View source for Extensions: INX widgets and parameters

This page contains the reference documentation for INX widgets and parameters. Their primary goal is to make it easy to design GUIs for [[Extension subsystem|Inkscape Extensions]] using the built-in [[INX extension descriptor format]], although (invisible) parameters can also be used for extensions that don't need to show a user interface.

== Introduction ==

Extension GUIs consists of an arbitrary number of GUI elements, so-called '''[[#Widgets|Widgets]]'''. These can be simple text labels, boxes and spacers to control layout or more complex UI elements like images.

A special class of Widgets are '''[[#Parameters|Parameters]]'''. They differ from other Widgets in that they have a user-settable value, for example a boolean (implemented as checkbox) or integer (implemented as number entry). The value of each Parameter is passed to the extension on execution and can be used to control its behavior.

All Widgets are described using an easy-to-learn XML schema with predefined tags and attributes which are described in detail below.

<!-- TODO: Simple "hello world"-like example -->


=== Available Widgets ===

A general Widget takes the form

<source lang="xml">
  <widget_name attribute1="value1" atribute2="value2" …>value</widget_name>
</source>

where <code>widget_name</code> specifies the name of the widget and is one of the following:

* <code>label</code>
* <code>hbox</code>/<code>vbox</code>
* <code>separator</code>/<code>spacer</code>
* <code>image</code>
* <code>param</code> (for all Parameter types)

=== Available Parameter types ===

A general Parameter takes the form

<source lang="xml">
  <param type="parameter_type" attribute1="value1" atribute2="value2" …>value</param >
</source>

where <code>parameter_type</code> specifies the type of the parameter and is one of the following:

* <code>bool</code>
* <code>int</code>
* <code>float</code>
* <code>string</code>
* <code>path</code>
* <code>optiongroup</code>
* <code>notebook</code>
* <code>color</code>

If a parameter is made invisible (see <code>gui-hidden</code> attribute in the [[#Common attributes|next section]]) it will not be shown in the GUI but it's value is still passed to an extension. This is useful if you want to hardcode parameter value the user  should not be able to change. If all parameters (and potential widgets) are invisible, Inkscape will not show a GUI and execute the extension immediately instead, but will still pass the values of the invisible parameters.

== Common attributes ==

{| class="wikitable" style="vertical-align:top;" valign="top"
|-
!colspan="5"|For all Widgets
|-
! Attribute name
! Allowed value(s)
! Default value
! Required?
! Description
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>gui-hidden</code>
| <code>true</code>,<code>false</code>
| <code>false</code>
| optional
| If set to <code>true</code> the Widget is hidden from the GUI (primarily used to add hidden parameters that are passed to the extension but are not supposed to be editable by the user.)

''Note: If there are '''no''' visible parameters defined in a GUI, the extension is executed immediately without showing a dialog.''
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>indent</code>
| <code>0,1,2,...</code>
| <code>0</code>
| optional
| Sets indentation level of the parameter. Increasing indentation adds padding to the start of the line.
|- style="border:none;background:none"
!colspan="5" style="border:none;background:none"|&nbsp;
|-
!colspan="5"|Only for Parameters
|-
! Attribute name
! Allowed value(s)
! Default value
! Required?
! Description
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>name</code>
| ''(text)''
| -
| required
| Used as an identifier of the parameter. It has to be unique since the value of this attribute is used to save and transmit parameter values internally!
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>type</code>
| (see [[#Available Parameter types|above]])
| -
| required
| Determines the type of the parameter, see the extensive description of [[#Parameters|Parameters]] below.
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>gui-text</code>
| ''(text)''
| -
| required ''(visible parameters)'',<br/>optional ''(hidden parameters + <code>notebook</code>s)''
| Label shown for the parameter in the GUI.
|- style="vertical-align:top;"
| style="white-space:nowrap" | <code>gui-description</code>
| ''(text)''
| -
| optional
| Tooltip shown for the parameter when the user hovers the mouse cursor over the active area of the parameter in question.
|-
|}

== Widgets ==

{| class="wikitable" style="width:100%"

|+ Parameter reference

|-
! Type
! Description / Code
! Result

|-
! label
|Creates a text element. Specifying the attribute <code>xml:space="preserve"</code> preserves whitespace in the text content  of the label and enables multiline text.

<source lang="xml">
<label>Some text here.</label>
</source>

''Note: Labels are intended to provide additional information / help. Do label parameters use the <code>gui-text</code> attribute instead; for short help texts that are specific to a single parameter consider using <code>gui-description</code> which will render as a tooltip.''

