combo.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 * Cuts the selected text.
 * <p>
 * The current selection is first copied to the
 * clipboard and then deleted from the widget.
 * </p>
 *
 * @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 2.1
 */
public void cut () {
	checkWidget ();
	OS.SendMessage (handle, OS.WM_CUT, 0, 0);
}

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

void deregister () {
	super.deregister ();
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndText != 0) display.removeControl (hwndText);
	int hwndList = OS.GetDlgItem (handle, CBID_LIST);
	if (hwndList != 0) display.removeControl (hwndList);
}

/**
 * Deselects the item at the given zero-relative index in the receiver's 
 * list.  If the item at the index was already deselected, it remains
 * deselected. Indices that are out of range are ignored.
 *
 * @param index the index of the item to deselect
 *
 * @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 deselect (int index) {
	checkWidget ();
	int selection = OS.SendMessage (handle, OS.CB_GETCURSEL, 0, 0);
	if (index != selection) return;
	OS.SendMessage (handle, OS.CB_SETCURSEL, -1, 0);
	sendEvent (SWT.Modify);
	// widget could be disposed at this point
}

/**
 * Deselects all selected items in the receiver's list.
 * <p>
 * Note: To clear the selection in the receiver's text field,
 * use <code>clearSelection()</code>.
 * </p>
 *
 * @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 #clearSelection
 */
public void deselectAll () {
	checkWidget ();
	OS.SendMessage (handle, OS.CB_SETCURSEL, -1, 0);
	sendEvent (SWT.Modify);
	// widget could be disposed at this point
}

/**
 * Returns the item at the given, zero-relative index in the
 * receiver's list. Throws an exception if the index is out
 * of range.
 *
 * @param index the index of the item to return
 * @return the item at the given index
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_ITEM - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public String getItem (int index) {
	checkWidget ();
	int length = OS.SendMessage (handle, OS.CB_GETLBTEXTLEN, index, 0);
	if (length != OS.CB_ERR) {
		TCHAR buffer = new TCHAR (getCodePage (), length + 1);
		int result = OS.SendMessage (handle, OS.CB_GETLBTEXT, index, buffer);
		if (result != OS.CB_ERR) return buffer.toString (0, length);
	}
	int count = OS.SendMessage (handle, OS.CB_GETCOUNT, 0, 0);
	if (0 <= index && index < count) error (SWT.ERROR_CANNOT_GET_ITEM);
	error (SWT.ERROR_INVALID_RANGE);
	return null;
}

/**
 * Returns the number of items contained in the receiver's list.
 *
 * @return the number of items
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_COUNT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getItemCount () {
	checkWidget ();
	int count = OS.SendMessage (handle, OS.CB_GETCOUNT, 0, 0);
	if (count == OS.CB_ERR) error (SWT.ERROR_CANNOT_GET_COUNT);
	return count;
}

/**
 * Returns the height of the area which would be used to
 * display <em>one</em> of the items in the receiver's list.
 *
 * @return the height of one item
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_ITEM_HEIGHT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getItemHeight () {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.CB_GETITEMHEIGHT, 0, 0);
	if (result == OS.CB_ERR) error (SWT.ERROR_CANNOT_GET_ITEM_HEIGHT);
	return result;
}

/**
 * Returns an array of <code>String</code>s which are the items
 * in the receiver's list. 
 * <p>
 * Note: This is not the actual structure used by the receiver
 * to maintain its list of items, so modifying the array will
 * not affect the receiver. 
 * </p>
 *
 * @return the items in the receiver's list
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_ITEM - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public String [] getItems () {
	checkWidget ();
	int count = getItemCount ();
	String [] result = new String [count];
	for (int i=0; i<count; i++) result [i] = getItem (i);
	return result;
}

String getNameText () {
	return getText ();
}

/**
 * Returns the orientation of the receiver.
 *
 * @return the orientation style
 * 
 * @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 2.1.2
 */
public int getOrientation () {
	checkWidget();
	return style & (SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT);
}

/**
 * Returns a <code>Point</code> whose x coordinate is the start
 * of the selection in the receiver's text field, and whose y
 * coordinate is the end of the selection. The returned values
 * are zero-relative. An "empty" selection as indicated by
 * the the x and y coordinates having the same value.
 *
 * @return a point representing the selection start and end
 *
 * @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 Point getSelection () {
	checkWidget ();
	if ((style & SWT.DROP_DOWN) != 0 && (style & SWT.READ_ONLY) != 0) {
		return new Point (0, OS.GetWindowTextLength (handle));
	}
	int [] start = new int [1], end = new int [1];
	OS.SendMessage (handle, OS.CB_GETEDITSEL, start, end);
	return new Point (start [0], end [0]);
}

