Using an event name with return type and arguments
The following description uses the first syntax. The class
has two events, onclick and ondoubleclick:
PBXEXPORT LPCTSTR PBXCALL PBX_GetDescription()
{
static const TCHAR desc[] = {
"class visualext from userobject\n"
"event int onclick()\n"
"event int ondoubleclick()\n"
"subroutine setcolor(int r, int g, int b)\n"
"subroutine settext(string txt)\n"
"end class\n"
};
return desc;
}
Capturing messages and mouse clicks
The code
in the extension captures the Windows messages that cause the window
to be drawn, as well as mouse clicks and double clicks:
LRESULT CALLBACK CVisualExt::WindowProc(
HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam
)
{
CVisualExt* ext = (CVisualExt*)::GetWindowLong(hwnd,
GWL_USERDATA);
switch(uMsg) {
case WM_CREATE:
return 0;
case WM_SIZE:
return 0;
case WM_COMMAND:
return 0;
case WM_PAINT: {
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd, &ps);
RECT rc;
GetClientRect(hwnd, &rc);
LOGBRUSH lb;
lb.lbStyle = BS_SOLID;
// Get color using the visual class's GetColor method
lb.lbColor = ext->GetColor();
HBRUSH hbrush = CreateBrushIndirect(&lb);
HBRUSH hbrOld = (HBRUSH)SelectObject(hdc,
hbrush);
Rectangle(hdc, rc.left, rc.top, rc.right-rc.left,
rc.bottom-rc.top);
SelectObject(hdc, hbrOld);
DeleteObject(hbrush);
// Get text using the visual class's GetText method
DrawText(hdc, ext->GetText(),
ext->GetTextLength(), &rc,
DT_CENTER|DT_VCENTER|DT_SINGLELINE);
EndPaint(hwnd, &ps);
}
return 0;
// Trigger event scripts in the PowerBuilder application
case WM_LBUTTONUP:
ext->TriggerEvent("onclick");
break;
case WM_LBUTTONDBLCLK:
ext->TriggerEvent("ondoubleclick");
break;
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}
Triggering click events
The following is the TriggerEvent method
that triggers the Onclick and Ondoubleclick events:
void CVisualExt::TriggerEvent(LPCTSTR eventName)
{
pbclass clz = d_session->GetClass(d_pbobj);
pbmethodID mid = d_session->GetMethodID(clz,
eventName, PBRT_EVENT, "I");
PBCallInfo ci;
d_session->InitCallInfo(clz, mid, &ci);
d_session->TriggerEvent(d_pbobj, mid, &ci);
d_session->FreeCallInfo(&ci);
}