tree.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import org.eclipse.swt.internal.win32.*;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.events.*;

/**
 * Instances of this class provide a selectable user interface object
 * that displays a hierarchy of items and issue notificiation when an
 * item in the hierarchy is selected.
 * <p>
 * The item children that may be added to instances of this class
 * must be of type <code>TreeItem</code>.
 * </p><p>
 * Note that although this class is a subclass of <code>Composite</code>,
 * it does not make sense to add <code>Control</code> children to it,
 * or set a layout on it.
 * </p><p>
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SINGLE, MULTI, CHECK</dd>
 * <dt><b>Events:</b></dt>
 * <dd>Selection, DefaultSelection, Collapse, Expand</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles SINGLE and MULTI may be specified.
 * </p><p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */
public class Tree extends Composite {
	int hAnchor;
	TreeItem [] items;
	ImageList imageList;
	boolean dragStarted, gestureCompleted;
	boolean ignoreSelect, ignoreExpand, ignoreDeselect;
	boolean customDraw;
	static final int TreeProc;
	static final TCHAR TreeClass = new TCHAR (0, OS.WC_TREEVIEW, true);
	static {
		WNDCLASS lpWndClass = new WNDCLASS ();
		OS.GetClassInfo (0, TreeClass, lpWndClass);
		TreeProc = lpWndClass.lpfnWndProc;
	}

/**
 * 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#SINGLE
 * @see SWT#MULTI
 * @see SWT#CHECK
 * @see Widget#checkSubclass
 * @see Widget#getStyle
 */
public Tree (Composite parent, int style) {
	super (parent, checkStyle (style));
}

static int checkStyle (int style) {
	/*
	* Feature in Windows.  It is not possible to create
	* a tree that scrolls and does not have scroll bars.
	* The TVS_NOSCROLL style will remove the scroll bars
	* but the tree will never scroll.  Therefore, no matter
	* what style bits are specified, set the H_SCROLL and
	* V_SCROLL bits so that the SWT style will match the
	* widget that Windows creates.
	*/
	style |= SWT.H_SCROLL | SWT.V_SCROLL;
	return checkBits (style, SWT.SINGLE, SWT.MULTI, 0, 0, 0, 0);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when the receiver's selection changes, by sending
 * it one of the messages defined in the <code>SelectionListener</code>
 * interface.
 * <p>
 * When <code>widgetSelected</code> is called, the item field of the event object is valid.
 * If the reciever has <code>SWT.CHECK</code> style set and the check selection changes,
 * the event object detail field contains the value <code>SWT.CHECK</code>.
 * <code>widgetDefaultSelected</code> is typically called when an item is double-clicked.
 * The item field of the event object is valid for default selection, but the detail field is not used.
 * </p>
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener 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>
 *
 * @see SelectionListener
 * @see #removeSelectionListener
 * @see SelectionEvent
 */
public void addSelectionListener(SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Selection, typedListener);
	addListener (SWT.DefaultSelection, typedListener);
}

/**
 * Adds the listener to the collection of listeners who will
 * be notified when an item in the receiver is expanded or collapsed
 * by sending it one of the messages defined in the <code>TreeListener</code>
 * interface.
 *
 * @param listener the listener which should be notified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the listener 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>
 *
 * @see TreeListener
 * @see #removeTreeListener
 */
public void addTreeListener(TreeListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Expand, typedListener);
	addListener (SWT.Collapse, typedListener);
} 

int callWindowProc (int msg, int wParam, int lParam) {
	if (handle == 0) return 0;
	return OS.CallWindowProc (TreeProc, handle, msg, wParam, lParam);
}

