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 * Copyright (c) 1996, 2003, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */

package sun.awt.motif;

import java.awt.*;
import java.awt.event.AdjustmentEvent;
import java.awt.peer.ScrollPanePeer;

import java.util.logging.*;

import sun.awt.PeerEvent;

class MScrollPanePeer extends MPanelPeer implements ScrollPanePeer {

    private static final Logger log = Logger.getLogger("sun.awt.motif.MScrollPanePeer");

    final static int UNIT_INCREMENT = 0;
    final static int BLOCK_INCREMENT = 1;

    boolean ignore;

    native void create(MComponentPeer parent);

    static {
        initIDs();
    }

    
Initialize JNI field and method IDs
/**
     * Initialize JNI field and method IDs
     */
    private static native void initIDs();

    MScrollPanePeer(Component target) {
        init(target);
        scrollPaneInit();
    }

    MScrollPanePeer(Component target, Object arg) {
        init(target, arg);
        scrollPaneInit();
    }

    void scrollPaneInit() {
        ignore = false;
        ScrollPane sp = (ScrollPane)target;
        Adjustable vadj, hadj;
        if ((vadj = sp.getVAdjustable()) != null) {
            pSetIncrement(Adjustable.VERTICAL, UNIT_INCREMENT, vadj.getUnitIncrement());
        }
        if ((hadj = sp.getHAdjustable()) != null) {
            pSetIncrement(Adjustable.HORIZONTAL, UNIT_INCREMENT, hadj.getUnitIncrement());
        }
        super.pSetScrollbarBackground(sp.getBackground());
    }

    public void setScrollChild(MComponentPeer child) {
        pSetScrollChild(child);
    }

    public void setBackground(Color c) {
        super.setBackground(c);
        pSetScrollbarBackground(c);
    }

    public void setForeground(Color c) {
        super.setForeground(c);
        pSetInnerForeground(c);
    }

    native void pSetScrollChild(MComponentPeer child);
    native void pSetIncrement(int orient, int type, int incr);
    native int pGetScrollbarSpace(int orient);
    native int pGetBlockIncrement(int orient);
    native Insets pInsets(int w, int h, int childw, int childh);
    native int pGetShadow();

    public int getHScrollbarHeight() {
        ScrollPane sp = (ScrollPane)target;
        if (sp.getScrollbarDisplayPolicy() == ScrollPane.SCROLLBARS_NEVER) {
            return 0;
        } else {
            return pGetScrollbarSpace(Adjustable.HORIZONTAL);
        }
    }

    public int getVScrollbarWidth() {
        ScrollPane sp = (ScrollPane)target;
        if (sp.getScrollbarDisplayPolicy() == ScrollPane.SCROLLBARS_NEVER) {
            return 0;
        } else {
            return pGetScrollbarSpace(Adjustable.VERTICAL);
        }
    }

    public Insets insets() {
        ScrollPane sp = (ScrollPane)target;
        Dimension d = sp.size();
        Dimension cd;
        Component c = getScrollChild();
        if (c != null) {
            cd = c.size();
        } else {
            cd = new Dimension(0, 0);
        }
        return pInsets(d.width, d.height, cd.width, cd.height);
    }

    public void setUnitIncrement(Adjustable adj, int u) {
        ScrollPane sp = (ScrollPane)target;
        if (sp.getScrollbarDisplayPolicy() != ScrollPane.SCROLLBARS_NEVER) {
            pSetIncrement(adj.getOrientation(), UNIT_INCREMENT, u);
        }
    }

    public void setValue(Adjustable adj, int v) {
        if (! ignore) {
            Point p;
            Component c = getScrollChild();
            if (c == null) {
                return;
            }
            p = c.getLocation();
            switch(adj.getOrientation()) {
            case Adjustable.VERTICAL:
                setScrollPosition(-(p.x), v);
                break;
            case Adjustable.HORIZONTAL:
                setScrollPosition(v, -(p.y));
                break;
            }
        }
    }

    public native void setScrollPosition(int x, int y);

    public void childResized(int w, int h) {
        // REMIND AIM:  May need to revisit this...
        if (((ScrollPane)target).getScrollbarDisplayPolicy() != ScrollPane.SCROLLBARS_NEVER) {
            ScrollPane sp = (ScrollPane)target;
            Adjustable vAdj = sp.getVAdjustable();
            Adjustable hAdj = sp.getHAdjustable();
            pSetIncrement(Scrollbar.VERTICAL, UNIT_INCREMENT, vAdj.getUnitIncrement());
            pSetIncrement(Scrollbar.HORIZONTAL, UNIT_INCREMENT, hAdj.getUnitIncrement());
            pSetIncrement(Scrollbar.VERTICAL, BLOCK_INCREMENT, vAdj.getBlockIncrement());
            pSetIncrement(Scrollbar.HORIZONTAL, BLOCK_INCREMENT, hAdj.getBlockIncrement());
        }

