);

     return new Rectangle(x, y, width, height);
   }

   private void paintMaxiThumb(Graphics2D g, Rectangle thumbBounds) {
     final boolean vertical = isVertical();
     int hGap = vertical ? 2 : 1;
     int vGap = vertical ? 1 : 2;

     int w = adjustThumbWidth(thumbBounds.width - hGap * 2);
     int h = thumbBounds.height - vGap * 2;

     // leave one pixel between thumb and right or bottom edge
     if (vertical) {
       h -= 1;
     }
     else {
       w -= 1;
     }

     final Paint paint;
     final Color start = adjustColor(getGradientLightColor());
     final Color end = adjustColor(getGradientDarkColor());

     if (vertical) {
       paint = UIUtil.getGradientPaint(1, 0, start, w + 1, 0, end);
     }
     else {
       paint = UIUtil.getGradientPaint(0, 1, start, 0, h + 1, end);
     }

     g.setPaint(paint);
     g.fillRect(hGap + 1, vGap + 1, w - 1, h - 1);

     final Stroke stroke = g.getStroke();
     g.setStroke(BORDER_STROKE);
     g.setColor(getGradientThumbBorderColor());
     g.drawRoundRect(hGap, vGap, w, h, 3, 3);
     g.setStroke(stroke);
   }

   @Override
   public boolean getSupportsAbsolutePositioning() {
     return true;
   }

   protected int adjustThumbWidth(int width) {
     return width;
   }

   protected Color adjustColor(Color c) {
     if (isMacOverlayScrollbar()) {
       int alpha = (int)((120 + (myMouseOverScrollbarExpandLevel * 20)) * (1 - myMacScrollbarFadeLevel));
       return new Color(c.getRed(), c.getGreen(), c.getBlue(), alpha);
     }
     else {
       if (myThumbFadeColorShift == 0) return c;
       final int sign = UIUtil.isUnderDarcula() ? -1 : 1;
       return Gray.get(Math.max(0, Math.min(255, c.getRed() - sign * myThumbFadeColorShift)));
     }
   }

   private boolean isVertical() {
     return scrollbar.getOrientation() == Adjustable.VERTICAL;
   }

   @Override
   protected JButton createIncreaseButton(int orientation) {
     return new EmptyButton();
   }

   @Override
   protected JButton createDecreaseButton(int orientation) {
     return new EmptyButton();
   }

   private static class EmptyButton extends JButton {
     private EmptyButton() {
       setFocusable(false);
       setRequestFocusEnabled(false);
     }

     @Override
     public Dimension getMaximumSize() {
       return new Dimension(0, 0);
     }

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

     @Override
     public Dimension getMinimumSize() {
       return getMaximumSize();
     }
   }
 }
	/*
	* 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.util.ui;

	import com.intellij.openapi.diagnostic.Logger;
	import com.intellij.openapi.util.Disposer;
	import com.intellij.openapi.util.SystemInfo;
	import com.intellij.openapi.util.registry.Registry;
	import com.intellij.ui.Gray;
	import com.intellij.ui.JBColor;
	import com.intellij.ui.LightColors;
	import com.intellij.ui.components.JBScrollPane;
	import com.intellij.util.ReflectionUtil;

	import javax.swing.*;
	import javax.swing.event.ChangeEvent;
	import javax.swing.plaf.basic.BasicScrollBarUI;
	import java.awt.*;
	import java.awt.event.*;
	import java.lang.reflect.Method;

	/**
	* @author max
	* @author Konstantin Bulenkov
	*/
	public class ButtonlessScrollBarUI extends BasicScrollBarUI {
	private static final Logger LOG = Logger.getInstance("#" + ButtonlessScrollBarUI.class.getName());

	public static JBColor getGradientLightColor() {
	return new JBColor(Gray._251, Gray._95);
	}

	public static JBColor getGradientDarkColor() {
	return new JBColor(Gray._215, Gray._80);
	}

	private static JBColor getGradientThumbBorderColor() {
	return new JBColor(Gray._201, Gray._85);
	}

	public static JBColor getTrackBackground() {
	return new JBColor(LightColors.SLIGHTLY_GRAY, UIUtil.getListBackground());
	}

	public static JBColor getTrackBorderColor() {
	return new JBColor(Gray._230, UIUtil.getListBackground());
	}

