Method GetTabDisplayAreaRect

source/script_gui.cpp:10162–10205

void GuiType::GetTabDisplayAreaRect(HWND aTabControlHwnd, RECT &aRect)
// Gets coordinates of tab control's display area relative to parent window's client area.
{
	RECT rect;
	GetClientRect(aTabControlHwnd, &rect); // Used because the coordinates of its upper-left corner are (0,0).
	DWORD style = GetWindowLong(aTabControlHwnd, GWL_STYLE);
	if (style & TCS_BUTTONS) // Workarounds are needed for TCS_BUTTONS.
	{
		RECT item_rect;
		TabCtrl_GetItemRect(aTabControlHwnd, 0, &item_rect);
		int row_count = TabCtrl_GetRowCount(aTabControlHwnd);
		const int offset = 3; // The margin between buttons seems to be 3 pixels.
		if (style & TCS_VERTICAL)
		{
			// TabCtrl_AdjustRect would not work for these cases.
			int width = (item_rect.right - item_rect.left + offset) * row_count;
			if (style & TCS_RIGHT)
				rect.right -= width;
			else
				rect.left += width;
		}
		else
		{
			int height = (item_rect.bottom - item_rect.top + offset) * row_count;
			if (style & TCS_BOTTOM)
				// TabCtrl_AdjustRect would not work for this case.
				rect.bottom -= height;
			else
				// TabCtrl_AdjustRect plus an adjustment of bottom += 3 would work,
				// but it's easier to handle this case alongside TCS_BOTTOM (above).
				rect.top += height;
		}
	}
	else
	{
		TabCtrl_AdjustRect(aTabControlHwnd, FALSE, &rect); // Retrieve the area beneath the tabs.
		rect.left -= 2;  // Testing shows that X (but not Y) is off by exactly 2.
	}
	MapWindowPoints(aTabControlHwnd, mHwnd, (LPPOINT)&rect, 2); // Convert tab-control-relative coordinates to Gui-relative.
	aRect.left = rect.left;
	aRect.right = rect.right;
	aRect.top = rect.top;
	aRect.bottom = rect.bottom;
}