text.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

 * space (' ') character.  The width of a single
 * tab stop is the pixel width of the spaces.
 * </p>
 *
 * @return the number of tab characters
 *
 * @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 getTabs () {
	checkWidget ();
	return tabs;
}

int getTabWidth (int tabs) {
	int oldFont = 0;
	RECT rect = new RECT ();
	int hDC = OS.GetDC (handle);
	int newFont = OS.SendMessage (handle, OS.WM_GETFONT, 0, 0);
	if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
	int flags = OS.DT_CALCRECT | OS.DT_SINGLELINE | OS.DT_NOPREFIX;
	TCHAR SPACE = new TCHAR (getCodePage (), " ", false);
	OS.DrawText (hDC, SPACE, SPACE.length (), rect, flags);
	if (newFont != 0) OS.SelectObject (hDC, oldFont);
	OS.ReleaseDC (handle, hDC);
	return (rect.right - rect.left) * tabs;
}

/**
 * Gets the widget text.
 * <p>
 * The text for a text widget is the characters in the widget.
 * </p>
 *
 * @return the widget 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);
}

/**
 * Gets a range of text.  Returns an empty string if the
 * start of the range is greater than the end.
 * <p>
 * Indexing is zero based.  The range of
 * a selection is from 0..N-1 where N is
 * the number of characters in the widget.
 * </p>
 *
 * @param start the start of the range
 * @param end the end of the range
 * @return the range of 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 (int start, int end) {
	checkWidget ();
	if (!(start <= end && 0 <= end)) return "";
	int length = OS.GetWindowTextLength (handle);
	if (OS.IsDBLocale) length = mbcsToWcsPos (length);
	start = Math.max (0, start);
	end = Math.min (end, length - 1);
	/*
	* NOTE: The current implementation uses substring ()
	* which can reference a potentially large character
	* array.
	*/
	return getText ().substring (start, end + 1);
}

/**
 * Returns the maximum number of characters that the receiver is capable of holding. 
 * <p>
 * If this has not been changed by <code>setTextLimit()</code>,
 * it will be the constant <code>Text.LIMIT</code>.
 * </p>
 * 
 * @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 ();
	return OS.SendMessage (handle, OS.EM_GETLIMITTEXT, 0, 0);
}

/**
 * Returns the zero-relative index of the line which is currently
 * at the top of the receiver.
 * <p>
 * This index can change when lines are scrolled or new lines are added or removed.
 * </p>
 *
 * @return the index of the top line
 *
 * @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 getTopIndex () {
	checkWidget ();
	if ((style & SWT.SINGLE) != 0) return 0;
	return OS.SendMessage (handle, OS.EM_GETFIRSTVISIBLELINE, 0, 0);
}

/**
 * Gets the top pixel.
 * <p>
 * The top pixel is the pixel position of the line
 * that is currently at the top of the widget.  On
 * some platforms, a text widget can be scrolled by
 * pixels instead of lines so that a partial line
 * is displayed at the top of the widget.
 * </p><p>
 * The top pixel changes when the widget is scrolled.
 * The top pixel does not include the widget trimming.
 * </p>
 *
 * @return the pixel position of the top line
 *
 * @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 getTopPixel () {
	checkWidget ();
	/*
	* Note, EM_GETSCROLLPOS is implemented in Rich Edit 3.0
	* and greater.  The plain text widget and previous versions
	* of Rich Edit return zero.
	*/
	int [] buffer = new int [2];
	int code = OS.SendMessage (handle, OS.EM_GETSCROLLPOS, 0, buffer);
	if (code == 1) return buffer [1];
	return getTopIndex () * getLineHeight ();
}

/**
 * Inserts a string.
 * <p>
 * The old selection is replaced with the new text.
 * </p>
 *
 * @param string the string
 *
 * @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 insert (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	string = Display.withCrLf (string);
	if (hooks (SWT.Verify) || filters (SWT.Verify)) {
		int [] start = new int [1], end = new int [1];
		OS.SendMessage (handle, OS.EM_GETSEL, start, end);
		string = verifyText (string, start [0], end [0], null);
		if (string == null) return;
	}
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	/*
	* Feature in Windows.  When an edit control with ES_MULTILINE
	* style that does not have the WS_VSCROLL style is full (i.e.
	* there is no space at the end to draw any more characters),
	* EM_REPLACESEL sends a WM_CHAR with a backspace character
	* to remove any further text that is added.  This is an
	* implementation detail of the edit control that is unexpected
	* and can cause endless recursion when EM_REPLACESEL is sent
	* from a WM_CHAR handler.  The fix is to ignore calling the
	* handler from WM_CHAR.
	*/
	ignoreCharacter = true;
	OS.SendMessage (handle, OS.EM_REPLACESEL, 0, buffer);
	ignoreCharacter = false;
}

