org.eclipse.swt.widgets.ScrollBar Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of org.eclipse.swt.gtk.linux.ppc64le Show documentation
Standard Widget Toolkit for GTK on ppc64le
The newest version!
/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.internal.gtk3.*;
import org.eclipse.swt.internal.gtk4.*;

/**
 * Instances of this class are selectable user interface
 * objects that represent a range of positive, numeric values.
 * 
 * At any given moment, a given scroll bar will have a
 * single 'selection' that is considered to be its
 * value, which is constrained to be within the range of
 * values the scroll bar represents (that is, between its
 * minimum and maximum values).
 * 

 * Typically, scroll bars will be made up of five areas:
 * 
 * an arrow button for decrementing the value
 * a page decrement area for decrementing the value by a larger amount
 * a thumb for modifying the value by mouse dragging
 * a page increment area for incrementing the value by a larger amount
 * an arrow button for incrementing the value
 * 
 * 
 * Based on their style, scroll bars are either HORIZONTAL
 * (which have a left facing button for decrementing the value and a
 * right facing button for incrementing it) or VERTICAL
 * (which have an upward facing button for decrementing the value
 * and a downward facing buttons for incrementing it).
 * 

 * On some platforms, the size of the scroll bar's thumb can be
 * varied relative to the magnitude of the range of values it
 * represents (that is, relative to the difference between its
 * maximum and minimum values). Typically, this is used to
 * indicate some proportional value such as the ratio of the
 * visible area of a document to the total amount of space that
 * it would take to display it. SWT supports setting the thumb
 * size even if the underlying platform does not, but in this
 * case the appearance of the scroll bar will not change.
 * 

 * Scroll bars are created by specifying either H_SCROLL,
 * V_SCROLL or both when creating a Scrollable.
 * They are accessed from the Scrollable using
 * getHorizontalBar and getVerticalBar.
 * 

 * Note: Scroll bars are not Controls.  On some platforms, scroll bars
 * that appear as part of some standard controls such as a text or list
 * have no operating system resources and are not children of the control.
 * For this reason, scroll bars are treated specially.  To create a control
 * that looks like a scroll bar but has operating system resources, use
 * Slider.
 * 
 * 
 * Styles:
 * HORIZONTAL, VERTICAL
 * Events:
 * Selection
 * 
 * 
 * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
 * 

 * IMPORTANT: This class is not intended to be subclassed.
 * 
 *
 * @see Slider
 * @see Scrollable
 * @see Scrollable#getHorizontalBar
 * @see Scrollable#getVerticalBar
 * @see SWT Example: ControlExample
 * @see Sample code and further information
 * @noextend This class is not intended to be subclassed by clients.
 */
public class ScrollBar extends Widget {
	Scrollable parent;
	long adjustmentHandle;
	int detail;
	boolean dragSent;

ScrollBar () {
}

/**
* Creates a new instance of the widget.
*/
ScrollBar (Scrollable parent, int style) {
	super (parent, checkStyle (style));
	this.parent = parent;
	createWidget (0);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the user changes the receiver's value, by sending
 * it one of the messages defined in the SelectionListener
 * interface.
 * 
 * When widgetSelected is called, the event object detail field contains one of the following values:
 * SWT.NONE - for the end of a drag.
 * SWT.DRAG.
 * SWT.HOME.
 * SWT.END.
 * SWT.ARROW_DOWN.
 * SWT.ARROW_UP.
 * SWT.PAGE_DOWN.
 * SWT.PAGE_UP.
 * widgetDefaultSelected is not called.
 * 
 *
 * @param listener the listener which should be notified when the user changes the receiver's value
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener (SelectionListener listener) {
	addTypedListener(listener, SWT.Selection, SWT.DefaultSelection);
}

static int checkStyle (int style) {
	return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0);
}

@Override
void deregister () {
	super.deregister ();
	if (adjustmentHandle != 0) display.removeWidget (adjustmentHandle);
}

@Override
void destroyWidget () {
	parent.destroyScrollBar (this);
	releaseHandle ();
}

/**
 * Returns true if the receiver is enabled, and
 * false otherwise. A disabled control is typically
 * not selectable from the user interface and draws with an
 * inactive or "grayed" look.
 *
 * @return the receiver's enabled state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #isEnabled
 */
public boolean getEnabled () {
	checkWidget ();
	if (handle != 0) return GTK.gtk_widget_get_sensitive (handle);
	return true;
}