	private static final BasicStroke BORDER_STROKE = new BasicStroke();

	private static int getAnimationColorShift() {
	return UIUtil.isUnderDarcula() ? 20 : 40;
	}

	private final AdjustmentListener myAdjustmentListener;
	private final MouseMotionAdapter myMouseMotionListener;
	private final MouseAdapter myMouseListener;
	private final HierarchyListener myHierarchyListener;
	private final AWTEventListener myAWTMouseListener;
	private final NSScrollerHelper.ScrollbarStyleListener myNSScrollerListener;
	private boolean myGlobalListenersAdded;

	public static final int DELAY_FRAMES = 4;
	public static final int FRAMES_COUNT = 10 + DELAY_FRAMES;

	private Animator myThumbFadeAnimator;
	private int myThumbFadeColorShift = 0;

	private boolean myMouseIsOverThumb = false;
	private boolean myMouseOverScrollbar;
	private double myMouseOverScrollbarExpandLevel = 0;

	private NSScrollerHelper.Style myMacScrollerStyle;
	private Animator myMouseOverScrollbarExpandAnimator;
	private Animator myMacScrollbarFadeAnimator;
	private double myMacScrollbarFadeLevel = 0;
	private boolean myMacScrollbarHidden;


	protected ButtonlessScrollBarUI() {
	myAdjustmentListener = new AdjustmentListener() {
	@Override
	public void adjustmentValueChanged(AdjustmentEvent e) {
	resetRegularThumbAnimator();
	resetMacScrollbarFadeout();
	}
	};

	myMouseMotionListener = new MouseMotionAdapter() {
	@Override
	public void mouseMoved(MouseEvent e) {
	boolean inside = isOverThumb(e.getPoint());
	if (inside != myMouseIsOverThumb) {
	myMouseIsOverThumb = inside;
	resetRegularThumbAnimator();
	}
	}
	};

	myMouseListener = new MouseAdapter() {
	@Override
	public void mouseEntered(MouseEvent e) {
	// only restart animations when fading hasn't started yet
	if (myMacScrollbarFadeLevel == 0) {
	myMouseOverScrollbar = true;
	resetMacScrollbarExpandAnimator();
	resetMacScrollbarFadeout();
	}
	}

	@Override
	public void mouseExited(MouseEvent e) {
	if (myMouseIsOverThumb) {
	myMouseIsOverThumb = false;
	resetRegularThumbAnimator();
	}

	if (myMouseOverScrollbar) {
	myMouseOverScrollbar = false;
	resetMacScrollbarExpandAnimator();
	resetMacScrollbarFadeout();
	}
	}
	};

	myHierarchyListener = new HierarchyListener() {
	@Override
	public void hierarchyChanged(HierarchyEvent e) {
	if (e.getChanged() == scrollbar) {
	if ((HierarchyEvent.DISPLAYABILITY_CHANGED & e.getChangeFlags()) != 0) {
	updateGlobalListeners(false);
	}

	if ((HierarchyEvent.SHOWING_CHANGED & e.getChangeFlags()) != 0) {
	resetRegularThumbAnimator();
	resetMacScrollbarFadeout();
	}
	}
	}
	};
	myAWTMouseListener = new AWTEventListener() {
	public void eventDispatched(AWTEvent event) {
	if (event.getID() == MouseEvent.MOUSE_MOVED) {

	// user is moving inside the scrollpane of the scrollbar and fade-out hasn't started yet
	Container scrollpane = SwingUtilities.getAncestorOfClass(JScrollPane.class, scrollbar);
	if (scrollpane != null) {
	Point loc = ((MouseEvent)event).getLocationOnScreen();
	SwingUtilities.convertPointFromScreen(loc, scrollpane);
	if (scrollpane.contains(loc) && !myMacScrollbarHidden && myMacScrollbarFadeLevel == 0) {
	resetMacScrollbarFadeout();
	}
	}
	}
	}
	};
	myNSScrollerListener = new NSScrollerHelper.ScrollbarStyleListener() {
	@Override
	public void styleChanged() {
	updateMacScrollbarStyle();
	}
	};
	}

	protected boolean isMacOverlayScrollbar() {
	return myMacScrollerStyle == NSScrollerHelper.Style.Overlay && isMacOverlayScrollbarSupported();
	}

	public static boolean isMacOverlayScrollbarSupported() {
	return SystemInfo.isMac && !Registry.is("ide.mac.disableMacScrollbars");
	}

	private void updateMacScrollbarStyle() {
	NSScrollerHelper.Style style = NSScrollerHelper.getScrollerStyle();

	if (style != myMacScrollerStyle && scrollbar != null) {
	myMacScrollerStyle = style;
	JScrollBar scrollBar = scrollbar;
	uninstallUI(scrollBar);
	installUI(scrollBar);

