Article-Writing Your Own Widget/Writing Your Own Widget_files/AppendixC.htm - www.eclipse.org/articles - Git at Google

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 <meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
 <meta name="GENERATOR" content="Microsoft FrontPage 4.0">
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 <meta name="Author" content="Carolyn MacLeod">
 <title>Appendix C: Spinner for Windows</title>
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 <body>
 <h2>Appendix C: Spinner for Windows</h2>
 This appendix contains the source code for the Windows version of the <i>Spinner</i> natives in spinner.c, and the batch file and makefile for building the Windows Dynamic Link Library
 spinner.dll.
 <h3><strong>spinner.c</strong></h3>
 <pre>
 /*
  * (c) Copyright IBM Corp. 2000, 2001.
  * All Rights Reserved.
  */

 #include &lt;jni.h&gt;
 #include &lt;windows.h&gt;
 #include &lt;commctrl.h&gt;

 static DWORD tlsIndex = 0;
 static jobject javaClass;
 static jmethodID mid;
 static WNDPROC oldProc;

 LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
     JNIEnv *env = TlsGetValue(tlsIndex);
     if (env != NULL) {
         /* If an exception has already occurred,
          * allow the stack to unwind so that the
          * exception will be thrown in Java. */
         if ((*env)-&gt;ExceptionOccurred(env)) return 0;
         switch (msg) {
             case WM_VSCROLL:
                 if ((wParam &amp; 0xFFFF) == SB_THUMBPOSITION) {
                     ((*env)-&gt;CallStaticVoidMethod(env, javaClass, mid, lParam));
                     return (LRESULT) 0;
                 }
                 break;
         }
     }
     return CallWindowProc(oldProc, hwnd, msg, wParam, lParam);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    createControl
  * Signature: (I)I
  */
 JNIEXPORT jint JNICALL Java_spinner_Spinner_createControl
     (JNIEnv *env, jclass that, jint hwndParent)
 {
     HWND hwndText, hwndUpDown;
     if (tlsIndex == 0) {
         tlsIndex = TlsAlloc();
         if (tlsIndex == -1) return (jint) 0;
         javaClass = (*env)-&gt;NewGlobalRef(env, (jobject) that);
         mid = (*env)-&gt;GetStaticMethodID(env, (jobject) that, &quot;widgetSelected&quot;, &quot;(I)V&quot;);
         oldProc = (WNDPROC) GetWindowLong((HWND) hwndParent, GWL_WNDPROC);
     }
     TlsSetValue(tlsIndex, (LPVOID) env);

     hwndText = CreateWindowEx(
         WS_EX_CLIENTEDGE,
         &quot;EDIT&quot;,
         NULL,
         WS_CHILD | WS_VISIBLE | WS_TABSTOP,
         0, 0, 0, 0,
         (HWND) hwndParent,
         0,
         GetModuleHandle(NULL),
         NULL);
     if (hwndText == 0) return (jint) 0;
     hwndUpDown = CreateWindowEx(
         0,
         UPDOWN_CLASS,
         NULL,
         WS_CHILD | WS_VISIBLE | UDS_AUTOBUDDY | UDS_SETBUDDYINT | UDS_ALIGNRIGHT | UDS_ARROWKEYS | UDS_NOTHOUSANDS,
         0, 0, 0, 0,
         (HWND) hwndParent,
         0,
         GetModuleHandle(NULL),
         NULL);
     if (hwndUpDown == 0) return (jint) 0;
     SetWindowLong((HWND) hwndParent, GWL_WNDPROC, (long) WindowProc);
     return (jint) hwndUpDown;
 }

 /*
  * Class:     spinner_Spinner
  * Method:    computeSize
  * Signature: (I[I)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_computeSize
     (JNIEnv *env, jclass that, jint hwndUpDown, jintArray result) {
     int width, height;
     TEXTMETRIC tm;
     RECT rect;
     int comboHeight;
     int max, digits;
     UINT flags;
     char text[64];
     HWND hwndText = (HWND) SendMessage((HWND) hwndUpDown, UDM_GETBUDDY, 0, 0);
     HDC hDC = GetDC(hwndText);
     HFONT oldFont = 0;
     HFONT newFont = (HFONT) SendMessage(hwndText, WM_GETFONT, 0, 0);

     jint *result1 = NULL;
     result1 = (*env)-&gt;GetIntArrayElements(env, result, NULL);