/**
 * Returns the amount that the receiver's value will be
 * modified by when the up/down (or right/left) arrows
 * are pressed.
 *
 * @return the increment
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getIncrement () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_step_increment (adjustmentHandle);
}

/**
 * Returns the maximum value which the receiver will allow.
 *
 * @return the maximum
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getMaximum () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_upper (adjustmentHandle);
}

/**
 * Returns the minimum value which the receiver will allow.
 *
 * @return the minimum
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getMinimum () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_lower (adjustmentHandle);
}

/**
 * Returns the amount that the receiver's value will be
 * modified by when the page increment/decrement areas
 * are selected.
 *
 * @return the page increment
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getPageIncrement () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_page_increment (adjustmentHandle);
}

/**
 * Returns the receiver's parent, which must be a Scrollable.
 *
 * @return the receiver's parent
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Scrollable getParent () {
	checkWidget ();
	return parent;
}

/**
 * Returns the single 'selection' that is the receiver's value.
 *
 * @return the selection
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public int getSelection () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_value (adjustmentHandle);
}


/**
 * Returns a point describing the receiver's size. The
 * x coordinate of the result is the width of the receiver.
 * The y coordinate of the result is the height of the
 * receiver.
 *
 * @return the receiver's size
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Point getSize () {
	checkWidget ();
	return DPIUtil.autoScaleDown (getSizeInPixels ());
}

Point getSizeInPixels () {
	checkWidget ();
	if (handle == 0) return new Point (0,0);
	GtkRequisition requisition = new GtkRequisition ();
	gtk_widget_get_preferred_size (handle, requisition);
	return new Point (requisition.width, requisition.height);
}

/**
 * Returns the receiver's thumb value.
 *
 * @return the thumb value
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see ScrollBar
 */
public int getThumb () {
	checkWidget ();
	return (int) GTK.gtk_adjustment_get_page_size (adjustmentHandle);
}

/**
 * Returns a rectangle describing the size and location of the
 * receiver's thumb relative to its parent.
 *
 * @return the thumb bounds, relative to the {@link #getParent() parent}
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.6
 */
public Rectangle getThumbBounds() {
	checkWidget();
	return DPIUtil.autoScaleDown(getThumbBoundsInPixels());
}

Rectangle getThumbBoundsInPixels() {
	checkWidget();

	int[] slider_start = new int[1], slider_end = new int[1];
	long rangeHandle = GTK.GTK4 ? GTK4.gtk_widget_get_first_child(handle) : handle;
	GTK.gtk_range_get_slider_range(rangeHandle, slider_start, slider_end);

	int x, y, width, height;
	GtkAllocation allocation = new GtkAllocation();
	GTK.gtk_widget_get_allocation(rangeHandle, allocation);
	if ((style & SWT.VERTICAL) != 0) {
		x = allocation.x;
		y = slider_start[0];
		width = allocation.width;
		height = slider_end[0] - slider_start[0];
	} else {
		x = slider_start[0];
		y = allocation.y;
		width = slider_end[0] - slider_start[0];
		height = allocation.height;
	}

	Rectangle rect = new Rectangle(x, y, width, height);
	if (GTK.GTK4) {
		double[] origin_x = new double[1], origin_y = new double[1];
		boolean success = GTK4.gtk_widget_translate_coordinates(parent.scrolledHandle, parent.getShell().shellHandle, 0, 0, origin_x, origin_y);
		if (success) {
			rect.x += origin_x[0];
			rect.y += origin_y[0];
		}
		success = GTK4.gtk_widget_translate_coordinates(parent.handle, parent.getShell().shellHandle, 0, 0, origin_x, origin_y);
		if (success) {
			rect.x -= origin_x[0];
			rect.y -= origin_y[0];
		}
	} else {
		int[] origin_x = new int[1], origin_y = new int[1];
		long window = gtk_widget_get_window(parent.scrolledHandle);
		if (window != 0) GDK.gdk_window_get_origin(window, origin_x, origin_y);
		rect.x += origin_x[0];
		rect.y += origin_y[0];
		window = gtk_widget_get_window(parent.handle);
		if (window != 0) GDK.gdk_window_get_origin(window, origin_x, origin_y);
		rect.x -= origin_x[0];
		rect.y -= origin_y[0];
	}

	return rect;
}

/**
 * Returns a rectangle describing the size and location of the
 * receiver's thumb track relative to its parent. This rectangle
 * comprises the areas 2, 3, and 4 as described in {@link ScrollBar}.
 *
 * @return the thumb track bounds, relative to the {@link #getParent() parent}
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.6
 */
public Rectangle getThumbTrackBounds () {
	checkWidget ();
	return DPIUtil.autoScaleDown(getThumbTrackBoundsInPixels());
}

