convert a rectangular selection into a multiple selection on arrow le…

…ft/right or home/end

closes #323

src/ScintillaWnd.cpp

@@ -373,6 +373,20 @@ LRESULT CALLBACK CScintillaWnd::WinMsgHandler(HWND hwnd, UINT uMsg, WPARAM wPara
  break;
  case WM_KEYDOWN:
  {
+ switch (wParam)
+ {
+ case VK_RIGHT:
+ case VK_LEFT:
+ case VK_HOME:
+ case VK_END:
+ if (Scintilla().SelectionMode() != Scintilla::SelectionMode::Stream)
+ {
+ // change to stream mode: converts the rectangular into a multiple selection
+ Scintilla().SetSelectionMode(Scintilla::SelectionMode::Stream);
+ // set stream mode again: cancels selection mode, so moving won't extend the selection anymore
+ Scintilla().SetSelectionMode(Scintilla::SelectionMode::Stream);
+ }
+ }
  auto ret = SendMessage(GetParent(*this), WM_SCICHAR, wParam, lParam);
  if (ret == 0)
  {
@@ -1493,7 +1507,7 @@ void CScintillaWnd::MarkSelectedWord(bool clear, bool edit)
  if (selTextDifferent || (lastStopPosition != 0) || edit)
  {
  int addSelCount = 0;
- auto start = std::chrono::steady_clock::now();
+ auto start  = std::chrono::steady_clock::now();
  if (selTextDifferent)
  {
  m_docScroll.Clear(DOCSCROLLTYPE_SELTEXT);