documentation: list of attributes and signals

[miguel-negrao]

It would be very useful if the documentation for each widget would contain the list of attributes and signals that can be used with #.

I see that in the source code these lists are already generated, so perhaps it wouldn't be too difficult to get that into the documentation. For the time being my trick is to open the source code in the documentation page and look for HasAttributeList.

#if defined(ENABLE_OVERLOADING)
instance O.HasAttributeList Widget
type instance O.AttributeList Widget = WidgetAttributeList
type WidgetAttributeList = ('[ '("accessibleRole", Gtk.Accessible.AccessibleAccessibleRolePropertyInfo), '("canFocus", WidgetCanFocusPropertyInfo), '("canTarget", WidgetCanTargetPropertyInfo), '("cssClasses", WidgetCssClassesPropertyInfo), '("cssName", WidgetCssNamePropertyInfo), '("cursor", WidgetCursorPropertyInfo), '("focusOnClick", WidgetFocusOnClickPropertyInfo), '("focusable", WidgetFocusablePropertyInfo), '("halign", WidgetHalignPropertyInfo), '("hasDefault", WidgetHasDefaultPropertyInfo), '("hasFocus", WidgetHasFocusPropertyInfo), '("hasTooltip", WidgetHasTooltipPropertyInfo), '("heightRequest", WidgetHeightRequestPropertyInfo), '("hexpand", WidgetHexpandPropertyInfo), '("hexpandSet", WidgetHexpandSetPropertyInfo), '("layoutManager", WidgetLayoutManagerPropertyInfo), '("marginBottom", WidgetMarginBottomPropertyInfo), '("marginEnd", WidgetMarginEndPropertyInfo), '("marginStart", WidgetMarginStartPropertyInfo), '("marginTop", WidgetMarginTopPropertyInfo), '("name", WidgetNamePropertyInfo), '("opacity", WidgetOpacityPropertyInfo), '("overflow", WidgetOverflowPropertyInfo), '("parent", WidgetParentPropertyInfo), '("receivesDefault", WidgetReceivesDefaultPropertyInfo), '("root", WidgetRootPropertyInfo), '("scaleFactor", WidgetScaleFactorPropertyInfo), '("sensitive", WidgetSensitivePropertyInfo), '("tooltipMarkup", WidgetTooltipMarkupPropertyInfo), '("tooltipText", WidgetTooltipTextPropertyInfo), '("valign", WidgetValignPropertyInfo), '("vexpand", WidgetVexpandPropertyInfo), '("vexpandSet", WidgetVexpandSetPropertyInfo), '("visible", WidgetVisiblePropertyInfo), '("widthRequest", WidgetWidthRequestPropertyInfo)] :: [(Symbol, *)])
#endif

This is related to issue #334.