boolean checkScroll (int hItem) {
	/*
	* Feature in Windows.  If redraw is turned off using WM_SETREDRAW 
	* and a tree item that is not a child of the first root is selected or
	* scrolled using TVM_SELECTITEM or TVM_ENSUREVISIBLE, then scrolling
	* does not occur.  The fix is to detect this case, and make sure
	* that redraw is temporarly enabled.  To avoid flashing, DefWindowProc()
	* is called to disable redrawing.
	* 
	* NOTE:  The code that actually works around the problem is in the
	* callers of this method.
	*/
	if (drawCount == 0) return false;
	int hRoot = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_ROOT, 0);
	int hParent = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_PARENT, hItem);
	while (hParent != hRoot && hParent != 0) {
		hParent = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_PARENT, hParent);
	}
	return hParent == 0;
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0;
	RECT rect = new RECT ();
	int hItem = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_ROOT, 0);
	while (hItem != 0) {
		rect.left = hItem;
		if (OS.SendMessage (handle, OS.TVM_GETITEMRECT, 1, rect) != 0) {
			width = Math.max (width, rect.right);
			height += rect.bottom - rect.top;
		}
		hItem = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_NEXT, hItem);
	}
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int border = getBorderWidth ();
	width += border * 2;  height += border * 2;
	if ((style & SWT.V_SCROLL) != 0) {
		width += OS.GetSystemMetrics (OS.SM_CXVSCROLL);
	}
	if ((style & SWT.H_SCROLL) != 0) {
		height += OS.GetSystemMetrics (OS.SM_CYHSCROLL);
	}
	return new Point (width, height);
}

void createHandle () {
	super.createHandle ();
	state &= ~CANVAS;
	
	/*
	* Feature in Windows.  In version 5.8 of COMCTL32.DLL,
	* if the font is changed for an item, the bounds for the
	* item are not updated, causing the text to be clipped.
	* The fix is to detect the version of COMCTL32.DLL, and
	* if it is one of the versions with the problem, then
	* use version 5.00 of the control (a version that does
	* not have the problem).  This is the recomended work
	* around from the MSDN.
	*/
	if (OS.COMCTL32_MAJOR < 6) {
		OS.SendMessage (handle, OS.CCM_SETVERSION, 5, 0);
	}

	/* Set the checkbox image list */
	if ((style & SWT.CHECK) != 0) setCheckboxImageList ();
	
	/*
	* Feature in Windows.  When the control is created,
	* it does not use the default system font.  A new HFONT
	* is created and destroyed when the control is destroyed.
	* This means that a program that queries the font from
	* this control, uses the font in another control and then
	* destroys this control will have the font unexpectedly
	* destroyed in the other control.  The fix is to assign
	* the font ourselves each time the control is created.
	* The control will not destroy a font that it did not
	* create.
	*/
	int hFont = OS.GetStockObject (OS.SYSTEM_FONT);
	OS.SendMessage (handle, OS.WM_SETFONT, hFont, 0);
}

void createItem (TreeItem item, int hParent, int hInsertAfter) {
	item.foreground = item.background = item.font = -1;
	int id = 0;
	while (id < items.length && items [id] != null) id++;
	if (id == items.length) {
		TreeItem [] newItems = new TreeItem [items.length + 4];
		System.arraycopy (items, 0, newItems, 0, items.length);
		items = newItems;
	}
	TVINSERTSTRUCT tvInsert = new TVINSERTSTRUCT ();
	tvInsert.hParent = hParent;
	tvInsert.hInsertAfter = hInsertAfter;
	tvInsert.lParam = id;
	tvInsert.iImage = OS.I_IMAGENONE;
	tvInsert.iSelectedImage = tvInsert.iImage;
	tvInsert.mask = OS.TVIF_HANDLE | OS.TVIF_PARAM | OS.TVIF_IMAGE | OS.TVIF_SELECTEDIMAGE;
	
	/* Set the initial unchecked state */
	if ((style & SWT.CHECK) != 0) {
		tvInsert.mask = tvInsert.mask | OS.TVIF_STATE;
		tvInsert.state = 1 << 12;
		tvInsert.stateMask = OS.TVIS_STATEIMAGEMASK;
	}

