/*******************************************************************************
 * 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
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.internal.carbon.OS;
import org.eclipse.swt.internal.carbon.RGBColor;
import org.eclipse.swt.internal.carbon.Rect;
import org.eclipse.swt.internal.carbon.CGPoint;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;

/**
 * Instances of this class provide an i-beam that is typically used
 * as the insertion point for text.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>(none)</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em>
 * within the SWT implementation.
 * </p>
 * 
 * @see <a href="http://www.eclipse.org/swt/snippets/#caret">Caret snippets</a>
 * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample, Canvas tab</a>
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
 * @noextend This class is not intended to be subclassed by clients.
 */
public class Caret extends Widget {
	Canvas parent;
	int x, y, width, height;
	boolean isVisible, isShowing;
	int blinkRate;
	Image image;
	Font font;

	static final int DEFAULT_WIDTH	= 1;
	
/**
 * 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>SWT</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>SWT</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 SWTException <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 SWT
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Caret (Canvas parent, int style) {
	super (parent, style);
	this.parent = parent;
	createWidget ();
}

boolean blinkCaret () {
	if (!isVisible) return true;
	if (!isShowing) return showCaret ();
	if (blinkRate == 0) return true;
	return hideCaret ();
}

void createWidget () {
	super.createWidget ();
	blinkRate = display.getCaretBlinkTime ();
	isVisible = true;
	if (parent.getCaret () == null) {
		parent.setCaret (this);
	}
}

boolean drawCaret () {
	if (parent == null) return false;
	if (parent.isDisposed ()) return false;
	int parentHandle = parent.handle;
	if (!parent.isDrawing ()) return false;
	if (!OS.IsControlVisible (parentHandle)) return false;
	int nWidth = width, nHeight = height;
	if (nWidth <= 0) nWidth = DEFAULT_WIDTH;
	if (OS.VERSION >= 0x1040) {
		if (image != null) {
			nWidth = OS.CGImageGetWidth (image.handle);
			nHeight = OS.CGImageGetHeight (image.handle);
		}
		parent.redrawWidget (parent.handle, x, y, nWidth, nHeight, false);
		return true;
	}
	int window = OS.GetControlOwner (parentHandle);
	int port = OS.GetWindowPort (window);
	int [] currentPort = new int [1];
	OS.GetPort (currentPort);
	OS.SetPort (port);
	int oldClip = OS.NewRgn ();
	int visibleRgn = parent.getVisibleRegion (parentHandle, true);
	OS.GetClip (oldClip);
	OS.SetClip (visibleRgn);
	Rect rect = new Rect ();
	OS.GetControlBounds (parentHandle, rect);
	CGPoint pt = new CGPoint ();
	int [] contentView = new int [1];
	OS.HIViewFindByID (OS.HIViewGetRoot (window), OS.kHIViewWindowContentID (), contentView);
	OS.HIViewConvertPoint (pt, OS.HIViewGetSuperview (parentHandle), contentView [0]);
	rect.left += (int) pt.x;
	rect.top += (int) pt.y;
	int left = rect.left + x;
	int top = rect.top + y;
	if (image == null) {
		OS.SetRect(rect, (short) left, (short) top, (short) (left + nWidth), (short) (top + nHeight));
		RGBColor color = new RGBColor ();
		color.red = (short) 0xFFFF;
		color.green = (short) 0xFFFF;
		color.blue = (short) 0xFFFF;
		OS.RGBBackColor (color);
		OS.InvertRect (rect);
	} else {
		int imageHandle = image.handle;
		nWidth = OS.CGImageGetWidth (imageHandle);
		nHeight = OS.CGImageGetHeight (imageHandle);
		int bpl = OS.CGImageGetBytesPerRow (imageHandle);
		Rect bounds = new Rect ();
		bounds.right = (short) nWidth;
		bounds.bottom = (short) nHeight;
		Rect portRect = new Rect ();
		OS.GetWindowBounds (window, (short) OS.kWindowContentRgn, portRect);
		left += portRect.left;
		top += portRect.top;		
		OS.SetRect(rect, (short) left, (short) top, (short) (left + nWidth), (short) (top + nHeight));
		int [] gWorld = new int [1];
		OS.NewGWorldFromPtr (gWorld, OS.k32ARGBPixelFormat, bounds, 0, 0, 0, image.data, bpl);
		int [] curPort = new int [1];
		int [] curGWorld = new int [1];
		OS.GetGWorld (curPort, curGWorld);	
		OS.SetGWorld (gWorld [0], curGWorld [0]);
		int portBitMap = OS.GetPortBitMapForCopyBits (port);
		int gworldBitMap = OS.GetPortBitMapForCopyBits (gWorld [0]);
		OS.OffsetRgn(visibleRgn, portRect.left, portRect.top);
		OS.CopyBits (gworldBitMap, portBitMap, bounds, rect, (short) OS.notSrcXor, visibleRgn);
		OS.OffsetRgn(visibleRgn, (short) -portRect.left, (short) -portRect.top);
		OS.SetGWorld (curPort [0], curGWorld [0]);
		OS.DisposeGWorld (gWorld [0]);
	}
	OS.SetClip (oldClip);
	OS.DisposeRgn (visibleRgn);
	OS.DisposeRgn (oldClip);
	OS.SetPort (currentPort [0]);
	return true;
}

