/*******************************************************************************
 * 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.Canvas;


import dwt.DWT;
import dwt.DWTException;
import dwt.graphics.Font;
import dwt.graphics.GC;
import dwt.graphics.Image;
import dwt.graphics.Rectangle;
import dwt.internal.cocoa.NSBezierPath;
import dwt.internal.cocoa.NSColor;
import dwt.internal.cocoa.NSCursor;
import dwt.internal.cocoa.NSEvent;
import dwt.internal.cocoa.NSGraphicsContext;
import dwt.internal.cocoa.NSPoint;
import dwt.internal.cocoa.NSRange;
import dwt.internal.cocoa.NSRect;
import dwt.internal.cocoa.NSSize;
import dwt.internal.cocoa.OS;

import dwt.dwthelper.utils;
import dwt.internal.objc.cocoa.Cocoa;
import objc = dwt.internal.objc.runtime;
import dwt.widgets.Caret;
import dwt.widgets.Composite;
import dwt.widgets.Control;
import dwt.widgets.IME;

/**
 * Instances of this class provide a surface for drawing
 * arbitrary graphics.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * This class may be subclassed by custom control implementors
 * who are building controls that are <em>not</em> constructed
 * from aggregates of other controls. That is, they are either
 * painted using DWT graphics calls or are handled by native
 * methods.
 * </p>
 *
 * @see Composite
 * @see <a href="http://www.eclipse.org/swt/snippets/#canvas">Canvas 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 Canvas : Composite {
    Caret caret;
    IME ime;

this () {
    /* Do nothing */
}

objc.id attributedSubstringFromRange (objc.id id, objc.SEL sel, objc.id range) {
    if (ime !is null) return ime.attributedSubstringFromRange (id, sel, range);
    return super.attributedSubstringFromRange(id, sel, range);
}

bool becomeFirstResponder (objc.id id, objc.SEL sel) {
    if (caret !is null) caret.setFocus ();
    return super.becomeFirstResponder(id, sel);
}

bool resignFirstResponder (objc.id id, objc.SEL sel) {
    if (caret !is null) caret.killFocus ();
    return super.resignFirstResponder(id, sel);
}


/**
 * 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>
 * </ul>
 *
 * @see DWT
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public this (Composite parent, int style) {
    super (parent, style);
}

NSInteger characterIndexForPoint (objc.id id, objc.SEL sel, objc.id point) {
    if (ime !is null) return ime.characterIndexForPoint (id, sel, point);
    return super.characterIndexForPoint (id, sel, point);
}

/** 
 * Fills the interior of the rectangle specified by the arguments,
 * with the receiver's background. 
 *
 * @param gc the gc where the rectangle is to be filled
 * @param x the x coordinate of the rectangle to be filled
 * @param y the y coordinate of the rectangle to be filled
 * @param width the width of the rectangle to be filled
 * @param height the height of the rectangle to be filled
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the gc has been disposed</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>
 * 
 * @since 3.2
 */
public void drawBackground (GC gc, int x, int y, int width, int height) {
    checkWidget ();
    if (gc is null) error (DWT.ERROR_NULL_ARGUMENT);
    if (gc.isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
    Control control = findBackgroundControl ();
    if (control !is null) {
        NSRect rect = NSRect();
        rect.x = x;
        rect.y = y;
        rect.width = width;
        rect.height = height;
        control.fillBackground (view, gc.handle, rect);
    } else {
        gc.fillRectangle (x, y, width, height);
    }
}

void drawWidget (objc.id id, NSRect rect) {
    super.drawWidget (id, rect);
    if (caret is null) return;
    if (caret.isShowing) {
        NSGraphicsContext context = NSGraphicsContext.currentContext();
        