    }

    // NOTE: This method may be called by privileged threads.
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
    private void postScrollEvent(int orient, int type,
                                 int pos, boolean isAdjusting)
    {
        Runnable adjustor = new Adjustor(orient, type, pos, isAdjusting);
        MToolkit.executeOnEventHandlerThread(new ScrollEvent(target, adjustor));
    }

    
This is used to change the adjustable on dispatch thread to
represent a change made in the native scrollbar.  Since the
change was reflected immediately at the native level,
notification from the adjustable is temporarily ignored.
/**
     * This is used to change the adjustable on dispatch thread to
     * represent a change made in the native scrollbar.  Since the
     * change was reflected immediately at the native level,
     * notification from the adjustable is temporarily ignored.
     */
    class ScrollEvent extends PeerEvent {
        ScrollEvent(Object source, Runnable runnable) {
            super(source, runnable, 0L);
        }

        public PeerEvent coalesceEvents(PeerEvent newEvent) {
            if (log.isLoggable(Level.FINEST)) {
                log.log(Level.FINEST, "ScrollEvent coalesced " + newEvent);
            }
            if (newEvent instanceof ScrollEvent) {
                return newEvent;
            }
            return null;
        }
    }

    native void setTypedValue(ScrollPaneAdjustable adjustable, int value, int type);

    
Runnable for the ScrollEvent that performs the adjustment.
/**
     * Runnable for the ScrollEvent that performs the adjustment.
     */
    class Adjustor implements Runnable {
        int orient;             // selects scrollbar
        int type;               // adjustment type
        int pos;                // new position (only used for absolute)
        boolean isAdjusting;    // isAdjusting status

        Adjustor(int orient, int type, int pos, boolean isAdjusting) {
            this.orient = orient;
            this.type = type;
            this.pos = pos;
            this.isAdjusting = isAdjusting;
        }

        public void run() {
            ScrollPane sp = (ScrollPane)MScrollPanePeer.this.target;
            ScrollPaneAdjustable adj = null;

            // ScrollPaneAdjustable made public in 1.4, but
            // get[HV]Adjustable can't be declared to return
            // ScrollPaneAdjustable because it would break backward
            // compatibility -- hence the cast

            if (orient == Adjustable.VERTICAL) {
                adj = (ScrollPaneAdjustable)sp.getVAdjustable();
            } else if (orient == Adjustable.HORIZONTAL) {
                adj = (ScrollPaneAdjustable)sp.getHAdjustable();
            } else {
                if (log.isLoggable(Level.FINE)) {
                    log.log(Level.FINE, "Assertion failed: unknown orient");
                }
            }

            if (adj == null) {
                return;
            }

            int newpos = adj.getValue();
            switch (type) {
              case AdjustmentEvent.UNIT_DECREMENT:
                  newpos -= adj.getUnitIncrement();
                  break;
              case AdjustmentEvent.UNIT_INCREMENT:
                  newpos += adj.getUnitIncrement();
                  break;
              case AdjustmentEvent.BLOCK_DECREMENT:
                  newpos -= adj.getBlockIncrement();
                  break;
              case AdjustmentEvent.BLOCK_INCREMENT:
                  newpos += adj.getBlockIncrement();
                  break;
              case AdjustmentEvent.TRACK:
                  newpos = this.pos;
                  break;
              default:
                  if (log.isLoggable(Level.FINE)) {
                      log.log(Level.FINE, "Assertion failed: unknown type");
                  }
                  return;
            }

            // keep scroll position in acceptable range
            newpos = Math.max(adj.getMinimum(), newpos);
            newpos = Math.min(adj.getMaximum(), newpos);

            // set value; this will synchronously fire an AdjustmentEvent
            try {
                MScrollPanePeer.this.ignore = true;
                adj.setValueIsAdjusting(isAdjusting);

