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• Composite.java

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org.eclipse.swt.widgets.Composite Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright (c) 2000, 2020 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import java.util.*;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.*;
import org.eclipse.swt.internal.cairo.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.internal.gtk3.*;
import org.eclipse.swt.internal.gtk4.*;

/**
 * Instances of this class are controls which are capable
 * of containing other controls.
 * 

 * 
Styles:
 * 
NO_BACKGROUND, NO_FOCUS, NO_MERGE_PAINTS, NO_REDRAW_RESIZE, NO_RADIO_GROUP, EMBEDDED, DOUBLE_BUFFERED
 * 
Events:
 * 
(none)
 * 
 * 

 * Note: The NO_BACKGROUND, NO_FOCUS, NO_MERGE_PAINTS,
 * and NO_REDRAW_RESIZE styles are intended for use with Canvas.
 * They can be used with Composite if you are drawing your own, but their
 * behavior is undefined if they are used with subclasses of Composite other
 * than Canvas.
 * 

 * Note: The CENTER style, although undefined for composites, has the
 * same value as EMBEDDED which is used to embed widgets from other
 * widget toolkits into SWT.  On some operating systems (GTK), this may cause
 * the children of this composite to be obscured.
 * 

 * This class may be subclassed by custom control implementors
 * who are building controls that are constructed from aggregates
 * of other controls.
 * 
 *
 * @see Canvas
 * @see Composite snippets
 * @see Sample code and further information
 */
public class Composite extends Scrollable {
	/**
	 * the handle to the OS resource
	 * (Warning: This field is platform dependent)
	 * 

	 * IMPORTANT: This field is not part of the SWT
	 * public API. It is marked public only so that it can be shared
	 * within the packages provided by SWT. It is not available on all
	 * platforms and should never be accessed from application code.
	 * 
	 *
	 * @noreference This field is not intended to be referenced by clients.
	 */
	public long  embeddedHandle;
	long imHandle, socketHandle;
	Layout layout;
	Control[] tabList;
	int layoutCount, backgroundMode;
	/**
	 * When this field is set, it indicates that a child widget of this Composite
	 * needs to have its clip set to its allocation. This is because on GTK3.20+
	 * some widgets (like Combo) have their clips merged with that of their parent.
	 */
	long fixClipHandle;
	/**
	 * If fixClipHandle is set, then the fixClipMap HashMap contains children
	 * of fixClipHandle that also need to have their clips adjusted.
	 *
	 * 
Each key is a Control which needs to have its clip adjusted, and each value
	 * is an array of handles (descendants of the Control) ordered by widget hierarchy.
	 * This array will be traversed in-order to adjust the clipping of each element.
	 * See bug 500703 and 535323.
	 */
	Map fixClipMap = new HashMap<> ();

	static final String NO_INPUT_METHOD = "org.eclipse.swt.internal.gtk.noInputMethod"; //$NON-NLS-1$
	Shell popupChild;
	/**
	 * If set to {@code true}, child widgets with negative y coordinate GTK allocation
	 * will not be drawn. Only relevant if such child widgets are being
	 * drawn via propagateDraw(), such as Tree/Table editing widgets.
	 *
	 * See bug 535978 and bug 547986.
	 */
	boolean noChildDrawing = false;
	/**
	 * A HashMap of child widgets that keeps track of which child has had their
	 * GdkWindow lowered/raised. Only relevant if such child widgets are being
	 * drawn via propagateDraw(), such as Tree/Table editing widgets.
	 *
	 * See bug 535978.
	 */
	HashMap childrenLowered = new HashMap<>();

Composite () {
	/* Do nothing */
}

/**
 * Constructs a new instance of this class given its parent
 * and a style value describing its behavior and appearance.
 * 

 * The style value is either one of the style constants defined in
 * class SWT which is applicable to instances of this
 * class, or must be built by bitwise OR'ing together
 * (that is, using the int "|" operator) two or more
 * of those SWT style constants. The class description
 * lists the style constants that are applicable to the class.
 * Style bits are also inherited from superclasses.
 * 
 *
 * @param parent a widget which will be the parent of the new instance (cannot be null)
 * @param style the style of widget to construct
 *
 * @exception IllegalArgumentException 

 *    
ERROR_NULL_ARGUMENT - if the parent is null
 * 
 * @exception SWTException 

 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
 * 
 *
 * @see SWT#NO_BACKGROUND
 * @see SWT#NO_FOCUS
 * @see SWT#NO_MERGE_PAINTS
 * @see SWT#NO_REDRAW_RESIZE
 * @see SWT#NO_RADIO_GROUP
 * @see SWT#EMBEDDED
 * @see SWT#DOUBLE_BUFFERED
 * @see Widget#getStyle
 */
public Composite (Composite parent, int style) {
	super (parent, checkStyle (style));
	/*
	 * Cache the NO_BACKGROUND flag for use in the Cairo setRegion()
	 * implementation. Only relevant to GTK3.10+, see bug 475784.
	 */
	if ((style & SWT.NO_BACKGROUND) != 0) {
		cachedNoBackground = true;
	}
}

static int checkStyle (int style) {
	style &= ~SWT.NO_BACKGROUND;
	style &= ~SWT.TRANSPARENT;
	return style;
}