	JScrollPane pane = JBScrollPane.findScrollPane(scrollBar);
	if (pane != null) pane.revalidate();
	}
	}

	public boolean alwaysShowTrack() {
	return !isMacOverlayScrollbar();
	}

	@Override
	public void layoutContainer(Container scrollbarContainer) {
	try {
	super.layoutContainer(scrollbarContainer);
	} catch (NullPointerException ignore) {
	//installUI is not performed yet or uninstallUI has set almost every field to null. Just ignore it //IDEA-89674
	}
	}

	@Override
	protected ModelListener createModelListener() {
	return new ModelListener() {
	@Override
	public void stateChanged(ChangeEvent e) {
	if (scrollbar != null) {
	super.stateChanged(e);
	}
	}
	};
	}

	public int getDecrementButtonHeight() {
	return Math.max(0, decrButton.getHeight());
	}
	public int getIncrementButtonHeight() {
	return Math.max(0, incrButton.getHeight());
	}

	private void resetRegularThumbAnimator() {
	if (isMacOverlayScrollbar()) return;

	myThumbFadeAnimator.reset();
	if (scrollbar != null && scrollbar.getValueIsAdjusting() \|\| myMouseIsOverThumb \|\| Registry.is("ui.no.bangs.and.whistles")) {
	myThumbFadeAnimator.suspend();
	myThumbFadeColorShift = getAnimationColorShift();
	}
	else {
	myThumbFadeAnimator.resume();
	}
	}

	private void resetMacScrollbarExpandAnimator() {
	if (!isMacOverlayScrollbar()) return;

	if (myMouseOverScrollbarExpandLevel == 0) {
	myMouseOverScrollbarExpandAnimator.reset();
	myMouseOverScrollbarExpandAnimator.suspend();
	if (myMouseOverScrollbar) {
	myMouseOverScrollbarExpandAnimator.resume();
	}
	}
	}

	private void resetMacScrollbarFadeout() {
	if (!isMacOverlayScrollbar()) return;

	myMacScrollbarFadeAnimator.suspend();
	myMacScrollbarFadeAnimator.reset();
	myMacScrollbarHidden = false;
	myMacScrollbarFadeLevel = 0;

	JScrollBar sb = scrollbar; // concurrency in background editors initialization
	if (sb != null) {
	sb.repaint();

	if (!myMouseOverScrollbar && !sb.getValueIsAdjusting()) {
	myMacScrollbarFadeAnimator.resume();
	}
	}
	}

	public static BasicScrollBarUI createNormal() {
	return new ButtonlessScrollBarUI();
	}


	public static BasicScrollBarUI createTransparent() {
	return new ButtonlessScrollBarUI() {
	@Override
	public boolean alwaysShowTrack() {
	return false;
	}
	};
	}

	@Override
	public void installUI(JComponent c) {
	super.installUI(c);
	scrollbar.setFocusable(false);
	scrollbar.setOpaque(alwaysShowTrack());
	}

	@Override
	protected void installDefaults() {
	myMacScrollerStyle = NSScrollerHelper.getScrollerStyle();

	final int incGap = UIManager.getInt("ScrollBar.incrementButtonGap");
	final int decGap = UIManager.getInt("ScrollBar.decrementButtonGap");
	try {
	UIManager.put("ScrollBar.incrementButtonGap", 0);
	UIManager.put("ScrollBar.decrementButtonGap", 0);
	super.installDefaults();
	}
	finally {
	UIManager.put("ScrollBar.incrementButtonGap", incGap);
	UIManager.put("ScrollBar.decrementButtonGap", decGap);
	}
	}

