/*******************************************************************************
* 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.graphics.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.*;
/**
* 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
* @see <a href="http://www.eclipse.org/swt/snippets/#canvas">Canvas snippets</a>
* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ControlExample</a>
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
*/
public class Canvas extends Composite {
Caret caret;
IME ime;
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, checkStyle (style));
}
/**
* Fills the interior of the rectangle specified by the arguments,
* with the receiver's background.
*
* @param gc the gc where the rectangle is to be filled
* @param x the x coordinate of the rectangle to be filled
* @param y the y coordinate of the rectangle to be filled
* @param width the width of the rectangle to be filled
* @param height the height of the rectangle to be filled
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the gc is null</li>
* <li>ERROR_INVALID_ARGUMENT - if the gc 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>
*
* @since 3.2
*/
public void drawBackground (GC gc, int x, int y, int width, int height) {
checkWidget ();
if (gc == null) error (SWT.ERROR_NULL_ARGUMENT);
if (gc.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
super.drawBackground (gc, x, y, width, height);
}
/**
* 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 for the receiver, may be 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 Caret getCaret () {
checkWidget();
return caret;
}
Point getIMCaretPos () {
if (caret == null) return super.getIMCaretPos ();
return new Point (caret.x, caret.y);
}
/**
* Returns the IME.
*
* @return the IME
*
* @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>
*
* @since 3.4
*/
public IME getIME () {
checkWidget ();
return ime;
}
int /*long*/ gtk_button_press_event (int /*long*/ widget, int /*long*/ event) {
if (ime != null) {
int /*long*/ result = ime.gtk_button_press_event (widget, event);
if (result != 0) return result;
}
return super.gtk_button_press_event (widget, event);
}
int /*long*/ gtk_commit (int /*long*/ imcontext, int /*long*/ text) {
if (ime != null) {
int /*long*/ result = ime.gtk_commit (imcontext, text);
if (result != 0) return result;
}
return super.gtk_commit (imcontext, text);
}
int /*long*/ gtk_expose_event (int /*long*/ widget, int /*long*/ event) {
if ((state & OBSCURED) != 0) return 0;
boolean isFocus = caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
int /*long*/ result = super.gtk_expose_event (widget, event);
if (isFocus) caret.setFocus ();
return result;
}
int /*long*/ gtk_focus_in_event (int /*long*/ widget, int /*long*/ event) {
int /*long*/ result = super.gtk_focus_in_event (widget, event);
if (caret != null) caret.setFocus ();
return result;
}
int /*long*/ gtk_focus_out_event (int /*long*/ widget, int /*long*/ event) {
int /*long*/ result = super.gtk_focus_out_event (widget, event);
if (caret != null) caret.killFocus ();
return result;
}
int /*long*/ gtk_preedit_changed (int /*long*/ imcontext) {
if (ime != null) {
int /*long*/ result = ime.gtk_preedit_changed (imcontext);
if (result != 0) return result;
}
return super.gtk_preedit_changed (imcontext);
}
void redrawWidget (int x, int y, int width, int height, boolean redrawAll, boolean all, boolean trim) {
boolean isFocus = caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
super.redrawWidget (x, y, width, height, redrawAll, all, trim);
if (isFocus) caret.setFocus ();
}
void releaseChildren (boolean destroy) {
if (caret != null) {
caret.release (false);
caret = null;
}
if (ime != null) {
ime.release (false);
ime = null;
}
super.releaseChildren (destroy);
}
/**
* 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();
if (width <= 0 || height <= 0) return;
if ((style & SWT.MIRRORED) != 0) {
int clientWidth = getClientWidth ();
x = clientWidth - width - x;
destX = clientWidth - width - destX;
}
int deltaX = destX - x, deltaY = destY - y;
if (deltaX == 0 && deltaY == 0) return;
if (!isVisible ()) return;
boolean isFocus = caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
int /*long*/ window = paintWindow ();
int /*long*/ visibleRegion = OS.gdk_drawable_get_visible_region (window);
GdkRectangle srcRect = new GdkRectangle ();
srcRect.x = x;
srcRect.y = y;
srcRect.width = width;
srcRect.height = height;
int /*long*/ copyRegion = OS.gdk_region_rectangle (srcRect);
OS.gdk_region_intersect(copyRegion, visibleRegion);
int /*long*/ invalidateRegion = OS.gdk_region_rectangle (srcRect);
OS.gdk_region_subtract (invalidateRegion, visibleRegion);
OS.gdk_region_offset (invalidateRegion, deltaX, deltaY);
GdkRectangle copyRect = new GdkRectangle();
OS.gdk_region_get_clipbox (copyRegion, copyRect);
if (copyRect.width != 0 && copyRect.height != 0) {
update ();
}
Control control = findBackgroundControl ();
if (control == null) control = this;
if (control.backgroundImage != null) {
redrawWidget (x, y, width, height, false, false, false);
redrawWidget (destX, destY, width, height, false, false, false);
} else {
// GC gc = new GC (this);
// gc.copyArea (x, y, width, height, destX, destY);
// gc.dispose ();
int /*long*/ gdkGC = OS.gdk_gc_new (window);
OS.gdk_gc_set_exposures (gdkGC, true);
OS.gdk_draw_drawable (window, gdkGC, window, copyRect.x, copyRect.y, copyRect.x + deltaX, copyRect.y + deltaY, copyRect.width, copyRect.height);
OS.g_object_unref (gdkGC);
boolean disjoint = (destX + width < x) || (x + width < destX) || (destY + height < y) || (y + height < destY);
if (disjoint) {
GdkRectangle rect = new GdkRectangle ();
rect.x = x;
rect.y = y;
rect.width = width;
rect.height = height;
OS.gdk_region_union_with_rect (invalidateRegion, rect);
} else {
GdkRectangle rect = new GdkRectangle ();
if (deltaX != 0) {
int newX = destX - deltaX;
if (deltaX < 0) newX = destX + width;
rect.x = newX;
rect.y = y;
rect.width = Math.abs(deltaX);
rect.height = height;
OS.gdk_region_union_with_rect (invalidateRegion, rect);
}
if (deltaY != 0) {
int newY = destY - deltaY;
if (deltaY < 0) newY = destY + height;
rect.x = x;
rect.y = newY;
rect.width = width;
rect.height = Math.abs(deltaY);
OS.gdk_region_union_with_rect (invalidateRegion, rect);
}
}
OS.gdk_window_invalidate_region(window, invalidateRegion, all);
OS.gdk_region_destroy (visibleRegion);
OS.gdk_region_destroy (copyRegion);
OS.gdk_region_destroy (invalidateRegion);
}
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 ();
}
int setBounds (int x, int y, int width, int height, boolean move, boolean resize) {
boolean isFocus = caret != null && caret.isFocusCaret ();
if (isFocus) caret.killFocus ();
int result = super.setBounds (x, y, width, height, move, resize);
if (isFocus) caret.setFocus ();
return result;
}
/**
* 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 (hasFocus ()) {
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);
}
/**
* Sets the receiver's IME.
*
* @param ime the new IME for the receiver, may be null
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the IME 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>
*
* @since 3.4
*/
public void setIME (IME ime) {
checkWidget ();
if (ime != null && ime.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
this.ime = ime;
}
void updateCaret () {
int /*long*/ imHandle = imHandle ();
if (imHandle == 0) return;
GdkRectangle rect = new GdkRectangle ();
rect.x = caret.x;
rect.y = caret.y;
rect.width = caret.width;
rect.height = caret.height;
OS.gtk_im_context_set_cursor_location (imHandle, rect);
}
}