Rectangle getThumbTrackBoundsInPixels () {
	checkWidget();
	int x = 0, y = 0, width, height;

	/*
	 * Only GTK3 scrollbars have steppers, even non-overlay scrollbars in
	 * GTK4 do not have steppers.
	 */
	boolean hasB = false, hasB2 = false, hasF = false, hasF2 = false;
	if (!GTK.GTK4) {
		int[] has_stepper = new int[1];
		GTK3.gtk_widget_style_get(handle, OS.has_backward_stepper, has_stepper, 0);
		hasB = has_stepper[0] != 0;
		GTK3.gtk_widget_style_get(handle, OS.has_secondary_backward_stepper, has_stepper, 0);
		hasB2 = has_stepper[0] != 0;
		GTK3.gtk_widget_style_get(handle, OS.has_forward_stepper, has_stepper, 0);
		hasF = has_stepper[0] != 0;
		GTK3.gtk_widget_style_get(handle, OS.has_secondary_forward_stepper, has_stepper, 0);
		hasF2 = has_stepper[0] != 0;
	}

	GtkAllocation allocation = new GtkAllocation();
	GTK.gtk_widget_get_allocation(handle, allocation);
	if ((style & SWT.VERTICAL) != 0) {
		int stepperSize = allocation.width;
		x = allocation.x;
		if (hasB) y += stepperSize;
		if (hasF2) y += stepperSize;
		width = allocation.width;
		height = allocation.height - y;
		if (hasB2) height -= stepperSize;
		if (hasF) height -= stepperSize;
		if (height < 0) {
			int[] slider_start = new int[1], slider_end = new int[1];
			long rangeHandle = GTK.GTK4 ? GTK4.gtk_widget_get_first_child(handle) : handle;
			GTK.gtk_range_get_slider_range(rangeHandle, slider_start, slider_end);
			y = slider_start[0];
			height = 0;
		}
	} else {
		int stepperSize = allocation.height;
		if (hasB) x += stepperSize;
		if (hasF2) x += stepperSize;
		y = allocation.y;
		width = allocation.width -x;
		if (hasB2) width -= stepperSize;
		if (hasF) width -= stepperSize;
		height = allocation.height;
		if (width < 0) {
			int[] slider_start = new int[1], slider_end = new int[1];
			long rangeHandle = GTK.GTK4 ? GTK4.gtk_widget_get_first_child(handle) : handle;
			GTK.gtk_range_get_slider_range(rangeHandle, slider_start, slider_end);
			x = slider_start[0];
			width = 0;
		}
	}

	Rectangle rect = new Rectangle(x, y, width, height);
	if (GTK.GTK4) {
		double[] origin_x = new double[1], origin_y = new double[1];
		boolean success = GTK4.gtk_widget_translate_coordinates(parent.scrolledHandle, parent.getShell().shellHandle, 0, 0, origin_x, origin_y);
		if (success) {
			rect.x += origin_x[0];
			rect.y += origin_y[0];
		}
		success = GTK4.gtk_widget_translate_coordinates(parent.handle, parent.getShell().shellHandle, 0, 0, origin_x, origin_y);
		if (success) {
			rect.x -= origin_x[0];
			rect.y -= origin_y[0];
		}
	} else {
		int[] origin_x = new int[1], origin_y = new int[1];
		long window = gtk_widget_get_window(parent.scrolledHandle);
		if (window != 0) GDK.gdk_window_get_origin(window, origin_x, origin_y);
		rect.x += origin_x[0];
		rect.y += origin_y[0];
		window = gtk_widget_get_window(parent.handle);
		if (window != 0) GDK.gdk_window_get_origin(window, origin_x, origin_y);
		rect.x -= origin_x[0];
		rect.y -= origin_y[0];
	}