        Image image = caret.image;
        if (image !is null) {
            NSRect fromRect = NSRect ();
            NSSize size = image.handle.size();
            fromRect.width = size.width;
            fromRect.height = size.height;
            NSPoint point = NSPoint();
            point.x = caret.x;
            point.y = caret.y;
            image.handle.drawAtPoint(point, rect, OS.NSCompositeXOR, 1);
        } else {
            context.saveGraphicsState();
            context.setCompositingOperation(OS.NSCompositeXOR);
            NSRect drawRect = NSRect();
            drawRect.x = caret.x;
            drawRect.y = caret.y;
            drawRect.width = caret.width !is 0 ? caret.width : Caret.DEFAULT_WIDTH;
            drawRect.height = caret.height;
            context.setShouldAntialias(false);
            NSColor color = NSColor.colorWithDeviceRed(1, 1, 1, 1);
            color.set();
            NSBezierPath.fillRect(drawRect);
            context.restoreGraphicsState();
        }
    }
}

NSRect firstRectForCharacterRange (objc.id id, objc.SEL sel, objc.id range) {
    if (ime !is null) return ime.firstRectForCharacterRange (id, sel, range);
    return super.firstRectForCharacterRange (id, sel, range);
}

/**
 * Returns the caret.
 * <p>
 * The caret for the control is automatically hidden
 * and shown when the control is painted or resized,
 * when focus is gained or lost and when an the control
 * is scrolled.  To avoid drawing on top of the caret,
 * the programmer must hide and show the caret when
 * drawing in the window any other time.
 * </p>
 *
 * @return the caret for the receiver, may be null
 *
 * @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 Caret getCaret () {
    checkWidget();
    return caret;
}

/**
 * Returns the IME.
 *
 * @return the IME
 *
 * @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>
 * 
 * @since 3.4
 */
public IME getIME () {
    checkWidget();
    return ime;
}

bool hasMarkedText (objc.id id, objc.SEL sel) {
    if (ime !is null) return ime.hasMarkedText (id, sel);
    return super.hasMarkedText (id, sel);
}

bool insertText (objc.id id, objc.SEL sel, objc.id string) {
    if (ime !is null) {
        if (!ime.insertText (id, sel, string)) return false;
    }
    return super.insertText (id, sel, string);
}

NSRange markedRange (objc.id id, objc.SEL sel) {
    if (ime !is null) return ime.markedRange (id, sel);
    return super.markedRange (id, sel);
}

//void redrawWidget (int control, bool children) {
//  bool isFocus = OS.VERSION < 0x1040 && caret !is null && caret.isFocusCaret ();
//  if (isFocus) caret.killFocus ();
//  super.redrawWidget (control, children);
//  if (isFocus) caret.setFocus ();
//}
//
//void redrawWidget (int control, int x, int y, int width, int height, bool all) {
//  bool isFocus = OS.VERSION < 0x1040 && caret !is null && caret.isFocusCaret ();
//  if (isFocus) caret.killFocus ();
//  super.redrawWidget (control, x, y, width, height, all);
//  if (isFocus) caret.setFocus ();
//}

void releaseChildren (bool destroy) {
    if (caret !is null) {
        caret.release (false);
        caret = null;
    }
    if (ime !is null) {
        ime.release (false);
        ime = null;
    }
    super.releaseChildren (destroy);
}

