ThirdParty-6/ParaView-5.0.1/Utilities/Doxygen/pages/PropertyHints.md

Property Hints

This page documents Property Hints, which are xml tags accepted under Hints for a Property element in Server-Manager configuration XMLs.

[TOC]

NoDefault

Skip setting run-time defaults during initalization.

Any property with a domain that is dynamic i.e. depends on run-time values such as data information or the information-only properties, often resets the property value during initialization of the newly created proxy (vtkSMParaViewPipelineController::PostInitializeProxy()). This, however, may be undesirable and one may want the property to simply use the XML default. In that case, use this property hint as follows.

<IntVectorProperty ...>
  ...
  <Hints>
    <NoDefault />
  </Hints>
</IntVectorProperty>

ComponentLabels

Show vector component labels for double vector properties.

A multi-component double vector property may represent several different types of coordinates. It may be useful to provide labels for each component's input to designate which type of vector is being represented.

<DoubleVectorProperty ...>
  ...
  <Hints>
    <ShowComponentLabels>
      <Label component="0" label="X:"/>
      ...
    </ShowComponentLabels>
  </Hints>
</DoubleVectorProperty>

PlaceholderText

Put a PlaceHolder text in the Text entry widget.

For StringVectorProperty elements, one can suggest a place-holder text to use in the UI using the <PlaceholderText/> tag.

<StringVectorProperty...>
  ...
  <Hints>
    <PlaceholderText>Enter label</PlaceholderText>
  </Hints>
</StringVectorProperty>

PropertyLink

Link properties to existing proxies at initialization time.

PropertyLink hints is typically used to link a non-UI property to a property on some other proxy known to exist when this proxy is created. Consider this, we have a (settings, RenderViewSettings) proxy that created when a new session is initialized in vtkSMParaViewPipelineController::InitializeSession(). Now, when a new (views, RenderView) proxy is created, we'd like a few properties from the RenderView proxy to be linked to session wide instance of RenderViewSettings proxy. That way, when the properties on RenderViewSettings proxy are changed, those on all the RenderView proxy instances also change. We use <PropertyLink/> hint for such a case. For example, consider the following:

<IntVectorProperty command="SetUseOffscreenRenderingForScreenshots"
                    name="UseOffscreenRenderingForScreenshots"
                    number_of_elements="1"
                    default_values="0"
                    panel_visibility="never">
  <Hints>
    <PropertyLink group="settings"
                  proxy="RenderViewSettings"
                  property="UseOffscreenRenderingForScreenshots"/>
  </Hints>
</IntVectorProperty>

Here, we want the UseOffscreenRenderingForScreenshots property linked with the corresponding property on the RenderViewSettings proxy. When this tag is encountered by vtkSMParaViewPipelineController::PostInitializeProxy(), it will try to locate an existing proxy of registered as (settings, RenderViewSettings). vtkSMParaViewPipelineController::InitializeSession() ensures that all proxies encountered in \c settings group are created and registered using the same group. Thus, when the vtkSMParaViewPipelineController::PostInitializeProxy() looks for (settings, RenderViewSettings) proxy, it will find one and then be able to setup a property link to ensure that the property on the RenderView proxy is kept in sync with the property on the RenderViewSettings proxy.

SelectionInput

Mark a input as a one that accepts a vtkSelection.

Sometimes an input to an algorithm is a vtkSelection, not any other dataset. In ParaView, vtkSelection inputs are treated specially to allow the user to copy active selection from the application. Also, it keeps the application from prompting the user to pick the second input when the filter is created. To indicate to the UI that this input is a selection input, use the <SelectionInput/> hint.

<InputProperty ...>
  ...
  <Hints>
    <SelectionInput />
  </Hints>
</InputProperty>

WidgetHeight

Specify height in rows for tabular/tree widgets.

Certain widgets that show a tablular widget of rows and columns i.e. any property widget that uses a pqTreeWidget including the ones for ArrayListDomain, ArraySelectionDomain, EnumerationDomain, CompositeTreeDomain, respect this hint to setup the default size for the tabular/tree widget.

<IntVectorProperty command="..." name="...">
  <CompositeTreeDomain mode="all" name="tree">
    <RequiredProperties>
      <Property function="Input" name="Input" />
    </RequiredProperties>
  </CompositeTreeDomain>
  <Hints>
    <!-- This tag sets the height of the CompositeTreeDomain -->
    <WidgetHeight number_of_rows="20" />
  </Hints>
</IntVectorProperty>