/**
 * Returns a rectangle describing the receiver's size and location
 * relative to its parent (or its display if its parent is null).
 *
 * @return the receiver's bounding rectangle
 *
 * @exception SWTException <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 Rectangle getBounds () {
	checkWidget();
	if (image != null) {
		Rectangle rect = image.getBounds ();
		return new Rectangle (x, y, rect.width, rect.height);
	} else {
		if (width == 0) {
			return new Rectangle (x, y, DEFAULT_WIDTH, height);
		}
	}
	return new Rectangle (x, y, width, height);
}

/**
 * Returns the font that the receiver will use to paint textual information.
 *
 * @return the receiver's font
 *
 * @exception SWTException <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 Font getFont () {
	checkWidget();
	if (font != null) return font;
	return parent.getFont ();
}

/**
 * Returns the image that the receiver will use to paint the caret.
 *
 * @return the receiver's image
 *
 * @exception SWTException <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 Image getImage () {
	checkWidget();
	return image;
}

/**
 * Returns a point describing the receiver's location relative
 * to its parent (or its display if its parent is null).
 *
 * @return the receiver's location
 *
 * @exception SWTException <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 Point getLocation () {
	checkWidget();
	return new Point (x, y);
}

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

/**
 * Returns a point describing the receiver's size.
 *
 * @return the receiver's size
 *
 * @exception SWTException <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 Point getSize () {
	checkWidget();
	if (image != null) {
		Rectangle rect = image.getBounds ();
		return new Point (rect.width, rect.height);
	} else {
		if (width == 0) {
			return new Point (DEFAULT_WIDTH, height);
		}
	}
	return new Point (width, height);
}

/**
 * Returns <code>true</code> if the receiver is visible, and
 * <code>false</code> otherwise.
 * <p>
 * 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.
 * </p>
 *
 * @return the receiver's visibility state
 *
 * @exception SWTException <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 boolean getVisible () {
	checkWidget();
	return isVisible;
}

boolean hideCaret () {
	if (!isShowing) return true;
	isShowing = false;
	return drawCaret ();
}

/**
 * Returns <code>true</code> if the receiver is visible and all
 * of the receiver's ancestors are visible and <code>false</code>
 * otherwise.
 *
 * @return the receiver's visibility state
 *
 * @exception SWTException <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 #getVisible
 */
public boolean isVisible () {
	checkWidget();
	return isVisible && parent.isVisible () && parent.hasFocus ();
}

boolean isFocusCaret () {
	return this == display.currentCaret;
}

void killFocus () {
	if (display.currentCaret != this) return;
	display.setCurrentCaret (null);
	if (isVisible) hideCaret ();
}

void releaseParent () {
	super.releaseParent ();
	if (this == parent.getCaret ()) parent.setCaret (null);
}

void releaseWidget () {
	super.releaseWidget ();
	if (display.currentCaret == this) {
		hideCaret ();
		display.setCurrentCaret (null);
	}
	parent = null;
	image = null;
}

