/*******************************************************************************
 * 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:
 *     Jacob Carlborg <doob@me.com>
 *******************************************************************************/
module dwt.widgets.ExpandItem;

import dwt.dwthelper.utils;

import dwt.DWT;
import dwt.DWTException;
import dwt.graphics.GC;
import dwt.graphics.Image;
import dwt.graphics.Point;
import dwt.graphics.Rectangle;

import dwt.widgets.Control;
import dwt.widgets.Display;
import dwt.widgets.ExpandBar;
import dwt.widgets.Item;

/**
 * Instances of this class represent a selectable user interface object
 * that represents a expandable item in a expand bar.
 * <p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 * 
 * @see ExpandBar
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 * 
 * @since 3.2
 */
public class ExpandItem : Item {
    ExpandBar parent;
    Control control;
    bool expanded;
    int x, y, width, height;
    int imageHeight, imageWidth;
    static const int TEXT_INSET = 6;
    static const int BORDER = 1;
    static const int CHEVRON_SIZE = 24;
    
/**
 * 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 Widget#checkSubclass
 * @see Widget#getStyle
 */
public this (ExpandBar parent, int style) {
    this (parent, style, checkNull (parent).getItemCount ());
}

/**
 * Constructs a new instance of this class given its parent, a
 * style value describing its behavior and appearance, and the index
 * at which to place it in the items maintained by its parent.
 * <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
 * @param index the zero-relative index to store the receiver in its parent
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the parent (inclusive)</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 Widget#checkSubclass
 * @see Widget#getStyle
 */
public this (ExpandBar parent, int style, int index) {
    super (parent, style);
    this.parent = parent;
    parent.createItem (this, style, index);
}

static ExpandBar checkNull (ExpandBar control) {
    if (control is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
    return control; 
}

public void dispose () {
    if (isDisposed ()) return;
    //if (!isValidThread ()) error (DWT.ERROR_THREAD_INVALID_ACCESS);
    parent.destroyItem (this);
    super.dispose();
    parent = null;
    control = null;
}

void drawChevron (GC gc, int x, int y) {
    int [] polyline1, polyline2;
    if (expanded) {
        int px = x + 4 + 5;
        int py = y + 4 + 7;
        polyline1 = [
                     px,py, px+1,py, px+1,py-1, px+2,py-1, px+2,py-2, px+3,py-2, px+3,py-3,
                     px+3,py-2, px+4,py-2, px+4,py-1, px+5,py-1, px+5,py, px+6,py];
        py += 4;
        polyline2 = [
                     px,py, px+1,py, px+1,py-1, px+2,py-1, px+2,py-2, px+3,py-2, px+3,py-3,
                     px+3,py-2, px+4,py-2, px+4,py-1,  px+5,py-1, px+5,py, px+6,py];
    } else {
        int px = x + 4 + 5;
        int py = y + 4 + 4;
        polyline1 = [
                     px,py, px+1,py, px+1,py+1, px+2,py+1, px+2,py+2, px+3,py+2, px+3,py+3,
                     px+3,py+2, px+4,py+2, px+4,py+1,  px+5,py+1, px+5,py, px+6,py];
        py += 4;
        polyline2 = [
                     px,py, px+1,py, px+1,py+1, px+2,py+1, px+2,py+2, px+3,py+2, px+3,py+3,
                     px+3,py+2, px+4,py+2, px+4,py+1,  px+5,py+1, px+5,py, px+6,py];
    }
    gc.setForeground (display.getSystemColor (DWT.COLOR_TITLE_FOREGROUND));
    gc.drawPolyline (polyline1);
    gc.drawPolyline (polyline2);
}

void drawItem (GC gc, bool drawFocus) {
    int headerHeight = parent.getBandHeight ();
    Display display = getDisplay ();
    gc.setForeground (display.getSystemColor (DWT.COLOR_TITLE_BACKGROUND));
    gc.setBackground (display.getSystemColor (DWT.COLOR_TITLE_BACKGROUND_GRADIENT));
    gc.fillGradientRectangle (x, y, width, headerHeight, true);
    if (expanded) {
        gc.setForeground (display.getSystemColor (DWT.COLOR_TITLE_BACKGROUND_GRADIENT));
        gc.drawLine (x, y + headerHeight, x, y + headerHeight + height - 1);
        gc.drawLine (x, y + headerHeight + height - 1, x + width - 1, y + headerHeight + height - 1);
        gc.drawLine (x + width - 1, y + headerHeight + height - 1, x + width - 1, y + headerHeight);
    }
    int drawX = x;
    if (image !is null) {
        drawX += ExpandItem.TEXT_INSET;
        if (imageHeight > headerHeight) {
            gc.drawImage (image, drawX, y + headerHeight - imageHeight);
        } else {
            gc.drawImage (image, drawX, y + (headerHeight - imageHeight) / 2);
        }
        drawX += imageWidth;
    }
    if (text.length() > 0) {
        drawX += ExpandItem.TEXT_INSET;
        Point size = gc.stringExtent (text);
        gc.setForeground (parent.getForeground ());
        gc.drawString (text, drawX, y + (headerHeight - size.y) / 2, true);
    }
    int chevronSize = ExpandItem.CHEVRON_SIZE;
    drawChevron (gc, x + width - chevronSize, y + (headerHeight - chevronSize) / 2);
    if (drawFocus) {
        gc.drawFocus (x + 1, y + 1, width - 2, headerHeight - 2);
    }
}