	return rect;
}

/**
 * Returns true if the receiver is visible, and
 * false otherwise.
 * 
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, this method
 * may still indicate that it is considered visible even though
 * it may not actually be showing.
 * 
 *
 * @return the receiver's visibility state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public boolean getVisible () {
	checkWidget ();
	long scrolledHandle = parent.scrolledHandle;
	int [] hsp = new int [1], vsp = new int [1];
	GTK.gtk_scrolled_window_get_policy (scrolledHandle, hsp, vsp);
	if ((style & SWT.HORIZONTAL) != 0) {
		return hsp [0] != GTK.GTK_POLICY_NEVER && hsp[0] != GTK.GTK_POLICY_EXTERNAL && GTK.gtk_widget_get_visible (handle);
	} else {
		return vsp [0] != GTK.GTK_POLICY_NEVER && vsp[0] != GTK.GTK_POLICY_EXTERNAL && GTK.gtk_widget_get_visible (handle);
	}
}

@Override
long gtk_button_press_event (long widget, long eventPtr) {
	long result = super.gtk_button_press_event (widget, eventPtr);
	if (result != 0) return result;
	detail = GTK.GTK_SCROLL_NONE;
	dragSent = false;
	return result;
}

@Override
boolean gtk_change_value (long widget, int scroll, double value, long user_data) {
	detail = scroll;
	return false;
}

@Override
long gtk_value_changed (long range) {
	Event event = new Event ();
	dragSent = detail == GTK.GTK_SCROLL_JUMP;
	switch (detail) {
		case GTK.GTK_SCROLL_NONE:			event.detail = SWT.NONE; break;
		case GTK.GTK_SCROLL_JUMP:			event.detail = SWT.DRAG; break;
		case GTK.GTK_SCROLL_START:			event.detail = SWT.HOME; break;
		case GTK.GTK_SCROLL_END:				event.detail = SWT.END; break;
		case GTK.GTK_SCROLL_PAGE_DOWN:
		case GTK.GTK_SCROLL_PAGE_RIGHT:
		case GTK.GTK_SCROLL_PAGE_FORWARD:	event.detail = SWT.PAGE_DOWN; break;
		case GTK.GTK_SCROLL_PAGE_UP:
		case GTK.GTK_SCROLL_PAGE_LEFT:
		case GTK.GTK_SCROLL_PAGE_BACKWARD:	event.detail = SWT.PAGE_UP; break;
		case GTK.GTK_SCROLL_STEP_DOWN:
		case GTK.GTK_SCROLL_STEP_RIGHT:
		case GTK.GTK_SCROLL_STEP_FORWARD:	event.detail = SWT.ARROW_DOWN; break;
		case GTK.GTK_SCROLL_STEP_UP:
		case GTK.GTK_SCROLL_STEP_LEFT:
		case GTK.GTK_SCROLL_STEP_BACKWARD:	event.detail = SWT.ARROW_UP; break;
	}
	if (!dragSent) detail = GTK.GTK_SCROLL_NONE;
	sendSelectionEvent (SWT.Selection, event, false);
	parent.updateScrollBarValue (this);
	GTK.gtk_widget_queue_draw(parent.handle);
	return 0;
}

@Override
long gtk_event_after (long widget, long gdkEvent) {
	int eventType = GDK.gdk_event_get_event_type(gdkEvent);
	eventType = Control.fixGdkEventTypeValues(eventType);
	switch (eventType) {
		case GDK.GDK_BUTTON_RELEASE: {
			int [] eventButton = new int [1];
			if (GTK.GTK4) {
				eventButton[0] = GDK.gdk_button_event_get_button(gdkEvent);
			} else {
				GDK.gdk_event_get_button(gdkEvent, eventButton);
			}

			if (eventButton[0] == 1 && detail == GTK.GTK_SCROLL_JUMP) {
				if (!dragSent) {
					Event event = new Event ();
					event.detail = SWT.DRAG;
					sendSelectionEvent (SWT.Selection, event, false);
				}
				sendSelectionEvent (SWT.Selection);
			}
			detail = GTK.GTK_SCROLL_NONE;
			dragSent = false;
			break;
		}
	}
	return super.gtk_event_after (widget, gdkEvent);
}

