/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwt.widgets.Scale;


import dwt.widgets.Control;
import dwt.widgets.Composite;
import dwt.widgets.TypedListener;
import dwt.DWT;
import dwt.internal.gtk.OS;
import dwt.graphics.Point;
import dwt.events.SelectionListener;

/**
 * Instances of the receiver represent a selectable user
 * interface object that present a range of continuous
 * numeric values.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>HORIZONTAL, VERTICAL</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.
 * </p><p>
 * <p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the DWT implementation.
 * </p>
 *
 * @see <a href="http://www.eclipse.org/swt/snippets/#scale">Scale snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">DWT Example: ControlExample</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 */
public class Scale : Control {

    alias Control.computeSize computeSize;


/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * <p>
 * The style value is either one of the style constants defined in
 * class <code>DWT</code> which is applicable to instances of this
 * class, or must be built by <em>bitwise OR</em>'ing together
 * (that is, using the <code>int</code> "|" operator) two or more
 * of those <code>DWT</code> style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * </p>
 *
 * @param parent a composite control which will be the parent of the new instance (cannot be null)
 * @param style the style of control to construct
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 * </ul>
 * @exception DWTException <ul>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
 *    <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
 * </ul>
 *
 * @see DWT#HORIZONTAL
 * @see DWT#VERTICAL
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public this (Composite parent, int style) {
    super (parent, checkStyle (style));
}

/**
 * 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 <code>SelectionListener</code>
 * interface.
 * <p>
 * <code>widgetSelected</code> is called when the user changes the receiver's value.
 * <code>widgetDefaultSelected</code> is not called.
 * </p>
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 */
public void addSelectionListener (SelectionListener listener) {
    checkWidget ();
    if (listener is null) error (DWT.ERROR_NULL_ARGUMENT);
    TypedListener typedListener = new TypedListener (listener);
    addListener (DWT.Selection,typedListener);
    addListener (DWT.DefaultSelection,typedListener);
}

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

public override Point computeSize (int wHint, int hHint, bool changed) {
    checkWidget();
    if (wHint !is DWT.DEFAULT && wHint < 0) wHint = 0;
    if (hHint !is DWT.DEFAULT && hHint < 0) hHint = 0;
    Point size = computeNativeSize(handle, wHint, hHint, changed);
    if ((style & DWT.HORIZONTAL) !is 0) {
        if (wHint is DWT.DEFAULT) size.x = 2 * size.x;
    } else {
        if (hHint is DWT.DEFAULT) size.y = 2 * size.y;
    }
    return size;
}

override void createHandle (int index) {
    state |= HANDLE | THEME_BACKGROUND;
    fixedHandle = cast(GtkWidget*)OS.g_object_new (display.gtk_fixed_get_type (), null);
    if (fixedHandle is null) error (DWT.ERROR_NO_HANDLES);
    OS.gtk_fixed_set_has_window (cast(GtkFixed*)fixedHandle, true);
    auto hAdjustment = OS.gtk_adjustment_new (0, 0, 100, 1, 10, 0);
    if (hAdjustment is null) error (DWT.ERROR_NO_HANDLES);
    if ((style & DWT.HORIZONTAL) !is 0) {
        handle = cast(GtkWidget*)OS.gtk_hscale_new (cast(GtkAdjustment*)hAdjustment);
    } else {
        handle = cast(GtkWidget*)OS.gtk_vscale_new (cast(GtkAdjustment*)hAdjustment);
    }
    if (handle is null) error (DWT.ERROR_NO_HANDLES);
    OS.gtk_container_add (cast(GtkContainer*)fixedHandle, handle);
    OS.gtk_scale_set_digits (cast(GtkScale*)handle, 0);
    OS.gtk_scale_set_draw_value (cast(GtkScale*)handle, false);
}

override void hookEvents () {
    super.hookEvents ();
    OS.g_signal_connect_closure (handle, OS.value_changed.ptr, display.closures [VALUE_CHANGED], false);
}

/**
 * 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 DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getIncrement () {
    checkWidget ();
    auto hAdjustment = OS.gtk_range_get_adjustment (cast(GtkRange*)handle);
    return cast(int) hAdjustment.step_increment;
}

/**
 * Returns the maximum value which the receiver will allow.
 *
 * @return the maximum
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getMaximum () {
    checkWidget ();
    auto hAdjustment = OS.gtk_range_get_adjustment (cast(GtkRange*)handle);
    return cast(int) hAdjustment.upper;
}

/**
 * Returns the minimum value which the receiver will allow.
 *
 * @return the minimum
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getMinimum () {
    checkWidget ();
    auto hAdjustment = OS.gtk_range_get_adjustment (cast(GtkRange*)handle);
    return cast(int) hAdjustment.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 DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getPageIncrement () {
    checkWidget ();
    auto hAdjustment = OS.gtk_range_get_adjustment (cast(GtkRange*)handle);
    return cast(int) hAdjustment.page_increment;
}

/**
 * Returns the 'selection', which is the receiver's position.
 *
 * @return the selection
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public int getSelection () {
    checkWidget ();
    auto hAdjustment = OS.gtk_range_get_adjustment (cast(GtkRange*)handle);
    return cast(int) hAdjustment.value;
}

int /*long*/ gtk_value_changed (int /*long*/ adjustment) {
    postEvent (DWT.Selection);
    return 0;
}

/**
 * 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 <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
 * </ul>
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 *
 * @see SelectionListener
 * @see #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
    checkWidget ();
    if (listener is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (eventTable is null) return;
    eventTable.unhook (DWT.Selection, listener);
    eventTable.unhook (DWT.DefaultSelection,listener);
}

/**
 * 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 increment the new increment (must be greater than zero)
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setIncrement (int value) {
    checkWidget ();
    if (value < 1) return;
    OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
    OS.gtk_range_set_increments (cast(GtkRange*)handle, value, getPageIncrement ());
    OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
}

/**
 * Sets the maximum value that the receiver will allow.  This new
 * value will be ignored if it is not greater than the receiver's current
 * minimum value.  If the new maximum is applied then the receiver's
 * selection value will be adjusted if necessary to fall within its new range.
 *
 * @param value the new maximum, which must be greater than the current minimum
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setMaximum (int value) {
    checkWidget ();
    int minimum = getMinimum();
    if (value <= minimum) return;
    OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
    OS.gtk_range_set_range (cast(GtkRange*)handle, minimum, value);
    OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
}

/**
 * Sets the minimum value that the receiver will allow.  This new
 * value will be ignored if it is negative or is not less than the receiver's
 * current maximum value.  If the new minimum is applied then the receiver's
 * selection value will be adjusted if necessary to fall within its new range.
 *
 * @param value the new minimum, which must be nonnegative and less than the current maximum
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setMinimum (int value) {
    checkWidget ();
    if (value < 0) return;
    int maximum = getMaximum ();
    if (value >= maximum) return;
    OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
    OS.gtk_range_set_range (cast(GtkRange*)handle, value, maximum);
    OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
}

/**
 * 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 pageIncrement the page increment (must be greater than zero)
 *
 * @exception DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setPageIncrement (int value) {
    checkWidget ();
    if (value < 1) return;
    OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
    OS.gtk_range_set_increments (cast(GtkRange*)handle, getIncrement (), value);
    OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
}

/**
 * Sets the 'selection', which 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 DWTException <ul>
 *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
 * </ul>
 */
public void setSelection (int value) {
    checkWidget ();
    OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
    OS.gtk_range_set_value (cast(GtkRange*)handle, value);
    OS.g_signal_handlers_unblock_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udVALUE_CHANGED);
}

}