/**
 * Returns the control that is shown when the item is expanded.
 * If no control has been set, return <code>null</code>.
 *
 * @return the control
 *
 * @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 Control getControl() {
    checkWidget ();
    return control;
}

/**
 * Returns <code>true</code> if the receiver is expanded,
 * and false otherwise.
 *
 * @return the expanded state
 *
 * @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 bool getExpanded() {
    checkWidget ();
    return expanded;
}

/**
 * Returns the height of the receiver's header 
 *
 * @return the height of the header 
 *
 * @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 getHeaderHeight () {
    checkWidget ();
    return Math.max (parent.getBandHeight (), imageHeight);
}

/**
 * Gets the height of the receiver.
 *
 * @return the height
 *
 * @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 getHeight () {
    checkWidget ();
    return height;
}

/**
 * Returns the receiver's parent, which must be a <code>ExpandBar</code>.
 *
 * @return the receiver's parent
 *
 * @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 ExpandBar getParent () {
    checkWidget ();
    return parent;
}

int getPreferredWidth (GC gc) {
    int width = ExpandItem.TEXT_INSET * 2 + ExpandItem.CHEVRON_SIZE;
    if (image !is null) {
        width += ExpandItem.TEXT_INSET + imageWidth;
    }
    if (text.length() > 0) {
        width += gc.stringExtent (text).x;
    }
    return width;
}

void redraw () {
    int headerHeight = parent.getBandHeight ();
    if (imageHeight > headerHeight) {
        parent.redraw (x + ExpandItem.TEXT_INSET, y + headerHeight - imageHeight, imageWidth, imageHeight, false);
    }
    parent.redraw (x, y, width, headerHeight + height, false);
}

void setBounds (int x, int y, int width, int height, bool move, bool size) {
    redraw ();
    int headerHeight = parent.getBandHeight ();
    if (move) {
        if (imageHeight > headerHeight) {
            y += (imageHeight - headerHeight);
        }
        this.x = x;
        this.y = y;
        redraw ();
    }
    if (size) {
        this.width = width;
        this.height = height;
        redraw ();
    }
    if (control !is null && !control.isDisposed ()) {
        if (move) control.setLocation (x + BORDER, y + headerHeight);
        if (size) control.setSize (Math.max (0, width - 2 * BORDER), Math.max (0, height - BORDER));
    }
}

/**
 * Sets the control that is shown when the item is expanded.
 *
 * @param control the new control (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the control has been disposed</li> 
 *    <li>ERROR_INVALID_PARENT - if the control is not in the same widget tree</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>
 */
public void setControl(Control control) {
    checkWidget ();
    if (control !is null) {
        if (control.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
        if (control.parent !is parent) error (DWT.ERROR_INVALID_PARENT);
    }
    this.control = control;
    if (control !is null) {
        control.setVisible (expanded);
        int headerHeight = parent.getBandHeight ();
        control.setBounds (x + BORDER, y + headerHeight, Math.max (0, width - 2 * BORDER), Math.max (0, height - BORDER));
    }
}

/**
 * Sets the expanded state of the receiver.
 *
 * @param expanded the new expanded state
 *
 * @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 setExpanded (bool expanded) {
    checkWidget ();
    this.expanded = expanded;
    parent.showItem (this);
}

public void setImage (Image image) {
    super.setImage (image);
    int oldImageHeight = imageHeight;
    if (image !is null) {
        Rectangle bounds = image.getBounds ();
        imageHeight = bounds.height;
        imageWidth = bounds.width;
    } else {
        imageHeight = imageWidth = 0;
    }
    if (oldImageHeight !is imageHeight) {
        parent.layoutItems (parent.indexOf (this), true);
    } else {
        redraw ();
    }
}

/**
 * Sets the height of the receiver. This is height of the item when it is expanded, 
 * excluding the height of the header.
 *
 * @param height the new height
 *
 * @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 setHeight (int height) {
    checkWidget ();
    if (height < 0) return;
    setBounds (0, 0, width, height, false, true);
    if (expanded) parent.layoutItems (parent.indexOf (this) + 1, true);
}

public void setText (String string) {
    super.setText (string);
    redraw ();
}
}