/*******************************************************************************
* Copyright (c) 2000, 2005 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.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Font;
/**
* 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 SWT graphics calls or are handled by native
* methods.
* </p>
*
* @see Composite
*/
public class Canvas extends Composite {
Caret caret;
/**
* Prevents uninitialized instances from being created outside the package.
* @j2sIgnore
*/
Canvas() {
}
/**
* 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>
* </ul>
*
* @see SWT
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public Canvas(Composite parent, int style) {
super (parent, style);
}
/*
* Not currently used.
*/
void clearArea(int x, int y, int width, int height) {
checkWidget();
/*
if (OS.IsWindowVisible (handle)) return;
RECT rect = new RECT ();
OS.SetRect (rect, x, y, x + width, y + height);
int hDC = OS.GetDCEx (handle, 0, OS.DCX_CACHE | OS.DCX_CLIPCHILDREN | OS.DCX_CLIPSIBLINGS);
drawBackground (hDC, rect);
OS.ReleaseDC (handle, hDC);
*/
}
/**
* 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
*
* @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 Caret getCaret() {
checkWidget();
return caret;
}
protected void releaseWidget() {
if (caret != null)
caret.releaseResources();
caret = null;
super .releaseWidget();
}
/**
* 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 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 scroll(int destX, int destY, int x, int y, int width,
int height, boolean all) {
checkWidget();
forceResize();
/*
boolean isFocus = caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
RECT sourceRect = new RECT ();
OS.SetRect (sourceRect, x, y, x + width, y + height);
RECT clientRect = new RECT ();
OS.GetClientRect (handle, clientRect);
if (OS.IntersectRect (clientRect, sourceRect, clientRect)) {
if (OS.IsWinCE) {
OS.UpdateWindow (handle);
} else {
int flags = OS.RDW_UPDATENOW | OS.RDW_ALLCHILDREN;
OS.RedrawWindow (handle, null, 0, flags);
}
}
int deltaX = destX - x, deltaY = destY - y;
int flags = OS.SW_INVALIDATE | OS.SW_ERASE;
/*
* Feature in Windows. If any child in the widget tree partially
* intersects the scrolling rectangle, Windows moves the child
* and copies the bits that intersect the scrolling rectangle but
* does not redraw the child.
*
* Feature in Windows. When any child in the widget tree does not
* intersect the scrolling rectangle but the parent does intersect,
* Windows does not move the child. This is the documented (but
* strange) Windows behavior.
*
* The fix is to not use SW_SCROLLCHILDREN and move the children
* explicitly after scrolling.
*-/
// if (all) flags |= OS.SW_SCROLLCHILDREN;
OS.ScrollWindowEx (handle, deltaX, deltaY, sourceRect, null, 0, null, flags);
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 ();
*/
}
/**
* 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 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 setCaret(Caret caret) {
checkWidget();
Caret newCaret = caret;
//Caret oldCaret = this.caret;
this .caret = newCaret;
/*
if (isFocusControl ()) {
if (oldCaret != null) oldCaret.killFocus ();
if (newCaret != null) {
if (newCaret.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
newCaret.setFocus ();
}
}
*/
}
public void setFont(Font font) {
checkWidget();
if (caret != null)
caret.setFont(font);
super .setFont(font);
}
/*
LRESULT WM_INPUTLANGCHANGE (int wParam, int lParam) {
LRESULT result = super.WM_INPUTLANGCHANGE (wParam, lParam);
if (caret != null && caret.isFocusCaret ()) {
caret.setIMEFont ();
caret.resizeIME ();
}
return result;
}
LRESULT WM_KILLFOCUS (int wParam, int lParam) {
LRESULT result = super.WM_KILLFOCUS (wParam, lParam);
if (caret != null) caret.killFocus ();
return result;
}
LRESULT WM_SETFOCUS (int wParam, int lParam) {
LRESULT result = super.WM_SETFOCUS (wParam, lParam);
if (caret != null) caret.setFocus ();
return result;
}
LRESULT WM_SIZE (int wParam, int lParam) {
LRESULT result = super.WM_SIZE (wParam, lParam);
if (caret != null && caret.isFocusCaret ()) caret.resizeIME ();
return result;
}
LRESULT WM_WINDOWPOSCHANGED (int wParam, int lParam) {
LRESULT result = super.WM_WINDOWPOSCHANGED (wParam, lParam);
if (result != null) return result;
/*
* Bug in Windows. When a window with style WS_EX_LAYOUTRTL
* that contains a caret is resized, Windows does not move the
* caret in relation to the mirrored origin in the top right.
* The fix is to hide the caret in WM_WINDOWPOSCHANGING and
* show the caret in WM_WINDOWPOSCHANGED.
*-/
boolean isFocus = (style & SWT.RIGHT_TO_LEFT) != 0 && caret != null && caret.isFocusCaret ();
if (isFocus) caret.setFocus ();
return result;
}
LRESULT WM_WINDOWPOSCHANGING (int wParam, int lParam) {
LRESULT result = super.WM_WINDOWPOSCHANGING (wParam, lParam);
if (result != null) return result;
/*
* Bug in Windows. When a window with style WS_EX_LAYOUTRTL
* that contains a caret is resized, Windows does not move the
* caret in relation to the mirrored origin in the top right.
* The fix is to hide the caret in WM_WINDOWPOSCHANGING and
* show the caret in WM_WINDOWPOSCHANGED.
*-/
boolean isFocus = (style & SWT.RIGHT_TO_LEFT) != 0 && caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
return result;
}
*/
}
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