@Override
void hookEvents () {
	super.hookEvents ();
	OS.g_signal_connect_closure (adjustmentHandle, OS.value_changed, display.getClosure (VALUE_CHANGED), false);
	if (GTK.GTK4) {
		//TODO: GTK4 change-value moved to gtk_scroll_child in Composite, event-after

		long clickGesture = GTK4.gtk_gesture_click_new();
		GTK4.gtk_widget_add_controller(handle, clickGesture);
		OS.g_signal_connect(clickGesture, OS.pressed, display.gesturePressReleaseProc, GESTURE_PRESSED);
	} else {
		OS.g_signal_connect_closure (handle, OS.change_value, display.getClosure (CHANGE_VALUE), false);
		OS.g_signal_connect_closure_by_id (handle, display.signalIds [BUTTON_PRESS_EVENT], 0, display.getClosure (BUTTON_PRESS_EVENT), false);
		OS.g_signal_connect_closure_by_id (handle, display.signalIds [EVENT_AFTER], 0, display.getClosure (EVENT_AFTER), false);
	}
}

/**
 * Returns true if the receiver is enabled and all
 * of the receiver's ancestors are enabled, and false
 * otherwise. A disabled control is typically not selectable from the
 * user interface and draws with an inactive or "grayed" look.
 *
 * @return the receiver's enabled state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #getEnabled
 */
public boolean isEnabled () {
	checkWidget ();
	return getEnabled () && getParent ().getEnabled ();
}

/**
 * Returns true if the receiver is visible and all
 * of the receiver's ancestors are visible and false
 * otherwise.
 *
 * @return the receiver's visibility state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #getVisible
 */
public boolean isVisible () {
	checkWidget ();
	return getVisible () && getParent ().isVisible ();
}

@Override
void register () {
	super.register ();
	if (adjustmentHandle != 0) display.addWidget (adjustmentHandle, this);
}

@Override
void releaseHandle () {
	super.releaseHandle ();
	parent = null;
}

@Override
void releaseParent () {
	super.releaseParent ();
	if (parent.horizontalBar == this) parent.horizontalBar = null;
	if (parent.verticalBar == this) parent.verticalBar = null;
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the user changes the receiver's value.
 *
 * @param listener the listener which should no longer be notified
 *
 * @exception IllegalArgumentException 
 *    ERROR_NULL_ARGUMENT - if the listener is null
 * 
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection,listener);
}

/**
 * Enables the receiver if the argument is true,
 * and disables it otherwise. A disabled control is typically
 * not selectable from the user interface and draws with an
 * inactive or "grayed" look.
 *
 * @param enabled the new enabled state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setEnabled (boolean enabled) {
	checkWidget ();
	if (handle != 0) GTK.gtk_widget_set_sensitive (handle, enabled);
}

/**
 * Sets the amount that the receiver's value will be
 * modified by when the up/down (or right/left) arrows
 * are pressed to the argument, which must be at least
 * one.
 *
 * @param value the new increment (must be greater than zero)
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setIncrement (int value) {
	checkWidget ();
	if (value < 1) return;
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_set_step_increment (adjustmentHandle, value);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Sets the maximum. If this value is negative or less than or
 * equal to the minimum, the value is ignored. If necessary, first
 * the thumb and then the selection are adjusted to fit within the
 * new range.
 *
 * @param value the new maximum
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setMaximum (int value) {
	checkWidget ();
	GtkAdjustment adjustment = new GtkAdjustment ();
	gtk_adjustment_get (adjustmentHandle, adjustment);
	int minimum = (int) adjustment.lower;
	if (value <= minimum) return;
	adjustment.upper = value;
	adjustment.page_size = Math.min ((int)adjustment.page_size, value - minimum);
	adjustment.value = Math.min ((int)adjustment.value, (int)(value - adjustment.page_size));
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_configure(adjustmentHandle, adjustment.value, adjustment.lower, adjustment.upper,
		adjustment.step_increment, adjustment.page_increment, adjustment.page_size);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Sets the minimum value. If this value is negative or greater
 * than or equal to the maximum, the value is ignored. If necessary,
 * first the thumb and then the selection are adjusted to fit within
 * the new range.
 *
 * @param value the new minimum
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setMinimum (int value) {
	checkWidget ();
	if (value < 0) return;
	GtkAdjustment adjustment = new GtkAdjustment ();
	gtk_adjustment_get (adjustmentHandle, adjustment);
	int maximum = (int) adjustment.upper;
	if (value >= maximum) return;
	adjustment.lower = value;
	adjustment.page_size = Math.min ((int)adjustment.page_size, maximum - value);
	adjustment.value = Math.max ((int)adjustment.value, value);
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_configure(adjustmentHandle, adjustment.value, adjustment.lower, adjustment.upper,
		adjustment.step_increment, adjustment.page_increment, adjustment.page_size);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

