1 /*
   2  * Copyright (c) 1996, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package sun.awt.windows;
  26 
  27 import java.awt.*;
  28 import java.awt.event.AdjustmentEvent;
  29 import java.awt.peer.ScrollPanePeer;
  30 
  31 import sun.awt.AWTAccessor;
  32 import sun.awt.AWTAccessor.ComponentAccessor;
  33 import sun.awt.PeerEvent;
  34 
  35 import sun.util.logging.PlatformLogger;
  36 
  37 final class WScrollPanePeer extends WPanelPeer implements ScrollPanePeer {
  38 
  39     private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.windows.WScrollPanePeer");
  40 
  41     int scrollbarWidth;
  42     int scrollbarHeight;
  43     int prevx;
  44     int prevy;
  45 
  46     static {
  47         initIDs();
  48     }
  49 
  50     static native void initIDs();
  51     @Override
  52     native void create(WComponentPeer parent);
  53     native int getOffset(int orient);
  54 
  55     WScrollPanePeer(Component target) {
  56         super(target);
  57         scrollbarWidth = _getVScrollbarWidth();
  58         scrollbarHeight = _getHScrollbarHeight();
  59     }
  60 
  61     @Override
  62     void initialize() {
  63         super.initialize();
  64         setInsets();
  65         Insets i = getInsets();
  66         setScrollPosition(-i.left,-i.top);
  67     }
  68 
  69     @Override
  70     public void setUnitIncrement(Adjustable adj, int p) {
  71         // The unitIncrement is grabbed from the target as needed.
  72     }
  73 
  74     @Override
  75     public Insets insets() {
  76         return getInsets();
  77     }
  78     private native void setInsets();
  79 
  80     @Override
  81     public synchronized native void setScrollPosition(int x, int y);
  82 
  83     @Override
  84     public int getHScrollbarHeight() {
  85         return scrollbarHeight;
  86     }
  87     private native int _getHScrollbarHeight();
  88 
  89     @Override
  90     public int getVScrollbarWidth() {
  91         return scrollbarWidth;
  92     }
  93     private native int _getVScrollbarWidth();
  94 
  95     public Point getScrollOffset() {
  96         int x = getOffset(Adjustable.HORIZONTAL);
  97         int y = getOffset(Adjustable.VERTICAL);
  98         return new Point(x, y);
  99     }
 100 
 101     /**
 102      * The child component has been resized.  The scrollbars must be
 103      * updated with the new sizes.  At the native level the sizes of
 104      * the actual windows may not have changed yet, so the size
 105      * information from the java-level is passed down and used.
 106      */
 107     @Override
 108     public void childResized(int width, int height) {
 109         ScrollPane sp = (ScrollPane)target;
 110         Dimension vs = sp.getSize();
 111         setSpans(vs.width, vs.height, width, height);
 112         setInsets();
 113     }
 114 
 115     synchronized native void setSpans(int viewWidth, int viewHeight,
 116                                       int childWidth, int childHeight);
 117 
 118     /**
 119      * Called by ScrollPane's internal observer of the scrollpane's adjustables.
 120      * This is called whenever a scroll position is changed in one
 121      * of adjustables, whether it was modified externally or from the
 122      * native scrollbars themselves.
 123      */
 124     @Override
 125     public void setValue(Adjustable adj, int v) {
 126         Component c = getScrollChild();
 127         if (c == null) {
 128             return;
 129         }
 130 
 131         Point p = c.getLocation();
 132         switch(adj.getOrientation()) {
 133         case Adjustable.VERTICAL:
 134             setScrollPosition(-(p.x), v);
 135             break;
 136         case Adjustable.HORIZONTAL:
 137             setScrollPosition(v, -(p.y));
 138             break;
 139         }
 140     }
 141 
 142     private Component getScrollChild() {
 143         ScrollPane sp = (ScrollPane)target;
 144         Component child = null;
 145         try {
 146             child = sp.getComponent(0);
 147         } catch (ArrayIndexOutOfBoundsException e) {
 148             // do nothing.  in this case we return null
 149         }
 150         return child;
 151     }
 152 
 153     /*
 154      * Called from Windows in response to WM_VSCROLL/WM_HSCROLL message
 155      */
 156     private void postScrollEvent(int orient, int type,
 157                                  int pos, boolean isAdjusting)
 158     {
 159         Runnable adjustor = new Adjustor(orient, type, pos, isAdjusting);
 160         WToolkit.executeOnEventHandlerThread(new ScrollEvent(target, adjustor));
 161     }
 162 
 163     /*
 164      * Event that executes on the Java dispatch thread to move the
 165      * scroll bar thumbs and paint the exposed area in one synchronous
 166      * operation.