     if (newFont != 0) oldFont = SelectObject(hDC, newFont);
     GetTextMetrics(hDC, &amp;tm);
     comboHeight = GetSystemMetrics(SM_CYVSCROLL);
     height = (comboHeight &gt; tm.tmHeight) ? comboHeight : tm.tmHeight;
     max = SendMessage((HWND) hwndUpDown, UDM_GETRANGE, 0, 0) &amp; 0xFFFF;
     if (max &gt; 0) {
         digits = 0;
         while (max &gt; 0) {
             text[digits] = '0';
             max /= 10;
             digits++;
         }
         flags = DT_CALCRECT | DT_EDITCONTROL | DT_NOPREFIX;
         DrawText(hDC, (LPCTSTR) text, digits, (LPRECT) &amp;rect, flags);
         width = rect.right - rect.left + 3;
     } else {
         width = 10;
     }
     if (newFont != 0) SelectObject(hDC, oldFont);
     ReleaseDC(hwndText, hDC);
     width += GetSystemMetrics(SM_CXVSCROLL);
     SendMessage(hwndText, EM_GETRECT, 0, (LPARAM) &amp;rect);
     if (rect.top == 0) rect.top = 1; // windows bug fix
     width += (rect.left + 1) * 2;
     height += (rect.top + 1) * 2;

     result1 [0] = width;
     result1 [1] = height;
     (*env)-&gt;ReleaseIntArrayElements(env, result, result1, 0);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    resizeControl
  * Signature: (IIIII)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_resizeControl
     (JNIEnv *env, jclass that, jint hwndUpDown, jint x, jint y, jint width, jint height)
 {
     HWND hwndText = (HWND) SendMessage((HWND) hwndUpDown, UDM_GETBUDDY, 0, 0);
     UINT flags = SWP_NOZORDER | SWP_DRAWFRAME | SWP_NOACTIVATE;
     int upDownWidth = GetSystemMetrics(SM_CXVSCROLL);
     SetWindowPos(hwndText, (HWND) 0, x, y, width - upDownWidth + 2, height, flags);
     SetWindowPos((HWND) hwndUpDown, (HWND) 0, x + width - upDownWidth, y, upDownWidth, height, flags);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    setPosition
  * Signature: (II)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_setPosition
     (JNIEnv *env, jclass that, jint hwnd, jint position)
 {
     SendMessage((HWND) hwnd, UDM_SETPOS, 0, position);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    getPosition
  * Signature: (I)I
  */
 JNIEXPORT jint JNICALL Java_spinner_Spinner_getPosition
     (JNIEnv *env, jclass that, jint hwnd)
 {
     return (jint) SendMessage((HWND) hwnd, UDM_GETPOS, 0, 0) &amp; 0xFFFF;
 }

 /*
  * Class:     spinner_Spinner
  * Method:    setMaximum
  * Signature: (II)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_setMaximum
     (JNIEnv *env, jclass that, jint hwnd, jint max)
 {
     int min = SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) &gt;&gt; 16;
     SendMessage((HWND) hwnd, UDM_SETRANGE, 0, (min &lt;&lt; 16) | max);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    getMaximum
  * Signature: (I)I
  */
 JNIEXPORT jint JNICALL Java_spinner_Spinner_getMaximum
     (JNIEnv *env, jclass that, jint hwnd)
 {
     return SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) &amp; 0xFFFF;
 }

 /*
  * Class:     spinner_Spinner
  * Method:    setMinimum
  * Signature: (II)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_setMinimum
     (JNIEnv *env, jclass that, jint hwnd, jint min)
 {
     int max = SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) &amp; 0xFFFF;
     SendMessage((HWND) hwnd, UDM_SETRANGE, 0, (min &lt;&lt; 16) | max);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    getMinimum
  * Signature: (I)I
  */
 JNIEXPORT jint JNICALL Java_spinner_Spinner_getMinimum
     (JNIEnv *env, jclass that, jint hwnd)
 {
     return SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) &gt;&gt; 16;
 }

 /*
  * Class:     spinner_Spinner
  * Method:    setFont
  * Signature: (II)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_setFont
     (JNIEnv *env, jclass that, jint hwnd, jint hFont)
 {
     HWND hwndText = (HWND) SendMessage((HWND) hwnd, UDM_GETBUDDY, 0, 0);
     SendMessage(hwndText, WM_SETFONT, hFont, 1);
 }

 /*
  * Class:     spinner_Spinner
  * Method:    setFocus
  * Signature: (I)V
  */
 JNIEXPORT void JNICALL Java_spinner_Spinner_setFocus
     (JNIEnv *env, jclass that, jint hwnd)
 {
     HWND hwndText = (HWND) SendMessage((HWND) hwnd, UDM_GETBUDDY, 0, 0);
     SetFocus(hwndText);
 }
 </pre>
 <p>
 <h3><strong>build.bat</strong></h3>
 <pre>
 @echo off

