path: root/bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Caret.java

package org.eclipse.swt.widgets;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved
 */

import org.eclipse.swt.internal.motif.*;
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>
 */

public /*final*/ class Caret extends Widget {
	Canvas parent;
	int x, y, width, height;
	boolean moved, resized;
	boolean isVisible, isShowing;
	int blinkRate = 500;
/**
 * 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
 * for all SWT widget classes should include a comment which
 * describes the style constants which are applicable to the class.
 * </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 (0);
}
boolean blinkCaret () {
	if (!isVisible) return true;
	if (!isShowing) return showCaret ();
	if (blinkRate == 0) return true;
	return hideCaret ();
}
void createWidget (int index) {
	super.createWidget (index);
	isVisible = true;
	if (parent.getCaret () == null) {
		parent.setCaret (this);
	}
}
boolean drawCaret () {
	if (parent == null) return false;
	if (parent.isDisposed ()) return false;
	int handle = parent.handle;
	int window = OS.XtWindow (handle);
	if (window == 0) return false;
	int xDisplay = OS.XtDisplay (handle);
	int gc = OS.XCreateGC (xDisplay, window, 0, null);
	int [] argList = {OS.XmNforeground, 0, OS.XmNbackground, 0};
	OS.XtGetValues (handle, argList, argList.length / 2);
	int foreground = argList [1];
	int background = argList [3];
	int color = foreground ^ background;
	OS.XSetFunction (xDisplay, gc, OS.GXxor);
	OS.XSetForeground (xDisplay, gc, color);
	int nWidth = width;
	if (nWidth <= 0) nWidth = 2;
	OS.XFillRectangle (xDisplay, window, gc, x, y, nWidth, height);
	OS.XFreeGC (xDisplay, gc);
	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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	return new Rectangle (x, y, width, height);
}
/**
* Gets the Display.
*/
public Display getDisplay () {
	Composite parent = this.parent;
	if (parent == null) error (SWT.ERROR_WIDGET_DISPOSED);
	return parent.getDisplay ();
}
/**
 * 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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	return parent.getFont ();
}
/**
 * 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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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 () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	return isVisible;
}
boolean hideCaret () {
	Display display = getDisplay ();
	if (display.currentCaret != this) return false;
	if (!isShowing) return true;
	isShowing = false;
	return drawCaret ();
}
/**
 * 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 isVisible () {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	return isVisible && parent.isVisible () && parent.hasFocus ();
}
boolean isFocusCaret () {
	Display display = getDisplay ();
	return this == display.currentCaret;
}
void killFocus () {
	Display display = getDisplay ();
	if (display.currentCaret != this) return;
	if (isVisible) hideCaret ();
	display.setCurrentCaret (null);
}
void releaseChild () {
	super.releaseChild ();
	if (this == parent.getCaret ()) parent.setCaret (null);
}
void releaseWidget () {
	super.releaseWidget ();
	Display display = getDisplay ();
	if (display.currentCaret == this) {
		if (isVisible) hideCaret ();
		display.setCurrentCaret (null);
	}
	parent = 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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	boolean samePosition, sameExtent, showing;
	samePosition = (this.x == x) && (this.y == y);
	sameExtent = (this.width == width) && (this.height == height);
	if ((samePosition) && (sameExtent)) return;
	if (isShowing) hideCaret ();
	this.x = x; this.y = y;
	this.width = width; this.height = height;
	if (sameExtent) {
			moved = true;
			if (isVisible ()) {
				moved = false;
				//IsDBLocale ifTrue: [
				//widget == nil ifFalse: [widget updateCaret]].
			}
	} else {
			resized = true;
			if (isVisible ()) {
				moved = false;
				//IsDBLocale ifTrue: [
				//widget == nil ifFalse: [widget updateCaret]].
				resized = false;
			}
	}
	if (isShowing) 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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	if (rect == null) error (SWT.ERROR_NULL_ARGUMENT);
	setBounds (rect.x, rect.y, rect.width, rect.height);
}
void setFocus () {
	Display display = getDisplay ();
	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 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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
}
/**
 * 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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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
 * @param height the new height 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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
	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) {
	if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
	if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);	
	if (visible == isVisible) return;
	if (isVisible = visible) {
		showCaret ();
	} else {
		hideCaret ();
	}
}
boolean showCaret () {
	if (getDisplay ().currentCaret != this) return false;
	if (isShowing) return true;
	isShowing = true;
	return drawCaret ();
}
}