Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2009 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 <em>not</em> intended to be subclassed. * </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); } }