Control[] _getChildren () {
	long parentHandle = parentingHandle();

	if (GTK.GTK4) {
		ArrayList childrenList = new ArrayList<>();
		for (long child = GTK4.gtk_widget_get_first_child(parentHandle); child != 0; child = GTK4.gtk_widget_get_next_sibling(child)) {
			Widget childWidget = display.getWidget(child);
			if (childWidget != null && childWidget instanceof Control && childWidget != this) {
				childrenList.add((Control)childWidget);
			}
		}

		return childrenList.toArray(new Control[childrenList.size()]);
	} else {
		long list = GTK3.gtk_container_get_children (parentHandle);
		if (list == 0) return new Control [0];
		int count = OS.g_list_length (list);
		Control [] children = new Control [count];
		int i = 0;
		long temp = list;
		while (temp != 0) {
			long handle = OS.g_list_data (temp);
			if (handle != 0) {
				Widget widget = display.getWidget (handle);
				if (widget != null && widget != this) {
					if (widget instanceof Control) {
						children [i++] = (Control) widget;
					}
				}
			}
			temp = OS.g_list_next (temp);
		}
		OS.g_list_free (list);
		if (i == count) return children;
		Control [] newChildren = new Control [i];
		System.arraycopy (children, 0, newChildren, 0, i);
		return newChildren;
	}
}

Control [] _getTabList () {
	if (tabList == null) return tabList;
	int count = 0;
	for (int i=0; i
 *    
ERROR_INVALID_ARGUMENT - if the changed array is null any of its controls are null or have been disposed
 *    
ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
 * 
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @deprecated use {@link Composite#layout(Control[], int)} instead
 * @since 3.1
 */
@Deprecated
public void changed (Control[] changed) {
	layout(changed, SWT.DEFER);
}

@Override
void checkBuffered () {
	if ((style & SWT.DOUBLE_BUFFERED) == 0 && (style & SWT.NO_BACKGROUND) != 0) {
		return;
	}
	super.checkBuffered();
}

@Override
protected void checkSubclass () {
	/* Do nothing - Subclassing is allowed */
}

@Override
Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
	checkWidget ();
	display.runSkin();
	if (wHint != SWT.DEFAULT && wHint < 0) wHint = 0;
	if (hHint != SWT.DEFAULT && hHint < 0) hHint = 0;
	Point size;
	if (layout != null) {
		if (wHint == SWT.DEFAULT || hHint == SWT.DEFAULT) {
			changed |= (state & LAYOUT_CHANGED) != 0;
			size = DPIUtil.autoScaleUp(layout.computeSize (this, DPIUtil.autoScaleDown(wHint), DPIUtil.autoScaleDown(hHint), changed));
			state &= ~LAYOUT_CHANGED;
		} else {
			size = new Point (wHint, hHint);
		}
	} else {
		size = minimumSize (wHint, hHint, changed);
		if (size.x == 0) size.x = DEFAULT_WIDTH;
		if (size.y == 0) size.y = DEFAULT_HEIGHT;
	}
	if (wHint != SWT.DEFAULT) size.x = wHint;
	if (hHint != SWT.DEFAULT) size.y = hHint;
	Rectangle trim = DPIUtil.autoScaleUp (computeTrim (0, 0, DPIUtil.autoScaleDown(size.x), DPIUtil.autoScaleDown(size.y)));
	return new Point (trim.width, trim.height);
}

@Override
Widget [] computeTabList () {
	Widget result [] = super.computeTabList ();
	if (result.length == 0) return result;
	Control [] list = tabList != null ? _getTabList () : _getChildren ();
	for (int i=0; i= 4.")
							.printStackTrace ();
				}
			} else {
				socketHandle = GTK.gtk_socket_new ();
				if (socketHandle == 0) error (SWT.ERROR_NO_HANDLES);
				GTK3.gtk_container_add (handle, socketHandle);
			}
		}
	}

	if (!GTK.GTK4) {
		if ((style & SWT.NO_REDRAW_RESIZE) != 0 && (style & SWT.RIGHT_TO_LEFT) == 0) {
			GTK3.gtk_widget_set_redraw_on_allocate (handle, false);
		}
		/*
		* Bug in GTK.  When a widget is double buffered and the back
		* pixmap is null, the double buffer pixmap is filled with the
		* background of the widget rather than the current contents of
		* the screen.  If nothing is drawn during an expose event,
		* the pixels are altered.  The fix is to clear double buffering
		* when NO_BACKGROUND is set and DOUBLE_BUFFERED
		* is not explicitly set.
		*/
		if ((style & SWT.DOUBLE_BUFFERED) == 0 && (style & SWT.NO_BACKGROUND) != 0) {
			GTK3.gtk_widget_set_double_buffered (handle, false);
		}
	}
}

