package com.google.gdt.eclipse.designer.ie.jsni;
import org.eclipse.wb.internal.core.utils.reflect.ReflectionUtils;
import org.eclipse.swt.internal.ole.win32.COM;
import org.eclipse.swt.internal.ole.win32.DISPPARAMS;
import org.eclipse.swt.internal.ole.win32.EXCEPINFO;
import org.eclipse.swt.internal.ole.win32.GUID;
import org.eclipse.swt.internal.ole.win32.IDispatch;
import org.eclipse.swt.internal.ole.win32.VARIANT;
import org.eclipse.swt.internal.win32.OS;
import org.eclipse.swt.ole.win32.OleAutomation;
import org.eclipse.swt.ole.win32.Variant;
/**
* This is extracted implementation from {@link OleAutomation} to fix bug in {@link Variant}. It
* handles {@link COM#VT_BSTR} <code>null</code> as {@link COM#VT_EMPTY}, but actually should handle
* it as an empty {@link String}.
* <p>
* http://blogs.msdn.com/b/ericlippert/archive/2003/09/12/52976.aspx
*
* @author scheglov_ke
*/
public class OleAutomationFix {
/**
* @see OleAutomation#invoke(int, Variant[])
*/
public static Variant invoke(OleAutomation automation, int dispIdMember, Variant[] rgvarg) {
try {
Variant pVarResult = new Variant();
int result = invoke(automation, dispIdMember, COM.DISPATCH_METHOD, rgvarg, null, pVarResult);
return (result == COM.S_OK) ? pVarResult : null;
} catch (Throwable e) {
throw ReflectionUtils.propagate(e);
}
}
private static int invoke(OleAutomation automation,
int dispIdMember,
int wFlags,
Variant[] rgvarg,
int[] rgdispidNamedArgs,
Variant pVarResult) throws Exception {
IDispatch objIDispatch = (IDispatch) ReflectionUtils.getFieldObject(automation, "objIDispatch");
// get the IDispatch interface for the control
if (objIDispatch == null)
return COM.E_FAIL;
// create a DISPPARAMS structure for the input parameters
DISPPARAMS pDispParams = new DISPPARAMS();
// store arguments in rgvarg
if (rgvarg != null && rgvarg.length > 0) {
pDispParams.cArgs = rgvarg.length;
pDispParams.rgvarg =
OS.GlobalAlloc(COM.GMEM_FIXED | COM.GMEM_ZEROINIT, VARIANT.sizeof * rgvarg.length);
int offset = 0;
for (int i = rgvarg.length - 1; i >= 0; i--) {
ReflectionUtils.invokeMethod(rgvarg[i], "getData(int)", pDispParams.rgvarg + offset);
offset += VARIANT.sizeof;
}
}
// if arguments have ids, store the ids in rgdispidNamedArgs
if (rgdispidNamedArgs != null && rgdispidNamedArgs.length > 0) {
pDispParams.cNamedArgs = rgdispidNamedArgs.length;
pDispParams.rgdispidNamedArgs =
OS.GlobalAlloc(COM.GMEM_FIXED | COM.GMEM_ZEROINIT, 4 * rgdispidNamedArgs.length);
int offset = 0;
for (int i = rgdispidNamedArgs.length; i > 0; i--) {
COM.MoveMemory(
pDispParams.rgdispidNamedArgs + offset,
new int[]{rgdispidNamedArgs[i - 1]},
4);
offset += 4;
}
}
// invoke the method
EXCEPINFO excepInfo = new EXCEPINFO();
int[] pArgErr = new int[1];
int /*long*/pVarResultAddress = 0;
if (pVarResult != null)
pVarResultAddress = OS.GlobalAlloc(OS.GMEM_FIXED | OS.GMEM_ZEROINIT, VARIANT.sizeof);
int result =
objIDispatch.Invoke(
dispIdMember,
new GUID(),
COM.LOCALE_USER_DEFAULT,
wFlags,
pDispParams,
pVarResultAddress,
excepInfo,
pArgErr);
if (pVarResultAddress != 0) {
// get VT_ type
int type;
{
short[] dataType = new short[1];
COM.MoveMemory(dataType, pVarResultAddress, 2);
type = dataType[0];
}
// initialize "pVarResult"
ReflectionUtils.invokeMethod(pVarResult, "setData(int)", pVarResultAddress);
COM.VariantClear(pVarResultAddress);
OS.GlobalFree(pVarResultAddress);
// if was VT_BSTR and become VT_EMPTY that this is bug in SWT Variant
if (type == COM.VT_BSTR && pVarResult.getType() == COM.VT_EMPTY) {
ReflectionUtils.setField(pVarResult, "type", COM.VT_BSTR);
ReflectionUtils.setField(pVarResult, "stringData", "");
}
}
// free the Dispparams resources
if (pDispParams.rgdispidNamedArgs != 0) {
OS.GlobalFree(pDispParams.rgdispidNamedArgs);
}
if (pDispParams.rgvarg != 0) {
int offset = 0;
for (int i = 0, length = rgvarg.length; i < length; i++) {
COM.VariantClear(pDispParams.rgvarg + offset);
offset += VARIANT.sizeof;
}
OS.GlobalFree(pDispParams.rgvarg);
}
// save error string and cleanup EXCEPINFO
//manageExcepinfo(result, excepInfo);
ReflectionUtils.invokeMethod(
automation,
"manageExcepinfo(int,org.eclipse.swt.internal.ole.win32.EXCEPINFO)",
result,
excepInfo);
return result;
}
}