coolbar.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.*;

/**
 * Instances of this class provide an area for dynamically
 * positioning the items they contain.
 * <p>
 * The item children that may be added to instances of this class
 * must be of type <code>CoolItem</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>FLAT</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * IMPORTANT: This class is <em>not</em> intended to be subclassed.
 * </p>
 */

public class CoolBar extends Composite {
	CoolItem [] items;
	CoolItem [] originalItems;
	boolean locked;
	boolean ignoreResize;
	static final int ReBarProc;
	static final TCHAR ReBarClass = new TCHAR (0, OS.REBARCLASSNAME, true);
	static {
		INITCOMMONCONTROLSEX icex = new INITCOMMONCONTROLSEX ();
		icex.dwSize = INITCOMMONCONTROLSEX.sizeof;
		icex.dwICC = OS.ICC_COOL_CLASSES;
		OS.InitCommonControlsEx (icex);
		WNDCLASS lpWndClass = new WNDCLASS ();
		OS.GetClassInfo (0, ReBarClass, lpWndClass);
		ReBarProc = lpWndClass.lpfnWndProc;
	}
	static final int SEPARATOR_WIDTH = 2;
	static final int MAX_WIDTH = 0x7FFF;

/**
 * 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 CoolBar (Composite parent, int style) {
	super (parent, checkStyle (style));
}

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

static int checkStyle (int style) {
	style |= SWT.NO_FOCUS;
	/*
	* Even though it is legal to create this widget
	* with scroll bars, they serve no useful purpose
	* because they do not automatically scroll the
	* widget's client area.  The fix is to clear
	* the SWT style.
	*/
	return style & ~(SWT.H_SCROLL | SWT.V_SCROLL);
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0;
	int border = getBorderWidth ();
	int newWidth = wHint == SWT.DEFAULT ? 0x3FFF : wHint + (border * 2);
	int newHeight = hHint == SWT.DEFAULT ? 0x3FFF : hHint + (border * 2);
	int count = OS.SendMessage (handle, OS.RB_GETBANDCOUNT, 0, 0);
	if (count != 0) {
		ignoreResize = true;
		boolean redraw = false;
		if (OS.IsWindowVisible (handle)) {
			if (OS.COMCTL32_MAJOR >= 6) {
				redraw = true;
				OS.UpdateWindow (handle);
				OS.DefWindowProc (handle, OS.WM_SETREDRAW, 0, 0);
			} else {
				redraw = drawCount == 0;
				if (redraw) {
					OS.UpdateWindow (handle);
					OS.SendMessage (handle, OS.WM_SETREDRAW, 0, 0);
				}
			}
		}	
		RECT oldRect = new RECT ();
		OS.GetWindowRect (handle, oldRect);
		int oldWidth = oldRect.right - oldRect.left;
		int oldHeight = oldRect.bottom - oldRect.top;
		int flags = OS.SWP_NOACTIVATE | OS.SWP_NOMOVE | OS.SWP_NOREDRAW | OS.SWP_NOZORDER;	
		SetWindowPos (handle, 0, 0, 0, newWidth, newHeight, flags);
		RECT rect = new RECT ();
		OS.SendMessage (handle, OS.RB_GETRECT, count - 1, rect);
		height = Math.max (height, rect.bottom);
		SetWindowPos (handle, 0, 0, 0, oldWidth, oldHeight, flags);
		REBARBANDINFO rbBand = new REBARBANDINFO ();
		rbBand.cbSize = REBARBANDINFO.sizeof;
		rbBand.fMask = OS.RBBIM_IDEALSIZE | OS.RBBIM_STYLE;
		int rowWidth = 0;
		int separator = (style & SWT.FLAT) == 0 ? SEPARATOR_WIDTH : 0;
		for (int i = 0; i < count; i++) {
			OS.SendMessage(handle, OS.RB_GETBANDINFO, i, rbBand);
			if ((rbBand.fStyle & OS.RBBS_BREAK) != 0) {
				width = Math.max(width, rowWidth - separator);
				rowWidth = 0;
			}
			rowWidth += rbBand.cxIdeal + getMargin (i) + separator;
		}
		width = Math.max(width, rowWidth - separator);
		if (redraw) {
			if (OS.COMCTL32_MAJOR >= 6) {
				OS.DefWindowProc (handle, OS.WM_SETREDRAW, 1, 0);
			} else {
				OS.SendMessage (handle, OS.WM_SETREDRAW, 1, 0);
			}
		}
		ignoreResize = false;
	}
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	height += border * 2;
	width += border * 2;	
	return new Point (width, height);
}

void createHandle () {
	super.createHandle ();
	state &= ~CANVAS;
	
	/*
	* 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 (CoolItem item, int index) {
	int count = OS.SendMessage (handle, OS.RB_GETBANDCOUNT, 0, 0);
	if (!(0 <= index && index <= count)) error (SWT.ERROR_INVALID_RANGE);
	int id = 0;
	while (id < items.length && items [id] != null) id++;
	if (id == items.length) {
		CoolItem [] newItems = new CoolItem [items.length + 4];
		System.arraycopy (items, 0, newItems, 0, items.length);
		items = newItems;
	}
	int hHeap = OS.GetProcessHeap ();
	int lpText = OS.HeapAlloc (hHeap, OS.HEAP_ZERO_MEMORY, TCHAR.sizeof);
	REBARBANDINFO rbBand = new REBARBANDINFO ();
	rbBand.cbSize = REBARBANDINFO.sizeof;
	rbBand.fMask = OS.RBBIM_TEXT | OS.RBBIM_STYLE | OS.RBBIM_ID;
	rbBand.fStyle = OS.RBBS_VARIABLEHEIGHT | OS.RBBS_GRIPPERALWAYS;
	if ((item.style & SWT.DROP_DOWN) != 0) {
		rbBand.fStyle |= OS.RBBS_USECHEVRON;
	}
	rbBand.lpText = lpText;
	rbBand.wID = id;