 167      */
 168     @SuppressWarnings("serial") // JDK-implementation class
 169     class ScrollEvent extends PeerEvent {
 170         ScrollEvent(Object source, Runnable runnable) {
 171             super(source, runnable, 0L);
 172         }
 173 
 174         @Override
 175         public PeerEvent coalesceEvents(PeerEvent newEvent) {
 176             if (log.isLoggable(PlatformLogger.Level.FINEST)) {
 177                 log.finest("ScrollEvent coalesced: " + newEvent);
 178             }
 179             if (newEvent instanceof ScrollEvent) {
 180                 return newEvent;
 181             }
 182             return null;
 183         }
 184     }
 185 
 186     /*
 187      * Runnable for the ScrollEvent that performs the adjustment.
 188      */
 189     class Adjustor implements Runnable {
 190         int orient;             // selects scrollbar
 191         int type;               // adjustment type
 192         int pos;                // new position (only used for absolute)
 193         boolean isAdjusting;    // isAdjusting status
 194 
 195         Adjustor(int orient, int type, int pos, boolean isAdjusting) {
 196             this.orient = orient;
 197             this.type = type;
 198             this.pos = pos;
 199             this.isAdjusting = isAdjusting;
 200         }
 201 
 202         @Override
 203         public void run() {
 204             if (getScrollChild() == null) {
 205                 return;
 206             }
 207             ScrollPane sp = (ScrollPane)WScrollPanePeer.this.target;
 208             ScrollPaneAdjustable adj = null;
 209 
 210             // ScrollPaneAdjustable made public in 1.4, but
 211             // get[HV]Adjustable can't be declared to return
 212             // ScrollPaneAdjustable because it would break backward
 213             // compatibility -- hence the cast
 214 
 215             if (orient == Adjustable.VERTICAL) {
 216                 adj = (ScrollPaneAdjustable)sp.getVAdjustable();
 217             } else if (orient == Adjustable.HORIZONTAL) {
 218                 adj = (ScrollPaneAdjustable)sp.getHAdjustable();
 219             } else {
 220                 if (log.isLoggable(PlatformLogger.Level.FINE)) {
 221                     log.fine("Assertion failed: unknown orient");
 222                 }
 223             }
 224 
 225             if (adj == null) {
 226                 return;
 227             }
 228 
 229             int newpos = adj.getValue();
 230             switch (type) {
 231               case AdjustmentEvent.UNIT_DECREMENT:
 232                   newpos -= adj.getUnitIncrement();
 233                   break;
 234               case AdjustmentEvent.UNIT_INCREMENT:
 235                   newpos += adj.getUnitIncrement();
 236                   break;
 237               case AdjustmentEvent.BLOCK_DECREMENT:
 238                   newpos -= adj.getBlockIncrement();
 239                   break;
 240               case AdjustmentEvent.BLOCK_INCREMENT:
 241                   newpos += adj.getBlockIncrement();
 242                   break;
 243               case AdjustmentEvent.TRACK:
 244                   newpos = this.pos;
 245                   break;
 246               default:
 247                   if (log.isLoggable(PlatformLogger.Level.FINE)) {
 248                       log.fine("Assertion failed: unknown type");
 249                   }
 250                   return;
 251             }
 252 
 253             // keep scroll position in acceptable range
 254             newpos = Math.max(adj.getMinimum(), newpos);
 255             newpos = Math.min(adj.getMaximum(), newpos);
 256 
 257             // set value, this will synchronously fire an AdjustmentEvent
 258             adj.setValueIsAdjusting(isAdjusting);
 259 
 260             // Fix for 4075484 - consider type information when creating AdjustmentEvent
 261             // We can't just call adj.setValue() because it creates AdjustmentEvent with type=TRACK
 262             // Instead, we call private method setTypedValue of ScrollPaneAdjustable.
 263             AWTAccessor.getScrollPaneAdjustableAccessor().setTypedValue(adj,
 264                                                                         newpos,
 265                                                                         type);
 266 
 267             // Paint the exposed area right away.  To do this - find
 268             // the heavyweight ancestor of the scroll child.
 269             Component hwAncestor = getScrollChild();
 270             final ComponentAccessor acc = AWTAccessor.getComponentAccessor();
 271             while (hwAncestor != null
 272                    && !(acc.getPeer(hwAncestor) instanceof WComponentPeer))
 273             {
 274                 hwAncestor = hwAncestor.getParent();
 275             }
 276             if (log.isLoggable(PlatformLogger.Level.FINE)) {
 277                 if (hwAncestor == null) {
 278                     log.fine("Assertion (hwAncestor != null) failed, " +
 279                              "couldn't find heavyweight ancestor of scroll pane child");
 280                 }
 281             }
 282             WComponentPeer hwPeer = acc.getPeer(hwAncestor);
 283             hwPeer.paintDamagedAreaImmediately();
 284         }
 285     }
 286 
 287 }
--- EOF ---