package org.eclipse.swt.widgets; /* * Copyright (c) 2000, 2002 IBM Corp. All rights reserved. * This file is made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html */ import org.eclipse.swt.*; import org.eclipse.swt.internal.gtk.*; import org.eclipse.swt.graphics.*; import org.eclipse.swt.events.*; /** * 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: *

    *
  1. an arrow button for decrementing the value
    2. *
  2. a page decrement area for decrementing the value by a larger amount
    3. *
  3. a thumb for modifying the value by mouse dragging
    4. *
  4. a page increment area for incrementing the value by a larger amount
    5. *
  5. an arrow button for incrementing the value
    6. *
* 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 */ public class ScrollBar extends Widget { Scrollable parent; 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 receiver's value changes, 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: * 0 - 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 * * @exception IllegalArgumentException * @exception SWTException * * @see SelectionListener * @see #removeSelectionListener * @see SelectionEvent */ public void addSelectionListener (SelectionListener listener) { checkWidget (); if (listener == null) error (SWT.ERROR_NULL_ARGUMENT); TypedListener typedListener = new TypedListener(listener); addListener (SWT.Selection,typedListener); addListener (SWT.DefaultSelection,typedListener); } static int checkStyle (int style) { return checkBits (style, SWT.HORIZONTAL, SWT.VERTICAL, 0, 0, 0, 0); } public Display getDisplay () { Scrollable parent = this.parent; if (parent == null) error (SWT.ERROR_WIDGET_DISPOSED); return parent.getDisplay (); } /** * 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 enabled state * * @exception SWTException */ public boolean getEnabled () { checkWidget (); int barHandle; if ((style & SWT.HORIZONTAL) != 0) { barHandle = OS.GTK_SCROLLED_WINDOW_HSCROLLBAR (parent.scrolledHandle); } else { barHandle = OS.GTK_SCROLLED_WINDOW_VSCROLLBAR (parent.scrolledHandle); } if (barHandle != 0) return OS.GTK_WIDGET_SENSITIVE (barHandle); 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 */ public int getIncrement () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.step_increment; } /** * Returns the maximum value which the receiver will allow. * * @return the maximum * * @exception SWTException */ public int getMaximum () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.upper; } /** * Returns the minimum value which the receiver will allow. * * @return the minimum * * @exception SWTException */ public int getMinimum () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.lower; } /** * 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 */ public int getPageIncrement () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.page_increment; } /** * Returns the receiver's parent, which must be scrollable. * * @return the receiver's parent * * @exception SWTException */ public Scrollable getParent () { checkWidget (); return parent; } /** * Returns the single selection that is the receiver's value. * * @return the selection * * @exception SWTException */ public int getSelection () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.value; } /** * 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 */ public Point getSize () { checkWidget (); int barHandle = 0; int scrolledHandle = parent.scrolledHandle; if ((style & SWT.HORIZONTAL) != 0) { barHandle = OS.GTK_SCROLLED_WINDOW_HSCROLLBAR (scrolledHandle); } else { barHandle = OS.GTK_SCROLLED_WINDOW_VSCROLLBAR (scrolledHandle); } if (barHandle == 0) return new Point (0,0); GtkRequisition requisition = new GtkRequisition (); OS.gtk_widget_size_request (barHandle, requisition); return new Point (requisition.width, requisition.height); } /** * Answers the size of the receiver's thumb relative to the * difference between its maximum and minimum values. * * @return the thumb value * * @exception SWTException * * @see ScrollBar */ public int getThumb () { checkWidget (); GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); return (int) adjustment.page_size; } /** * 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 */ public boolean getVisible () { checkWidget (); int scrolledHandle = parent.scrolledHandle; int [] hsp = new int [1], vsp = new int [1]; OS.gtk_scrolled_window_get_policy (scrolledHandle, hsp, vsp); if ((style & SWT.HORIZONTAL) != 0) { return hsp [0] != OS.GTK_POLICY_NEVER; } else { return vsp [0] != OS.GTK_POLICY_NEVER; } } int gtk_value_changed (int adjustment) { postEvent (SWT.Selection); return 0; } void hookEvents () { super.hookEvents (); Display display = getDisplay (); OS.g_signal_connect (handle, OS.value_changed, display.windowProc2, VALUE_CHANGED); } /** * 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 * * @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 * * @see #getVisible */ public boolean isVisible () { checkWidget (); return getVisible () && getParent ().isVisible (); } void