/**
 * Iterates though the array of child widgets that need to have their clips
 * adjusted, and calls Control.adjustChildClipping() on it.
 *
 * The default implementation in Composite is: if a child has a negative clip, adjust it.
 * Also check if the child's allocation is negative, and adjust it as necessary.
 *
 * 
If the array is empty this method just returns. See bug 500703, and 539367.
 */
void fixClippings () {
	if (fixClipHandle == 0 || fixClipMap.isEmpty()) {
		return;
	} else {
		Control [] children = _getChildren();
		for (Control child : children) {
			if (fixClipMap.containsKey(child)) {
				long [] childHandles = fixClipMap.get(child);
				for (long widget : childHandles) {
					child.adjustChildClipping(widget);
				}
			}
		}
	}
}

@Override
void adjustChildClipping (long widget) {
	GtkRequisition minimumSize = new GtkRequisition ();
	GtkRequisition naturalSize = new GtkRequisition ();
	GtkAllocation clip = new GtkAllocation ();
	GtkAllocation allocation = new GtkAllocation ();
	GTK.gtk_widget_get_allocation(widget, allocation);
	GTK3.gtk_widget_get_clip(widget, clip);
	/*
	 * If the clip is negative, add the x coordinate to the width
	 * and set the x coordinate to 0.
	 */
	if (clip.x < 0) {
		/*
		 * Some "transient" widgets like menus get allocations of
		 * {-1, -1, 1, 1}. Check to make sure this isn't the case
		 * before proceeding.
		 */
		if (allocation.x < -1 && (allocation.width > 1 || allocation.height > 1)) {
			// Adjust the allocation just like the clip, if it's negative
			allocation.width = allocation.width + allocation.x;
			allocation.x = 0;
			// Call gtk_widget_get_preferred_size() to prevent warnings
			GTK.gtk_widget_get_preferred_size(widget, minimumSize, naturalSize);
			// Allocate and queue a resize event
			gtk_widget_size_allocate(widget, allocation, -1);
			GTK.gtk_widget_queue_resize(widget);
		}
	}
	// Adjust the clip
	GTK3.gtk_widget_set_clip(widget, allocation);
}

@Override
long gtk_draw (long widget, long cairo) {
	long context = GTK.gtk_widget_get_style_context(widget);
	GtkAllocation allocation = new GtkAllocation();
	GTK.gtk_widget_get_allocation (widget, allocation);
	int width = (state & ZERO_WIDTH) != 0 ? 0 : allocation.width;
	int height = (state & ZERO_HEIGHT) != 0 ? 0 : allocation.height;
	// We specify a 0 value for x & y as we want the whole widget to be
	// colored, not some portion of it.
	GTK.gtk_render_background(context, cairo, 0, 0, width, height);
	// If fixClipHandle is set: iterate through the children of widget
	// and set their clips to be that of their allocation
	if (widget == fixClipHandle) fixClippings();
	return super.gtk_draw(widget, cairo);
}


@Override
boolean mustBeVisibleOnInitBounds() {
	// Bug 540298: if we return false, we will be invisible if the size is
	// not set, but our layout will not properly work, so that not all children
	// will be shown properly
	return true;
}

@Override
void deregister () {
	super.deregister ();
	if (socketHandle != 0) display.removeWidget (socketHandle);
}

/**
 * Fills the interior of the rectangle specified by the arguments,
 * with the receiver's background.
 *
 * 
The offsetX and offsetY are used to map from
 * the gc origin to the origin of the parent image background. This is useful
 * to ensure proper alignment of the image 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
 * @param offsetX the image background x offset
 * @param offsetY the image background y offset
 *
 * @exception IllegalArgumentException 