int mbcsToWcsPos (int mbcsPos) {
	if (mbcsPos == 0) return 0;
	if (OS.IsUnicode) return mbcsPos;
	int cp = getCodePage ();
	int wcsTotal = 0, mbcsTotal = 0;
	byte [] buffer = new byte [128];
	String delimiter = getLineDelimiter();
	int delimiterSize = delimiter.length ();
	int count = OS.SendMessageA (handle, OS.EM_GETLINECOUNT, 0, 0);
	for (int line=0; line<count; line++) {
		int wcsSize = 0;
		int linePos = OS.SendMessageA (handle, OS.EM_LINEINDEX, line, 0);
		int mbcsSize = OS.SendMessageA (handle, OS.EM_LINELENGTH, linePos, 0);
		if (mbcsSize != 0) {
			if (mbcsSize + delimiterSize > buffer.length) {
				buffer = new byte [mbcsSize + delimiterSize];
			}
			buffer [0] = (byte) (mbcsSize & 0xFF);
			buffer [1] = (byte) (mbcsSize >> 8);
			mbcsSize = OS.SendMessageA (handle, OS.EM_GETLINE, line, buffer);
			wcsSize = OS.MultiByteToWideChar (cp, OS.MB_PRECOMPOSED, buffer, mbcsSize, null, 0);
		}
		if (line - 1 != count) {
			for (int i=0; i<delimiterSize; i++) {
				buffer [mbcsSize++] = (byte) delimiter.charAt (i);
			}
			wcsSize += delimiterSize;
		}
		if ((mbcsTotal + mbcsSize) >= mbcsPos) {
			int bufferSize = mbcsPos - mbcsTotal;
			wcsSize = OS.MultiByteToWideChar (cp, OS.MB_PRECOMPOSED, buffer, bufferSize, null, 0);
			return wcsTotal + wcsSize;
		}
		wcsTotal += wcsSize;
		mbcsTotal += mbcsSize;
	}
	return wcsTotal;
}

/**
 * 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>
 */
public void paste () {
	checkWidget ();
	OS.SendMessage (handle, OS.WM_PASTE, 0, 0);
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the receiver's text is modified.
 *
 * @param listener the listener which should no longer 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 ModifyListener
 * @see #addModifyListener
 */
public void removeModifyListener (ModifyListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Modify, listener);	
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control is selected.
 *
 * @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 #addSelectionListener
 */
public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection,listener);	
}

/**
 * Removes the listener from the collection of listeners who will
 * be notified when the control is verified.
 *
 * @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 VerifyListener
 * @see #addVerifyListener
 */
public void removeVerifyListener (VerifyListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Verify, listener);	
}

/**
 * Selects all the text 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 selectAll () {
	checkWidget ();
	OS.SendMessage (handle, OS.EM_SETSEL, 0, -1);
}

boolean sendKeyEvent (int type, int msg, int wParam, int lParam, Event event) {
	if (!super.sendKeyEvent (type, msg, wParam, lParam, event)) {
		return false;
	}
	if (ignoreVerify) return true;
	if (type != SWT.KeyDown) return true;
	if (msg != OS.WM_CHAR && msg != OS.WM_KEYDOWN && msg != OS.WM_IME_CHAR) {
		return true;
	}
	if (event.character == 0) return true;
	if (!hooks (SWT.Verify) && !filters (SWT.Verify)) return true;
	char key = event.character;
	int stateMask = event.stateMask;
	
	/*
	* Disable all magic keys that could modify the text
	* and don't send events when Alt, Shift or Ctrl is
	* pressed.
	*/
	switch (msg) {
		case OS.WM_CHAR:
			if (key != 0x08 && key != 0x7F && key != '\r' && key != '\t' && key != '\n') break;
			// FALL THROUGH
		case OS.WM_KEYDOWN:
			if ((stateMask & (SWT.ALT | SWT.SHIFT | SWT.CONTROL)) != 0) return false;
			break;
	}

	/*
	* If the left button is down, the text widget refuses the character.
	*/
	if (OS.GetKeyState (OS.VK_LBUTTON) < 0) {
		return true;
	}

	/* Verify the character */
	String oldText = "";
	int [] start = new int [1], end = new int [1];
	OS.SendMessage (handle, OS.EM_GETSEL, start, end);
	switch (key) {
		case 0x08:	/* Bs */
			if (start [0] == end [0]) {
				if (start [0] == 0) return true;
				int lineStart = OS.SendMessage (handle, OS.EM_LINEINDEX, -1, 0);
				if (start [0] == lineStart) {
					start [0] = start [0] - DELIMITER.length ();
				} else {
					start [0] = start [0] - 1;
					if (OS.IsDBLocale) {
						int [] newStart = new int [1], newEnd = new int [1];
						OS.SendMessage (handle, OS.EM_SETSEL, start [0], end [0]);
						OS.SendMessage (handle, OS.EM_GETSEL, newStart, newEnd);
						if (start [0] != newStart [0]) start [0] = start [0] - 1;
					}
				}
				start [0] = Math.max (start [0], 0);
			}
			break;
		case 0x7F:	/* Del */
			if (start [0] == end [0]) {
				int length = OS.GetWindowTextLength (handle);
				if (start [0] == length) return true;
				int line = OS.SendMessage (handle, OS.EM_LINEFROMCHAR, end [0], 0);
				int lineStart = OS.SendMessage (handle, OS.EM_LINEINDEX, line + 1, 0);