	@Override
	protected void installListeners() {
	initRegularThumbAnimator();
	initMacScrollbarAnimators();

	super.installListeners();
	scrollbar.addAdjustmentListener(myAdjustmentListener);
	scrollbar.addMouseListener(myMouseListener);
	scrollbar.addMouseMotionListener(myMouseMotionListener);

	scrollbar.addHierarchyListener(myHierarchyListener);
	updateGlobalListeners(false);

	resetRegularThumbAnimator();
	resetMacScrollbarFadeout();
	}

	private static final Method setValueFrom = ReflectionUtil.getDeclaredMethod(TrackListener.class, "setValueFrom", MouseEvent.class);
	static {
	LOG.assertTrue(setValueFrom != null, "Cannot get TrackListener.setValueFrom method");
	}

	@Override
	protected TrackListener createTrackListener() {
	return new TrackListener() {
	@Override
	public void mousePressed(MouseEvent e) {
	if (scrollbar.isEnabled()
	&& SwingUtilities.isLeftMouseButton(e)
	&& !getThumbBounds().contains(e.getPoint())
	&& NSScrollerHelper.getClickBehavior() == NSScrollerHelper.ClickBehavior.JumpToSpot
	&& setValueFrom != null) {

	switch (scrollbar.getOrientation()) {
	case Adjustable.VERTICAL:
	offset = getThumbBounds().height / 2;
	break;
	case Adjustable.HORIZONTAL:
	offset = getThumbBounds().width / 2;
	break;
	}
	isDragging = true;
	try {
	setValueFrom.invoke(this, e);
	}
	catch (Exception ex) {
	LOG.error(ex);
	}

	return;
	}

	super.mousePressed(e);
	}
	};
	}

	private void updateGlobalListeners(boolean forceRemove) {
	boolean shouldAdd = scrollbar.isDisplayable();

	if (myGlobalListenersAdded && (!shouldAdd \|\| forceRemove)) {
	Toolkit.getDefaultToolkit().removeAWTEventListener(myAWTMouseListener);
	NSScrollerHelper.removeScrollbarStyleListener(myNSScrollerListener);
	myGlobalListenersAdded = false;
	}

	if (!myGlobalListenersAdded && shouldAdd && !forceRemove) {
	Toolkit.getDefaultToolkit().addAWTEventListener(myAWTMouseListener, AWTEvent.MOUSE_MOTION_EVENT_MASK);
	NSScrollerHelper.addScrollbarStyleListener(myNSScrollerListener);
	myGlobalListenersAdded = true;
	}
	}

	private void initRegularThumbAnimator() {
	myThumbFadeAnimator = new Animator("Regular scrollbar thumb animator", FRAMES_COUNT, FRAMES_COUNT * 50, false) {
	@Override
	public void paintNow(int frame, int totalFrames, int cycle) {
	myThumbFadeColorShift = getAnimationColorShift();
	if (frame > DELAY_FRAMES) {
	myThumbFadeColorShift *= 1 - ((double)(frame - DELAY_FRAMES)) / ((double)(totalFrames - DELAY_FRAMES));
	}

	if (scrollbar != null) {
	scrollbar.repaint(((ButtonlessScrollBarUI)scrollbar.getUI()).getThumbBounds());
	}
	}
	};
	}

	private void initMacScrollbarAnimators() {
	myMouseOverScrollbarExpandAnimator = new Animator("Mac scrollbar mouse over animator", 10, 200, false) {
	@Override
	protected void paintCycleEnd() {
	myMouseOverScrollbarExpandLevel = 1;
	if (scrollbar != null) scrollbar.repaint();
	}

	@Override
	public void paintNow(int frame, int totalFrames, int cycle) {
	int delay = totalFrames / 2;
	int frameAfterDelay = frame - delay;

	if (frameAfterDelay > 0) {
	myMouseOverScrollbarExpandLevel = frameAfterDelay / (float)(totalFrames - delay);
	if (scrollbar != null) scrollbar.repaint();
	}
	}
	};

	myMacScrollbarFadeAnimator = new Animator("Mac scrollbar fade animator", 30, 1000, false) {
	@Override
	protected void paintCycleEnd() {
	myMacScrollbarHidden = true;
	myMouseOverScrollbar = false;
	myMouseOverScrollbarExpandLevel = 0;

	if (scrollbar != null) scrollbar.repaint();
	}

	@Override
	public void paintNow(int frame, int totalFrames, int cycle) {
	int delay = (int)(totalFrames / 1.5);
	int frameAfterDelay = frame - delay;

	if (frameAfterDelay > 0) {
	myMacScrollbarFadeLevel = frameAfterDelay / (float)(totalFrames - delay);
	}
	if (scrollbar != null) scrollbar.repaint();
	}
	};
	}

	private boolean isOverThumb(Point p) {
	final Rectangle bounds = getThumbBounds();
	return bounds != null && bounds.contains(p);
	}