/**
 * Returns the zero-relative index of the item which is currently
 * selected in the receiver's list, or -1 if no item is selected.
 *
 * @return the index of the selected item
 *
 * @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 int getSelectionIndex () {
	checkWidget ();
	if (noSelection) return -1;
	return OS.SendMessage (handle, OS.CB_GETCURSEL, 0, 0);
}

/**
 * Returns a string containing a copy of the contents of the
 * receiver's text field.
 *
 * @return the receiver's text
 *
 * @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 String getText () {
	checkWidget ();
	int length = OS.GetWindowTextLength (handle);
	if (length == 0) return "";
	TCHAR buffer = new TCHAR (getCodePage (), length + 1);
	OS.GetWindowText (handle, buffer, length + 1);
	return buffer.toString (0, length);
}

/**
 * Returns the height of the receivers's text field.
 *
 * @return the text height
 *
 * @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>
 * @exception SWTError <ul>
 *    <li>ERROR_CANNOT_GET_ITEM_HEIGHT - if the operation fails because of an operating system failure</li>
 * </ul>
 */
public int getTextHeight () {
	checkWidget ();
	int result = OS.SendMessage (handle, OS.CB_GETITEMHEIGHT, -1, 0);
	if (result == OS.CB_ERR) error (SWT.ERROR_CANNOT_GET_ITEM_HEIGHT);
	return result + 6;
}

/**
 * Returns the maximum number of characters that the receiver's
 * text field is capable of holding. If this has not been changed
 * by <code>setTextLimit()</code>, it will be the constant
 * <code>Combo.LIMIT</code>.
 * 
 * @return the text limit
 * 
 * @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 int getTextLimit () {
	checkWidget ();
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndText == 0) return LIMIT;
	return OS.SendMessage (hwndText, OS.EM_GETLIMITTEXT, 0, 0);
}

/**
 * Gets the number of items that are visible in the drop
 * down portion of the receiver's list.
 *
 * @return the number of items that are visible
 *
 * @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 3.0
 */
public int getVisibleItemCount () {
	checkWidget ();
	return visibleCount;
}

boolean hasFocus () {
	int hwndFocus = OS.GetFocus ();
	if (hwndFocus == handle) return true;
	if (hwndFocus == 0) return false;
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndFocus == hwndText) return true;
	int hwndList = OS.GetDlgItem (handle, CBID_LIST);
	if (hwndFocus == hwndList) return true;
	return false;
}

/**
 * Searches the receiver's list starting at the first item
 * (index 0) until an item is found that is equal to the 
 * argument, and returns the index of that item. If no item
 * is found, returns -1.
 *
 * @param string the search item
 * @return the index of the item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string 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>
 */
public int indexOf (String string) {
	return indexOf (string, 0);
}

/**
 * Searches the receiver's list starting at the given, 
 * zero-relative index until an item is found that is equal
 * to the argument, and returns the index of that item. If
 * no item is found or the starting index is out of range,
 * returns -1.
 *
 * @param string the search item
 * @param start the zero-relative index at which to begin the search
 * @return the index of the item
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the string 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>
 */
public int indexOf (String string, int start) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	
	/*
	* Bug in Windows.  For some reason, CB_FINDSTRINGEXACT
	* will not find empty strings even though it is legal
	* to insert an empty string into a combo.  The fix is
	* to search the combo, an item at a time.
	*/
	if (string.length () == 0) {
		int count = getItemCount ();
		for (int i=start; i<count; i++) {
			if (string.equals (getItem (i))) return i;
		}
		return -1;
	}

	/* Use CB_FINDSTRINGEXACT to search for the item */	
	int count = OS.SendMessage (handle, OS.CB_GETCOUNT, 0, 0);
	if (!(0 <= start && start < count)) return -1;
	int index = start - 1, last = 0;
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	do {
		index = OS.SendMessage (handle, OS.CB_FINDSTRINGEXACT, last = index, buffer);
		if (index == OS.CB_ERR || index <= last) return -1;
	} while (!string.equals (getItem (index)));
	return index;
}

/**
 * Pastes text from clipboard.
 * <p>
 * The selected text is deleted from the widget
 * and new text inserted from the clipboard.
 * </p>
 *
 * @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 2.1
 */
public void paste () {
	checkWidget ();
	OS.SendMessage (handle, OS.WM_PASTE, 0, 0);
}

void register () {
	super.register ();
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndText != 0) display.addControl (hwndText, this);
	int hwndList = OS.GetDlgItem (handle, CBID_LIST);
	if (hwndList != 0) display.addControl (hwndList, this);
}

/**
 * Removes the item from the receiver's list at the given
 * zero-relative index.
 *