 *    
ERROR_NULL_ARGUMENT - if the gc is null
 *    
ERROR_INVALID_ARGUMENT - if the gc has been disposed
 * 
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.6
 */
public void drawBackground (GC gc, int x, int y, int width, int height, int offsetX, int offsetY) {
	checkWidget();
	Rectangle rect = DPIUtil.autoScaleUp(new Rectangle (x, y, width, height));
	offsetX = DPIUtil.autoScaleUp(offsetX);
	offsetY = DPIUtil.autoScaleUp(offsetY);
	drawBackgroundInPixels(gc, rect.x, rect.y, rect.width, rect.height, offsetX, offsetY);
}

void drawBackgroundInPixels (GC gc, int x, int y, int width, int height, int offsetX, int offsetY) {
	checkWidget ();
	if (gc == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (gc.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
	Control control = findBackgroundControl ();
	if (control != null) {
		GCData data = gc.getGCData ();
		long cairo = data.cairo;
		Cairo.cairo_save (cairo);
		if (control.backgroundImage != null) {
			Point pt = display.mapInPixels (this, control, 0, 0);
			Cairo.cairo_translate (cairo, -pt.x - offsetX, -pt.y - offsetY);
			x += pt.x + offsetX;
			y += pt.y + offsetY;
			long surface = control.backgroundImage.surface;
			if (surface == 0) error (SWT.ERROR_NO_HANDLES);
			Cairo.cairo_surface_reference(surface);
			long pattern = Cairo.cairo_pattern_create_for_surface (surface);
			if (pattern == 0) error (SWT.ERROR_NO_HANDLES);
			Cairo.cairo_pattern_set_extend (pattern, Cairo.CAIRO_EXTEND_REPEAT);
			if ((data.style & SWT.MIRRORED) != 0) {
				double[] matrix = {-1, 0, 0, 1, 0, 0};
				Cairo.cairo_pattern_set_matrix(pattern, matrix);
			}
			Cairo.cairo_set_source (cairo, pattern);
			Cairo.cairo_surface_destroy (surface);
			Cairo.cairo_pattern_destroy (pattern);
		} else {
			GdkRGBA rgba = control.getBackgroundGdkRGBA ();
			Cairo.cairo_set_source_rgba (cairo, rgba.red, rgba.green, rgba.blue, rgba.alpha);
		}
		Cairo.cairo_rectangle (cairo, x, y, width, height);
		Cairo.cairo_fill (cairo);
		Cairo.cairo_restore (cairo);
	} else {
		gc.fillRectangle(DPIUtil.autoScaleDown(new Rectangle(x, y, width, height)));

	}
}

@Override
void enableWidget (boolean enabled) {
	if ((state & CANVAS) != 0) return;
	super.enableWidget (enabled);
}

Composite findDeferredControl () {
	return layoutCount > 0 ? this : parent.findDeferredControl ();
}

@Override
Menu [] findMenus (Control control) {
	if (control == this) return new Menu [0];
	Menu result [] = super.findMenus (control);
	Control [] children = _getChildren ();
	for (int i=0; iSWT:
 * INHERIT_NONE, INHERIT_DEFAULT,
 * INHERIT_FORCE.
 *
 * @return the background mode
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see SWT
 *
 * @since 3.2
 */
public int getBackgroundMode () {
	checkWidget ();
	return backgroundMode;
}

/**
 * Returns a (possibly empty) array containing the receiver's children.
 * Children are returned in the order that they are drawn.  The topmost
 * control appears at the beginning of the array.  Subsequent controls
 * draw beneath this control and appear later in the array.
 * 

 * Note: This is not the actual structure used by the receiver
 * to maintain its list of children, so modifying the array will
 * not affect the receiver.
 * 
 *
 * @return an array of children
 *
 * @see Control#moveAbove
 * @see Control#moveBelow
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Control [] getChildren () {
	checkWidget();
	return _getChildren ();
}

int getChildrenCount () {
	int count = 0;

	if (GTK.GTK4) {
		for (long child = GTK4.gtk_widget_get_first_child(handle); child != 0; child = GTK4.gtk_widget_get_next_sibling(child)) {
			count++;
		}
	} else {
		/*
		* NOTE: The current implementation will count
		* non-registered children.
		*/
		long list = GTK3.gtk_container_get_children(handle);
		if (list != 0) {
			count = OS.g_list_length(list);
			OS.g_list_free(list);
		}
	}

	return count;
}

@Override
Rectangle getClientAreaInPixels () {
	checkWidget();
	if ((state & CANVAS) != 0) {
		if ((state & ZERO_WIDTH) != 0 && (state & ZERO_HEIGHT) != 0) {
			return new Rectangle (0, 0, 0, 0);
		}
		if(RESIZE_ON_GETCLIENTAREA) {
			forceResize ();
		}
		long clientHandle = clientHandle ();
		GtkAllocation allocation = new GtkAllocation();
		GTK.gtk_widget_get_allocation (clientHandle, allocation);
		int width = (state & ZERO_WIDTH) != 0 ? 0 : allocation.width;
		int height = (state & ZERO_HEIGHT) != 0 ? 0 : allocation.height;
		return new Rectangle (0, 0, width, height);
	}
	return super.getClientAreaInPixels();
}

/**
 * Returns layout which is associated with the receiver, or
 * null if one has not been set.
 *
 * @return the receiver's layout or null
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public Layout getLayout () {
	checkWidget();
	return layout;
}

