/*******************************************************************************
 * 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.wpf.*;
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;
	int imageHandle;
	boolean isVisible;
	Image image;
	Font font;

/**
 * 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 ();
}

void createWidget () {
	createHandle ();
	if (parent.getCaret () == null) {
		parent.setCaret (this);
	}
}

void createHandle() {
	handle = OS.gcnew_StackPanel ();
	//handle = OS.gcnew_ContentControl ();
	if (handle == 0) error (SWT.ERROR_NO_HANDLES);
	
	int animation = OS.gcnew_DoubleAnimationUsingKeyFrames ();
	if (animation == 0) error (SWT.ERROR_NO_HANDLES);
	int timespan = OS.gcnew_TimeSpan (6000000);
	if (timespan == 0) error (SWT.ERROR_NO_HANDLES);
	int duration = OS.gcnew_Duration (timespan);
	if (duration == 0) error (SWT.ERROR_NO_HANDLES);
	int repeatBehavior = OS.RepeatBehavior_Forever();
	
	OS.Timeline_AutoReverse(animation, true);	
	OS.Timeline_Duration(animation, duration);
	OS.Timeline_RepeatBehavior(animation, repeatBehavior);
	int keyFrames = OS.DoubleAnimationUsingKeyFrames_KeyFrames(animation);
	int keyTime = OS.KeyTime_Uniform();
	int keyFrame0 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
	int keyFrame1 = OS.gcnew_DiscreteDoubleKeyFrame(0, keyTime);
	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame0);
	OS.DoubleKeyFrameCollection_Add(keyFrames, keyFrame1);
	int opacityProperty = OS.UIElement_OpacityProperty();
	OS.UIElement_BeginAnimation(handle, opacityProperty, animation);
	
	int brush = OS.SystemColors_ControlTextBrush ();
	OS.Panel_Background(handle, brush);
	
	imageHandle = OS.gcnew_Image ();
	if (imageHandle == 0) error (SWT.ERROR_NO_HANDLES);
	OS.Image_Stretch (imageHandle, OS.Stretch_None);
	OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);
	
	int children = OS.Panel_Children (handle);
	OS.UIElementCollection_Add (children, imageHandle);
	OS.GCHandle_Free (children);
	hide ();
	OS.GCHandle_Free(brush);
	OS.GCHandle_Free(opacityProperty);
	OS.GCHandle_Free(keyFrames);
	OS.GCHandle_Free(keyTime);
	OS.GCHandle_Free(keyFrame0);
	OS.GCHandle_Free(keyFrame1);
	OS.GCHandle_Free(animation);
	OS.GCHandle_Free(duration);
	OS.GCHandle_Free(timespan);
	OS.GCHandle_Free(repeatBehavior);
}

/**
 * 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);
	}
	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 parent.display.systemFont;
	}
	return font;
}

/**
 * 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);
	}
	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 hasFocus () {	
	return OS.UIElement_IsKeyboardFocused (parent.handle);
}

boolean isFocusCaret () {
	return parent.caret == this && hasFocus ();
}

/**
 * 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 OS.UIElement_IsVisible (handle) && parent.isVisible () && hasFocus ();
}

void hide () {
	OS.UIElement_Visibility (handle, OS.Visibility_Collapsed);
} 

void move (int x, int y) {
	OS.Canvas_SetLeft (handle, x);
	OS.Canvas_SetTop (handle, y);
}

void releaseHandle() {
	if (handle != 0) OS.GCHandle_Free (handle);
	handle = 0;
	if (imageHandle != 0) OS.GCHandle_Free (imageHandle);
	imageHandle = 0; 
	super.releaseHandle ();
}

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

void releaseWidget () {
	super.releaseWidget ();
	parent = null;
	image = null;
	font = null;
}

void resize (int width, int height) {
	if (image != null) {
		Rectangle rect = image.getBounds();
		width = rect.width;
		height = rect.height;
	}
	if (width == 0) width = 1;
	OS.FrameworkElement_Width (handle, width);
	OS.FrameworkElement_Height (handle, height);
}

/**
 * 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();
	boolean samePosition = this.x == x && this.y == y;
	boolean sameExtent = this.width == width && this.height == height;
	if (samePosition && sameExtent) return;
	this.x = x;  this.y = y;
	this.width = width;  this.height = height;
	if (!sameExtent) resize (width, height);
	if (!samePosition) move (x, y);
}

/**
 * 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) {
	if (rect == null) error (SWT.ERROR_NULL_ARGUMENT);
	setBounds (rect.x, rect.y, rect.width, rect.height);
}

void show () {
	OS.UIElement_Visibility (handle, OS.Visibility_Visible);
}

/**
 * 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);
	}
	this.image = image;
	if (image != null) {
		OS.Image_Source (imageHandle, image.handle);
		OS.UIElement_Visibility (imageHandle, OS.Visibility_Visible);
	} else {
		OS.Image_Source (imageHandle, 0);
		OS.UIElement_Visibility (imageHandle, OS.Visibility_Collapsed);
	}
	resize (width, height);
}

/**
 * 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();
	if (this.x == x && this.y == y) return;
	this.x = x;  this.y = y;
	move (x, y);
}

/**
 * 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();
	if (this.width == width && this.height == height) return;
	this.width = width;  this.height = height;
	resize (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 (!hasFocus()) return;
	OS.UIElement_Visibility(handle, visible ? OS.Visibility_Visible : OS.Visibility_Hidden);
}

}