	@Override
	public Rectangle getThumbBounds() {
	return super.getThumbBounds();
	}

	@Override
	protected void uninstallListeners() {
	if (scrollTimer != null) {
	// it is already called otherwise
	super.uninstallListeners();
	}

	scrollbar.removeAdjustmentListener(myAdjustmentListener);
	scrollbar.removeMouseListener(myMouseListener);
	scrollbar.removeMouseMotionListener(myMouseMotionListener);

	scrollbar.removeHierarchyListener(myHierarchyListener);
	updateGlobalListeners(true);

	Disposer.dispose(myThumbFadeAnimator);
	Disposer.dispose(myMouseOverScrollbarExpandAnimator);
	Disposer.dispose(myMacScrollbarFadeAnimator);
	}

	@Override
	protected Dimension getMinimumThumbSize() {
	final int thickness = getThickness();
	return isVertical() ? new Dimension(thickness, thickness * 2) : new Dimension(thickness * 2, thickness);
	}

	protected int getThickness() {
	return isMacOverlayScrollbar() ? 15 : 13;
	}

	@Override
	public Dimension getMaximumSize(JComponent c) {
	int thickness = getThickness();
	return new Dimension(thickness, thickness);
	}

	@Override
	public Dimension getMinimumSize(JComponent c) {
	return getMaximumSize(c);
	}

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

	@Override
	public boolean contains(JComponent c, int x, int y) {
	if (isMacOverlayScrollbar() && !alwaysShowTrack() && myMacScrollbarHidden) return false;
	return super.contains(c, x, y);
	}


	@Override
	protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds) {
	if (alwaysShowTrack() \|\| myMouseOverScrollbarExpandLevel > 0) {
	doPaintTrack(g, c, trackBounds);
	}
	}

	protected void doPaintTrack(Graphics g, JComponent c, Rectangle bounds) {
	if (isMacOverlayScrollbar() && !alwaysShowTrack()) {
	bounds = getMacScrollBarBounds(bounds, false);
	boolean vertical = isVertical();

	final Paint paint;
	final Color start = adjustColor(UIUtil.getSlightlyDarkerColor(getTrackBackground()));
	final Color end = adjustColor(getTrackBackground().brighter());

	if (vertical) {
	paint = UIUtil.getGradientPaint(bounds.x + 1, bounds.y, start, bounds.width + 1, bounds.y, end);
	}
	else {
	paint = UIUtil.getGradientPaint(bounds.x, bounds.y + 1, start, bounds.x, bounds.height + 1, end);
	}

	Graphics2D g2d = (Graphics2D)g;
	g2d.setPaint(paint);
	g2d.fillRect(bounds.x, bounds.y, bounds.width, bounds.height);

	g.setColor(adjustColor(start.darker()));
	}
	else {
	g.setColor(getTrackBackground());
	g.fillRect(bounds.x, bounds.y, bounds.width, bounds.height);

	g.setColor(getTrackBorderColor());
	}

	if (isVertical()) {
	g.drawLine(bounds.x, bounds.y, bounds.x, bounds.y + bounds.height);
	}
	else {
	g.drawLine(bounds.x, bounds.y, bounds.x + bounds.width, bounds.y);
	}
	}

	@Override
	protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
	doPaintThumb(g, thumbBounds);
	}

	private void doPaintThumb(Graphics g, Rectangle thumbBounds) {
	if (thumbBounds.isEmpty() \|\| !scrollbar.isEnabled()) {
	return;
	}

	if (isMacOverlayScrollbar()) {
	paintMacThumb(g, thumbBounds);
	}
	else {
	g.translate(thumbBounds.x, thumbBounds.y);
	paintMaxiThumb((Graphics2D)g, thumbBounds);
	g.translate(-thumbBounds.x, -thumbBounds.y);
	}
	}

	private void paintMacThumb(Graphics g, Rectangle thumbBounds) {
	if (myMacScrollbarHidden) return;

