combo.java

源码为Eclipse开源开发平台桌面开发工具SWT的源代码,

		* style bits.  The fix is to force the widget to be resized by
		* temporarily shrinking and then growing the width and height.
		*/
		RECT rect = new RECT ();
		OS.GetWindowRect (hwndText, rect);
		int width = rect.right - rect.left, height = rect.bottom - rect.top;
		OS.GetWindowRect (handle, rect);
		int widthCombo = rect.right - rect.left, heightCombo = rect.bottom - rect.top;
		int uFlags = OS.SWP_NOMOVE | OS.SWP_NOZORDER | OS.SWP_NOACTIVATE;
		SetWindowPos (hwndText, 0, 0, 0, width - 1, height - 1, uFlags);
		SetWindowPos (handle, 0, 0, 0, widthCombo - 1, heightCombo - 1, uFlags);
		SetWindowPos (hwndText, 0, 0, 0, width, height, uFlags);
		SetWindowPos (handle, 0, 0, 0, widthCombo, heightCombo, uFlags);
		OS.InvalidateRect (handle, null, true);
	}	
	if (hwndList != 0) {
		int exStyle = OS.GetWindowLong (hwndList, OS.GWL_EXSTYLE);		
		if ((style & SWT.RIGHT_TO_LEFT) != 0) {
			exStyle |= OS.WS_EX_LAYOUTRTL;
		} else {
			exStyle &= ~OS.WS_EX_LAYOUTRTL;
		}
		OS.SetWindowLong (hwndList, OS.GWL_EXSTYLE, exStyle);
	}
}

/**
 * Sets the selection in the receiver's text field to the
 * range specified by the argument whose x coordinate is the
 * start of the selection and whose y coordinate is the end
 * of the selection. 
 *
 * @param selection a point representing the new selection start and end
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the point 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 void setSelection (Point selection) {
	checkWidget ();
	if (selection == null) error (SWT.ERROR_NULL_ARGUMENT);
	int bits = selection.x | (selection.y << 16);
	OS.SendMessage (handle, OS.CB_SETEDITSEL, 0, bits);
}

/**
 * Sets the contents of the receiver's text field to the
 * given string.
 * <p>
 * Note: The text field in a <code>Combo</code> is typically
 * only capable of displaying a single line of text. Thus,
 * setting the text to a string containing line breaks or
 * other special characters will probably cause it to 
 * display incorrectly.
 * </p>
 *
 * @param string the new text
 *
 * @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 void setText (String string) {
	checkWidget ();
	if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
	if ((style & SWT.READ_ONLY) != 0) {
		int index = indexOf (string);
		if (index != -1) select (index);
		return;
	}
	TCHAR buffer = new TCHAR (getCodePage (), string, true);
	if (OS.SetWindowText (handle, buffer)) {
		sendEvent (SWT.Modify);
		// widget could be disposed at this point
	}
}

/**
 * Sets the maximum number of characters that the receiver's
 * text field is capable of holding to be the argument.
 *
 * @param limit new text limit
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_CANNOT_BE_ZERO - if the limit is zero</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 void setTextLimit (int limit) {
	checkWidget ();
	if (limit == 0) error (SWT.ERROR_CANNOT_BE_ZERO);
	OS.SendMessage (handle, OS.CB_LIMITTEXT, limit, 0);
}