releaseChild () { super.releaseChild (); if (parent.horizontalBar == this) parent.horizontalBar = null; if (parent.verticalBar == this) parent.verticalBar = null; } void releaseWidget () { super.releaseWidget (); parent = null; } /** * Removes the listener from the collection of listeners who will * be notified when the receiver's value changes. * * @param listener the listener which should no longer be notified * * @exception IllegalArgumentException * @exception SWTException * * @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 */ public void setEnabled (boolean enabled) { checkWidget (); int barHandle; if ((style & SWT.HORIZONTAL) != 0) { barHandle = OS.GTK_SCROLLED_WINDOW_HSCROLLBAR (parent.scrolledHandle); } else { barHandle = OS.GTK_SCROLLED_WINDOW_VSCROLLBAR (parent.scrolledHandle); } if (barHandle != 0) OS.gtk_widget_set_sensitive (barHandle, 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 */ public void setIncrement (int value) { checkWidget (); if (value < 1) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.step_increment = (float) value; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); } /** * Sets the maximum value which the receiver will allow * to be the argument which must be greater than or * equal to zero. * * @param value the new maximum (must be zero or greater) * * @exception SWTException */ public void setMaximum (int value) { checkWidget (); if (value < 0 || value <= getMinimum()) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.upper = (float) value; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); if (value < getSelection() + getThumb()) setSelection (value - getThumb()); } /** * Sets the minimum value which the receiver will allow * to be the argument which must be greater than or * equal to zero. * * @param value the new minimum (must be zero or greater) * * @exception SWTException */ public void setMinimum (int value) { checkWidget (); if (value < 0 || value >= getMaximum()) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.lower = (float) value; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); if (value > getSelection()) setSelection (value); } /** * 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. * * @return the page increment (must be greater than zero) * * @exception SWTException */ public void setPageIncrement (int value) { checkWidget (); if (value < 1) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.page_increment = (float) value; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.g_signal_handlers_unblock_matched (handle, 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 value the new selection (must be zero or greater) * * @exception SWTException */ public void setSelection (int value) { checkWidget (); value = Math.min(value, getMaximum() - getThumb()); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_set_value (handle, value); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); } /** * Sets the size of the receiver's thumb relative to the * difference between its maximum and minimum values to the * argument which must be at least one. * * @param value the new thumb value (must be at least one) * * @exception SWTException * * @see ScrollBar */ public void setThumb (int value) { checkWidget (); int maximum = getMaximum(); if (value < 1 || value > maximum - getMinimum()) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.page_size = (float) value; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); if (getSelection() + value > maximum) setSelection (maximum - value); } /** * Sets the receiver's selection, minimum value, maximum * value, thumb, increment and page increment all at once. *

* Note: This is equivalent 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 */ 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 (maximum - minimum - thumb < 0) return; if (increment < 1) return; if (pageIncrement < 1) return; GtkAdjustment adjustment = new GtkAdjustment (); OS.memmove (adjustment, handle); adjustment.lower = minimum; adjustment.upper = maximum; adjustment.step_increment = increment; adjustment.page_increment = pageIncrement; adjustment.page_size = thumb; adjustment.value = selection; OS.memmove (handle, adjustment); OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); OS.gtk_adjustment_changed (handle); OS.gtk_adjustment_value_changed (handle); OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, 0, 0, VALUE_CHANGED); if (minimum > getSelection()) setSelection (minimum); if (maximum < selection + thumb) setSelection (maximum - thumb); } /** * 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 */ public void setVisible (boolean visible) { checkWidget (); int scrolledHandle = parent.scrolledHandle; int [] hsp = new int [1], vsp = new int [1]; OS.gtk_scrolled_window_get_policy (scrolledHandle, hsp, vsp); int policy = visible ? OS.GTK_POLICY_ALWAYS : OS.GTK_POLICY_NEVER; if ((style & SWT.HORIZONTAL) != 0) { hsp [0] = policy; } else { vsp [0] = policy; } OS.gtk_scrolled_window_set_policy (scrolledHandle, hsp [0], vsp [0]); } }