/**
 * Scrolls a rectangular area of the receiver by first copying 
 * the source area to the destination and then causing the area
 * of the source which is not covered by the destination to
 * be repainted. Children that intersect the rectangle are
 * optionally moved during the operation. In addition, outstanding
 * paint events are flushed before the source area is copied to
 * ensure that the contents of the canvas are drawn correctly.
 *
 * @param destX the x coordinate of the destination
 * @param destY the y coordinate of the destination
 * @param x the x coordinate of the source
 * @param y the y coordinate of the source
 * @param width the width of the area
 * @param height the height of the area
 * @param all <code>true</code>if children should be scrolled, and <code>false</code> otherwise
 *
 * @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 scroll (int destX, int destY, int x, int y, int width, int height, bool all) {
    checkWidget();
    if (width <= 0 || height <= 0) return;
    int deltaX = destX - x, deltaY = destY - y;
    if (deltaX is 0 && deltaY is 0) return;
//  if (!isDrawing (handle)) return;
    bool isFocus = caret !is null && caret.isFocusCaret ();
    if (isFocus) caret.killFocus ();
    Rectangle clientRect = getClientArea ();
    Rectangle sourceRect = new Rectangle (x, y, width, height);
    if (sourceRect.intersects (clientRect)) {
        update (all);
    }
    NSRect damage = NSRect();
    damage.x = x;
    damage.y = y;
    damage.width = width;
    damage.height = height;
    view.setNeedsDisplayInRect(damage);
    damage.x = destX;
    damage.y = destY;
    view.setNeedsDisplayInRect(damage);
//  Control control = findBackgroundControl ();
//  if ((control !is null && control.backgroundImage !is null)) {
//      redrawWidget (handle, x, y, width, height, false);
//      redrawWidget (handle, destX, destY, width, height, false);
//  } else {
//      GC gc = new GC (this);
//      gc.copyArea (x, y, width, height, destX, destY);
//      gc.dispose ();
//  }
    if (all) {
        Control [] children = _getChildren ();
        for (int i=0; i<children.length; i++) {
            Control child = children [i];
            Rectangle rect = child.getBounds ();
            if (Math.min(x + width, rect.x + rect.width) >= Math.max (x, rect.x) && 
                Math.min(y + height, rect.y + rect.height) >= Math.max (y, rect.y)) {
                    child.setLocation (rect.x + deltaX, rect.y + deltaY);
            }
        }
    }
    if (isFocus) caret.setFocus ();
}

NSRange selectedRange (objc.id id, objc.SEL sel) {
    if (ime !is null) return ime.selectedRange (id, sel);
    return super.selectedRange (id, sel);
}

bool sendKeyEvent (NSEvent nsEvent, int type) {
    if (caret !is null) NSCursor.setHiddenUntilMouseMoves (true);
    return super.sendKeyEvent (nsEvent, type);
}

/**
 * Sets the receiver's caret.
 * <p>
 * The caret for the control is automatically hidden
 * and shown when the control is painted or resized,
 * when focus is gained or lost and when an the control
 * is scrolled.  To avoid drawing on top of the caret,
 * the programmer must hide and show the caret when
 * drawing in the window any other time.
 * </p>
 * @param caret the new caret for the receiver, may be null
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the caret has been disposed</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 setCaret (Caret caret) {
    checkWidget();
    Caret newCaret = caret;
    Caret oldCaret = this.caret;
    this.caret = newCaret;
    if (hasFocus ()) {
        if (oldCaret !is null) oldCaret.killFocus ();
        if (newCaret !is null) {
            if (newCaret.isDisposed()) error(DWT.ERROR_INVALID_ARGUMENT);
            newCaret.setFocus ();
        }
    }
}

public void setFont (Font font) {
    checkWidget ();
    if (caret !is null) caret.setFont (font);
    super.setFont (font);
}

/**
 * Sets the receiver's IME.
 * 
 * @param ime the new IME for the receiver, may be null
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the IME has been disposed</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>
 * 
 * @since 3.4
 */
public void setIME (IME ime) {
    checkWidget ();
    if (ime !is null && ime.isDisposed()) error(DWT.ERROR_INVALID_ARGUMENT);
    this.ime = ime;
}

bool setMarkedText_selectedRange (objc.id id, objc.SEL sel, objc.id string, objc.id range) {
    if (ime !is null) {
        if (!ime.setMarkedText_selectedRange (id, sel, string, range)) return false;
    }
    return super.setMarkedText_selectedRange (id, sel, string, range);
}

objc.id validAttributesForMarkedText (objc.id id, objc.SEL sel) {
    if (ime !is null) return ime.validAttributesForMarkedText (id, sel);
    return super.validAttributesForMarkedText(id, sel);
}

}