Function LocalGetWindowPlacement

src/window.cpp:1728–1785

* Compute the position of the top-left corner of a new window that is opened. * * By default position a child window at an offset of 10/10 of its parent. * With the exception of WC_BUILD_TOOLBAR (build railway/roads/ship docks/airports) * and WC_SCEN_LAND_GEN (landscaping). Whose child window has an offset of 0/toolbar-height of * its parent. So it's exactly under the parent toolbar and no bu

 * @return Coordinate of the top-left corner of the new window.
 */
static Point LocalGetWindowPlacement(const WindowDesc &desc, int16_t sm_width, int16_t sm_height, int window_number)
{
	Point pt;
	const Window *w;

	int16_t default_width  = std::max(desc.GetDefaultWidth(),  sm_width);
	int16_t default_height = std::max(desc.GetDefaultHeight(), sm_height);

	if (desc.parent_cls != WC_NONE && (w = FindWindowById(desc.parent_cls, window_number)) != nullptr) {
		bool rtl = _current_text_dir == TD_RTL;
		if (desc.parent_cls == WC_BUILD_TOOLBAR || desc.parent_cls == WC_SCEN_LAND_GEN) {
			pt.x = w->left + (rtl ? w->width - default_width : 0);
			pt.y = w->top + w->height;
			return pt;
		} else {
			/* Position child window with offset of closebox, but make sure that either closebox or resizebox is visible
			 *  - Y position: closebox of parent + closebox of child + statusbar
			 *  - X position: closebox on left/right, resizebox on right/left (depending on ltr/rtl)
			 */
			int indent_y = std::max<int>(NWidgetLeaf::closebox_dimension.height, GetCharacterHeight(FS_NORMAL) + WidgetDimensions::scaled.captiontext.Vertical());
			if (w->top + 3 * indent_y < _screen.height) {
				pt.y = w->top + indent_y;
				int indent_close = NWidgetLeaf::closebox_dimension.width;
				int indent_resize = NWidgetLeaf::resizebox_dimension.width;
				if (_current_text_dir == TD_RTL) {
					pt.x = std::max(w->left + w->width - default_width - indent_close, 0);
					if (pt.x + default_width >= indent_close && pt.x + indent_resize <= _screen.width) return pt;
				} else {
					pt.x = std::min(w->left + indent_close, _screen.width - default_width);
					if (pt.x + default_width >= indent_resize && pt.x + indent_close <= _screen.width) return pt;
				}
			}
		}
	}

	switch (desc.default_pos) {
		case WDP_ALIGN_TOOLBAR: // Align to the toolbar
			return GetToolbarAlignedWindowPosition(default_width);

		case WDP_AUTO: // Find a good automatic position for the window
			return GetAutoPlacePosition(default_width, default_height);

		case WDP_CENTER: // Centre the window horizontally
			pt.x = (_screen.width - default_width) / 2;
			pt.y = (_screen.height - default_height) / 2;
			break;

		case WDP_MANUAL:
			pt.x = 0;
			pt.y = 0;
			break;

		default:
			NOT_REACHED();
	}

	return pt;
}