/**
 * Sets the number of items that are visible in the drop
 * down portion of the receiver's list.
 *
 * @param count the new number of items to be 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 void setVisibleItemCount (int count) {
	checkWidget ();
	if (count < 0) return;
	visibleCount = count;
	if ((style & SWT.DROP_DOWN) != 0) {
		forceResize ();
		RECT rect = new RECT ();
		OS.GetWindowRect (handle, rect);
		int flags = OS.SWP_NOMOVE | OS.SWP_NOZORDER | OS.SWP_DRAWFRAME | OS.SWP_NOACTIVATE;
		setBounds (0, 0, rect.right - rect.left, rect.bottom - rect.top, flags);
	}
}

void subclass () {
	super.subclass ();
	int newProc = display.windowProc;
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndText != 0) {
		OS.SetWindowLong (hwndText, OS.GWL_WNDPROC, newProc);
	}
	int hwndList = OS.GetDlgItem (handle, CBID_LIST);
	if (hwndList != 0) {	
		OS.SetWindowLong (hwndList, OS.GWL_WNDPROC, newProc);
	}
}

boolean translateTraversal (MSG msg) {
	/*
	* When the combo box is dropped down, allow return
	* to select an item in the list and escape to close
	* the combo box.
	*/
	switch (msg.wParam) {
		case OS.VK_RETURN:
		case OS.VK_ESCAPE:
			if (OS.SendMessage (handle, OS.CB_GETDROPPEDSTATE, 0, 0) != 0) {
				return false;
			}
	}
	return super.translateTraversal (msg);
}

boolean traverseEscape () {
	if (OS.SendMessage (handle, OS.CB_GETDROPPEDSTATE, 0, 0) != 0) {
		OS.SendMessage (handle, OS.CB_SHOWDROPDOWN, 0, 0);
		return true;
	}
	return super.traverseEscape ();
}

void unsubclass () {
	super.unsubclass ();
	int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
	if (hwndText != 0 && EditProc != 0) {
		OS.SetWindowLong (hwndText, OS.GWL_WNDPROC, EditProc);
	}
	int hwndList = OS.GetDlgItem (handle, CBID_LIST);
	if (hwndList != 0 && ListProc != 0) {
		OS.SetWindowLong (hwndList, OS.GWL_WNDPROC, ListProc);
	}
}

int widgetExtStyle () {
	return super.widgetExtStyle () & ~OS.WS_EX_NOINHERITLAYOUT;
}

int widgetStyle () {
	int bits = super.widgetStyle () | OS.CBS_AUTOHSCROLL | OS.CBS_NOINTEGRALHEIGHT | OS.WS_VSCROLL;
	if ((style & SWT.SIMPLE) != 0) return bits | OS.CBS_SIMPLE;
	if ((style & SWT.READ_ONLY) != 0) return bits | OS.CBS_DROPDOWNLIST;
	return bits | OS.CBS_DROPDOWN;
}

TCHAR windowClass () {
	return ComboClass;
}

int windowProc () {
	return ComboProc;
}

int windowProc (int hwnd, int msg, int wParam, int lParam) {
	if (handle == 0) return 0;
	if (hwnd != handle) {
		int hwndText = OS.GetDlgItem (handle, CBID_EDIT);
		int hwndList = OS.GetDlgItem (handle, CBID_LIST);
		if ((hwndText != 0 && hwnd == hwndText) || (hwndList != 0 && hwnd == hwndList)) {
			LRESULT result = null;
			switch (msg) {
				case OS.WM_CHAR:		result = WM_CHAR (wParam, lParam); break;
				case OS.WM_IME_CHAR:	result = WM_IME_CHAR (wParam, lParam); break;
				case OS.WM_KEYDOWN:		result = WM_KEYDOWN (wParam, lParam); break;
				case OS.WM_KEYUP:		result = WM_KEYUP (wParam, lParam); break;
				case OS.WM_SYSCHAR:		result = WM_SYSCHAR (wParam, lParam); break;
				case OS.WM_SYSKEYDOWN:	result = WM_SYSKEYDOWN (wParam, lParam); break;
				case OS.WM_SYSKEYUP:	result = WM_SYSKEYUP (wParam, lParam); break;
				case OS.WM_CONTEXTMENU:
					/* Pretend the WM_CONTEXTMENU was sent to the combo box */
					result = WM_CONTEXTMENU (handle, lParam); break;
			}
			if (result != null) return result.value;
			int windowProc = hwnd == hwndText ? EditProc : ListProc;
			return OS.CallWindowProc (windowProc, hwnd, msg, wParam, lParam);
		}
	}	
	return super.windowProc (hwnd, msg, wParam, lParam);
}