 IF NOT &quot;%IVE_HOME%&quot;==&quot;&quot; GOTO MAKE

 set IVE_HOME=j:\teamswt\swt-builddir\ive\bin
 set path=%IVE_HOME%;%path%

 rem NOTE:
 rem Initialize MSVC 6.0/MSSDK environment
 call k:\dev\products\msvc60\vc98\bin\vcvars32.bat
 set Mssdk=j:\teamswt\swt-builddir\mssdk
 call %Mssdk%\setenv.bat

 :MAKE
 nmake makefile.mak
 </pre>
 <p>
 <h3><strong>makefile.mak</strong></h3>
 <pre>
 # Makefile for module 'spinner.dll'
 # assumes IVE_HOME is set in the environment from which nmake is run

 !include &lt;win32.mak&gt;

 DLLPREFIX=spinner
 DLLNAME=$(DLLPREFIX).dll

 CFLAGS=-c -W3 -G6 -GD -O1 -nologo -D_X86_=1 -D_WIN32 -D_WIN95 -D_WIN32_WINDOWS=0x0400 -D_MT -MT -DWIN32 -D_WIN32_DCOM /I$(IVE_HOME)\include /I.
 LFLAGS=/INCREMENTAL:NO /PDB:NONE /RELEASE /NOLOGO /BASE:0x10000000 /DLL

 LINK_LIBS=comctl32.lib user32.lib gdi32.lib

 OBJS=$(DLLPREFIX).obj

 all: $(OBJS) $(DLLPREFIX)

 $(DLLPREFIX): $(OBJS)
     echo $(LINK_LIBS) &gt;templrf
     echo $(LFLAGS) &gt;&gt;templrf
     echo -machine:IX86 &gt;&gt;templrf
     echo -subsystem:windows &gt;&gt;templrf
     echo -out:$(DLLNAME) &gt;&gt;templrf
     echo $(OBJS) &gt;&gt;templrf
     link @templrf
     del templrf

 clean:
     del *.obj
     del *.dll
     del *.exp

 .c.obj:
     cl $(CFLAGS) $*.c
 </pre>
 </body>

 </html>
	<html>

	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
	<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
	<meta name="ProgId" content="FrontPage.Editor.Document">
	<meta name="Author" content="Carolyn MacLeod">
	<title>Appendix C: Spinner for Windows</title>
	</head>

	<body>
	<h2>Appendix C: Spinner for Windows</h2>
	This appendix contains the source code for the Windows version of the <i>Spinner</i> natives in spinner.c, and the batch file and makefile for building the Windows Dynamic Link Library
	spinner.dll.
	<h3><strong>spinner.c</strong></h3>
	<pre>
	/*
	* (c) Copyright IBM Corp. 2000, 2001.
	* All Rights Reserved.
	*/

	#include <jni.h>
	#include <windows.h>
	#include <commctrl.h>

	static DWORD tlsIndex = 0;
	static jobject javaClass;
	static jmethodID mid;
	static WNDPROC oldProc;

	LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
	JNIEnv *env = TlsGetValue(tlsIndex);
	if (env != NULL) {
	/* If an exception has already occurred,
	* allow the stack to unwind so that the
	* exception will be thrown in Java. */
	if ((*env)->ExceptionOccurred(env)) return 0;
	switch (msg) {
	case WM_VSCROLL:
	if ((wParam & 0xFFFF) == SB_THUMBPOSITION) {
	((*env)->CallStaticVoidMethod(env, javaClass, mid, lParam));
	return (LRESULT) 0;
	}
	break;
	}
	}
	return CallWindowProc(oldProc, hwnd, msg, wParam, lParam);
	}

	/*
	* Class: spinner_Spinner
	* Method: createControl
	* Signature: (I)I
	*/
	JNIEXPORT jint JNICALL Java_spinner_Spinner_createControl
	(JNIEnv *env, jclass that, jint hwndParent)
	{
	HWND hwndText, hwndUpDown;
	if (tlsIndex == 0) {
	tlsIndex = TlsAlloc();
	if (tlsIndex == -1) return (jint) 0;
	javaClass = (*env)->NewGlobalRef(env, (jobject) that);
	mid = (*env)->GetStaticMethodID(env, (jobject) that, "widgetSelected", "(I)V");
	oldProc = (WNDPROC) GetWindowLong((HWND) hwndParent, GWL_WNDPROC);
	}
	TlsSetValue(tlsIndex, (LPVOID) env);

