Function SetObjectToPlace

src/viewport.cpp:3525–3570

* Change the cursor and mouse click/drag handling to a mode for performing special operations like tile area selection, object placement, etc. * @param icon New shape of the mouse cursor. * @param pal Palette to use. * @param mode Mode to perform. * @param window_class %Window class of the window requesting the mode change. * @param window_num Number of the window in its class requesting the

 * @param window_num Number of the window in its class requesting the mode change.
 */
void SetObjectToPlace(CursorID icon, PaletteID pal, HighLightStyle mode, WindowClass window_class, WindowNumber window_num)
{
	if (_thd.window_class != WC_INVALID) {
		/* Undo clicking on button and drag & drop */
		Window *w = _thd.GetCallbackWnd();
		/* Call the abort function, but set the window class to something
		 * that will never be used to avoid infinite loops. Setting it to
		 * the 'next' window class must not be done because recursion into
		 * this function might in some cases reset the newly set object to
		 * place or not properly reset the original selection. */
		_thd.window_class = WC_INVALID;
		if (w != nullptr) {
			w->OnPlaceObjectAbort();
			HideMeasurementTooltips();
		}
	}

	/* Mark the old selection dirty, in case the selection shape or colour changes */
	if ((_thd.drawstyle & HT_DRAG_MASK) != HT_NONE) SetSelectionTilesDirty();

	SetTileSelectSize(1, 1);

	_thd.make_square_red = false;

	if (mode == HT_DRAG) { // HT_DRAG is for dragdropping trains in the depot window
		mode = HT_NONE;
		_special_mouse_mode = WSM_DRAGDROP;
	} else {
		_special_mouse_mode = WSM_NONE;
	}

	_thd.place_mode = mode;
	_thd.window_class = window_class;
	_thd.window_number = window_num;

	if ((mode & HT_DRAG_MASK) == HT_SPECIAL) { // special tools, like tunnels or docks start with presizing mode
		VpStartPreSizing();
	}

	if ((icon & ANIMCURSOR_FLAG) != 0) {
		SetAnimatedMouseCursor(_animcursors[icon & ~ANIMCURSOR_FLAG]);
	} else {
		SetMouseCursor(icon, pal);
	}

}

/** Reset the cursor and mouse mode handling back to default (normal cursor, only clicking in windows). */
void ResetObjectToPlace()