@Override
void setOrientation (boolean create) {
	super.setOrientation (create);
	if ((parent.style & SWT.MIRRORED) != 0 || !create) {
		if ((parent.state & CANVAS) != 0) {
			if ((style & SWT.HORIZONTAL) != 0) {
				GTK.gtk_range_set_inverted (handle, (parent.style & SWT.RIGHT_TO_LEFT) != 0);
			}
		}
	}
}

/**
 * Sets the amount that the receiver's value will be
 * modified by when the page increment/decrement areas
 * are selected to the argument, which must be at least
 * one.
 *
 * @param value the page increment (must be greater than zero)
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setPageIncrement (int value) {
	checkWidget ();
	if (value < 1) return;
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_set_page_increment (adjustmentHandle, value);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Sets the single selection that is the receiver's
 * value to the argument which must be greater than or equal
 * to zero.
 *
 * @param selection the new selection (must be zero or greater)
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setSelection (int selection) {
	checkWidget ();
	selection = Math.min (selection, getMaximum() - getThumb());
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_set_value (adjustmentHandle, selection);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Sets the thumb value. The thumb value should be used to represent
 * the size of the visual portion of the current range. This value is
 * usually the same as the page increment value.
 * 
 * This new value will be ignored if it is less than one, and will be
 * clamped if it exceeds the receiver's current range.
 * 
 *
 * @param value the new thumb value, which must be at least one and not
 * larger than the size of the current range
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setThumb (int value) {
	checkWidget ();
	if (value < 1) return;
	GtkAdjustment adjustment = new GtkAdjustment ();
	gtk_adjustment_get (adjustmentHandle, adjustment);
	value = (int) Math.min (value, (int)(adjustment.upper - adjustment.lower));
	adjustment.page_size = (double) value;
	adjustment.value = Math.min ((int)adjustment.value, (int)(adjustment.upper - value));
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_configure(adjustmentHandle, adjustment.value, adjustment.lower, adjustment.upper,
		adjustment.step_increment, adjustment.page_increment, adjustment.page_size);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Sets the receiver's selection, minimum value, maximum
 * value, thumb, increment and page increment all at once.
 * 
 * Note: This is similar to setting the values individually
 * using the appropriate methods, but may be implemented in a
 * more efficient fashion on some platforms.
 * 
 *
 * @param selection the new selection value
 * @param minimum the new minimum value
 * @param maximum the new maximum value
 * @param thumb the new thumb value
 * @param increment the new increment value
 * @param pageIncrement the new pageIncrement value
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setValues (int selection, int minimum, int maximum, int thumb, int increment, int pageIncrement) {
	checkWidget ();
	if (minimum < 0) return;
	if (maximum < 0) return;
	if (thumb < 1) return;
	if (increment < 1) return;
	if (pageIncrement < 1) return;
	thumb = Math.min (thumb, maximum - minimum);
	GtkAdjustment adjustment = new GtkAdjustment ();
	adjustment.lower = minimum;
	adjustment.upper = maximum;
	adjustment.step_increment = increment;
	adjustment.page_increment = pageIncrement;
	adjustment.page_size = thumb;
	adjustment.value = Math.min (Math.max (selection, minimum), maximum - thumb);
	OS.g_signal_handlers_block_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
	GTK.gtk_adjustment_configure(adjustmentHandle, adjustment.value, adjustment.lower, adjustment.upper,
		adjustment.step_increment, adjustment.page_increment, adjustment.page_size);
	OS.g_signal_handlers_unblock_matched (adjustmentHandle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED);
}

/**
 * Marks the receiver as visible if the argument is true,
 * and marks it invisible otherwise.
 * 
 * If one of the receiver's ancestors is not visible or some
 * other condition makes the receiver not visible, marking
 * it visible may not actually cause it to be displayed.
 * 
 *
 * @param visible the new visibility state
 *
 * @exception SWTException 
 *    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setVisible (boolean visible) {
	checkWidget ();
	if (parent.setScrollBarVisible (this, visible)) {
		sendEvent (visible ? SWT.Show : SWT.Hide);
		parent.sendEvent (SWT.Resize);
	}
}

}