	hwndText = CreateWindowEx(
	WS_EX_CLIENTEDGE,
	"EDIT",
	NULL,
	WS_CHILD \| WS_VISIBLE \| WS_TABSTOP,
	0, 0, 0, 0,
	(HWND) hwndParent,
	0,
	GetModuleHandle(NULL),
	NULL);
	if (hwndText == 0) return (jint) 0;
	hwndUpDown = CreateWindowEx(
	0,
	UPDOWN_CLASS,
	NULL,
	WS_CHILD \| WS_VISIBLE \| UDS_AUTOBUDDY \| UDS_SETBUDDYINT \| UDS_ALIGNRIGHT \| UDS_ARROWKEYS \| UDS_NOTHOUSANDS,
	0, 0, 0, 0,
	(HWND) hwndParent,
	0,
	GetModuleHandle(NULL),
	NULL);
	if (hwndUpDown == 0) return (jint) 0;
	SetWindowLong((HWND) hwndParent, GWL_WNDPROC, (long) WindowProc);
	return (jint) hwndUpDown;
	}

	/*
	* Class: spinner_Spinner
	* Method: computeSize
	* Signature: (I[I)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_computeSize
	(JNIEnv *env, jclass that, jint hwndUpDown, jintArray result) {
	int width, height;
	TEXTMETRIC tm;
	RECT rect;
	int comboHeight;
	int max, digits;
	UINT flags;
	char text[64];
	HWND hwndText = (HWND) SendMessage((HWND) hwndUpDown, UDM_GETBUDDY, 0, 0);
	HDC hDC = GetDC(hwndText);
	HFONT oldFont = 0;
	HFONT newFont = (HFONT) SendMessage(hwndText, WM_GETFONT, 0, 0);

	jint *result1 = NULL;
	result1 = (*env)->GetIntArrayElements(env, result, NULL);

	if (newFont != 0) oldFont = SelectObject(hDC, newFont);
	GetTextMetrics(hDC, &tm);
	comboHeight = GetSystemMetrics(SM_CYVSCROLL);
	height = (comboHeight > tm.tmHeight) ? comboHeight : tm.tmHeight;
	max = SendMessage((HWND) hwndUpDown, UDM_GETRANGE, 0, 0) & 0xFFFF;
	if (max > 0) {
	digits = 0;
	while (max > 0) {
	text[digits] = '0';
	max /= 10;
	digits++;
	}
	flags = DT_CALCRECT \| DT_EDITCONTROL \| DT_NOPREFIX;
	DrawText(hDC, (LPCTSTR) text, digits, (LPRECT) &rect, flags);
	width = rect.right - rect.left + 3;
	} else {
	width = 10;
	}
	if (newFont != 0) SelectObject(hDC, oldFont);
	ReleaseDC(hwndText, hDC);
	width += GetSystemMetrics(SM_CXVSCROLL);
	SendMessage(hwndText, EM_GETRECT, 0, (LPARAM) &rect);
	if (rect.top == 0) rect.top = 1; // windows bug fix
	width += (rect.left + 1) * 2;
	height += (rect.top + 1) * 2;

	result1 [0] = width;
	result1 [1] = height;
	(*env)->ReleaseIntArrayElements(env, result, result1, 0);
	}

	/*
	* Class: spinner_Spinner
	* Method: resizeControl
	* Signature: (IIIII)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_resizeControl
	(JNIEnv *env, jclass that, jint hwndUpDown, jint x, jint y, jint width, jint height)
	{
	HWND hwndText = (HWND) SendMessage((HWND) hwndUpDown, UDM_GETBUDDY, 0, 0);
	UINT flags = SWP_NOZORDER \| SWP_DRAWFRAME \| SWP_NOACTIVATE;
	int upDownWidth = GetSystemMetrics(SM_CXVSCROLL);
	SetWindowPos(hwndText, (HWND) 0, x, y, width - upDownWidth + 2, height, flags);
	SetWindowPos((HWND) hwndUpDown, (HWND) 0, x + width - upDownWidth, y, upDownWidth, height, flags);
	}

	/*
	* Class: spinner_Spinner
	* Method: setPosition
	* Signature: (II)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_setPosition
	(JNIEnv *env, jclass that, jint hwnd, jint position)
	{
	SendMessage((HWND) hwnd, UDM_SETPOS, 0, position);
	}