LRESULT WM_CHAR (int wParam, int lParam) {
	if (ignoreCharacter) return null;
	LRESULT result = super.WM_CHAR (wParam, lParam);
	if (result != null) return result;
	/*
	* Feature in Windows.  For some reason, when the
	* widget is a single line text widget, when the
	* user presses tab, return or escape, Windows beeps.
	* The fix is to look for these keys and not call
	* the window proc.
	* 
	* NOTE: This only happens when the drop down list
	* is not visible.
	*/
	switch (wParam) {
		case OS.VK_TAB: return LRESULT.ZERO;
		case OS.VK_RETURN:
			postEvent (SWT.DefaultSelection);
			// FALL THROUGH
		case OS.VK_ESCAPE: 
			if (OS.SendMessage (handle, OS.CB_GETDROPPEDSTATE, 0, 0) == 0) {
				return LRESULT.ZERO;
			}
	}
	return result;
}

LRESULT WM_CTLCOLOR (int wParam, int lParam) {
	return wmColorChild (wParam, lParam);
}

LRESULT WM_GETDLGCODE (int wParam, int lParam) {
	int code = callWindowProc (OS.WM_GETDLGCODE, wParam, lParam);
	return new LRESULT (code | OS.DLGC_WANTARROWS);
}

LRESULT WM_IME_CHAR (int wParam, int lParam) {

	/* Process a DBCS character */
	Display display = this.display;
	display.lastKey = 0;
	display.lastAscii = wParam;
	display.lastVirtual = display.lastNull = display.lastDead = false;
	if (!sendKeyEvent (SWT.KeyDown, OS.WM_IME_CHAR, wParam, lParam)) {
		return LRESULT.ZERO;
	}

	/*
	* Feature in Windows.  The Windows text widget uses
	* two 2 WM_CHAR's to process a DBCS key instead of
	* using WM_IME_CHAR.  The fix is to allow the text
	* widget to get the WM_CHAR's but ignore sending
	* them to the application.
	*/
	ignoreCharacter = true;
	int result = callWindowProc (OS.WM_IME_CHAR, wParam, lParam);
	MSG msg = new MSG ();
	int flags = OS.PM_REMOVE | OS.PM_NOYIELD | OS.PM_QS_INPUT | OS.PM_QS_POSTMESSAGE;
	while (OS.PeekMessage (msg, handle, OS.WM_CHAR, OS.WM_CHAR, flags)) {
		OS.TranslateMessage (msg);
		OS.DispatchMessage (msg);
	}
	ignoreCharacter = false;
	
	sendKeyEvent (SWT.KeyUp, OS.WM_IME_CHAR, wParam, lParam);
	// widget could be disposed at this point
	display.lastKey = display.lastAscii = 0;
	return new LRESULT (result);
}

LRESULT WM_KILLFOCUS (int wParam, int lParam) {
	/*
	* Return NULL - Focus notification is
	* done in WM_COMMAND by CBN_KILLFOCUS.
	*/
	return null;
}

LRESULT WM_SETFOCUS (int wParam, int lParam) {
	/*
	* Return NULL - Focus notification is
	* done by WM_COMMAND with CBN_SETFOCUS.
	*/
	return null;
}