/**
 * Returns true if the receiver has deferred
 * the performing of layout, and false otherwise.
 *
 * @return the receiver's deferred layout state
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #setLayoutDeferred(boolean)
 * @see #isLayoutDeferred()
 *
 * @since 3.1
 */
public boolean getLayoutDeferred () {
	checkWidget ();
	return layoutCount > 0 ;
}

/**
 * Gets the (possibly empty) tabbing order for the control.
 *
 * @return tabList the ordered list of controls representing the tab order
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #setTabList
 */
public Control [] getTabList () {
	checkWidget ();
	Control [] tabList = _getTabList ();
	if (tabList == null) {
		int count = 0;
		Control [] list =_getChildren ();
		for (int i=0; itrue if the receiver or any ancestor
 * up to and including the receiver's nearest ancestor shell
 * has deferred the performing of layouts.  Otherwise, false
 * is returned.
 *
 * @return the receiver's deferred layout state
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #setLayoutDeferred(boolean)
 * @see #getLayoutDeferred()
 *
 * @since 3.1
 */
public boolean isLayoutDeferred () {
	checkWidget ();
	return findDeferredControl () != null;
}

@Override
boolean isTabGroup() {
	if ((state & CANVAS) != 0) return true;
	return super.isTabGroup();
}

/**
 * If the receiver has a layout, asks the layout to lay out
 * (that is, set the size and location of) the receiver's children.
 * If the receiver does not have a layout, do nothing.
 * 

 * Use of this method is discouraged since it is the least-efficient
 * way to trigger a layout. The use of layout(true)
 * discards all cached layout information, even from controls which
 * have not changed. It is much more efficient to invoke
 * {@link Control#requestLayout()} on every control which has changed
 * in the layout than it is to invoke this method on the layout itself.
 * 
 * 

 * This is equivalent to calling layout(true).
 * 
 * 

 * Note: Layout is different from painting. If a child is
 * moved or resized such that an area in the parent is
 * exposed, then the parent will paint. If no child is
 * affected, the parent will not paint.
 * 
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void layout () {
	checkWidget ();
	layout (true);
}

/**
 * If the receiver has a layout, asks the layout to lay out
 * (that is, set the size and location of) the receiver's children.
 * If the argument is true the layout must not rely
 * on any information it has cached about the immediate children. If it
 * is false the layout may (potentially) optimize the
 * work it is doing by assuming that none of the receiver's
 * children has changed state since the last layout.
 * If the receiver does not have a layout, do nothing.
 * 

 * It is normally more efficient to invoke {@link Control#requestLayout()}
 * on every control which has changed in the layout than it is to invoke
 * this method on the layout itself. Clients are encouraged to use
 * {@link Control#requestLayout()} where possible instead of calling
 * this method.
 * 
 * 

 * If a child is resized as a result of a call to layout, the
 * resize event will invoke the layout of the child.  The layout
 * will cascade down through all child widgets in the receiver's widget
 * tree until a child is encountered that does not resize.  Note that
 * a layout due to a resize will not flush any cached information
 * (same as layout(false)).
 * 
 * 

 * Note: Layout is different from painting. If a child is
 * moved or resized such that an area in the parent is
 * exposed, then the parent will paint. If no child is
 * affected, the parent will not paint.
 * 
 *
 * @param changed true if the layout must flush its caches, and false otherwise
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void layout (boolean changed) {
	checkWidget ();
	if (layout == null) return;
	layout (changed, false);
}

/**
 * If the receiver has a layout, asks the layout to lay out
 * (that is, set the size and location of) the receiver's children.
 * If the changed argument is true the layout must not rely
 * on any information it has cached about its children. If it
 * is false the layout may (potentially) optimize the
 * work it is doing by assuming that none of the receiver's
 * children has changed state since the last layout.
 * If the all argument is true the layout will cascade down
 * through all child widgets in the receiver's widget tree, regardless of
 * whether the child has changed size.  The changed argument is applied to
 * all layouts.  If the all argument is false, the layout will
 * not cascade down through all child widgets in the receiver's widget
 * tree.  However, if a child is resized as a result of a call to layout, the
 * resize event will invoke the layout of the child.  Note that
 * a layout due to a resize will not flush any cached information
 * (same as layout(false)).
 * 

 * It is normally more efficient to invoke {@link Control#requestLayout()}
 * on every control which has changed in the layout than it is to invoke
 * this method on the layout itself. Clients are encouraged to use
 * {@link Control#requestLayout()} where possible instead of calling
 * this method.
 * 
 * 