                // Fix for 4075484 - consider type information when creating AdjustmentEvent
                // We can't just call adj.setValue() because it creates AdjustmentEvent with type=TRACK
                // Instead, we call private method setTypedValue of ScrollPaneAdjustable.
                // Because ScrollPaneAdjustable is in another package we should call it through native code.
                setTypedValue(adj, newpos, type);
            } finally {
                MScrollPanePeer.this.ignore = false;
            }
        }
    } // class Adjustor


    private Component getScrollChild() {
        ScrollPane sp = (ScrollPane)target;
        Component child = null;
        try {
            child = sp.getComponent(0);
        } catch (ArrayIndexOutOfBoundsException e) {
            // do nothing.  in this case we return null
        }
        return child;
    }

    final static int    MARGIN = 1;
    final static int    SCROLLBAR = 16;
    int hsbSpace;
    int vsbSpace;
    int vval;
    int hval;
    int vmax;
    int hmax;
    /*
     * Print the native component by rendering the Motif look ourselves.
     * ToDo(aim): needs to query native motif for more accurate size and
     * color information.
     */
    public void print(Graphics g) {
        ScrollPane sp = (ScrollPane)target;
        Dimension d = sp.size();
        Color bg = sp.getBackground();
        Color fg = sp.getForeground();
        Point p = sp.getScrollPosition();
        Component c = getScrollChild();
        Dimension cd;
        if (c != null) {
            cd = c.size();
        } else {
            cd = new Dimension(0, 0);
        }
        int sbDisplay = sp.getScrollbarDisplayPolicy();
        int vvis, hvis, vmin, hmin, vmax, hmax, vval, hval;

        switch (sbDisplay) {
          case ScrollPane.SCROLLBARS_NEVER:
            hsbSpace = vsbSpace = 0;
            break;
          case ScrollPane.SCROLLBARS_ALWAYS:
            hsbSpace = vsbSpace = SCROLLBAR;
            break;
          case ScrollPane.SCROLLBARS_AS_NEEDED:
            hsbSpace = (cd.width <= (d.width - 2*MARGIN)? 0 : SCROLLBAR);
            vsbSpace = (cd.height <= (d.height - 2*MARGIN)? 0 : SCROLLBAR);

            if (hsbSpace == 0 && vsbSpace != 0) {
                hsbSpace = (cd.width <= (d.width - SCROLLBAR - 2*MARGIN)? 0 : SCROLLBAR);
            }
            if (vsbSpace == 0 && hsbSpace != 0) {
                vsbSpace = (cd.height <= (d.height - SCROLLBAR - 2*MARGIN)? 0 : SCROLLBAR);
            }
        }

        vvis = hvis = vmin = hmin = vmax = hmax = vval = hval = 0;

        if (vsbSpace > 0) {
            vmin = 0;
            vvis = d.height - (2*MARGIN) - hsbSpace;
            vmax = Math.max(cd.height - vvis, 0);
            vval = p.y;
        }
        if (hsbSpace > 0) {
            hmin = 0;
            hvis = d.width - (2*MARGIN) - vsbSpace;
            hmax = Math.max(cd.width - hvis, 0);
            hval = p.x;
        }

        // need to be careful to add the margins back in here because
        // we're drawing the margin border, after all!
        int w = d.width - vsbSpace;
        int h = d.height - hsbSpace;

        g.setColor(bg);
        g.fillRect(0, 0, d.width, d.height);

        if (hsbSpace > 0) {
            int sbw = d.width - vsbSpace;
            g.fillRect(1, d.height - SCROLLBAR - 3, sbw - 1, SCROLLBAR - 3);
            Graphics ng = g.create();
            try {
                ng.translate(0, d.height - (SCROLLBAR - 2));
                drawScrollbar(ng, bg, SCROLLBAR - 2, sbw,
                               hmin, hmax, hval, hvis, true);
            } finally {
                ng.dispose();
            }
        }
        if (vsbSpace > 0) {
            int sbh = d.height - hsbSpace;
            g.fillRect(d.width - SCROLLBAR - 3, 1, SCROLLBAR - 3, sbh - 1);
            Graphics ng = g.create();
            try {
                ng.translate(d.width - (SCROLLBAR - 2), 0);
                drawScrollbar(ng, bg, SCROLLBAR - 2, sbh,
                               vmin, vmax, vval, vvis, false);
            } finally {
                ng.dispose();
            }
        }

        draw3DRect(g, bg, 0, 0, w - 1, h - 1, false);

        target.print(g);
        sp.printComponents(g);
    }

    
See Also:
restack.restack/**
     * @see ContainerPeer#restack
     */
    public void restack() {
        // Since ScrollPane can only have one child its restacking does nothing.
        // Also, it is dangerous, since SP child is actually not a child of SP widget
        // but the child of SP content widget.
    }
}