/**
 * Sets the receiver's size and location to the rectangular
 * area specified by the arguments. The <code>x</code> and 
 * <code>y</code> arguments are relative to the receiver's
 * parent (or its display if its parent is null).
 *
 * @param x the new x coordinate for the receiver
 * @param y the new y coordinate for the receiver
 * @param width the new width for the receiver
 * @param height the new height for the receiver
 *
 * @exception SWTException <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 setBounds (int x, int y, int width, int height) {
	checkWidget();
	if (this.x == x && this.y == y && this.width == width && this.height == height) return;
	boolean isFocus = isFocusCaret ();
	if (isFocus && isVisible) hideCaret ();
	this.x = x;
	this.y = y;
	this.width = width;
	this.height = height;
	if (isFocus && isVisible) showCaret ();
}

/**
 * Sets the receiver's size and location to the rectangular
 * area specified by the argument. The <code>x</code> and 
 * <code>y</code> fields of the rectangle are relative to
 * the receiver's parent (or its display if its parent is null).
 *
 * @param rect the new bounds for the receiver
 *
 * @exception SWTException <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 setBounds (Rectangle rect) {
	checkWidget();
	if (rect == null) error (SWT.ERROR_NULL_ARGUMENT);
	setBounds (rect.x, rect.y, rect.width, rect.height);
}

void setFocus () {
	if (display.currentCaret == this) return;
	display.setCurrentCaret (this);
	if (isVisible) showCaret ();
}

/**
 * Sets the font that the receiver will use to paint textual information
 * to the font specified by the argument, or to the default font for that
 * kind of control if the argument is null.
 *
 * @param font the new font (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the font has been disposed</li>
 * </ul> 
 * @exception SWTException <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 setFont (Font font) {
	checkWidget();
	if (font != null && font.isDisposed ()) {
		error (SWT.ERROR_INVALID_ARGUMENT);
	}
	this.font = font;
}

/**
 * Sets the image that the receiver will use to paint the caret
 * to the image specified by the argument, or to the default
 * which is a filled rectangle if the argument is null
 *
 * @param image the new image (or null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 * </ul> 
 * @exception SWTException <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 setImage (Image image) {
	checkWidget();
	if (image != null && image.isDisposed ()) {
		error (SWT.ERROR_INVALID_ARGUMENT);
	}
	boolean isFocus = isFocusCaret ();
	if (isFocus && isVisible) hideCaret ();
	this.image = image;
	if (isFocus && isVisible) showCaret ();
}

/**
 * Sets the receiver's location to the point specified by
 * the arguments which are relative to the receiver's
 * parent (or its display if its parent is null).
 *
 * @param x the new x coordinate for the receiver
 * @param y the new y coordinate for the receiver
 *
 * @exception SWTException <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 setLocation (int x, int y) {
	checkWidget();
	setBounds (x, y, width, height);
}

/**
 * Sets the receiver's location to the point specified by
 * the argument which is relative to the receiver's
 * parent (or its display if its parent is null).
 *
 * @param location the new location for the receiver
 *
 * @exception SWTException <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 setLocation (Point location) {
	checkWidget();
	if (location == null) error (SWT.ERROR_NULL_ARGUMENT);
	setLocation (location.x, location.y);
}

/**
 * Sets the receiver's size to the point specified by the arguments.
 *
 * @param width the new width for the receiver
 * @param height the new height for the receiver
 *
 * @exception SWTException <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 setSize (int width, int height) {
	checkWidget();
	setBounds (x, y, width, height);
}

/**
 * Sets the receiver's size to the point specified by the argument.
 *
 * @param size the new extent for the receiver
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point is null</li>
 * </ul>
 * @exception SWTException <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 setSize (Point size) {
	checkWidget();
	if (size == null) error (SWT.ERROR_NULL_ARGUMENT);
	setSize (size.x, size.y);
}

/**
 * Marks the receiver as visible if the argument is <code>true</code>,
 * and marks it invisible otherwise. 
 * <p>
 * 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.
 * </p>
 *
 * @param visible the new visibility state
 *
 * @exception SWTException <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 setVisible (boolean visible) {
	checkWidget();
	if (visible == isVisible) return;
	isVisible = visible;
	if (!isFocusCaret ()) return;
	if (isVisible) {
		showCaret ();
	} else {
		hideCaret ();
	}
}

boolean showCaret () {
	if (isShowing) return true;
	isShowing = true;
	return drawCaret ();
}

}