	thumbBounds = getMacScrollBarBounds(thumbBounds, true);
	Graphics2D g2d = (Graphics2D)g;
	RenderingHints oldHints = g2d.getRenderingHints();
	g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

	g2d.setColor(adjustColor(new JBColor(Gray._0, Gray._128)));

	int arc = Math.min(thumbBounds.width, thumbBounds.height);
	g2d.fillRoundRect(thumbBounds.x, thumbBounds.y, thumbBounds.width, thumbBounds.height, arc, arc);

	g2d.setRenderingHints(oldHints);
	}

	private Rectangle getMacScrollBarBounds(Rectangle baseBounds, boolean thumb) {
	boolean vertical = isVertical();

	int borderSize = 2;
	int baseSize = vertical ? baseBounds.width : baseBounds.height;

	int maxSize = baseSize - (thumb ? borderSize * 2 : 0);
	int minSize = Math.min(baseSize / 2, 7) + (thumb ? 0 : borderSize * 2);

	int currentSize = minSize + (int)(myMouseOverScrollbarExpandLevel * (maxSize - minSize));

	int currentBolderSize = thumb ? borderSize : 0;

	int x = baseBounds.x;
	int y = baseBounds.y;
	int width;
	int height;

	if (vertical) {
	x += baseBounds.width - currentSize - currentBolderSize;
	y += currentBolderSize;
	width = currentSize;
	height = baseBounds.height - currentBolderSize * 2;
	}
	else {
	x += currentBolderSize;
	y += baseBounds.height - currentSize - currentBolderSize;
	width = baseBounds.width - currentBolderSize * 2;
	height = currentSize;
	}

	width = Math.max(width, currentSize);
	height = Math.max(height, currentSize);

	return new Rectangle(x, y, width, height);
	}

	private void paintMaxiThumb(Graphics2D g, Rectangle thumbBounds) {
	final boolean vertical = isVertical();
	int hGap = vertical ? 2 : 1;
	int vGap = vertical ? 1 : 2;

	int w = adjustThumbWidth(thumbBounds.width - hGap * 2);
	int h = thumbBounds.height - vGap * 2;

	// leave one pixel between thumb and right or bottom edge
	if (vertical) {
	h -= 1;
	}
	else {
	w -= 1;
	}

	final Paint paint;
	final Color start = adjustColor(getGradientLightColor());
	final Color end = adjustColor(getGradientDarkColor());

	if (vertical) {
	paint = UIUtil.getGradientPaint(1, 0, start, w + 1, 0, end);
	}
	else {
	paint = UIUtil.getGradientPaint(0, 1, start, 0, h + 1, end);
	}

	g.setPaint(paint);
	g.fillRect(hGap + 1, vGap + 1, w - 1, h - 1);

	final Stroke stroke = g.getStroke();
	g.setStroke(BORDER_STROKE);
	g.setColor(getGradientThumbBorderColor());
	g.drawRoundRect(hGap, vGap, w, h, 3, 3);
	g.setStroke(stroke);
	}

	@Override
	public boolean getSupportsAbsolutePositioning() {
	return true;
	}

	protected int adjustThumbWidth(int width) {
	return width;
	}

	protected Color adjustColor(Color c) {
	if (isMacOverlayScrollbar()) {
	int alpha = (int)((120 + (myMouseOverScrollbarExpandLevel * 20)) * (1 - myMacScrollbarFadeLevel));
	return new Color(c.getRed(), c.getGreen(), c.getBlue(), alpha);
	}
	else {
	if (myThumbFadeColorShift == 0) return c;
	final int sign = UIUtil.isUnderDarcula() ? -1 : 1;
	return Gray.get(Math.max(0, Math.min(255, c.getRed() - sign * myThumbFadeColorShift)));
	}
	}

	private boolean isVertical() {
	return scrollbar.getOrientation() == Adjustable.VERTICAL;
	}

	@Override
	protected JButton createIncreaseButton(int orientation) {
	return new EmptyButton();
	}

	@Override
	protected JButton createDecreaseButton(int orientation) {
	return new EmptyButton();
	}

	private static class EmptyButton extends JButton {
	private EmptyButton() {
	setFocusable(false);
	setRequestFocusEnabled(false);
	}

	@Override
	public Dimension getMaximumSize() {
	return new Dimension(0, 0);
	}

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

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