When setting the attribute <code>appearance="header"</code> the text is styled as a heading and can be used as another possibility to group parameters.
<source lang="xml"><label appearance="header">Header</label></source>

When setting the attribute <code>appearance="url"</code> the text is rendered as a clickable link.
<source lang="xml"><label appearance="url">https://inkscape.org</label></source>
''Note: The text is escaped and used as the link target as-is. Creating a link text that differs from the URL is prevented for security reasons.''

|[[File:INX_sample-description.png]]<br><small>default appearance</small><br><br><br><br>
[[File:INX_sample-description_header.png]]<br><small>with <code>appearance="header"</code></small><br><br><br>&nbsp;
<!-- TODO: image for appearance="url" -->

|-

|}


; TODO:
<source lang="xml">
<label [indent="1"] [appearance="header"]>Some text</label>
<label [indent="1"] [appearance="url"]>http://some/url</label>
<image>some/inx/relative/path/to/img.svg</image>
<spacer/>
<separator [indent="1"]/>
<hbox [indent="1"]></hbox>
<vbox [indent="1"]></vbox>
</source>


== Parameters ==

{| class="wikitable" style="width:100%"

|+ Parameter reference

|-
! Type
! Description / Code
! Result

|-
! boolean
|Creates a checkbox input to set a '''boolean value'''. Set the default value to <code>true</code> or <code>1</code>, <code>false</code> or <code>0</code>.

<source lang="xml">
<param name="name" type="boolean" gui-text="Some label text">false</param>
</source>
|[[File:INX_sample-boolean.png]]

|-
! color
|Creates a control to select a '''color value'''.
The '''returned value''' is an RGBA-value.

<source lang="xml">
<param name="name" type="color"></param>
</source>

|[[File:INX_sample-color.png]] [[File:INX color-btn.png]]

|-
! description
|Creates a text element. Specifying the attribute <code>xml:space="preserve"</code> preserves whitespace in the text content  of the description and enables multiline text.

<source lang="xml">
<param name="name" type="description">Some text here.</param>
</source>

When additionally setting the attribute <code>appearance="header"</code> the text is styled as a heading and can be used as another possibility to group parameters.
<source lang="xml"><param name="name" type="description" appearance="header">Header</param></source>

All <code>description</code> type parameters are purely informational (they do not return any value). They are intended to be used to provide additional information / help on other parameters (Consider using the <code>gui-description</code> attribute for short help texts that are specific to a single parameter, though).


|[[File:INX_sample-description.png]]<br><small>default appearance</small><br><br><br><br>
[[File:INX_sample-description_header.png]]<br><small>with <code>appearance="header"</code></small><br><br><br>&nbsp;

|-
! float
|Creates a textbox input to enter a '''floating point number'''. Limit the input range with the <code>min</code> and <code>max</code> attributes; set the number of decimal places with the <code>precision</code> attribute. (Default: <code>min="0"</code>, <code>max="10"</code> and <code>precision="1"</code>)

<source lang="xml">
<param name="name" type="float" precision="3" min="0" max="9999" 
gui-text="Some label text">1.234</param>
</source>

Use the attribute <code>appearance="full"</code> to create a slider with which the floating point value can be adjusted dynamically over the full range.
|[[File:INX_sample-float.png]]<br><br>[[File:INX_sample-float_full.png|240px]]

|-
! int
|Creates a textbox input to enter an '''integer number'''. Limit the input range with the <code>min</code> and <code>max</code> attributes. (Default: <code>min="0"</code> and <code>max="10"</code>)

<source lang="xml">
<param name="name" type="int" min="1" max="100" gui-text="Some label text">1</param>
</source>

Use the attribute <code>appearance="full"</code> to create a slider with which the integer value can be adjusted dynamically over the full range.
|[[File:INX_sample-int.png]]<br><br>[[File:INX_sample-int_full.png|240px]]

|-
! notebook
|Creates a set of pages (aka tab control). The user can switch between individual pages, each page can contain an arbitrary set of other parameters. Individual pages are created with the <code><page></code> element.
The '''returned value''' for <code>notebook</code> type parameters is the value of the <code>name</code> attribute of the selected <code><page></code>.

<source lang="xml">
<param name="name" type="notebook">
    <page name="page_1" gui-text="First page">
        <param>...</param>
    </page>
    <page name="page_2" gui-text="Second page">
        <param>...</param>
    </page>
</param>
</source>
|[[File:INX_sample-notebook.png]]

|-
! optiongroup
|Creates a set of radio buttons from which '''one predefined value''' can be chosen. The different choices are created with <code><option></code> elements. The first <code><option></code> is selected by default.
The '''returned value''' for <code>optiongroup</code> type parameters is the value of the <code>value</code> attribute of the selected <code><option></code>.

