MScrollbarPeer.java

/*
 * Copyright 1995-2002 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */
package sun.awt.motif;

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

class MScrollbarPeer extends MComponentPeer implements ScrollbarPeer {
    static {
        initIDs();
    }

    private boolean inUpCall = false;

    native void create(MComponentPeer parent);

    MScrollbarPeer(Scrollbar target) {
        super(target);
    }

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

    public native void pSetValues(int value, int visible, int minimum, int maximum);
    public native void setLineIncrement(int l);
    public native void setPageIncrement(int l);

    /**
     * Returns default size of Motif scrollbar on the platform
     * Currently uses hardcoded values
     */
    int getDefaultDimension() {
        if (System.getProperty("os.name").equals("Linux")) {
            return 15;
        } else {
            return 19;
        }
    }

    public Dimension getMinimumSize() {
        if (((Scrollbar)target).getOrientation() == Scrollbar.VERTICAL) {
            return new Dimension(getDefaultDimension(), 50);
        } else {
            return new Dimension(50, getDefaultDimension());
        }
    }

    // NOTE: Callback methods are called by privileged threads.
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!

    private void postAdjustmentEvent(final int type, final int value,
                                     final boolean isAdjusting)
    {
        final Scrollbar sb = (Scrollbar)target;
        MToolkit.executeOnEventHandlerThread(sb, new Runnable() {
            public void run() {
                inUpCall = true;
                sb.setValueIsAdjusting(isAdjusting);
                sb.setValue(value);
                postEvent(new AdjustmentEvent(sb,
                                AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED,
                                type, value, isAdjusting));
                inUpCall = false;
            }
        });
    }

    void lineUp(int value) {
        postAdjustmentEvent(AdjustmentEvent.UNIT_DECREMENT, value, false);
    }

    void lineDown(int value) {
        postAdjustmentEvent(AdjustmentEvent.UNIT_INCREMENT, value, false);
    }

    void pageUp(int value) {
        postAdjustmentEvent(AdjustmentEvent.BLOCK_DECREMENT, value, false);
    }

    void pageDown(int value) {
        postAdjustmentEvent(AdjustmentEvent.BLOCK_INCREMENT, value, false);
    }

    // SB_TOP/BOTTOM are mapped to tracking
    void warp(int value) {
        postAdjustmentEvent(AdjustmentEvent.TRACK, value, false);
    }

    private boolean dragInProgress = false;

    void drag(final int value) {
        if (!dragInProgress) {
            dragInProgress = true;
        }
        postAdjustmentEvent(AdjustmentEvent.TRACK, value, true);
    }

    void dragEnd(final int value) {
        final Scrollbar sb = (Scrollbar)target;

        if (!dragInProgress) {
            return;
        }

        dragInProgress = false;
        MToolkit.executeOnEventHandlerThread(sb, new Runnable() {
            public void run() {
                // NB: notification only, no sb.setValue()
                // last TRACK event will have done it already
                inUpCall = true;
                sb.setValueIsAdjusting(false);
                postEvent(new AdjustmentEvent(sb,
                                AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED,
                                AdjustmentEvent.TRACK, value, false));
                inUpCall = false;
            }
        });
    }

    /**
     * Set the value of the slider in the ScrollBar.
     */
    public void setValues(int value, int visible, int minimum, int maximum) {
        // Fix for BugTraq ID 4048060.  Prevent unnecessary redrawing
        // of the slider, when the slider is already in the correct
        // position.  Since the ScrollBar widget now receives the
        // ButtonRelease X event before the Java Adjustor event is
        // handled, the slider is already in the correct position and
        // does not need to be set again and redrawn, when processing
        // the Adjustor event.
        if (!inUpCall) {
            pSetValues(value, visible, minimum, maximum);
        }
    }

    public void print(Graphics g) {
        Scrollbar sb = (Scrollbar)target;
        Dimension d = sb.size();
        Color bg = sb.getBackground();

        boolean horiz = (sb.getOrientation() == Scrollbar.HORIZONTAL);

        drawScrollbar(g, bg, horiz? d.height : d.width,
                          horiz? d.width : d.height,
                          sb.getMinimum(), sb.getMaximum(),
                          sb.getValue(), sb.getVisible(),
                          horiz);

        target.print(g);
    }


    /**
     * DEPRECATED
     */
    public Dimension minimumSize() {
            return getMinimumSize();
    }

    protected boolean shouldFocusOnClick() {
        // Changed in 1.4 - scroll bars are made focusable by mouse clicks.
        return true;
    }
}