LRESULT WM_SIZE (int wParam, int lParam) {	
	/*
	* Feature in Windows.  When an editable drop down combo box
	* contains text that does not correspond to an item in the
	* list, when the widget is resized, it selects the closest
	* match from the list.  The fix is to remember the original
	* text and reset it after the widget is resized.
	*/
	if ((style & SWT.READ_ONLY) != 0 || (style & SWT.DROP_DOWN) == 0) {
		return super.WM_SIZE (wParam, lParam);
	}
	int index = OS.SendMessage (handle, OS.CB_GETCURSEL, 0, 0);
	boolean redraw = false;
	TCHAR buffer = null;
	int [] start = null, end = null;
	if (index == OS.CB_ERR) {
		int length = OS.GetWindowTextLength (handle);
		if (length != 0) {
			buffer = new TCHAR (getCodePage (), length + 1);
			OS.GetWindowText (handle, buffer, length + 1);
			start = new int [1];  end = new int [1];
			OS.SendMessage (handle, OS.CB_GETEDITSEL, start, end);
			redraw = drawCount == 0 && OS.IsWindowVisible (handle);
			if (redraw) setRedraw (false);
		}
	}
	LRESULT result = super.WM_SIZE (wParam, lParam);
	/*
	* It is possible (but unlikely), that application
	* code could have disposed the widget in the resize
	* event.  If this happens, end the processing of the
	* Windows message by returning the result of the
	* WM_SIZE message.
	*/
	if (isDisposed ()) return result;
	if (buffer != null) {
		OS.SetWindowText (handle, buffer);
		int bits = start [0] | (end [0] << 16);
		OS.SendMessage (handle, OS.CB_SETEDITSEL, 0, bits);
		if (redraw) setRedraw (true);
	}
	return result; 
}

LRESULT wmCommandChild (int wParam, int lParam) {
	int code = wParam >> 16;
	switch (code) {
		case OS.CBN_EDITCHANGE:
			/*
			* Feature in Windows.  If the combo box list selection is
			* queried using CB_GETCURSEL before the WM_COMMAND (with
			* CBM_EDITCHANGE) returns, CB_GETCURSEL returns the previous
			* selection in the list.  It seems that the combo box sends
			* the WM_COMMAND before it makes the selection in the list box
			* match the entry field.  The fix is remember that no selection
			* in the list should exist in this case.
			*/
			noSelection = true;
			/*
			* It is possible (but unlikely), that application
			* code could have disposed the widget in the modify
			* event.  If this happens, end the processing of the
			* Windows message by returning zero as the result of
			* the window proc.
			*/
			sendEvent (SWT.Modify);
			if (isDisposed ()) return LRESULT.ZERO;
			noSelection = false;
			break;
		case OS.CBN_SELCHANGE:
			/*
			* Feature in Windows.  If the text in an editable combo box
			* is queried using GetWindowText () before the WM_COMMAND
			* (with CBM_SELCHANGE) returns, GetWindowText () returns is
			* the previous text in the combo box.  It seems that the combo
			* box sends the WM_COMMAND before it updates the text field to
			* match the list selection.  The fix is to force the text field
			* to match the list selection by re-selecting the list item.
			*/
			int index = OS.SendMessage (handle, OS.CB_GETCURSEL, 0, 0);
			if (index != OS.CB_ERR) OS.SendMessage (handle, OS.CB_SETCURSEL, index, 0);
			/*
			* It is possible (but unlikely), that application
			* code could have disposed the widget in the modify
			* event.  If this happens, end the processing of the
			* Windows message by returning zero as the result of
			* the window proc.
			*/
			sendEvent (SWT.Modify);
			if (isDisposed ()) return LRESULT.ZERO;
			postEvent (SWT.Selection);
			break;
		case OS.CBN_SETFOCUS:
		case OS.CBN_KILLFOCUS:
			/*
			* It is possible (but unlikely), that application
			* code could have disposed the widget in the focus
			* event.  If this happens, end the processing of the
			* Windows message by returning zero as the result of
			* the window proc.
			*/
			sendFocusEvent (code == OS.CBN_SETFOCUS ? SWT.FocusIn : SWT.FocusOut, -1);
			if (isDisposed ()) return LRESULT.ZERO;
			break;
	}
	return super.wmCommandChild (wParam, lParam);
}

}