 * Note: Layout is different from painting. If a child is
 * moved or resized such that an area in the parent is
 * exposed, then the parent will paint. If no child is
 * affected, the parent will not paint.
 * 
 *
 * @param changed true if the layout must flush its caches, and false otherwise
 * @param all true if all children in the receiver's widget tree should be laid out, and false otherwise
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.1
 */
public void layout (boolean changed, boolean all) {
	checkWidget ();
	if (layout == null && !all) return;
	markLayout (changed, all);
	updateLayout (all);
}

/**
 * Forces a lay out (that is, sets the size and location) of all widgets that
 * are in the parent hierarchy of the changed control up to and including the
 * receiver.  The layouts in the hierarchy must not rely on any information
 * cached about the changed control or any of its ancestors.  The layout may
 * (potentially) optimize the work it is doing by assuming that none of the
 * peers of the changed control have changed state since the last layout.
 * If an ancestor does not have a layout, skip it.
 * 

 * It is normally more efficient to invoke {@link Control#requestLayout()}
 * on every control which has changed in the layout than it is to invoke
 * this method on the layout itself. Clients are encouraged to use
 * {@link Control#requestLayout()} where possible instead of calling
 * this method.
 * 
 * 

 * Note: Layout is different from painting. If a child is
 * moved or resized such that an area in the parent is
 * exposed, then the parent will paint. If no child is
 * affected, the parent will not paint.
 * 
 *
 * @param changed a control that has had a state change which requires a recalculation of its size
 *
 * @exception IllegalArgumentException 

 *    
ERROR_INVALID_ARGUMENT - if the changed array is null any of its controls are null or have been disposed
 *    
ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
 * 
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.1
 */
public void layout (Control [] changed) {
	checkWidget ();
	if (changed == null) error (SWT.ERROR_INVALID_ARGUMENT);
	layout (changed, SWT.NONE);
}

/**
 * Forces a lay out (that is, sets the size and location) of all widgets that
 * are in the parent hierarchy of the changed control up to and including the
 * receiver.
 * 

 * The parameter flags may be a combination of:
 * 
 * 

 * 
SWT.ALL
 * 
all children in the receiver's widget tree should be laid out
 * 
SWT.CHANGED
 * 
the layout must flush its caches
 * 
SWT.DEFER
 * 
layout will be deferred
 * 
 * 

 * When the changed array is specified, the flags SWT.ALL
 * and SWT.CHANGED have no effect. In this case, the layouts in the
 * hierarchy must not rely on any information cached about the changed control or
 * any of its ancestors.  The layout may (potentially) optimize the
 * work it is doing by assuming that none of the peers of the changed
 * control have changed state since the last layout.
 * If an ancestor does not have a layout, skip it.
 * 
 * 

 * When the changed array is not specified, the flag SWT.ALL
 * indicates that the whole widget tree should be laid out. And the flag
 * SWT.CHANGED indicates that the layouts should flush any cached
 * information for all controls that are laid out.
 * 
 * 

 * The SWT.DEFER flag always causes the layout to be deferred by
 * calling Composite.setLayoutDeferred(true) and scheduling a call
 * to Composite.setLayoutDeferred(false), which will happen when
 * appropriate (usually before the next event is handled). When this flag is set,
 * the application should not call Composite.setLayoutDeferred(boolean).
 * 
 * 

 * Note: Layout is different from painting. If a child is
 * moved or resized such that an area in the parent is
 * exposed, then the parent will paint. If no child is
 * affected, the parent will not paint.
 * 
 *
 * @param changed a control that has had a state change which requires a recalculation of its size
 * @param flags the flags specifying how the layout should happen
 *
 * @exception IllegalArgumentException 

 *    
ERROR_INVALID_ARGUMENT - if any of the controls in changed is null or has been disposed
 *    
ERROR_INVALID_PARENT - if any control in changed is not in the widget tree of the receiver
 * 
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @since 3.6
 */
public void layout (Control [] changed, int flags) {
	checkWidget ();
	if (changed != null) {
		for (int i=0; i=0; i--) {
			update [i].updateLayout (false);
		}
	} else {
		if (layout == null && (flags & SWT.ALL) == 0) return;
		markLayout ((flags & SWT.CHANGED) != 0, (flags & SWT.ALL) != 0);
		if (!display.externalEventLoop && (flags & SWT.DEFER) != 0) {
			setLayoutDeferred (true);
			display.addLayoutDeferred (this);
		}
		updateLayout ((flags & SWT.ALL) != 0);
	}
}