	/* Insert the item */
	int hItem = OS.SendMessage (handle, OS.TVM_INSERTITEM, 0, tvInsert);
	if (hItem == 0) error (SWT.ERROR_ITEM_NOT_ADDED);
	item.handle = hItem;
	items [id] = item;
	
	/*
	* This code is intentionally commented.
	*/
//	if (hParent != 0) {
//		int bits = OS.GetWindowLong (handle, OS.GWL_STYLE);
//		bits |= OS.TVS_LINESATROOT;
//		OS.SetWindowLong (handle, OS.GWL_STYLE, bits);
//	}

	/*
	* Bug in Windows.  When a child item is added to a parent item
	* that has no children outside of WM_NOTIFY with control code
	* TVN_ITEMEXPANDED, the tree widget does not redraw the +/-
	* indicator.  The fix is to detect the case when the first
	* child is added to a visible parent item and redraw the parent.
	*/
	if (!OS.IsWindowVisible (handle) || drawCount > 0) return;
	int hChild = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_CHILD, hParent);
	if (hChild != 0 && OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_NEXT, hChild) == 0) {
		RECT rect = new RECT ();
		rect.left = hParent;
		if (OS.SendMessage (handle, OS.TVM_GETITEMRECT, 0, rect) != 0) {
			OS.InvalidateRect (handle, rect, true);
		}
	}
}

void createWidget () {
	super.createWidget ();
	items = new TreeItem [4];
}

int defaultBackground () {
	return OS.GetSysColor (OS.COLOR_WINDOW);
}

/**
 * Deselects all selected items in 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 deselectAll () {
	checkWidget ();
	TVITEM tvItem = new TVITEM ();
	tvItem.mask = OS.TVIF_STATE;
	tvItem.stateMask = OS.TVIS_SELECTED;
	if ((style & SWT.SINGLE) != 0) {
		int hItem = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_CARET, 0);
		if (hItem != 0) {
			tvItem.hItem = hItem;
			OS.SendMessage (handle, OS.TVM_SETITEM, 0, tvItem);
		}
		return;
	}
	int oldProc = OS.GetWindowLong (handle, OS.GWL_WNDPROC);
	OS.SetWindowLong (handle, OS.GWL_WNDPROC, TreeProc);	
	for (int i=0; i<items.length; i++) {
		TreeItem item = items [i];
		if (item != null) {
			tvItem.hItem = item.handle;
			OS.SendMessage (handle, OS.TVM_SETITEM, 0, tvItem);
		}
	}
	OS.SetWindowLong (handle, OS.GWL_WNDPROC, oldProc);
}

void destroyItem (TreeItem item) {
	/*
	* Feature in Windows.  When an item is removed that is not
	* visible in the tree because it belongs to a collapsed branch,
	* Windows redraws the tree causing a flash for each item that
	* is removed.  The fix is to detect whether the item is visible,
	* force the widget to be fully painted, turn off redraw, remove
	* the item and validate the damage caused by the removing of
	* the item.
	*/
	int hItem = item.handle, hParent = 0;
	boolean fixRedraw = false;
	if (drawCount == 0 && OS.IsWindowVisible (handle)) {
		RECT rect = new RECT ();
		rect.left = hItem;
		fixRedraw = OS.SendMessage (handle, OS.TVM_GETITEMRECT, 0, rect) == 0;
	}
	if (fixRedraw) {
		hParent = OS.SendMessage (handle, OS.TVM_GETNEXTITEM, OS.TVGN_PARENT, hItem);
		OS.UpdateWindow (handle);
		OS.SendMessage (handle, OS.WM_SETREDRAW, 0, 0);
	}
	TVITEM tvItem = new TVITEM ();
	tvItem.mask = OS.TVIF_HANDLE | OS.TVIF_PARAM;
	releaseItems (item.getItems (), tvItem);