Wt  3.2.1
Public Member Functions
Wt::WImage Class Reference

A widget that displays an image. More...

#include <Wt/WImage>

Inheritance diagram for Wt::WImage:
Inheritance graph
[legend]

List of all members.

Public Member Functions

 WImage (WContainerWidget *parent=0)
 Creates an empty image widget.
 WImage (const WLink &imageLink, WContainerWidget *parent=0)
 Creates an image widget with a given image link.
 WImage (const WLink &imageLink, const WString &altText, WContainerWidget *parent=0)
 Creates an image widget with a given image link and alternate text.
void setAlternateText (const WString &text)
 Sets an alternate text.
const WStringalternateText () const
 Returns the alternate text.
void setImageLink (const WLink &link)
 Sets the image link.
const WLinkimageLink () const
 Returns the image link.
void setImageRef (const std::string &url)
 Sets the image URL (deprecated).
const std::string imageRef () const
 Returns the image URL (deprecated).
void setResource (WResource *resource)
 Sets the image resource (deprecated).
WResourceresource () const
 Returns the image resource (deprecated.
void addArea (WAbstractArea *area)
 Adds an interactive area.
void insertArea (int index, WAbstractArea *area)
 Inserts an interactive area.
void removeArea (WAbstractArea *area)
 Removes an interactive area.
WAbstractAreaarea (int index) const
 Returns the interactive area at the given index.
const std::vector
< WAbstractArea * > 
areas () const
 Returns the interactive areas set for this widget.
EventSignalimageLoaded ()
 Event emitted when the image was loaded.

Detailed Description

A widget that displays an image.

The image may be specified either as a URL, or may be dynamically generated by a WResource.

You may listen to events by attaching event listeners to signals such as clicked(). Since mouse events pass the coordinates through a WMouseEvent object, it is possible to react to clicks in specific parts of the image. An alternative is to define interactive areas on the image using addArea(), which in addition allows to have customized tool tips for certain image areas (using WAbstractArea::setToolTip()).

Usage example:

 Wt::WImage *img = new Wt::WImage("images/johnny_cash.png", this);
 img->setAlternateText("Johnny Cash sings a song");

WImage is an inline widget.

CSS

The widget corresponds to the HTML <img> tag and does not provide styling. It can be styled using inline or external CSS as appropriate.

See also:
WResource, WPaintedWidget

Constructor & Destructor Documentation

Wt::WImage::WImage ( const WLink imageLink,
WContainerWidget parent = 0 
)

Creates an image widget with a given image link.

The imageLink may link to a URL or resource.

Wt::WImage::WImage ( const WLink imageLink,
const WString altText,
WContainerWidget parent = 0 
)

Creates an image widget with a given image link and alternate text.

The imageLink may link to a URL or resource.


Member Function Documentation

void Wt::WImage::addArea ( WAbstractArea area)

Adds an interactive area.

Adds the area which listens to events in a specific region of the image. Areas are organized in an indexed list, to which the given area is appended. When areas overlap, the area with the lowest index receives the event.

Ownership of the area is transferred to the image.

See also:
insertArea(int, WAbstractArea *)
const WString& Wt::WImage::alternateText ( ) const

Returns the alternate text.

See also:
setAlternateText()
WAbstractArea * Wt::WImage::area ( int  index) const

Returns the interactive area at the given index.

Returns 0 if index was invalid.

See also:
insertArea(int, WAbstractArea *)
const std::vector< WAbstractArea * > Wt::WImage::areas ( ) const

Returns the interactive areas set for this widget.

See also:
addArea()
const WLink& Wt::WImage::imageLink ( ) const

Returns the image link.

See also:
setLink()
const std::string Wt::WImage::imageRef ( ) const

Returns the image URL (deprecated).

When the image is specified as a resource, this returns the current resource URL.

Deprecated:
Use imageLink() instead.
void Wt::WImage::insertArea ( int  index,
WAbstractArea area 
)

Inserts an interactive area.

Inserts the area which listens to events in the coresponding area of the image. Areas are organized in a list, and the area is inserted at index index. When areas overlap, the area with the lowest index receives the event.

Ownership of the area is transferred to the image.

See also:
addArea(WAbstractArea *)
void Wt::WImage::removeArea ( WAbstractArea area)

Removes an interactive area.

Removes the area from this widget, and also returns the ownership.

See also:
addArea(WAbstractArea *)
WResource * Wt::WImage::resource ( ) const

Returns the image resource (deprecated.

Returns 0 if no image resource was set.

Deprecated:
Use setImageLink() instead.
void Wt::WImage::setAlternateText ( const WString text)

Sets an alternate text.

The alternate text should provide a fallback for browsers that do not display an image. If no sensible fallback text can be provided, an empty text is preferred over nonsense.

This should not be confused with toolTip() text, which provides additional information that is displayed when the mouse hovers over the image.

The default alternate text is an empty text ("").

See also:
alternateText()
void Wt::WImage::setImageLink ( const WLink link)

Sets the image link.

The image may be specified as a URL or as a resource. A resource specifies application-dependent content, which may be used to generate an image on demand.

void Wt::WImage::setImageRef ( const std::string &  url)

Sets the image URL (deprecated).

Deprecated:
Use setImageLink() instead.
void Wt::WImage::setResource ( WResource resource)

Sets the image resource (deprecated).

Deprecated:
Use setImageLink() instead.
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator

Generated on Fri Mar 30 2012 for the C++ Web Toolkit (Wt) by doxygen 1.7.5.1