@Override
void markLayout (boolean changed, boolean all) {
	if (layout != null) {
		state |= LAYOUT_NEEDED;
		if (changed) state |= LAYOUT_CHANGED;
	}
	if (all) {
		Control [] children = _getChildren ();
		for (int i=0; i 0) x = oldWidth - controlWidth - x;
		int clientWidth = getClientWidth ();
		x = clientWidth - controlWidth - x;
		if (!GTK.GTK4) {
			if (child.enableWindow != 0) {
				GDK.gdk_window_move (child.enableWindow, x, y);
			}
		}
		child.moveHandle (x, y);
		/*
		* Cause a size allocation this widget's topHandle.  Note that
		* all calls to gtk_widget_size_allocate() must be preceded by
		* a call to gtk_widget_size_request().
		*/
		GtkRequisition requisition = new GtkRequisition ();
		gtk_widget_get_preferred_size (topHandle, requisition);
		allocation.x = x;
		allocation.y = y;
		gtk_widget_size_allocate(topHandle, allocation, -1);
		Control control = child.findBackgroundControl ();
		if (control != null && control.backgroundImage != null) {
			if (child.isVisible ()) child.redrawWidget (0, 0, 0, 0, true, true, true);
		}
	}
}

Point minimumSize (int wHint, int hHint, boolean changed) {
	Control [] children = _getChildren ();
	/*
	 * Since getClientArea can be overridden by subclasses, we cannot
	 * call getClientAreaInPixels directly.
	 */
	Rectangle clientArea = DPIUtil.autoScaleUp(getClientArea ());
	int width = 0, height = 0;
	for (int i=0; i=0; --i) {
		Control child = children [i];
		if (child.getVisible ()) {
			Point location = child.getLocationInPixels ();
			child.printWidget (gc, drawable, depth, x + location.x, y + location.y);
		}
	}
	gc.setClipping (oldClip);
	oldClip.dispose ();
	newClip.dispose ();
}

/**
 * Connects this widget's fixedHandle to the "draw" signal.

 * NOTE: only the "draw" (EXPOSE) signal is connected, not EXPOSE_EVENT_INVERSE.
 */
void connectFixedHandleDraw () {
	long paintHandle = fixedHandle;
	int paintMask = GDK.GDK_EXPOSURE_MASK;
	GTK3.gtk_widget_add_events (paintHandle, paintMask);

	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [DRAW], 0, display.getClosure (DRAW), true);
}

/**
 * 
Propagates draw events from a parent container to its children using
 * gtk_container_propagate_draw(). This method only works if the fixedHandle
 * has been connected to the "draw" signal, and only propagates draw events
 * to other siblings of handle (i.e. other children of fixedHandle, but not
 * handle itself).
 *
 * 
It's useful to propagate draw events to other child widgets for things
 * like Table/Tree editors, or other scenarios where a widget is a child of
 * a non-standard container widget (i.e., not a direct child of a Composite).
 *
 * @param container the parent container, i.e. fixedHandle
 * @param cairo the cairo context provided by GTK
 */
void propagateDraw (long container, long cairo) {
	if (container == fixedHandle) {
		if (GTK.GTK4) {
			for (long child = GTK4.gtk_widget_get_first_child(container); child != 0; child = GTK4.gtk_widget_get_next_sibling(child)) {
				//TODO: GTK4 no gtk_container_propagate_draw. Possibly not required at all.
			}
		} else {
			long list = GTK3.gtk_container_get_children (container);
			long temp = list;
			while (temp != 0) {
				long child = OS.g_list_data (temp);
				if (child != 0) {
					Widget widget = display.getWidget (child);
					if (widget != this) {
						if (noChildDrawing) {
							Boolean childLowered = childrenLowered.get(widget);
							if (childLowered == null) {
								childrenLowered.put(widget, false);
								childLowered = false;
							}
							GtkAllocation allocation = new GtkAllocation ();
							GTK.gtk_widget_get_allocation(child, allocation);
							if (allocation.y < 0) {
								if (!childLowered) {
									long window = gtk_widget_get_window(child);
									GDK.gdk_window_lower(window);
									childrenLowered.put(widget, true);
								}
							} else {
								if (childLowered) {
									long window = gtk_widget_get_window(child);
									GDK.gdk_window_raise(window);
									childrenLowered.put(widget, false);
								}
								GTK3.gtk_container_propagate_draw(container, child, cairo);
							}
						} else {
							GTK3.gtk_container_propagate_draw(container, child, cairo);
						}
					}
				}
				temp = OS.g_list_next (temp);
			}
			OS.g_list_free (list);
		}
	}
}

@Override
void redrawChildren () {
	super.redrawChildren ();
	Control [] children = _getChildren ();
	for (int i = 0; i < children.length; i++) {
		Control child = children [i];
		if ((child.state & PARENT_BACKGROUND) != 0) {
			child.redrawWidget (0, 0, 0, 0, true, false, true);
			child.redrawChildren ();
		}
	}
}

@Override
void register () {
	super.register ();
	if (socketHandle != 0) display.addWidget (socketHandle, this);
}

