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Prima::Widget::Link(3) User Contributed Perl Documentation Prima::Widget::Link(3)

NAME

Prima::Widget::Link - routines for interactive links

DESCRIPTION

The class can be used in widgets that need to feature links, i e highlighted rectangles, usually with a line of text. When the user moves the mouse or clicks on a link, depending on the link type, various actions can be executed. A "tooltip" link can display a hint with (rich) text, and a "hyperlink" link can open a browser or a pod viewer. The programmer can also customize these actions.

SYNOPSIS

  use Prima qw(Label Application);
  my $main_window = Prima::MainWindow->new( size => [400, 100] );
  $main_window->insert( Label =>
    centered => 1,
    text   => \ "L<tip://$0/ttt|tip>, L<pod://Prima/|podviewer>, L<http://google.com/|browser>, L<id|custom>",
    onLink => sub { print "$_[2]\n" },
  );
  run Prima;
  =pod
  =head1 ttt
  this is a tooltip
  =for podview <img src="data:base64">
  R0lGODdhFgAVAIAAAAAAAP///ywAAAAAFgAVAIAAAAD///8CLIyPqcutsKALQKI6qT11R69lWDJm
  5omm6jqBjucycEx+bVOSNNf1+/NjCREFADs=

Link types

Link types can be set with the url syntax. Four recognized link types behave differently

Tooltips

These are not links in the strict sense, as clicking on them doesn't cause any action, however when the user hovers the mouse over a tooltip, the module loads the pod content from the URL and displays it as a hint.

The idea behind this feature is to collect all tooltip cards in a pod section and reference them in the text like in the example code in SYNOPSIS above.

Syntax: "L<tip://FILEPATH_OR_MODULE/SECTION>" or "L<tip://FILEPATH_OR_MODULE>" where "FILEPATH_OR_MODULE" can refer either to a file (path with slashes/backslashes) or a perl module (with "::"s ).

The tooltip text, when selected, is underscored by a dashed line, vs all other link types that use a solid line.

Pod sections

These links display a pod section preview like the tooltip but also open a pod viewer with the referred section when clicked on.

Syntax: "L<pod://FILEPATH_OR_MODULE/SECTION>" or "L<pod://FILEPATH_OR_MODULE>" where "FILEPATH_OR_MODULE" can refer either to a file (path with slashes/backslashes) or a perl module (with "::"s ).

Links with schemes "ftp://", "http://", and "https://" open a browser when clicked on.

All other URLs, not matched by either scheme above, are expected to be handled programmatically. The preview, if any, should be handled by the "LinkPreview" event, and the mouse click by the "Link" event.

See Events below.

Usage

Since "Prima::Widget::Link" is not a widget by itself but a collection of routines in a class, an object of such class should be instantiated programmatically and attached to an owner widget that needs to display links.

The owner widget needs to call the mouse and paint methods from inside its "on_mousedown" etc relevant events. The owner widget class might also want to overload link events, see below how.

Markup

Prima::Drawable::Markup understands the "L<..|..>" command, which, unlike perlpod, is formatted with its arguments reversed, to stay consistent with the other markup commands (i e it is "L<http://google.com|search>", not "L<search|http://google.com>" .

The simple way to incorporate rich text in both the widget and link handler is to use "Prima::Drawable::Markup" to handle the markup parsing and use the resulting object from the same class both for widget drawing and for the link reactions. One just needs to add " markup =" $markup_object > to " Prima::Widget::Link-"new() >.

API

Properties

Contains an array of rectangles in arbitrary coordinates that could be used to map screen coordinates to a URL. Filled automatically.
An array of URLs

Methods

Used when the link object is not bound to any markup object but recalculation of the visual rectangle that the link occupies is needed due to change in formatting, f ex after a change in widget size, font size, etc. %DEFAULTS is sent internally to "tb::block_walk" which may need eventual default parameters.

Scans BLOCKS and add monotonically increasing LINK_ID to new link rectangles. Return new LINK_ID.

Clears the content of "rectangles"
Returns rectangles mapped to a link ID. There can be more than 1 rectangle bound to a single link ID since link text could be f ex wrapped.
Opens a pod viewer with the URL
Opens a web browser with the URL
Used when the link object is bound to a markup object and recalculation of the visual rectangle that the link occupies is needed due to change in formatting, f ex after a change in widget size, font size, etc. %DEFAULTS is sent internally to "tb::block_walk" which may need eventual default parameters.

Events

All events are sent to the owner, not to the link object itself, however, the "SELF" parameter which contains the link object is always the first parameter

Sent to the owner, if any, from within the "on_mousedown" event to indicate that the link was pressed on.
Sent to the owner, if any, from within the "on_mousemove" event. The owner may want to fill URL_REF with (rich) text that will be displayed as a link preview
Since the owner may implement a scrollable view or any other view that has a coordinate system that is not necessarily consistent with the rectangles stored in the link object, this event will be called when a link rectangle needs to be mapped to the owner coordinates.

AUTHOR

Dmitry Karasik, <dmitry@karasik.eu.org>.

SEE ALSO

Prima, Prima::Drawable::Markup, Prima::Label, Prima::Drawable::Pod

2024-08-20 perl v5.40.0