	/*
	* Class: spinner_Spinner
	* Method: getPosition
	* Signature: (I)I
	*/
	JNIEXPORT jint JNICALL Java_spinner_Spinner_getPosition
	(JNIEnv *env, jclass that, jint hwnd)
	{
	return (jint) SendMessage((HWND) hwnd, UDM_GETPOS, 0, 0) & 0xFFFF;
	}

	/*
	* Class: spinner_Spinner
	* Method: setMaximum
	* Signature: (II)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_setMaximum
	(JNIEnv *env, jclass that, jint hwnd, jint max)
	{
	int min = SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) >> 16;
	SendMessage((HWND) hwnd, UDM_SETRANGE, 0, (min << 16) \| max);
	}

	/*
	* Class: spinner_Spinner
	* Method: getMaximum
	* Signature: (I)I
	*/
	JNIEXPORT jint JNICALL Java_spinner_Spinner_getMaximum
	(JNIEnv *env, jclass that, jint hwnd)
	{
	return SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) & 0xFFFF;
	}

	/*
	* Class: spinner_Spinner
	* Method: setMinimum
	* Signature: (II)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_setMinimum
	(JNIEnv *env, jclass that, jint hwnd, jint min)
	{
	int max = SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) & 0xFFFF;
	SendMessage((HWND) hwnd, UDM_SETRANGE, 0, (min << 16) \| max);
	}

	/*
	* Class: spinner_Spinner
	* Method: getMinimum
	* Signature: (I)I
	*/
	JNIEXPORT jint JNICALL Java_spinner_Spinner_getMinimum
	(JNIEnv *env, jclass that, jint hwnd)
	{
	return SendMessage((HWND) hwnd, UDM_GETRANGE, 0, 0) >> 16;
	}

	/*
	* Class: spinner_Spinner
	* Method: setFont
	* Signature: (II)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_setFont
	(JNIEnv *env, jclass that, jint hwnd, jint hFont)
	{
	HWND hwndText = (HWND) SendMessage((HWND) hwnd, UDM_GETBUDDY, 0, 0);
	SendMessage(hwndText, WM_SETFONT, hFont, 1);
	}

	/*
	* Class: spinner_Spinner
	* Method: setFocus
	* Signature: (I)V
	*/
	JNIEXPORT void JNICALL Java_spinner_Spinner_setFocus
	(JNIEnv *env, jclass that, jint hwnd)
	{
	HWND hwndText = (HWND) SendMessage((HWND) hwnd, UDM_GETBUDDY, 0, 0);
	SetFocus(hwndText);
	}
	</pre>
	<p>
	<h3><strong>build.bat</strong></h3>
	<pre>
	@echo off

	IF NOT "%IVE_HOME%"=="" GOTO MAKE

	set IVE_HOME=j:\teamswt\swt-builddir\ive\bin
	set path=%IVE_HOME%;%path%

	rem NOTE:
	rem Initialize MSVC 6.0/MSSDK environment
	call k:\dev\products\msvc60\vc98\bin\vcvars32.bat
	set Mssdk=j:\teamswt\swt-builddir\mssdk
	call %Mssdk%\setenv.bat

	:MAKE
	nmake makefile.mak
	</pre>
	<p>
	<h3><strong>makefile.mak</strong></h3>
	<pre>
	# Makefile for module 'spinner.dll'
	# assumes IVE_HOME is set in the environment from which nmake is run

	!include <win32.mak>

	DLLPREFIX=spinner
	DLLNAME=$(DLLPREFIX).dll

	CFLAGS=-c -W3 -G6 -GD -O1 -nologo -D_X86_=1 -D_WIN32 -D_WIN95 -D_WIN32_WINDOWS=0x0400 -D_MT -MT -DWIN32 -D_WIN32_DCOM /I$(IVE_HOME)\include /I.
	LFLAGS=/INCREMENTAL:NO /PDB:NONE /RELEASE /NOLOGO /BASE:0x10000000 /DLL

	LINK_LIBS=comctl32.lib user32.lib gdi32.lib

	OBJS=$(DLLPREFIX).obj

	all: $(OBJS) $(DLLPREFIX)

	$(DLLPREFIX): $(OBJS)
	echo $(LINK_LIBS) >templrf
	echo $(LFLAGS) >>templrf
	echo -machine:IX86 >>templrf
	echo -subsystem:windows >>templrf
	echo -out:$(DLLNAME) >>templrf
	echo $(OBJS) >>templrf
	link @templrf
	del templrf

	clean:
	del *.obj
	del *.dll
	del *.exp

	.c.obj:
	cl $(CFLAGS) $*.c
	</pre>
	</body>

	</html>