@Override
void releaseChildren (boolean destroy) {
	try (ExceptionStash exceptions = new ExceptionStash ()) {
		for (Control child : _getChildren ()) {
			if (child == null || child.isDisposed ())
				continue;

			try {
				child.release (false);
			} catch (Error | RuntimeException ex) {
				exceptions.stash (ex);
			}
		}
		super.releaseChildren (destroy);
	}
}

@Override
void releaseHandle () {
	super.releaseHandle ();
	socketHandle = embeddedHandle = 0;
}

@Override
void releaseWidget () {
	super.releaseWidget ();
	if (imHandle != 0) OS.g_object_unref (imHandle);
	imHandle = 0;
	layout = null;
	tabList = null;
}

void removeControl (Control control) {
	fixTabList (control);
}

@Override
void reskinChildren (int flags) {
	super.reskinChildren (flags);
	Control [] children = _getChildren ();
	for (int i=0; iSWT:
 * INHERIT_NONE, INHERIT_DEFAULT,
 * INHERIT_FORCE.
 *
 * @param mode the new background mode
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see SWT
 *
 * @since 3.2
 */
public void setBackgroundMode (int mode) {
	checkWidget ();
	backgroundMode = mode;
	Control[] children = _getChildren ();
	for (int i = 0; i < children.length; i++) {
		children [i].updateBackgroundMode ();
	}
}

@Override
int setBounds (int x, int y, int width, int height, boolean move, boolean resize) {

	/* Bug 487757
	 * Deal with bug where for Gtk3.8+, ScrolledComposites appear empty or internal widgets don't
	 * get sized properly. When resizing shell, widgets appear or grow into correct size.
	 *
	 * The issue is that upon widget creation ZERO_HEIGHT/WIDTH is assigned to widget's state (createWidget());
	 * then if you call setVisible(false), setVisible(true) before a layout operation,
	 * in the setVisible(true) call, the widget is never shown. In Gtk3.8+ hidden widgets have a
	 * size of 0x0, and as such allocation is not done correctly until you manually re-size the parent.
	 *
	 * To resolve the issue we check if widget is not HIDDEN on SWT side, but is hidden on GTK side. If it
	 * is, then show it. This correctly initializes layout of internal widgets.
	 *
	 * Future note: If you observe non Composite widgets to have incorrect sizing on first display
	 * but fix themselfes upon first resize by mouse, then
	 * consider moving this fix higher into Control's setBound(...) method instead.
	 */
	long topHandle = topHandle ();
	if (fixedHandle != 0 && handle != 0
			&& getVisible() && !GTK.gtk_widget_get_visible(topHandle) //if SWT State is not HIDDEN, but widget is hidden on GTK side.
			&& topHandle == fixedHandle && width > 0 && height > 0 && resize) {
		GTK.gtk_widget_show(topHandle);
	}

	int result = super.setBounds (x, y, width, height, move, resize);
	if ((result & RESIZED) != 0 && layout != null) {
		markLayout (false, false);
		updateLayout (false);
	}
	return result;
}

@Override
public boolean setFocus () {
	checkWidget();
	Control [] children = _getChildren ();
	for (int i=0; i
 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setLayout (Layout layout) {
	checkWidget();
	this.layout = layout;
}

/**
 * If the argument is true, causes subsequent layout
 * operations in the receiver or any of its children to be ignored.
 * No layout of any kind can occur in the receiver or any of its
 * children until the flag is set to false.
 * Layout operations that occurred while the flag was
 * true are remembered and when the flag is set to
 * false, the layout operations are performed in an
 * optimized manner.  Nested calls to this method are stacked.
 *
 * @param defer the new defer state
 *
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 *
 * @see #layout(boolean)
 * @see #layout(Control[])
 *
 * @since 3.1
 */
public void setLayoutDeferred (boolean defer) {
	checkWidget();
	if (!defer) {
		if (--layoutCount == 0) {
			if ((state & LAYOUT_CHILD) != 0 || (state & LAYOUT_NEEDED) != 0) {
				updateLayout (true);
			}
		}
	} else {
		layoutCount++;
	}
}

@Override
void setOrientation (boolean create) {
	super.setOrientation (create);
	if (!create) {
		int flags = SWT.RIGHT_TO_LEFT | SWT.LEFT_TO_RIGHT;
		int orientation = style & flags;
		Control [] children = _getChildren ();
		for (int i=0; i
 *    
ERROR_INVALID_ARGUMENT - if a widget in the tabList is null or has been disposed
 *    
ERROR_INVALID_PARENT - if widget in the tabList is not in the same widget tree
 * 
 * @exception SWTException 

 *    
ERROR_WIDGET_DISPOSED - if the receiver has been disposed
 *    
ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
 * 
 */
public void setTabList (Control [] tabList) {
	checkWidget ();
	if (tabList != null) {
		for (int i=0; i