	/*
	* Feature in Windows.  When inserting an item at end of a row,
	* sometimes, Windows will begin to place the item on the right
	* side of the cool bar.  The fix is to resize the new items to
	* the maximum size and then resize the next to last item to the
	* ideal size.
	*/
	int lastIndex = getLastIndexOfRow (index - 1);
	boolean fixLast = index == lastIndex + 1;
	if (fixLast) {  	
		rbBand.fMask |= OS.RBBIM_SIZE;
		rbBand.cx = MAX_WIDTH; 
	}
	
	/*
	* Feature in Windows. Is possible that the item at index zero
	* has the RBBS_BREAK flag set. When a new item is inserted at
	* position zero, the previous item at position zero moves to
	* a new line.  The fix is to detect this case and clear the
	* RBBS_BREAK flag on the previous item before inserting the
	* new item.
	*/
	if (index == 0 && count > 0) {
		getItem (0).setWrap (false); 
	}
	
	/* Insert the item */
	if (OS.SendMessage (handle, OS.RB_INSERTBAND, index, rbBand) == 0) {
		error (SWT.ERROR_ITEM_NOT_ADDED);
	}
	
	/* Resize the next to last item to the ideal size */
	if (fixLast) {  	
		resizeToPreferredWidth (lastIndex);
	}
	
	OS.HeapFree (hHeap, 0, lpText);
	items [item.id = id] = item;
	int length = originalItems.length;
	CoolItem [] newOriginals = new CoolItem [length + 1];
	System.arraycopy (originalItems, 0, newOriginals, 0, index);
	System.arraycopy (originalItems, index, newOriginals, index + 1, length - index);
	newOriginals [index] = item;
	originalItems = newOriginals;
}

void createWidget () {
	super.createWidget ();
	items = new CoolItem [4];
	originalItems = new CoolItem [0];
}

void destroyItem (CoolItem item) {
	int index = OS.SendMessage (handle, OS.RB_IDTOINDEX, item.id, 0);
	int count = OS.SendMessage (handle, OS.RB_GETBANDCOUNT, 0, 0);
	if (count != 0) {
		int lastIndex = getLastIndexOfRow (index);
		if (index == lastIndex) {
			/*
			* Feature in Windows.  If the last item in a row is
			* given its ideal size, it will be placed at the far
			* right hand edge of the coolbar.  It is preferred
			* that the last item appear next to the second last
			* item.  The fix is to size the last item of each row 
			* so that it occupies all the available space to the
			* right in the row.
			*/
			resizeToMaximumWidth (lastIndex - 1);
		}						
	}	
		
	/*
	* Feature in Windows.  When Windows removed a rebar
	* band, it makes the band child invisible.  The fix
	* is to show the child.
	*/		
	Control control = item.control;
	boolean wasVisible = control != null && !control.isDisposed() && control.getVisible ();

	/*
	* When a wrapped item is being deleted, make the next
	* item in the row wrapped in order to preserve the row.
	* In order to avoid an unnecessary layout, temporarily
	* ignore WM_SIZE.  If the next item is wrapped then a
	* row will be deleted and the WM_SIZE is necessary.
	*/
	CoolItem nextItem = null;
	if (item.getWrap ()) {
		if (index + 1 < count) {
			nextItem = getItem (index + 1);
			ignoreResize = !nextItem.getWrap ();
		}
	}
	if (OS.SendMessage (handle, OS.RB_DELETEBAND, index, 0) == 0) {
		error (SWT.ERROR_ITEM_NOT_REMOVED);
	}
	items [item.id] = null;
	item.id = -1;
	if (ignoreResize) {
		nextItem.setWrap (true);
		ignoreResize = false;
	}
	
	/* Restore the visible state tof the control */
	if (wasVisible) control.setVisible (true);
	
	index = 0;
	while (index < originalItems.length) {
		if (originalItems [index] == item) break;
		index++;
	}
	int length = originalItems.length - 1;
	CoolItem [] newOriginals = new CoolItem [length];
	System.arraycopy (originalItems, 0, newOriginals, 0, index);
	System.arraycopy (originalItems, index + 1, newOriginals, index, length - index);
	originalItems = newOriginals;
}

int getMargin (int index) {
	int margin = 0;
	if (OS.COMCTL32_MAJOR >= 6) {
		MARGINS margins = new MARGINS ();
		OS.SendMessage (handle, OS.RB_GETBANDMARGINS, 0, margins);
		margin += margins.cxLeftWidth + margins.cxRightWidth;
	}
	RECT rect = new RECT ();
	OS.SendMessage (handle, OS.RB_GETBANDBORDERS, index, rect);
	if ((style & SWT.FLAT) != 0) {
		/*
		* Bug in Windows.  When the style bit  RBS_BANDBORDERS is not set
		* the rectangle returned by RBS_BANDBORDERS is four pixels too small.
		* The fix is to add four pixels to the result.
		*/	
		margin += rect.left + 4;
	} else {
		margin += rect.left + rect.right; 
	}
	return margin;
}

/**
 * Returns the item that is currently displayed at the given,
 * zero-relative index. Throws an exception if the index is
 * out of range.
 *
 * @param index the visual index of the item to return
 * @return the item at the given visual index