<source lang="xml">
<param name="name" type="optiongroup"
gui-text="Some label text">
   <option value="1">First option</option>
   <option value="2">Second option</option>
</param>
</source>

Set the attribute <code>appearance="minimal"</code> to display a drop-down list instead of radio buttons.<br>
<small>''The option group will occupy the minimum space on the right hand side of the dialog. Versus the Enum, which expands to fill available space.''</small>
|[[File:INX_sample-optiongroup.png]]<br><br><br><br><br>[[File:INX_sample-optiongroup-minimal.png]]

|-
! path
|

<source lang="xml">
<param type="path" name="varname" gui-text="label" mode="file"     filetypes="svg,png"/>
<param type="path" name="varname" gui-text="label" mode="files"    filetypes="svg,png"/>
<param type="path" name="varname" gui-text="label" mode="file_new" filetypes="svg,png"/>
<param type="path" name="varname" gui-text="label" mode="folder"/>
<param type="path" name="varname" gui-text="label" mode="folders"/>
<param type="path" name="varname" gui-text="label" mode="folder_new"/>
</source>
|[[File:INX path.png]]

|-
! string
|Creates a textbox input to enter a '''character string'''. Limit the number of characters the user is allowed to enter with the <code>max_length</code> attribute. (Default: no limit)

<source lang="xml">
<param name="name" type="string" gui-text="Some text label">Some default text</param>
</source>
|[[File:INX_sample-string.png]]

|}


== Translation of widgets and parameters ==

<!-- TODO -->


== Deprecated Functionality ==

These widgets and parameters have been deprecated and should not be used anymore. Extension authors are encouraged to update their existing extensions wherever possible. Documentation is kept for authors that need to make their extensions backwards-compatible but please be aware that deprecated functionality '''''will''''' be removed eventually and without further notice.

{| class="wikitable" style="width:100%"

|+ Deprecated Parameters

|-
! Type
! Description / Code
! Result

|-
! description{{deprecated_in|1.0}}
|'''Replace with <code><label>...</label></code> widget.'''

Creates a text element. Specifying the attribute <code>xml:space="preserve"</code> preserves whitespace in the text content  of the description and enables multiline text.

<source lang="xml">
<param name="name" type="description">Some text here.</param>
</source>

When additionally setting the attribute <code>appearance="header"</code> the text is styled as a heading and can be used as another possibility to group parameters.
<source lang="xml"><param name="name" type="description" appearance="header">Header</param></source>

All <code>description</code> type parameters are purely informational (they do not return any value). They are intended to be used to provide additional information / help on other parameters (Consider using the <code>gui-description</code> attribute for short help texts that are specific to a single parameter, though).


|[[File:INX_sample-description.png]]<br><small>default appearance</small><br><br><br><br>
[[File:INX_sample-description_header.png]]<br><small>with <code>appearance="header"</code></small><br><br><br>&nbsp;


|-
! enum{{deprecated_in|1.0}}
|'''Replace with <code><optiongroup appearance="combo" ...></code> parameter.'''

Creates a drop-down list from which '''one predefined value''' can be chosen. The different choices are created with <code><item></code> elements. The first <code><item></code> is selected by default.
The '''returned value''' for <code>enum</code> type parameters is the value of the <code>value</code> attribute of the selected <code><item></code>.

<source lang="xml">
<param name="name" type="enum" gui-text="Some label text">
   <item value="1">First option</item>
   <item value="2">Second option</item>
</param>
</source>
|[[File:INX_sample-enum.png]]

|}

=== Deprecated localization functionality of parameters{{deprecated_in|1.0}} ===

To mark parameters to be included into the translation files variants of all relevant attributes and tag names existed that started with an underscore.

While the underscored variants are still accepted for backwards-compatibility, translations are handled differently since Inkscape 1.0, which solved a number of limitations of the prior implementation, while also making the INX specification significantly cleaner. See [[Translation of widgets and parameters]] for details.

= Editing INX Parameters in 1.0 =

In this section:
* When an attribute is in square brackets (<code>[name="value"]</code>), it means that <code>name</code> is optional.
* The 1 in <code>indent="1"</code> is the indentation level that you want.









<!-- TODO

Use parameter elements to capture user input for further use by a script. The basic structure of the element is:

<source lang="xml">
<param name="some_name" type="some_type">default value</param>
</source>

The default value is the value that is shown in the input control the first time the user opens the dialog window. Inkscape automatically displays the values used last time when the dialog window is opened again.


* Parameter values (when opening the dialog) are set to the last used value, which is saved in the user's preferences file (e.g. ~/.config/inkscape/preferences.xml on GNU/Linux systems):
<source lang="xml">
<inkscape>
  <group id="extensions" com.attrib.id.param_name="param value"/>
</inkscape>
</source>
The (default) values in the inx file are visible only when the user first uses the extension.


-->

[[Category:Developer Documentation]]
[[Category:Extensions]]