dw::core::ui Namespace Reference

Anything related to embedded UI widgets is defined here. More...

Classes
class	ButtonResource
class	CheckButtonResource
class	ComplexButtonResource
class	Embed
	A widget for embedding UI widgets. More...
class	EntryResource
class	LabelButtonResource
	Interface for labelled buttons resources. More...
class	ListResource
class	MultiLineTextResource
class	OptionMenuResource
class	RadioButtonResource
class	Resource
	Basic interface for all resources. More...
class	ResourceFactory
	A factory for the common resource. More...
class	SelectionResource
	Base interface for dw::core::ui::ListResource and dw::core::ui::OptionMenuResource. More...
class	TextResource
class	ToggleButtonResource

Detailed Description

Anything related to embedded UI widgets is defined here.

UI resources are another abstraction for Dw widgets, which are not fully implemented in a platform-independent way. Typically, they involve creating widgets, which the underlying UI toolkit provides.

As you see in this diagram:

[legend]

there are several levels:

1. The Dw widget is dw::core::ui::Embed. It delegates most to dw::core::ui::Resource, which has similar methods like dw::core::Widget.

2. There are several sub interfaces of dw::core::ui::Resource, which may provide methods, as e.g. dw::core::ui::ListResource::addItem. In a platform independent context, you can cast the result of dw::core::ui::Embed::getResource to a specific sub class, if you know, which one is used. E.g., if you know, that a given instance dw::core::ui::Embed refers to a dw::core::ui::ListResource, you can write something like:

   dw::core::ui::Embed *embed;
   //...
   ((dw::core::ui::ListResource*)embed->getResource ())->addItem ("Hello!");

3. These sub classes are then fully implemented in a platform specific way. For an example, look at dw::fltk::ui.

There is a factory interface, dw::core::ui::ResourceFactory, which provides methods for creating common resources. By calling dw::core::Layout::getResourceFactory, which calls dw::core::Platform::getResourceFactory, you get the factory for the used platform.

It is possible to define additional sub classes of dw::core::ui::Resource, but since they are not provided by dw::core::ui::ResourceFactory, you have to define some other abstractions, if you want to remain platform independent.

...

Resouces needed for HTML

This chapter describes, how the form controls defined by HTML are implemented in Dw. Some of them do not refer to UI resources, but to other widgets, links to the respective documentations are provided here.

Resouces created with <INPUT>

The HTML <INPUT> is always implemented by using UI resources. <INPUT> element has the following attributes:

Attribute	Implementation
type	This defines the resource you have to instantiate.
name	Not needed within Dw.
value	The initial value is treated differently by different resources.
checked	Parameter to dw::core::ui::ResourceFactory::createCheckButtonResource and dw::core::ui::ResourceFactory::createRadioButtonResource.
disabled	This is provided for all resources by dw::core::ui::Resource::setEnabled.
readonly	This is provided by dw::core::ui::TextResource::setEditable.
size	This is handled by styles.
maxlength	Parameter of dw::core::ui::ResourceFactory::createEntryResource.
src	Handled by the caller (HTML parser).
alt	Handled by the caller (HTML parser).
usemap	Handled by the caller (HTML parser).
ismap	Handled by the caller (HTML parser).
tabindex	Not supported currently.
accesskey	Not supported currently.
onfocus	Not supported currently.
onblur	Not supported currently.
onselect	Not supported currently.
onchange	Not supported currently.
accept	Not supported currently.

For the different values of type, the following resources can be used:

Type	Resource	Factory Method
text	dw::core::ui::EntryResource	dw::core::ui::ResourceFactory::createEntryResource
password	dw::core::ui::EntryResource	dw::core::ui::ResourceFactory::createEntryResource
checkbox	dw::core::ui::CheckButtonResource	dw::core::ui::ResourceFactory::createCheckButtonResource
radio	dw::core::ui::RadioButtonResource	dw::core::ui::ResourceFactory::createRadioButtonResource
submit	dw::core::ui::LabelButtonResource	dw::core::ui::ResourceFactory::createLabelButtonResource
image	dw::core::ui::ComplexButtonResource	dw::core::ui::ResourceFactory::createComplexButtonResource, width a dw::Image inside and relief = false.
reset	dw::core::ui::LabelButtonResource	dw::core::ui::ResourceFactory::createLabelButtonResource
button	dw::core::ui::LabelButtonResource	dw::core::ui::ResourceFactory::createLabelButtonResource
hidden	No rendering necessary.	-
file	Not supported currently.	-

<SELECT>, <OPTGROUP>, and <OPTION>

<SELECT> is implemented either by dw::core::ui::OptionMenuResource (better suitable for size = 1 and single selection) or dw::core::ui::ListResource, which have a common base, dw::core::ui::SelectionResource. In the latter case, size must be specified via dw::core::style::Style.

Factory methods are dw::core::ui::ResourceFactory::createListResource and dw::core::ui::ResourceFactory::createOptionMenuResource.

<OPTION>'s are added via dw::core::ui::SelectionResource::addItem.

<OPTGROUP> are created by using dw::core::ui::SelectionResource::pushGroup and dw::core::ui::SelectionResource::popGroup.

For lists, the selection mode must be set in dw::core::ui::ResourceFactory::createListResource.

<TEXTAREA>

<TEXTAREA> is implemented by dw::core::ui::MultiLineTextResource, the factory method is dw::core::ui::ResourceFactory::createMultiLineTextResource. dw::core::ui::TextResource::setEditable can be used, as for entries.

<BUTTON>

For handling <BUTTON>, dw::core::ui::ComplexButtonResource should be used, with a dw::Textblock inside, and relief = true. The contents of <BUTTON> is then added to the dw::Textblock.

Todo:

describe activation signal